Rational Design of Potent and Selective Inhibitors of an EpoxideHydrolase Virulence Factor from Pseudomonas aeruginosaSeiya Kitamura,† Kelli L. Hvorecny,‡ Jun Niu,† Bruce D. Hammock,† Dean R. Madden,‡

and Christophe Morisseau*,†

†Department of Entomology and Nematology, and UC Davis Comprehensive Cancer Center, University of California, Davis, OneShields Avenue, Davis, California 95616, United States‡Department of Biochemistry, Geisel School of Medicine at Dartmouth, 7200 Vail Building, Hanover, New Hampshire 03755, UnitedStates

*S Supporting Information

ABSTRACT: The virulence factor cystic fibrosis transmembrane conductance regulator (CFTR) inhibitory factor (Cif) issecreted by Pseudomonas aeruginosa and is the founding member of a distinct class of epoxide hydrolases (EHs) that triggers thecatalysis-dependent degradation of the CFTR. We describe here the development of a series of potent and selective Cif inhibitorsby structure-based drug design. Initial screening revealed 1a (KB2115), a thyroid hormone analog, as a lead compound with lowmicromolar potency. Structural requirements for potency were systematically probed, and interactions between Cif and 1a werecharacterized by X-ray crystallography. On the basis of these data, new compounds were designed to yield additional hydrogenbonding with residues of the Cif active site. From this effort, three compounds were identified that are 10-fold more potenttoward Cif than our first-generation inhibitors and have no detectable thyroid hormone-like activity. These inhibitors will beuseful tools to study the pathological role of Cif and have the potential for clinical application.

■ INTRODUCTION

Pseudomonas aeruginosa is a ubiquitous opportunistic pathogenthat infects various sites of the human body, including the lungsin patients with diseases such as chronic obstructive pulmonarydisease and cystic fibrosis.1 The bacterium is naturally resistantto a large range of antibiotics and can acquire additionalresistance,2 creating a pressing need for novel therapeuticapproaches.Among its strategies for subverting host defenses, P.

aeruginosa targets the cystic fibrosis transmembrane con-ductance regulator (CFTR), an ion channel important forepithelial fluid transport, mucociliary clearance and mucosalimmunity in the lung.3 P. aeruginosa secretes the CFTRinhibitory factor (Cif) that blocks the postendocyticdeubiquitination of CFTR and thus facilitates its lysosomaldegradation.4 Cif is a member of the α/β hydrolase family andhas demonstrated epoxide hydrolase (EH) activity.5 Using sitedirected mutations and inhibitors, we observed that Cif EHactivity is critical for the inhibition of CFTR deubiquitination.However, the endogenous substrate and exact mechanism ofCif virulence remain unknown, and the mechanistic linkbetween EH activity of Cif and deubiquitination of CFTR stillremains speculative. The availability of potent and selective Cif

inhibitors should thus help to better understand Cifpathobiology and to explore possible clinical applications.We recently identified tiratricol as a moderate Cif inhibitor

with an IC50 of 4.7 μM.5b This compound protects CFTR fromboth purified Cif protein and P. aeruginosa PA14 applied topolarized human airway epithelial cells.5b This suggests thatinhibition of the EH activity of Cif could be a therapeuticapproach to maintain CFTR levels on the surface of epithelialcells following Pseudomonas infection, thus permitting fasterelimination of the pathogenic bacteria. However, tiratricol bindsthe endogenous human liver nuclear thyroid hormone receptorwith subnanomolar affinity. In fact, tiratricol has a higheraffinity than the endogenous thyroid hormone T3 (triiodothyr-onine),6 consistent with reports of severe side effects that ledthe FDA to suspend the availability of tiratricol.7 Relatively lowpotency toward Cif and extremely high potency toward thethyroid hormone receptor thus limit the application of tiratricolfor further biological studies and possible human clinicalapplication.

Received: February 1, 2016Published: April 27, 2016

Article

pubs.acs.org/jmc

© 2016 American Chemical Society 4790 DOI: 10.1021/acs.jmedchem.6b00173J. Med. Chem. 2016, 59, 4790−4799

To circumvent the limitations of tiratricol, in this report, weidentified related compounds and studied the interactionsrequired for Cif inhibition, using two complementaryapproaches: chemical modification and X-ray crystallographyof inhibitor complexes. On the basis of the results from bothapproaches, we designed and synthesized compounds withimproved potency toward Cif and with no detectable thyroidhormone-like activity in a transgenic reporter system.

■ RESULTS AND DISCUSSION

Initial Screening Based on the Tiratricol Structure.Initial screening of commercially available and synthetic8

compounds similar to the tiratricol structure (Table S1 inSupporting Information) revealed 1a (KB21159) to be slightlymore potent than tiratricol. While 1a is also a ligand selectivefor the thyroid hormone receptor β,9,10 1a does not contain anyiodine atoms, in contrast to tiratricol (Figure 1). Given thepotency and relative ease of analog synthesis, 1a represents abetter initial lead compound for medicinal chemistryapproaches to improve its potency against Cif.Probing the Structural Requirements of Lead Com-

pound 1a for Cif Inhibition. On the basis of the generalstructure of the Cif inhibitors shown in Figure 1, we exploredthe structural requirements of Cif inhibition by 1a morerigorously. Compound 1a analogs were synthesized usingmethods similar to the one previously described for thyroidhormone analogs as shown in Scheme 1.11 Briefly, SNArreaction between a phenol 2 and compound 3 gave a diphenylether 4. Deprotection of a methoxy moiety by boron tribromide

yielded a phenol 5. The nitro group was then reduced into aprimary amine 6 using sodium dithionite. Finally, an amidebond was formed by reacting the aniline 6 with acid chloride.The requirement for the R1 functional group was studied first

(Table 1). Compounds with a primary amine (6a) or a nitromoiety (5a) still possessed inhibitory activity, although potencydropped approximately 3-fold. Inhibitory activity was alsomodestly affected when the primary amine was replaced by analkylamide (1b, 1c). The ethyl ester form of the leadcompound (1d) was also slightly less potent than the freeacid form (1a). The compound with an additional methylenemoiety (1e) was as potent as 1a, with the ethyl ester form (1f)having slightly lower inhibitory activity than the free acid form.These data suggest that the terminal free carboxylic moietyinteracts only weakly with the enzyme. In further synthesis ofanalogs for this initial study, we encountered difficulty inpurifying some of the analogs with free acid forms on R1.Therefore, the malonate ethyl ester moiety was selected as R1

for the purpose of determining structural requirements at otherpositions.Results for the structural requirements of the R2, R3, R4, and

R5 functional groups are shown in Table 2. When the hydroxylmoiety at R2 was replaced by either hydrogen (1g) ormethoxide (1h), these analogs failed to show inhibitory activityat 50 μM or 25 μM, suggesting that the hydroxyl moiety iscritical for inhibitory activity and that a hydrogen bondacceptor is not sufficient for the interaction. Replacement ofbromines on R3 and R3′ with chlorines (1i) resulted in anapproximately 2-fold increase in activity. Removal of one of the

Figure 1. Structures of lead compounds and their potency are shown, while a general structure for Cif inhibitors and the substrate used for Cif assayare below.

Scheme 1. General Synthetic Schemea

aReagents and conditions: (a) NaOHaq, DMF; (b) BBr3, DCM; (c) Na2S2O4, THF/H2O, 50 °C; (d) R-COCl, MTBE, saturated NaHCO3 aq or 1 MNaOHaq.

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chlorines (1j) led to a decrease in activity, reflecting theimportance of the halide R3 substituents.Replacement of the R4 isopropyl with a proton yielded the

nonsubstituted compound (1k), which showed no inhibition at50 μM, indicating that the substituent at R4 is critical forpotency. Replacement of the isopropyl moiety with bromine(1l), iodine (1m), trifluoromethyl (1n), or acetylene (1p)moieties did not change the potency of the compound. Thissuggests the existence of available space in the binding pocketof Cif that can be filled by an R4 substituent of the appropriatesteric volume but that its exact chemistry is not preciselyconstrained. A compound with bromine at the R5 position (1q)had potency much lower than the corresponding R4 substituent(1l) but slightly greater than the unsubstituted compound (1k),reflecting greater selectivity at the R5 position.Replacing the R4 isopropyl moiety with a trifluoromethyl

moiety (1n), which is a strong electron withdrawing group,increases the acidity of the phenol on R2. Thus, we expectedthat compound 1n would form stronger hydrogen bonds,leading to higher inhibitory potency. However, compared to 1i,the potency of 1n did not improve dramatically.

Cif:1a Structure. In parallel with our SAR studies, wedetermined the X-ray crystallographic structure of Cifcomplexed with lead compound 1a at a resolution of 1.65 Å(Figure 2A, Table S2, Figures S1 and S2). The resulting modelrevealed that 1a occludes access of the substrates to thecatalytic pocket (Figure 2B). In general, the structure

Table 1. Effect of R1 Moiety on Cif Inhibitory Potency

aIC50 values were determined with a fluorescent-based assay usingCMNGC as a fluorescent reporter substrate (see methods section).Reported IC50 values are the average of triplicates with at least twodata points above and at least two below the IC50. The fluorescent-based assay as performed here has a standard error between 10% and20%, suggesting that differences of 2-fold or greater are significant.

Table 2. Effect of R2−R5 Moieties on Cif Inhibitory Potency

compd R2 R3 R4 R5 IC50a (μM)

1d OH R3 = R3′ = Br isopropyl H 6.71g H R3= R3′ = Br isopropyl H >501h OCH3 R3 = R3′ = Br isopropyl H >25b

1i OH R3 = R3′ = Cl isopropyl H 3.81j OH R3=Cl, R3’=H isopropyl H 11.61k OH R3 = R3′ = Cl H H >501l OH R3 = R3′ = Cl Br H 4.91m OH R3 = R3′ = Cl I H 3.81n OH R3 = R3′ = Cl CF3 H 31p OH R3 = R3′ = Cl ethynyl H 2.91q OH R3 = R3′ = Cl H Br 29.3

aIC50 values were determined with a fluorescent-based assay usingCMNGC as a fluorescent reporter substrate (see methods section).Reported IC50 values are the average of triplicates with at least twodata points above and at least two below the IC50. The fluorescent-based assay as performed here has a standard error between 10% and20%, suggesting that differences of 2-fold or greater are significant.bLimited by the solubility (25 < S < 50 μM) of the compound underassay conditions (1% DMSO, 0.1 mg/mL BSA at 37 °C). Solubilitywas measured using a previously described method.29

Figure 2. X-ray crystal structure of lead compound 1a in complex withCif. (A) A Cα-trace shows the conformation of the Cif dimer, withactive-site side chains and 1a included as stick figures. (B) Anexpansion of the chain B inset highlighted in (A) displays thehydrogen bonding network and ring-stacking interaction (dashedlines) formed among 1a, an acetate ion (green carbons), watermolecules (green spheres), and active-site residues (carbons fromcatalytic residues in green; others in gray). Compound 1a blocksentrance to the active site from the upper right. Potential bonds withhalogens are shown in Figure S3. (C) The Cif active site rotated byroughly 135° highlights the hydrogen bonding network that connectsCif, 1a, and a bound acetate ion. (D) The same view of apo Cif (cyancarbons and waters) shows the conserved positions of active-site sidechains. Non-carbon atoms are colored by element (O, red; N, darkblue; Br, maroon).

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confirmed the findings from our medicinal chemistry approach.For example, the structure showed that the R1 moiety is locatedoutside the active-site tunnel and is not critical for theinteraction with Cif (Figure 2B), consistent with our SAR datashowing that changes in the R1 chain have little effect on Cifinhibitory potency (Table 1). The structure also showed thatthe hydroxyl moiety at the R2 position forms a hydrogen bondwith the main-chain carbonyl oxygen of Gly270 (Figure 2).This supports our observation that removing this hydroxylmoiety resulted in great loss of potency (Table 2). One of thebromines (R3) is close to the hydroxyl of Ser173 and the main-chain amide nitrogens of Leu174 and Val175, while the otherbromine (R3′) is close to the thioether of Met272, indicatingpotential interactions between the halogens and these residues(Figure S3).12 In addition, the dibromophenyl ring ofcompound 1a appears to form a π-stacking interaction withPhe164, which may be strengthened by halogen substituents(Figure 2B).13 The catalytic cavity opens around the isopropylmoiety of 1a, indicating that larger groups could be present atposition R4, as we observed with our medicinal chemistryapproach (Table 2).The structural requirements of Cif inhibitors overlap with

those of thyroid hormone receptor ligands10a at severalpositions. Tiratricol and 1a reflect the intersection of theserequirements and thus serve as both thyroid hormone mimicsand Cif inhibitors.5b For example, the hydroxyl group on R2and two halogens on R3 and R3′ are required in both cases, anda bulky substituent is preferred on R4. In the case of the thyroidhormone receptor, the terminal free acid of R1 forms hydrogenbonds (Figure S4). On the other hand, the terminal free acid isnot required for Cif inhibition (Table 1). Therefore,compounds with different R1 groups were screened to evaluatetheir thyroid hormone activity.14 The compound with propylamide (1c) showed the lowest thyroid hormone activity whilestill effectively inhibiting Cif (Table S3, Figure S5). Therefore,the propylamide moiety was selected as the R1 moiety forfurther structural optimization.Comparison to Mammalian EHs and Their Inhibitors,

and Inhibitor Design Strategy. In the case of mammalianepoxide hydrolases, urea and amide moieties are known tofunction as transition state analogs.15 These moieties bind tothe catalytic site very tightly by interacting noncovalently withthe catalytic nucleophile Asp and the accessory Tyr-Tyr pair,leading to potent inhibition of these enzymes.15a,c,16 Cif has aconserved EH catalytic triad consisting of residues Asp129,Glu153, and His297, while it uses a noncanonical His177-Tyr239 accessory pair to coordinate the epoxide oxygen duringring opening.5c On the basis of the similar active-site chemistry,we expected that urea or amide functionalities could alsointeract with the catalytic site of Cif. However, simple alkylurea/amide/carbamate compounds failed to show Cif inhib-itory activity at 50 μM, as did a series of additional potentmammalian EH inhibitors with urea or amide pharmacophores(Table S4). The differential sensitivity of the mammalian andbacterial EHs is consistent with our previous discovery thatthey differ in the relative kinetics of formation vs hydrolysis of acovalent intermediate17 and suggests that the fine details of thetransition states of the two EH families are distinct.In the Cif:1a complex structure, an acetate ion was found in

the catalytic site of the enzyme (Figure 2B and Figure 2C),which was crystallized in a buffer containing sodium acetate.The active-site hydrogen bonding network includes interactionsbetween the acetate ion and the catalytic site residues Asp129,

His177, and Tyr239 (Figure 2C), replicating many of theinteractions of the local water network observed in the apostructure (Figure 2D). The distance between the isopropylmoiety and the acetate is roughly 4.5 Å (Figure 2B). Thetheoretical distance between the carbonyl and phenyl ring incompounds that have a phenyl carbonyl moiety at the R4position is approximately 4.3 Å, indicating that a phenyl linkermay have the appropriate length to reach the catalytic site.

Improving Potency by Targeting the Catalytic Site.On the basis of the above results, we hypothesized that theinhibitory potency toward Cif could be improved by connectingthe lead compound to a moiety that directly interacts withcatalytic residues. A series of compounds were designed totarget the catalytic site by extending the R4 position. As shownin Scheme 2, these compounds were synthesized by Suzuki−

Miyaura cross coupling between an iododiphenyl ether 7 andvarious substituted phenylboronic acids or esters, usingPd(PPh3)4 as a palladium catalyst and sodium carbonate as abase.18 Their potencies as Cif inhibitors are shown in Table 3.A compound with para carboxylic acid (8b) showed a

significant loss of activity, while compounds with para amide(8c), urea (8h), or ketone (8j) showed potencies almost 10-fold higher than that of the lead compound, reaching thetheoretical limit of quantification (half of the enzymeconcentration) of our fluorescent-based Cif inhibition assay([E] = 0.6 μM in the assay). For more classical epoxidehydrolases, ureas and amides are pharmacophores for potentinhibitors that establish bonds with catalytic residues, butketones are not,16b underscoring the distinct chemistry of theCif active site. In the case of free amides, both para (8c) andmeta (8d) substituents yielded high potencies, with the parasubstituent slightly favored. In the case of nitrile, the metasubstituent (8f) showed higher potency but the parasubstituent (8e) showed significant decrease in potency.Compounds with a methylamide (8g) or a sulfonamidesubstituent (8k) also showed significantly lower potency thancorresponding free amide.

Surface Plasmon Resonance (SPR). To confirm potency,particularly for our highest-affinity compounds, bindinginteractions between Cif and inhibitors were further examinedby surface plasmon resonance (SPR). Results are shown inTable S5 and Figure S6. Compound 1a and tiratricol showedsimilar affinity (KD), and compounds 8c, 8h, and 8j showed 30-to 50-fold higher affinity than lead compound 1a. Overall, theaffinity values from the SPR experiments were approximately10- to 40-fold weaker than the IC50 values obtained from theenzyme activity-based assay. Discrepancies between SPR andsolution phase experiments have been reported in severalprotein−ligand interaction analyses19 and may be due toconformational change by immobilization on the chip surface,cooperative effects, or differences in experimental conditions,

Scheme 2. Synthesis of Compounds 8a−k by Suzuki−Miyaura Couplinga

aReagents and conditions: R6-phenylboronic acid or ester, Pd(PPh3)4,Na2CO3, DME/EtOH/H2O, 71 °C.

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such as the presence of surfactant and DMSO concentration inthe running buffer. Identification of the cause of thisdiscrepancy is the subject of further research. The dissociationrate constants (kd; Table S5) suggest that 8c, 8h, and 8j haveresidence times between 2 and 4 s. This is much shorter thanthe best inhibitors for the human soluble epoxide hydrolase(sEH),20 suggesting that further optimization of Cif inhibitorsis possible.Structures of Second-Generation Cif Inhibitors. To

further characterize the interaction between the new inhibitorsand the Cif protein, we pursued a cocrystallization strategy anddetermined structures of the resulting complexes by X-raydiffraction. As shown in Figure 3A and Figure 3B, the amide orurea moieties in compounds 8c (purple) and 8h (blue) interactwith catalytic residues: the nucleophile Asp129, and Tyr239and His177, which coordinate with the epoxide substrate.5a TheNH group of amide and urea forms hydrogen bonds withAsp129, while the oxygen in the carbonyl forms hydrogenbonds to His177 and Tyr239. As with the acetate in the Cif:1astructure, the binding of 8c and 8h occupies the volume andthus replaces the tetrahedral water network found in the apocrystal structure (Figure 2D, cyan). By shifting the specifichydrogen-bonding network in the active site, 8c and 8hpromote a hydrogen bond between His297 and Asp129. Thisnew bond displaces the hydrogen bond with the catalytic waterthat is activated by the His297/Glu153 pair under hydrolysisconditions.The structures also provide a framework to interpret the

structure−activity relationship of Cif inhibitors targeting the

catalytic site (Table 3, Table S5). It appears that the metasubstituents (8d and 8f) can each be accommodated at theedge of the catalytic core. Interestingly, among the parasubstituents either an amide (8c), a urea (8h), or a ketone (8j)moiety causes a substantial increase in potency against Cif.Although chemically distinct, each of these groups can besterically accommodated between the catalytic aspartic acid andthe ring-opening pair, forming hydrogen bonds that lie roughlywithin the plane of view defined by Figure 3. In contrast,weaker binding affinities are observed for para substituents withcharge incompatibility (8b), out-of-plane hydrogen-bondorientations (8k), or a combination of steric and hydrogen-bonding incompatibility (8e, 8g, 8i).

Selectivity Profile and in Vitro Metabolic Stability ofSelected Compounds. Three inhibitors, 8c, 8h, and 8j, wereselected based on their Cif inhibitory potency (Table 3).Thyroid receptor induction activity (relative to 10 nM T3) wasmeasured at a concentration of 10 μM. Results (Table 4)showed that compounds 8c, 8h, and 8j lost their thyroidhormone agonistic activity (EC50 > 10 μM), while theydisplayed a weak antagonistic activity (Table 4, Tables S6 andS7). Globally, compared to 1a, the novel Cif inhibitors aremore than 150 000-fold more selective for Cif than for thethyroid hormone receptor. Next, inhibition of human sEH andmicrosomal epoxide hydrolase (mEH) was measured. The IC50values obtained (∼8 μM for sEH and 20−100 μM for mEH)are 100- to 10 000-fold higher than the best inhibitors for theseenzymes,16b suggesting that 8c, 8h, and 8j are poor inhibitorsfor the mammalian EHs. Given the potency of thesecompounds against Cif, they have at least a 27-fold selectivitytoward Cif over sEH and at least a 50-fold selectivity toward Cifover mEH.Metabolic stability of the three selected compounds was then

studied in both liver microsomes and cell cultures.21 Results(Table 4) indicate that compound 8h is the most stable of thetrio, followed in order by 8c and 8j. Compound 8a, which doesnot have a substituent on the biphenyl ring (Table 3), had ahalf-life longer than 60 min in the human liver microsomalstability assay (63% remained after 60 min incubation). Thisvalue is more than double the corresponding value for 8h,suggesting that the substituent on the biphenyl ring is the mostsusceptible to metabolism. It should be noted that phenolicmoieties are subject to phase II metabolic processes such asglucuronidation and sulfation,22 which could increase the

Table 3. Inhibitory Potency of a Series of CompoundsDesigned To Target the Catalytic Site of Cif

aIC50 values were determined with a fluorescent-based assay usingCMNGC as a fluorescent reporter substrate (see methods section).Reported IC50 values are the average of triplicates with at least twodata points above and at least two below the IC50. The fluorescent-based assay as performed here has a standard error between 10% and20%, suggesting that differences of 2-fold or greater are significant.

Figure 3. X-ray structures of Cif:8c (A, purple carbons) and 8h (B,blue carbons) complexes, with respective hydrogen bonding networksrepresented by dashed lines for chain B. Carbon atoms of catalytic andnoncatalytic residues are shown in the same color as the correspondingligand and in gray, respectively. Potential bonds with halogens are notshown. Non-carbon atoms are colored by element (O, red; N, darkblue; Cl, green).

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clearance and thus decrease the bioavailability of thesecompounds in vivo.Finally, we investigated the physicochemical properties of the

selected compounds. While the three compounds have similarmolecular weight, compound 8h has a lower melting point. Inaddition, this compound has a lower predicted log P and muchhigher aqueous solubility, without DMSO as a cosolvent, than8c and 8j, suggesting that 8h should be easier to formulate andshould be more bioavailable. As expected from their lip-ophilicity, these compounds showed high plasma proteinbinding, which may limit their target accessibility and thushamper their efficacy in vivo. It should be noted, however, thatplasma protein binding could also help drug solubilization anddistribution in the body.23 Note that the reported Cif IC50values were determined in the presence of high BSAconcentration (0.1 mg/mL) to make the assay morerepresentative of in vivo conditions. In terms of toxicity invitro, neither 8c nor 8h showed cytotoxicity when applied toGH3.TRE-Luc cells or polarized monolayers of airwayepithelial cells at concentrations up to 10 μM (Figures S7and S8). Overall, in terms of potency, selectivity, metabolicstability, solubility, and toxicity, compound 8h is the mostsuitable for further in vitro and in vivo experiments todetermine efficacy of Cif inhibitors against Pseudomonasinfection.

■ CONCLUSION

Here we describe a series of potent and selective Cif inhibitors,rationally designed by combining insights from classicalmedicinal chemistry and crystallographic analysis of Cif−leadbinding interactions. Compounds synthesized using thisstrategy show an approximately 10-fold increase in inhibitorypotency toward the primary target and also a more than 15 000-fold decrease in the critical off-target potency toward thyroidhormone receptor. The binding of these second-generationinhibitors was further analyzed by SPR and X-ray crystallog-raphy.Given their in vitro stability and physicochemical properties

(Table 4), these inhibitors may have a short half-life, lowbioavailability, and low accessibility to the target enzyme invivo. Nevertheless, because of their increased potency againstCif and lack of thyroid hormone-like activity (Table 4), these

new inhibitors will be useful in the study of the mechanisms ofCif virulence, as well as determining the in vivo functions of Cifand the efficacy of Cif inhibitors against Pseudomonas infection.Cif prevents deubiquitination of CFTR by ubiquitin specificpeptidase 10.24 To our knowledge, there are no reports ofendogenous epoxides or diols that regulate the ubiquitin/proteasome system. An approach combining inhibitors andmetabolomics should help identify the endogenous substratesof Cif.25 These inhibitors not only are improved Cif inhibitorsbut also represent potential inhibitors of bacterial EHs withsimilar active-site geometries.

■ EXPERIMENTAL SECTIONGeneral. All reagents and solvents were purchased from

commercial suppliers and were used without further purification.Compound 1a was purchased from Cayman Chemicals (purity≥98%). All reactions were performed in an inert atmosphere of drynitrogen or argon. Melting points were determined using an OptiMeltmelting point apparatus. 1H and 13C NMR spectra were collectedusing a Varian 600, 400, or 300 MHz spectrometer with chemical shiftsreported relative to residual deuterated solvent peaks or atetramethylsilane internal standard. Accurate masses were measuredusing an LTQ orbitrap hybrid mass spectrometer (HRMS) orMicromass LCT ESI-TOF-MS (ESI-TOF-MS). The purity of thecompounds that were tested in the assay was determined by reversephase HPLC-DAD and found to be >95% based on monitoringabsorption at 254 nm. Reactions were monitored on TLC plates (silicagel matrix, fluorescent indicator, Sigma-Aldrich, 99569), and spotswere either monitored under UV light (254 mm) or stained withphosphomolybdic acid. The same TLC system was used to test purity,and all final products showed a single spot on TLC with bothphosphomolybdic acid and UV absorbance, and when measured gave asharp melting point for crystalline compounds. FT-IR spectra wererecorded on a Thermo Scientific NICOLET IR100 FT-IRspectrometer. The elemental analysis was conducted by MidwestMicrolab, Indianapolis, IN. Compound 1a analogs were synthesizedusing methods similar to the one previously described for thyroidhormone analogs.11 Chemical characterization of representativecompounds is described below, and others are included in detailedsynthetic methods in Supporting Information.

General Procedure A: SNAr. To an ice-cold DMF solution ofphenol 2 (1.1 equiv) was slowly added 1 M NaOHaq (1.1 equiv),followed by compound 3 (1.0 equiv) in DMF. The reaction was slowlywarmed up to rt and stirred for 1−24 h. To this solution was addedwater. The mixture was extracted with hexane/ethyl acetate (5:1)

Table 4. Selectivity Profiles, in Vitro Metabolic Stability, and Physicochemical Properties of Selected Compounds

compound

parameter 1a 8c 8h 8j

TR agonist EC50 (nM) 0.43 ± 0.14 >10 000 >10 000 >10 000TR antagonist (% inhibition at 10 μM) 66 28 33human sEH IC50 (μM)a 8.6 7.5 7.7human mEH IC50 (μM)b 17.2 26.3 97.8human liver microsomal stability t1/2 (min) 15 29 5.7stability in cell culture (%)c 106 ± 8 103 ± 12 74 ± 30molecular weight 487 445 460 444melting point (°C) 261.3−262.0 162.0−162.9 190−194log P d 4.71 4.44 4.11 4.85solubility (μM)e 0.17 21 <0.04mouse plasma protein bindingf (%) 99 >99 >99 >99

aMeasured using t-DPPO ([3H]-trans-diphenylpropene oxide) as a substrate. The IC50 of 12-(3-adamantan-1-ylureido)dodecanoic acid is 16 nM.bMeasured using CMNGC as a substrate. The IC50 of 2-(nonylthio)propanamide is 6.0 μM. cPercentage remaining after a 24 h incubation (initialconc: 10 μM) with GH3.TRE-Luc cell (mean ± SD). dPredicted value using Chembiodraw Ultra 13.0. eEquilibrium solubility measured in sodiumphosphate buffer (0.1 M, pH 7.4) without cosolvent or BSA at room temperature. fMeasured at 1 μM using a rapid equilibrium dialysis device (no.89809, Thermo Scientific, IL) as described previously.35

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mixture three times. The organic layer was combined, washed withbrine, dried over MgSO4, filtered, and concentrated in vacuo.1,3-Dibromo-2-(3-isopropyl-4-methoxyphenoxy)-5-nitrobenzene

(4a). Compound 4a was synthesized from 3-isopropyl-4-methoxyphe-nol (2a) and 1,3-dibromo-2-iodo-5-nitrobenzene (3a) to give thedesired product (1.85 g, 85%) as a yellow powder. 1H NMR (600MHz, CDCl3) δ 8.50 (s, 2H, H-7, H-9), 6.81 (d, J = 3.5 Hz, 1H, H-1),6.71 (d, J = 9.2 Hz, 1H, H-4), 6.43 (dd, J = 8.9, 3.5 Hz, 1H, H-5), 3.79(s, 3H, CH3O), 3.30−3.28 (m, 1H, isopropyl CH), 1.18 (d, J = 6.9 Hz,6H, isopropyl (CH3)2).

13C NMR (151 MHz, CDCl3) δ 155.5, 152.9,150.0, 145.0, 139.3, 128.5, 119.5, 114.4, 111.9, 111.0, 55.9, 27.1, 22.6.General Procedure B: Deprotection of Methoxy Moiety. To

an ice-cold DCM solution of diphenylether 4, a 1 M boron tribromide(1.2 equiv) solution in DCM was added dropwise. The reaction wasslowly warmed up to rt and stirred for 1−24 h. To this solution wasslowly added methanol at 0 °C, then warmed to rt. The solution waswashed with saturated NaHCO3 aqueous solution, and the aqueouslayer was extracted with DCM three times. The organic layer wascombined and washed with brine, dried over MgSO4, filtered, andconcentrated in vacuo.4-(2,6-Dibromo-4-nitrophenoxy)-2-isopropylphenol (5a). Com-

pound 5a was synthesized from 4a to give the desired product (1.9g, quant) as a yellow powder; mp 106−107 °C; 1H NMR (600 MHz,CDCl3) δ 8.50 (s, 2H, H-7, H-9), 6.79 (d, J = 3.1 Hz, 1H, H-1), 6.65(d, J = 8.7 Hz, 1H, H-4), 6.39 (dd, J = 8.7, 3.1 Hz, 1H, H-5), 4.54 (s,1H, OH), 3.18 (septet, J = 6.9 Hz, 1H, isopropyl CH), 1.23 (d, J = 6.9Hz, 6H, isopropyl (CH3)2).

13C NMR (151 MHz, CDCl3) δ 155.5,150.2, 148.8, 145.0, 136.7, 128.6, 119.4, 116.0, 114.4, 112.6, 27.5, 22.5.ESI-TOF-MS (+) calcd for C15H14Br2NO4 (M + H)+ 429.92, found429.89. Purity (HPLC−UV): 95% (tR = 13.0 min).General Procedure C: Reduction of Nitro Moiety to a

Primary Amine. To a THF solution of compound 5 (1.0 equiv) wasadded an aqueous solution of sodium dithionite (3.8 equiv) at rt, thenthe solution was heated to 50 °C and stirred 1−24 h. After cooling tort, aqueous 1 M HCl was added, and then the solution was neutralizedby a solution of saturated NaHCO3. The organic layer was separated,and the aqueous layer was extracted with ethyl acetate. The organiclayer was combined and washed with brine, dried over MgSO4, filtered,and concentrated in vacuo.4-(4-Amino-2,6-dibromophenoxy)-2-isopropylphenol (6a). Com-

pound 6a was synthesized from 5a to give the desired product (1.38 g,87%) as yellowish crystals; mp 186−187 °C; 1H NMR (600 MHz,DMSO-d6) δ 8.93 (s, 1H, OH), 6.87 (s, 2H, H-7, H-9), 6.64 (d, J = 8.7Hz, 1H, H-4), 6.60 (d, J = 3.1 Hz, 1H, H-1), 6.25 (dd, J = 8.7, 3.1 Hz,1H, H-5), 5.53 (s, 2H, NH2), 3.14 (septet, J = 6.9 Hz, 1H, isopropylCH), 1.10 (d, J = 6.9 Hz, 6H, isopropyl (CH3)2).

13C NMR (151MHz, DMSO-d6) δ 150.1, 149.1, 148.2, 137.8, 135.3, 118.0, 117.0,115.2, 112.6, 111.3, 26.5, 22.4. ESI-TOF-MS (+) calcd forC15H16Br2NO2 (M + H)+ 399.95, found 399.94. Purity (HPLC−UV): 99% (tR = 10.9 min).General Procedure D: Amide Bond Formation. To an ice-cold

MTBE solution of aniline 6 (1.0 equiv) was added a solution ofsaturated NaHCO3 or 1 M NaOH, followed by slowly adding thecorresponding acid chloride (1.1 equiv). This solution was stirred at rtfor 1−24 h, then 1 M HCl aqueous solution was added. The reactionmixture was extracted with ethyl acetate. The organic layer wascombined and washed with 1 M HClaq twice, saturated aqueousNaHCO3 solution 4 times, and brine, dried over MgSO4, filtered, andconcentrated in vacuo. The target compound was purified by columnchromatography and further purified by recrystallization fromacetone/DCM/hexane when possible.N-(3,5-Dibromo-4-(4-hydroxy-3-isopropylphenoxy)phenyl)-

acetamide (1b). Compound 1b was synthesized from 6a and acetylchloride to give the desired product (99 mg, 56%) as a white powder;mp 172−173 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.24 (s, 1H,NH), 9.02 (s, 1H, OH), 7.96 (s, 2H, H-7, H-9), 6.67−6.64 (m, 2H, H-1, H-4), 6.26 (dd, J = 9.4, 2.2 Hz, 1H, H-5), 3.16−3.14 (m, 1H,isopropyl CH), 2.07 (s, 3H, COCH3), 1.11 (d, J = 7.0 Hz, 6H,isopropyl (CH3)2).

13C NMR (151 MHz, DMSO-d6) δ 168.8, 149.5,149.3, 143.8, 138.2, 135.6, 122.7, 117.8, 115.3, 112.8, 111.4, 26.5, 24.0,

22.3. ESI-TOF-MS (−) calcd for C17H16Br2NO3 (M − H)− calcd439.96 found 439.97. Purity (HPLC−UV): 98% (tR = 10.8 min).

General Procedure E: Suzuki−Miyaura Coupling. To a DMEsolution of compound 7 (80 mg, 177 μmol, 1.0 equiv) were addedPd(PPh3)4 (10 mg, 8.7 μmol, 0.05 equiv), an aqueous solution ofNa2CO3 (400 mg in 1 mL of H2O), and corresponding boronic acid orboronate ester (212 μmol, 1.2 equiv) in 1 mL of ethanol. This solutionwas stirred at 71 °C overnight. After cooling to rt, ethyl acetate and 1M HClaq were added and extracted 4 times with ethyl acetate. Theorganic layer was combined and washed with brine, dried over MgSO4,filtered, and concentrated in vacuo. The target compound was purifiedby column chromatography and recrystallized from acetone/DCM/hexane.

5′-(2,6-Dichloro-4-propionamidophenoxy)-2′-hydroxy[1,1′-bi-phenyl]-4-carboxamide (8c). Compound 8c was synthesized fromcompound 7 and 4-aminocarbonylphenylboronic acid. The productwas obtained as an off-white powder (14 mg, 18%); TLC Rf = 0.4(DCM/MeOH = 30:1); mp 261.3−262.0 °C; IR (neat) 3339 (broad),1648, 1592, 1532, 1531, 1462 cm−1; 1H NMR (600 MHz, DMSO-d6)δ 10.22 (s, 1H, NH), 9.48 (s, 1H, OH), 7.96 (s, 1H, NHH), 7.88−7.83(m, 2H, biphenyl-H2), 7.82 (s, 2H, H-7, H-9), 7.57−7.55 (m, 2H,biphenyl-H2), 7.34 (s, 1H, NHH), 6.90 (d, J = 8.8 Hz, 1H, H-4), 6.75(d, J = 3.1 Hz, 1H, H-1), 6.64 (dd, J = 8.8, 3.2 Hz, 1H, H-5), 2.34 (q, J= 7.5 Hz, 2H, CH2), 1.09 (t, J = 7.5 Hz, 3H, CH3).

13C NMR (151MHz, DMSO-d6) δ 172.6, 167.7, 149.7, 149.6, 141.5, 140.6, 137.7,132.6, 128.7, 128.6, 127.6, 127.2, 119.1, 117.1, 116.0, 114.8, 30.7, 9.4.HRMS (+) calcd for C22H19Cl2N2O4

+ (M + H) 445.0716. Found445.0717. Purity (HPLC−UV): 99% (tR = 9.2 min). Anal. C 59.09, H4.14, N 6.13%, calcd for C22H18Cl2N2O4, C 59.34, H 4.07, N 6.29%.

Cif Preparation. Recombinant Cif-His was prepared as describedpreviously.5b,26 Stocks of purified proteins were stored at 4 °C untilused. Since esterase and glutathione transferases can give a highbackground fluorescence when using cyano(6-methoxynaphthalen-2-yl)methyl glycidyl carbonate (CMNGC) as Cif substrate, it isimportant to evaluate the purity of Cif for the absence of these andof similar biochemicals. The purified enzyme was tested forcontamination with esterase activity and glutathione transferaseactivity as previously described.27

Fluorescent-Based Cif Inhibitory Assay. IC50 values weredetermined using a sensitive fluorescent-based assay similar to themethod previously described for other EHs.5b,28 Cyano(6-methoxy-naphthalen-2-yl)methyl glycidyl carbonate (CMNGC) was used as afluorescent reporter substrate. Recombinant Cif (0.6 μM) wasincubated with inhibitors for 5 min in sodium phosphate buffer (20mM, pH 7.0) containing 50 mM NaCl and 0.1 mg/mL of BSA at 37°C prior to substrate introduction ([S] = 25 μM).

Activity was measured by determining the appearance of the 6-methoxy-2-naphthaldehyde with an excitation wavelength of 330 nmand an emission wavelength of 465 nm for 10 min. Reported IC50values are the average of triplicates with at least two data points aboveand at least two below the IC50. The fluorescent-based assay asperformed here has a standard error between 10% and 20%, suggestingthat differences of 2-fold or greater are significant. Controlexperiments without Cif (inhibitor and substrate) were used toevaluate the intrinsic fluorescence of inhibitors. For compoundsshowing IC50 > 50 μM (compounds 1g, 1h, and 1k), solubility underassay conditions was measured using a method described previously.29

Compounds 1g and 1k showed solubility 50 < S < 100 μM, whilecompound 1h showed 25 < S < 50 μM.

Surface Plasmon Resonance. The interactions between Cif andinhibitors were analyzed by surface plasmon resonance using aBIAcore T100. The running buffer for immobilization was HBS-P (pH7.4), which contains 10 mM HEPES, 150 mM NaCl, and 0.05% (v/v)Tween 20 surfactant. Cif was coupled to the surface of a CM5 sensorchip using standard amine-coupling chemistry with a 7 min injection ofCif (15 μg/mL) diluted in 10 mM sodium acetate (pH 4.5). Cifprotein was immobilized at 4000−5000 RU. Remaining activatedgroups were blocked with a 7 min injection of 1 M ethanolamine HCl(pH 8.5). Binding assays were performed at 37 °C at a flow rate of 30μL/min with a 40 s injection of inhibitors followed by washing with

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buffer for 40 s. Sodium phosphate buffer (20 mM pH 7.0) containing50 mM NaCl and 0.05% (v/v) Tween 20 with 4% (v/v) DMSO wasused as a running buffer in the assay. The measured signals weredouble-referenced from reference curves generated by an uncoatedflow cell and several injections of running buffer. Experimental datawere analyzed using BIAevaluation 1.0 software (BIAcore).X-ray Structure Analysis. Cif−inhibitor cocrystals were obtained

by vapor diffusion against 400 μL of reservoir solution in a 4 μLhanging drop at 291 K.5a,30 A solution of 5 mg/mL Cif proteincontaining 200 μM inhibitor was mixed in a 1:1 ratio with reservoirsolution consisting of 12−16% (w/v) polyethylene glycol 8000, 125mM CaCl2, 100 mM sodium acetate (pH 5), 200 μM inhibitor, and0.2% (v/v) DMSO. Prior to data collection, crystals were washed incryoprotectant solution consisting of 12−16% (w/v) polyethyleneglycol 8000, 125 mM CaCl2, 100 mM sodium acetate (pH 5), 200 μMinhibitor, 0.2% (v/v) DMSO, and 20% (w/v) glycerol and flash cooledby plunging into a liquid nitrogen bath. Oscillation data were collectedat 100 K at the X6A beamline of the National Synchrotron LightSource at Brookhaven National Laboratory (PDB code 5HKB) andthe 5.0.1 beamline of the Advance Light Source at Lawrence BerkeleyNational Laboratory (PDB codes 5HKA, 5HK9). Diffraction imageswere processed and scaled with the XDS package (version January 10,2014).31 Molecular replacement using apo-Cif-WT as the searchmodel (PDB code 3KD2) revealed two dimers in the asymmetric unit.Iterative rounds of automated refinement were carried out with Phenix(version 1.7.3-928).32 WinCoot (version 0.7)33 was used for manualadjustment of the model, and PyMOL (version 1.3)34 was used torender structure images of the final models of chain B, in which theactive-site structures are best defined. Structure figures were assembledin Adobe Illustrator CS6 (version 16.0.4).Thyroid Hormone Activity Assay. Thyroid hormone activity was

measured by the assay described previously with slight modifications.14

GH3.TRE-Luc cells were seeded at 80% confluency in 75 cm2 cultureflasks (Corning, Schiphol-Rijk, The Netherlands) in regular growthmedium. Cells were collected and seeded into 24-well plates for anadditional period of 24 h and incubated for 24 h in the presence orabsence of T3, with the indicated test chemical in DMSO. The DMSOconcentration in 500 μL of exposure medium was always the same forall exposures within an experiment and always kept at ≤0.5% (v/v) toavoid cytotoxicity. Cell viability in each well was determined bymeasuring total protein concentration using the bicinchoninic acid(BCA) assay following the manufacturer’s protocol. Luciferase activitywas measured on lysed cells on an Infinite M1000 plate reader (TecanGroup AG, Zurich, Switzerland).

■ ASSOCIATED CONTENT

*S Supporting InformationThe Supporting Information is available free of charge on theACS Publications website at DOI: 10.1021/acs.jmed-chem.6b00173.

LC−MS/MS conditions, additional SAR data, SPR data,thyroid hormone activity assay data, and detailedexperimental methods (PDF)Molecular formula strings (CSV)

Accession CodesCif:1a complex: 5HKB. Cif:8c complex. 5HKA. Cif:8hcomplex: 5HK9.

■ AUTHOR INFORMATION

Corresponding Author*Phone: 530-752-6571 (office). Fax: 530-752-1537. E-mail:chmorisseau@ucdavis.edu.

NotesThe authors declare no competing financial interest.

■ ACKNOWLEDGMENTSWe express our sincere thanks and appreciation to Dr. Brenda J.Mengeling and Dr. J. David Furlow for help on the thyroidhormone activity assay; Dr. Vikrant Singh, Brandon Pressly,and Dr. Heike Wulff for kindly providing us thyroid hormoneanalogs; Dr. Amelia A. Rand, Dr. Jun Yang, and Dr. Debin Wanfor their help with LC−MS analysis; Dr. Peter Hwang forassistance on SPR experiments; and Dr. Christopher Bahl forcontributions to the cocrystallization and screening experi-ments. This work was partially funded by the National Instituteof Environmental Health Sciences (Grants R01ES002710 andP42 ES04699), the National Institute of Allergy and InfectiousDiseases (Grant R01AI091699), the National Institute ofGeneral Medical Sciences (Grants P30-GM106394 and T32-GM008704), and the Munck-Pfefferkorn Fund. The content issolely the responsibility of the authors and does not necessarilyrepresent the official views of the NIH. B.D.H. is a George andJudy Marcus Senior Fellow of the American AsthmaFoundation. S.K. is financially supported by Japan StudentServices Organization.

■ ABBREVIATIONS USEDCFTR, cystic fibrosis transmembrane conductance regulator;Cif, cystic fibrosis transmembrane conductance regulatorinhibitory factor; EH, epoxide hydrolase; T3, triiodothyronine;sEH, soluble epoxide hydrolase; mEH, microsomal epoxidehydrolase; CMNGC, cyano(6-methoxynaphthalen-2-yl)methylglycidyl carbonate; t-DPPO, [3H]-trans-diphenylpropene oxide;TR, thyroid hormone receptor; SPR, surface plasmonresonance

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of urea-based soluble epoxide hydrolases. Biochem. Pharmacol. 2002,63 (9), 1599−1608.(30) Bahl, C. D.; MacEachran, D. P.; O’Toole, G. A.; Madden, D. R.Purification, crystallization and preliminary X-ray diffraction analysis ofCif, a virulence factor secreted by Pseudomonas aeruginosa. ActaCrystallogr., Sect. F: Struct. Biol. Cryst. Commun. 2010, 66 (Part 1), 26−28.(31) Kabsch, W. Automatic processing of rotation diffraction datafrom crystals of initially unknown symmetry and cell constants. J. Appl.Crystallogr. 1993, 26, 795−800.(32) Adams, P. D.; Afonine, P. V.; Bunkoczi, G.; Chen, V. B.; Davis,I. W.; Echols, N.; Headd, J. J.; Hung, L.-W.; Kapral, G. J.; Grosse-Kunstleve, R. W.; McCoy, A. J.; Moriarty, N. W.; Oeffner, R.; Read, R.J.; Richardson, D. C.; Richardson, J. S.; Terwilliger, T. C.; Zwart, P. H.PHENIX: a comprehensive Python-based system for macromolecularstructure solution. Acta Crystallogr., Sect. D: Biol. Crystallogr. 2010, 66(2), 213−221.(33) Emsley, P.; Cowtan, K. Coot: Model-building tools formolecular graphics. Acta Crystallogr., Sect. D: Biol. Crystallogr. 2004,60 (Part 12, Part 1), 2126−2132.(34) DeLano, W. L. The PyMOL Molecular Graphics System; DeLanoScientific LLC: Palo Alto, CA, U.S., 2008; http://www.pymol.org.(35) Ulu, A.; Appt, S.; Morisseau, C.; Hwang, S. H.; Jones, P. D.;Rose, T. E.; Dong, H.; Lango, J.; Yang, J.; Tsai, H. J.; Miyabe, C.;Fortenbach, C.; Adams, M. R.; Hammock, B. D. Pharmacokinetics andin vivo potency of soluble epoxide hydrolase inhibitors in cynomolgusmonkeys. Br. J. Pharmacol. 2012, 165 (5), 1401−1412.

Journal of Medicinal Chemistry Article

DOI: 10.1021/acs.jmedchem.6b00173J. Med. Chem. 2016, 59, 4790−4799

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S1

Supporting Information

Rational design of potent and selective inhibitors of an epoxide hydrolase virulence factor from Pseudomonas aeruginosa

Seiya Kitamura†, Kelli L. Hvorecny‡, Jun Niu†, Bruce D. Hammock†, Dean R. Madden‡,

Christophe Morisseau*†

† Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, One Shields Avenue, Davis, California 95616 ‡Department of Biochemistry, Geisel School of Medicine at Dartmouth, 7200 Vail Building, Hanover, New Hampshire, 03755 Table of contents Tables

Table S1. Inhibition of Cif by a series of compounds similar to tiratricol Table S2. X-ray data collection and refinement statistics Table S3. Structure-activity relationships of the R1 substituents on thyroid hormone activity Table S4. Structures of inactive compounds tested on Cif inhibitory assay Table S5. Equilibrium and kinetic parameters obtained from surface plasmon resonance experiments Table S6. Thyroid hormone activity and selectivity of selected compounds Table S7. Result of thyroid hormone activity of selected compounds Table S8. Optimum mass transition conditions and key fragmentation Table S9. HPLC solvent gradient for the quantification of inhibitors by LC-MS/MS Table S10. HPLC solvent gradient for the purity determination

Figures

Figure S1. 2mFo-DFc simulated annealing omit maps of D129/H297 in Chain B Figure S2. Fo-Fc and 2Fo-Fc maps of bound 1a, 8c, and 8h, from Chain B Figure S3. Potential halogen bonds between Cif Chain B and 1a

Figure S4. X-ray structure of KB compound bound to TRβ Figure S5. Thyroid hormone assay concentration-response curve Figure S6. Cif:inhibitor binding interaction analysis by SPRFigure S7. Effects of the tested compounds on protein concentration in GH3.TRE-Luc cells Figure S8. Cytotoxicity of 8c and 8h on CFBE cells

Methods Measurement of mEH inhibition by fluorescent assay Measurement of sEH inhibition by radioactivity-based assay (t-DPPO assay) Measurement of solubility in sodium phosphate buffer Measurement of in vitro stability Quantification of the inhibitors by mass spectrometry Plasma protein binding assay Purity assessment of the inhibitors by HPLC-UV Detailed synthetic methods

S2

Table S1. Inhibition of Cif by a series of compounds similar to tiratricol

Structure Cif IC50 (µM)a

Structure Cif IC50 (µM)a

Tiratricol

4.7 ± 0.6

> 100

20 ± 2

44 ± 4

4.4 ± 0.5

> 100b

100 ± 2

> 100b

80 ± 10

64 ± 4b

21 ± 2

84 ± 6b

> 100

> 100

1a (KB2115)

2.6 ± 0.4

> 100

> 100

aConditions: [E] = 0.6 µM; [S] = 25 µM; 37 °C for 15 min; pre-incubation 5 min at 37 °C. Results are average ± standard deviation (n = 3). bSynthesized elsewhere.1

O

Br

Br NH

HO

O O

OH

S3

Table S2. X-ray data collection and refinement statistics

Cif with

KB2115 (1a) Cif with

8c

Cif with 8h

Data Collection Wavelength (Å) 1.0000 0.9770 0.9774 Space Group C2221 C2 C2 Unit cell dimensions:

a,b,c (Å) 84.2, 169.5, 175.6 169.0, 83.7, 88.9 169.3, 84.1, 89.2

α,β,γ (°) 90, 90, 90 90, 100.7, 90 90, 100.6, 90

Resolutiona (Å) 19.9-1.65 (1.75-1.65) 20.0-2.05 (2.08-2.05) 19.8-1.80 (1.90-1.80) Rmrgd-F

b (%) 10.2 (41.8) 9.3 (44.5) 9.5 (48.1) I/σI 21.76 (7.22) 15.25 (3.53) 13.3 (3.26) Completeness (%) 99.9 (100.0) 98.5 (97.2) 98.3 (97.5) Redundancy 14.6 (14.2) 3.8 (3.6) 3.8 (3.8) Refinement Total number of reflections 150068 75324 111909 Reflections in the test set 7519 3764 5590 Rwork

c/Rfreed (%) 18.6/21.6 15.5/19.8 16.2/19.6

Number of atoms: Protein 9602 9481 9536 Solvent 1426 769 1146 Ligand 120 120 93

Ramachandran plote (%) 97.8/2.1/0.0 97.9/2.1/0.0 98.1/1.9/0.0 Bav (Å

2) Protein 10.2 19.8 15.6 Solvent 25.1 28.9 28.5 Ligand 20.5 38.3 33.5

Bond length RMSD 0.007 0.008 0.007 Bond angle RMSD 1.161 1.143 1.115 PDB ID 5HKB 5HKA 5HK9 aValues in parentheses are for data in the highest-resolution shell. bRmrgd-F is a robust indicator of the agreement of structure factors of symmetry-related reflections

and is described in detail in Diederichs & Karplus2. cRwork = Σh |Fobs(h) – Fcalc(h)|/Σh Fobs(h), hε [working set]

dRfree = Σh |Fobs(h) – Fcalc(h)|/Σh Fobs(h), hε [test set]

efavored/allowed/outliers

S4

Table S3. Structure-activity relationships of the R1 substituents on thyroid hormone

activity

Thyroid hormone activity at 10 nM (% relative to T3)

a

Cif IC50

(µM)

# R1

T3 - 100±8 -

1a (KB2115)

94±3 2.6

6a 68±7 9.7

1b

71±8 8.8

1c

58±2 7.5

1e

72±6 3.2

aValues are shown as mean ± SD (n = 3).

S5

Table S4. Structures of inactive compounds tested on Cif inhibitory assay

Structure Cif IC50 (µM)

Terminal amide/Substructure of 8c

>50

Terminal amide/Potent mEH inhibitor

> 50

Carbamate with small substituent+long alkyl chain

> 50

Carbamate with small substituent+long alkyl chain

> 50 (40%)

Carbamate with small substituent+long alkyl chain

> 50

O

O

NH

Carbamate with small substituent+long alkyl chain

> 50

Carbamate with small substituent+long alkyl chain

> 50 (45%)

Terminal amide/Potent mEH inhibitor

> 50

Terminal hydrazide > 50

Urea with small substituent+long alkyl chain

> 50

Amide with small substituent+long alkyl chain

> 50

S6

Terminal N-hydroxyamide > 50

Amide with small substituent+long alkyl chain

> 50

N-hydroxyamide with small substituent+long alkyl chain

> 50

Amide with small substituent+long alkyl chain

> 50

Paraoxon/Potent esterase inhibitor

> 50

NH

O

O

Carbamate/Potent esterase inhibitor

> 50

Trifluoromethylketone/Potent esterase inhibitor

> 50

Fhosfomycin/Antibiotics > 50

S7

Table S5. Equilibrium and kinetic parameters obtained from surface plasmon resonance

experiments

Tiratricol 1a

(KB2115) 8c 8h 8j

KDa

(µM) 115±11 113±24 2.0±0.6 3.3±0.4 4.4±0.5

ka (1/Ms)

-b -b

1.3 (±0.3)×105 6.6 (±0.9)×104

4.7 (±0.9)×104

kd (1/s)

-b -b

0.17 (±0.03) 0.33 (±0.07) 0.34 (±0.07)

KDc

(µM) - - 1.4 (±0.3) 4.9 (±0.5) 7.2 (±0.1)

Results are shown as Mean ± SD (n = 3-6). aData calculated based on steady state analysis. bKinetic constants were outside the limit that can be measured. cData calculated based on kinetic analysis.

S8

Table S6. Thyroid hormone activity and selectivity of selected compounds

Structure EC50

a

(nM,TR activity)

Cif IC50 (µM,

CMNGC)

Selectivity Indexb

Relative Selectivity

Indexc

1a (KB

2115)

0.43±0.14 2.6 0.0002 1

1c HO Br

O

NH

O

Br

7.0±2.1 7.5 0.0009 5.3

8c

HO Cl

O

NH

O

ClH2N

O

>10,000 <0.35 29 161,000

8h HO Cl

O

NH

O

Cl

HNH2N

O

>10,000 <0.35 29 161,000

8j

>10,000 <0.35 29 161,000

T3

0.10±0.02 - - -

aMean ± SD values are shown. bSelectivity Index=TR EC50 of the compound/Cif IC50 of the compound. cRelative selectivity = (TR EC50 of the compound/Cif IC50 of the compound)/ (TR EC50 of KB2115/Cif IC50 of KB2115). For compounds 8c, 8h and 8j, Cif IC50 values of 0.35 µM and TR EC50 values of 10,000 nM were used for the calculation.

S9

Table S7. Result of thyroid hormone activity of selected compounds

Compound 8c 8h 8j

Structure HO Cl

O

NH

O

ClH2N

O

TR agonist (induction % at 3 µM)

23% -3.5% 11%

TR agonist (induction

% at 10 µM) 5.7% 2.4% 20.4%

TR antagonist (inhibition

% at 10 µM) 66% 28% 33%

S10

Table S8. Optimum mass transition conditions and key fragmentation

Ionization mode

Transition

Cone voltage

(V)

Collision voltage

(V)

8c - 443 -> 216 50 27

8h - 458 -> 415 50 20

8j - 442 -> 216 50 25

AUDA - 391 -> 214 30 30

AUDA (12-(3-adamantan-1-yl-ureido) dodecanoic acid) was used as an internal standard for

instrument sensitivity.

Table S9. HPLC solvent gradient for the quantification of inhibitors by LC-MS/MS

Time Aqueous phasea Organic phaseb Flow rate (mL/min)

0.00 95 5 0.2

3.00 95 5 0.2

5.00 2 98 0.2

10.00 2 98 0.2

10.01 95 5 0.2

12.00 95 5 0.2

aMilli-Q water 99.9, formic acid 0.1, volume %, bMethanol 99.9, formic acid 0.1, volume %.

Table S10. HPLC solvent gradient for the purity determination

Time Aqueous phasea Organic phaseb Flow rate (mL/min)

0.00 90 10 0.3

15.00 0 100 0.6

25.00 0 100 0.6

25.01 90 10 0.3

35.00 90 10 0.3

S11

aMilli-Q water 99.9, formic acid 0.1, volume %, bAcetonitrile 99.9, formic acid 0.1, volume %.

Figure S1. 2mFo-DFc simulated annealing omit maps of D129/H297 in Chain B. Each panel contains stick representations of the residues Asp 129 and His 297 from the final models of Cif with 1a (A, carbons in green), Cif with 8c (B, carbons in purple), and Cif with 8h (C, carbons in blue). The residues have been overlaid with the 2mFo-Fc map (blue mesh) from a simulated annealing omit map heated to 3000K, with residues Asp 129 and His 297 removed. The maps are contoured to 1σ. All panels display the same view of the two active site residues from the final model. Non-carbon atoms are colored by element (O, red; N, dark blue).

S12

Figure S2. Fo-Fc and 2Fo-Fc maps of bound 1a, 8c, and 8h, from Chain B. Each panel contains stick representations of the inhibitors from the final models of Cif with 1a and acetate (A, carbons in green), Cif with 8c (B, carbons in purple), and Cif with 8h (C, carbons in blue). The models have been overlaid with the 2mFo-Fc map (blue mesh) and mFo-Fc map (green mesh) from the map generated before the inhibitors were placed into the model. 2mFo-Fc contoured to 1σ,andmFo-Fccontouredto3σ.Non-carbon atoms are colored by element (O, red; N, dark blue; Br, maroon; Cl, green).

S13

Figure S3. Potential halogen bonds between Cif Chain B and 1a. Stick representations of 1a

(carbons in green) and Cif (carbons in dark grey) depict the halogen bonds (dashed lines in pale green) forming among the bromines on the small molecule and residues S173, L174, V175, and M272 of the protein. Non-carbon atoms are colored by element (O, red; N, dark blue; S, yellow; Br, maroon).

S14

Figure S4. X-ray structure of KB compound bound to TRβ. Human thyroid hormone receptor β ligand binding domain in complex with KB131084 (PDB: 2J4A).

S15

Figure S5. Thyroid hormone assay concentration-response curve. Percentages of maximal

luciferase induction for each test compound were calculated by taking luciferase response in

solvent control (DMSO) as 0% and the maximum luciferase induction by each compound as

100%. Every assay was repeated at least three separate times, and mean ± se values are shown.

S16

Figure S6. Cif:inhibitor binding interaction analysis by SPR. (A) Representative sensorgram for

compound 8h. Compound 8h was injected in a two-fold concentration series at 156 nM-20 µM.

Fitted curves (orange lines) are superimposed over experimental curves. The figure was

generated using Scrubber2 software (BioLogic Software). (B) Binding isotherms for affinity

determination. Responses at equilibrium were plotted against compound concentration and fit to

a simple binding isotherm. Compound 8c, 8h or 8j was injected in a two-fold concentration

series at 156 nM-20 µM. RU: Resonance units.

S17

Figure S7. Effects of the tested compounds on protein concentration of GH3.TRE-Luc cells. Cell viability in each well was determined by measuring total protein concentration using the bicinchoninic acid (BCA) assay following the manufacture’s protocol. Treatment with T3 (10 nM) or inhibitor (10 µM) did not change the protein concentration significantly compared to control (DMSO treatment). Data were analyzed using SigmaPlot 11.0 for Windows (Systat Software Inc., San Jose, CA). Kruskal-Wallis One Way ANOVA on Ranks was performed with p values<0.05 considered significant.

S18

Figure S8. Cytotoxicity of 8c and 8h on CFBE cells. Percent cytoxicity was quantified using CFBE cells and the Cytotox 96 non-radioactive cytotoxicity assay (Promega). A490 values were corrected by subtraction of the corresponding value for negative control treatment (medium) and normalized to yield 100% toxicity for the positive control treatment (0.1% Triton-X100). n = 3, error bars = se. ***, P< 0.001 by ANOVA followed by Tukey’s HSD post-hoc test.

-5

15

35

55

75

95

% Cytotoxicity

Treatment

8c 8h

***

S19

Methods

Measurement of mEH inhibition by fluorescent assay

Human microsomal epoxide hydrolase (mEH) was produced in a polyhedron positive baculovirus expression system and was partially purified as described previously.3 No esterase or glutathione transferase activities, which can interfere with EH assays, were detected in the purified enzyme. IC50 values were determined as described previously4 using cyano (6-methoxy-naphthalen-2-yl) methyl glycidyl carbonate (CMNGC) as a fluorescent substrate. Recombinant human mEH (1.6 µg/mL) was incubated with compound for 5 min in 100 mM Tris/HCl buffer (pH 8.5) containing 0.1 mg/mL of BSA at 30 °C prior to substrate introduction ([S] = 25 µM). Activity was measured by determining the appearance of the 6-methoxy-2-naphthaldehyde with an excitation wavelength of 330 nm and an emission wavelength of 465 nm for 10 min. 2-(Nonylthio) propanamide was used as positive control giving an IC50 of 6.0 µM.

Measurement of sEH inhibition by radioactivity-based assay (t-DPPO assay)

Recombinant human sEH was produced in insect High Five cells using recombinant baculovirus expression vectors, and purified by affinity chromatography as reported previously.5 The enzymes appeared as single bands of ca. 62 kDa by Coomassie Brilliant Blue staining following SDS-PAGE separation.

IC50 values were determined as described previously6 with slight modifications, using racemic [3H] trans-diphenylpropene oxide (t-DPPO). Purified recombinant human sEH was diluted in 100 mM sodium phosphate buffer (pH 7.4) containing 0.1 mg/mL BSA, and was incubated in triplicate with inhibitors for 5 min at 30 ºC prior to the introduction of the radiolabeled substrate (t-DPPO: 50 µM; ~10,000 cpm/assay). The mixture was incubated at 30 ºC for 10 min and the reaction was quenched by the addition of 60 µL of methanol. The remaining substrate was extracted by vigorous mixing with 200 µL of isooctane. The radioactivity of the aqueous phase was measured using a liquid scintillation counter (Perkin Elmer Tri-Carb 2810TR, Shelton, CT). Epoxide hydrolase activity was determined as a percentage of the radioactivity corresponding to the diol in the aqueous phase relative to the control. A potent soluble epoxide hydrolase inhibitor 12-(3-adamantan-1-yl-ureido) dodecanoic acid (AUDA) was used as positive control giving an IC50 of 16 ± 4 nM.

Measurement of solubility in sodium phosphate buffer

An excess of the test compound (~0.5 mg) was added to a vial containing sodium phosphate buffer, 0.1 M pH 7.4 (0.25 mL) without co-solvent, and a suspension of the mixture was equilibrated during 1 h of sonication and 24 h of shaking at room temperature, followed by centrifugation. The aqueous supernatant was analyzed by LC–MS/MS.

Measurement of in vitro stability

The in vitro human liver microsomal stability assay was performed as described previously with slight modifications.7 Human liver microsomal protein (0.2 mg/mL) was incubated with a solution of test compound (1 µM) in Tris-HCl buffer (pH 7.4) containing 5 mM MgCl2 and 1 mM NADPH. The incubation mixture was shaken at 37 ºC for 60 min. Samples were taken out

S20

every 10 min. The absolute quantity of parent compounds remaining at each time point was analyzed by LC-MS/MS described below and was converted to a percentage.

Quantification of the inhibitors by mass spectrometry

Inhibitors were quantified using a Waters Quattro Premier triple quadrupole tandem mass spectrometer (Micromass, Manchester, UK) interfaced to an electrospray ionization (ESI) source. The ESI was performed following HPLC in the negative mode at 2.51 kV capillary voltage. The source and the desolvation temperatures were set at 120 and 350 ºC, respectively. Cone gas (N2) and desolvation gas (N2) were maintained at flow rates of 10 and 700 L/h, respectively. Optimized conditions for mass spectrometry are shown in Table S8. Dwell time was set to 0.1 s. A regression curve for each compound was obtained from at least five different concentrations of standard stock solutions (r2 > 0.99). 12-(3-Adamantan-1-yl-ureido) dodecanoic acid (AUDA) was used as an internal standard for instrument sensitivity and was added just before the analysis. The final concentration of AUDA was adjusted to 50 nM. The MS was coupled with a Waters Acquity UPLC (Waters, and Milford, MA, USA). The Phenomenex Kinetex C18 RP UPLC column (150 mm × 2.1 mm, particle size 1.7 µm) was used to separate these compounds. The HPLC solvent gradient is shown in Table S9.

Plasma protein binding assay

Mouse plasma protein binding assay was performed with inhibitor concentration at 1 µM as described previously8. Balb C mouse plasma was purchased from Innovative Research, Inc. (catalog #:IMSBC-N). A rapid equilibrium dialysis device method was used (#89809, Thermo Scientific, IL).

Purity assessment of the inhibitors by HPLC-UV Purity determination of synthetic compounds was performed on an Agilent 1200 Series HPLC with a G1322A degasser, a G1311A Quatpump, and a G1315D Agilent detector. The Varian Pursuit5 C18 RP HPLC column (150 mm × 2.1 mm, particle size 5 µm) was used. The UV absorption between 190 nm and 400 nm was monitored, and the purity was determined by the peak area at 254 nm. Gradients are described in Table S10. In addition, all final products showed a single spot on TLC (silica gel matrix, fluorescent indicator, Sigma-Aldrich, 99569) under UV light (254 mm), >95% purity on 1H NMR, and gave sharp melting point for crystalline compounds when measured. Detailed synthetic methods

3-Isopropyl-4-methoxybenzaldehyde.

The title compound was synthesized as described previously.9 To a DMF solution of 2-isopropylanisole (8.59 g, 57.3 mmol) was added dropwise phosphoryl chloride (26.9 g, 176 mmol, 3.1 equiv) at 90 °C, and stirred overnight at 90 °C. The reaction mixture was cooled to rt,

S21

then ice-cold water was slowly added. The reaction mixture was extracted with ethyl acetate. The organic layer was combined and washed with saturated NaHCO3 aqueous solution and brine, dried over MgSO4, filtered and concentrated in vacuo to afford 8.50 g (47.8 mmol, 83%) of title compound as a mixture with starting material (~2:1) as a brown oil. The compound was taken to the next step without further purification. 1H NMR (600 MHz, CDCl3) δ 9.88 (s, 1H, CHO), 7.77 (d, 1H, J = 2.1 Hz, H-3), 7.71 (dd, 1H, J = 8.4, 2.1 Hz, H-5), 6.95 (d, J = 8.4 Hz, 1H, H-6), 3.92 (s, 3H, OCH3), 3.36 – 3.27 (m, 1H, isopropyl CH), 1.24 (d, J = 6.9 Hz, 6H, isopropyl (CH3)2).

Hydroxy (3-isopropyl-4-methoxyphenyl) methanesulfonic acid.

The title compound was synthesized as described previously.9 To a THF: hexane (60 mL:48 mL) solution of 3-isopropyl-4-methoxybenzaldehyde (8.5g, 47.8 mmol) was added sodium bisulfite (13.1 g, 125 mmol, 2.6 equiv) in 48 mL water at rt and stirred overnight. The resulting precipitate was filtered and the residue was washed with THF:hexane (3:1), then dried to give pure title compound as a white powder (8.3 g, 31.9 mmol, 67%). 1H NMR (400 MHz, DMSO-d6) δ 7.26 (d, J = 2.1 Hz, 1H), 7.22 (dd, J = 8.5, 2.3 Hz, 1H), 6.80 (d, J = 8.4 Hz, 1H), 5.61 (d, J = 5.1 Hz, 1H), 4.86 (d, J = 5.1 Hz, 1H), 3.76 (s, 3H), 3.19 (septet, J = 7.0 Hz, 1H), 1.14 (d, J = 6.9 Hz, 6H).

3-Isopropyl-4-methoxyphenol (2a).

The title compound was synthesized as described previously.9 To a MeOH solution of hydroxy (3-isopropyl-4-methoxyphenyl) methanesulfonic acid (8.2 g, 31.5 mmol) was added p-toluene sulfonic acid monohydrate (7.20 g, 37.8 mmol, 1.2 equiv) at rt, then cooled to 0 °C. To this was added dropwise 16 mL of H2O2 30% aqueous solution and stirred overnight at rt. To this was added 65 mL of sodium dithionite (18.6 g) in water at 0 °C, and stirred 0.5 h. The mixture was filtered, and the residue was washed with ethyl acetate. Hexane was added to the filtrate until the organic layer was separated, and the aqueous layer was extracted with ethyl acetate/hexane. The organic layer was combined and washed with saturated NaHCO3 aqueous solution and brine, dried over MgSO4, filtered and concentrated in vacuo to afford 4.10 g (24.7 mmol, 78%) of pure title compound as a yellowish oil. 1H NMR (600 MHz, CDCl3) δ 6.73 – 6.71 (m, 2H), 6.61 (dd, J = 8.8, 3.5 Hz, 1H), 4.44 (s, 1H), 3.78 (s, 3H), 3.28 (m, 1H), 1.18 (d, J = 6.9 Hz, 1H).

2, 6-Dibromo-4-nitrophenyl trifluoromethanesulfonate.

S22

The title compound was synthesized as described previously.9 To an ice-cold DCM solution of 2, 6-dibromo-4-nitrophenol (8 g, 26.9 mmol) was added pyridine (4.36 mL), and to this mixture was added dropwise 5.44 mL of triflic anhydride (32.4 mmol, 1.2 equiv) in 4 mL DCM. The reaction mixture was slowly warmed to rt, and stirred 0.5 h at rt. Aqueous 1 M HCl solution was added dropwise and the DCM layer was separated. The aqueous layer was extracted with DCM. The DCM layer was combined and washed with saturated NaHCO3 aqueous solution and brine, dried over MgSO4, filtered and concentrated in vacuo to afford 10.6 g (24.7 mmol, 92%) of title compound as a white powder. 1H NMR (600 MHz, CDCl3) δ 8.53 (s, 2H).

1, 3-Dibromo-2-iodo-5-nitrobenzene (3a).

O

Br

Br

I

N

O

The title compound was synthesized as described previously.9 To a DMF solution of 2, 6-dibromo-4-nitrophenyl trifluoromethanesulfonate (10.6 g, 24.7 mmol) was added sodium iodide (16 g, 107 mmol, 4.3 equiv) at rt, then heated to 100 °C, cooled to rt, and stirred overnight at rt. Water was added and stirred for 0.5 h, then the mixture was filtered. The residue was washed with water, then dried to give a title compound (8.31 g, 20.4 mmol, 83%) as a brown powder. 1H NMR (600 MHz, CDCl3) δ 8.38 (s, 2H).

1,3-Dibromo-2-(3-isopropyl-4-methoxyphenoxy)-5-nitrobenzene (4a). See main text. 4-(2, 6-Dibromo-4-nitrophenoxy)-2-isopropylphenol (5a). See main text. 4-(4-Amino-2, 6-dibromophenoxy)-2-isopropylphenol (6a). See main text. N-(3, 5-Dibromo-4-(4-hydroxy-3-isopropylphenoxy) phenyl) acetamide (1b). See main text. N-(3,5-Dibromo-4-(4-hydroxy-3-isopropylphenoxy)phenyl)propionamide (1c).

S23

The title compound was synthesized from 6a and propionyl chloride following the general procedure D to give the desired product as an off-white powder (46 mg, 51%); mp 199-200 °C; 1H NMR (600 MHz, CDCl3) δ 7.84 (s, 2H), 7.08 (s, 1H), 6.78 (d, J = 3.0 Hz, 1H), 6.63 (d, J = 8.7 Hz, 1H), 6.39 (dd, J = 8.7, 3.0 Hz, 1H), 4.45 (s, 1H), 3.17 (septet, J = 6.9 Hz, 1H), 2.41 (q, J = 7.6 Hz, 2H), 1.26 (t, J = 7.5 Hz, 3H). 1.23 (d, J = 6.9 Hz, 6H). 13C NMR (151 MHz, DMSO-d6) δ 172.5, 149.5, 149.3, 143.7, 138.2, 135.6, 122.7, 117.8, 115.3, 112.8, 111.5, 29.6, 26.5, 22.3, 9.4. ESI-TOF-MS (+) calcd for C18H20Br2NO3(M+H)+ 455.97. Found 455.97. Purity (HPLC-UV): 99% (tR=11.3 min).

Ethyl 3-((3, 5-dibromo-4-(4-hydroxy-3-isopropylphenoxy) phenyl) amino)-3-oxopropanoate

(1d).

The title compound was synthesized from 6a and ethyl malonyl chloride following the general procedure D to give the desired product (150 mg, 73%) as a yellowish amorphous solid; mp 47-60 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.51 (s, 1H), 9.03 (s, 1H), 7.95 (s, 2H), 6.67 – 6.65 (m, 2H), 6.27 (dd, J = 8.7, 3.1 Hz, 1H), 4.13 (q, J = 7.1 Hz, 2H), 3.49 (s, 2H), 3.15 (septet, J = 6.9 Hz, 1H), 1.21 (t, J = 7.1 Hz, 3H), 1.11 (d, J = 6.9 Hz, 6H). ESI-TOF-MS (+) calcd for C20H22Br2NO5 (M+H)+ 513.98. Found 513.98. Purity (HPLC-UV): >99% (tR=11.5 min).

Ethyl 4-((3, 5-dibromo-4-(4-hydroxy-3-isopropylphenoxy) phenyl) amino)-4-oxobutanoate (1f).

The title compound was synthesized from 6a and ethyl 4-chloro-4-oxobutyrate following the general procedure D to give the desired product (111 mg, 53%) as white needles; mp 146-150 °C; 1H NMR (600 MHz, CDCl3) δ 7.83 (s, 2H), 7.81 (s, 1H), 6.78 (d, J = 3.0 Hz, 1H), 6.63 (d, J = 8.7 Hz, 1H), 6.38 (dd, J = 8.6, 3.1 Hz, 1H), 4.50 (s, 1H), 4.20 (q, J = 7.1 Hz, 2H), 3.17 (septet, J = 6.9 Hz, 1H), 2.76 (t, J = 6.5 Hz, 2H), 2.67 – 2.65 (m, 2H), 1.29 (t, J = 7.1 Hz, 3H), 1.23 (d, J = 6.9 Hz, 6H). ESI-TOF-MS (-) calcd for C21H24Br2NO5 (M+H)+ 527.99, found 527.97. Purity (HPLC-UV): 95% (tR=11.78 min).

4-((3, 5-Dibromo-4-(4-hydroxy-3-isopropylphenoxy) phenyl) amino)-4-oxobutanoic acid (1e).

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Compound 1f (60 mg, 114 µmol) was dissolved in 20 mL of 1 M NaOHaq, then stirred 5h at 40 °C. After cooling to rt, to this reaction mixture was slowly added 1 M HClaq, and extracted with ethyl acetate 4 times. The organic layer was combined and washed with brine, dried over MgSO4, filtered and concentrated in vacuo. The title compound was recrystallized from acetone/hexane to give the title compound (8 mg, 14%) as a white powder. 1H NMR (400 MHz, DMSO-d6) δ 12.18 (s, 1H), 10.28 (s, 1H), 9.02 (s, 1H), 7.97 (s, 2H), 6.66 – 6.64 (m, 2H), 6.26 (dd, J = 8.7, 3.1 Hz, 1H), 3.15 (septet, J = 7.0 Hz, 1H), 2.55 (m, 4H), 1.11 (d, J = 6.9 Hz, 6H). ESI-TOF-MS (+) calcd for C19H20Br2NO5 (M+H)+ 499.96 found 499.94. Purity (HPLC-UV): 96% (tR=10.2 min).

1,3-Dibromo-2-(3-isopropylphenoxy)-5-nitrobenzene.

The title compound was synthesized from 3-isopropylphenol and 3a following the general procedure A to give the desired product (536 mg, 96%) as a yellow solid. 1H NMR (600 MHz, CDCl3) δ 8.51 (s, 2H), 7.22 (t, J = 7.9 Hz, 1H), 6.98 (d, J = 8.5 Hz, 1H), 6.74 (d, J = 2.0 Hz, 1H), 6.54 (dd, J = 8.2, 2.6 Hz, 1H), 2.88 (septet, J = 6.7 Hz, 1H), 1.24 (d, J = 6.9 Hz, 6H).

3, 5-Dibromo-4-(3-isopropylphenoxy) aniline.

The title compound was synthesized from 1,3-dibromo-2-(3-isopropylphenoxy)-5-nitrobenzene following the general procedure C to give the desired product (204 mg, 80%). 1H NMR (600 MHz, DMSO-d6) δ 7.19 (t, J = 7.9 Hz, 1H), 6.90 (m, 3H), 6.68 (t, J = 2.1 Hz, 1H), 6.46 (dd, J = 8.2, 2.6 Hz, 1H), 5.59 (s, 2H), 2.89 – 2.79 (m, 1H), 1.16 (d, J = 6.9 Hz, 6H).

Ethyl 3-((3,5-dibromo-4-(3-isopropylphenoxy)phenyl)amino)-3-oxopropanoate (1g).

The title compound was synthesized from 3, 5-dibromo-4-(3-isopropylphenoxy) aniline and ethyl malonyl chloride following the general procedure D to give the desired product (56 mg, 54%) as a white amorphous solid; mp 87-89 °C; 1H NMR (600 MHz, CDCl3) δ 9.51 (s, 1H), 7.89 (s, 2H), 7.19 (t, J = 7.9 Hz, 1H), 6.92 (d, J = 7.6 Hz, 1H), 6.73 (t, J = 2.0 Hz, 1H), 6.55 (dd, J = 8.2, 2.6 Hz, 1H), 4.28 (q, J = 7.1 Hz, 2H), 3.49 (s, 2H), 2.86 (septet, J = 6.9 Hz, 1H), 1.35 (t,

S25

J = 7.1 Hz, 3H), 1.23 (d, J = 6.9 Hz, 6H). ESI-TOF-MS (+) calcd for C20H22Br2NO4 (M+H)+ 497.98, found 497.96. Purity (HPLC-UV): 99% (tR=13.2 min).

3, 5-Dibromo-4-(3-isopropyl-4-methoxyphenoxy) aniline.

The title compound was synthesized from compound 4a following the general procedure C to give the desired product (292 mg, 89%). 1H NMR (600 MHz, DMSO-d6) δ 6.88 (s, 2H), 6.82 (d, J = 8.8 Hz, 1H), 6.71 (d, J = 3.1 Hz, 1H), 6.36 (dd, J = 8.9, 3.1 Hz, 1H), 5.56 (s, 2H), 3.73 (s, 3H), 3.19 (septet, J = 6.9 Hz, 1H), 1.11 (d, J = 6.9 Hz, 7H).

Ethyl 3-((3, 5-dibromo-4-(3-isopropyl-4-methoxyphenoxy) phenyl) amino)-3-oxopropanoate

(1h).

The title compound was synthesized from 3, 5-dibromo-4-(3-isopropyl-4-methoxyphenoxy) aniline following the general procedure D to give the desired product (44 mg, 40%) as pink crystals; mp 145-149 °C; 1H NMR (600 MHz, CDCl3) δ 9.49 (s, 1H), 7.88 (s, 2H), 6.82 (d, J = 3.1 Hz, 1H), 6.70 (d, J = 8.9 Hz, 1H), 6.44 (dd, J = 8.8, 3.1 Hz, 1H), 4.28 (q, J = 7.2 Hz, 2H), 3.78 (s, 3H), 3.49 (s, 2H), 3.28 (septet, J = 6.9 Hz, 1H), 1.34 (t, J = 7.2 Hz, 3H), 1.10 – 1.09 (m, 6H).ESI-TOF-MS (+) calcd for C21H24Br2NO5 (M+H)+ 527.99 found 527.99. Purity (HPLC-UV): >99% (tR=13.2 min).

1, 3-Dichloro-2-(3-isopropyl-4-methoxyphenoxy)-5-nitrobenzene (4i).

The title compound was synthesized from 2a and 1,3-dichloro-2-fluoro-5-nitrobenzene following the general procedure A to give the desired product (510 mg, 87%). 1H NMR (400 MHz, CDCl3) δ 8.30 (s, 2H), 6.84 (d, J = 3.1 Hz, 1H), 6.72 (d, J = 8.9 Hz, 1H), 6.46 (dd, J = 8.8, 3.1 Hz, 1H), 3.80 (s, 3H), 3.30 (m, 1H), 1.19 (d, J = 6.9 Hz, 6H).

4-(2, 6-Dichloro-4-nitrophenoxy)-2-isopropylphenol (5i).

S26

The title compound was synthesized from 4i following the general procedure B to give the desired product (467 mg, 95%). 1H NMR (600 MHz, CDCl3) δ 8.30 (s, 2H), 6.81 (d, J = 3.1 Hz, 1H), 6.66 (d, J = 8.7 Hz, 1H), 6.41 (dd, J = 8.7, 3.1 Hz, 1H), 4.64 (s, 1H), 3.19 (septet, J = 6.9 Hz, 1H), 1.24 (d, J=6.9 Hz, 6H).

4-(4-Amino-2, 6-dichlorophenoxy)-2-isopropylphenol (6i).

The title compound was synthesized from 5i following the general procedure C to give the desired product (156 mg, 60%). 1H NMR (600 MHz, DMSO-d6) δ 8.95 (s, 1H), 6.68 (s, 2H), 6.67 – 6.61 (m, 2H), 6.27 (d, J = 8.7 Hz, 1H), 5.57 (s, 2H), 3.16 – 3.12 (m, 1H), 1.10 (d, J = 6.9 Hz, 6H).

Ethyl 3-((3, 5-dichloro-4-(4-hydroxy-3-isopropylphenoxy) phenyl) amino)-3-oxopropanoate (1i).

The title compound was synthesized from 6i following the general procedure D to give the desired product as a yellowish amorphous solid (63 mg, 58%); 125-131°C; 1H NMR (600 MHz, CDCl3) δ 9.51 (s, 1H), 7.67 (s, 2H), 6.80 (d, J = 3.1 Hz, 1H), 6.63 (d, J = 8.7 Hz, 1H), 6.40 (dd, J = 8.6, 3.1 Hz, 1H), 4.73 (s, 1H), 4.28 (q, J = 7.1 Hz, 2H), 3.49 (s, 2H), 3.17 (septet, J = 6.9 Hz, 1H), 1.34 (t, J = 7.1 Hz, 3H), 1.22 (d, J = 6.9 Hz, 6H). ESI-TOF-MS (-) calcd for C20H20Cl2NO5 (M-H)- 424.08 found 424.09. Purity (HPLC-UV): 98% (tR=11.2 min).

2-Chloro-1-(3-isopropyl-4-methoxyphenoxy)-4-nitrobenzene (4j).

The title compound was synthesized from 2a and 3-chloro-4-fluoronitrobenzene following the general procedure A to give the desired product (893 mg, 84%) as a yellowish oil. 1H NMR (400 MHz, CDCl3) δ 8.37 (d, J = 2.7 Hz, 1H), 8.02 (dd, J = 9.2, 2.7 Hz, 1H), 6.97 (d, J = 2.7 Hz, 1H),

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6.89 – 6.85 (m, 2H), 6.78 (d, J = 9.2 Hz, 1H), 3.86 (d, J = 3.1 Hz, 3H), 3.41 – 3.24 (m, 1H), 1.20 (d, J = 6.9 Hz, 6H).

4-(2-Chloro-4-nitrophenoxy)-2-isopropylphenol (5j).

The title compound was synthesized from 4j following the general procedure B to give the desired product (1.0 g, quant.) as a brown powder. 1H NMR (600 MHz, CDCl3) δ 8.37 (d, J = 2.7 Hz, 1H), 8.02 (dd, J = 9.2, 2.7 Hz, 1H), 6.96 (t, J = 1.6 Hz, 1H), 6.84 – 6.75 (m, 3H), 4.85 (s, 1H), 3.23 (septet, J = 6.8 Hz, 1H), 1.25 (d, J = 6.9 Hz, 6H).

4-(4-Amino-2-chlorophenoxy)-2-isopropylphenol (6j).

The title compound was synthesized from 5j following the general procedure C to give the desired product as a reddish solid (616 mg, 68%). 1H NMR (600 MHz, DMSO-d6) δ 9.01 (s, 1H), 6.76 (d, J = 8.7 Hz, 1H), 6.69 (s, 1H), 6.69 – 6.66 (m, 2H), 6.51 (dt, J = 8.3, 1.9 Hz, 1H), 6.41 (dd, J = 8.7, 3.0 Hz, 1H), 5.32 (s, 2H), 3.15 (septet, J = 6.9 Hz, 1H), 1.11 (d, J = 6.8 Hz, 6H).

Ethyl 3-((3-chloro-4-(4-hydroxy-3-isopropylphenoxy) phenyl) amino)-3-oxopropanoate (1j).

The title compound was synthesized from 6j following the general procedure D to give the desired product as white crystals (82 mg, 36%); mp 132.2-133.3 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.31 (s, 1H), 9.23 (s, 1H), 7.88 (d, J = 2.5 Hz, 1H), 7.34 (dd, J = 9.0, 2.6 Hz, 1H), 6.88 (d, J = 8.9 Hz, 1H), 6.79 (d, J = 3.0 Hz, 1H), 6.76 (d, J = 8.6 Hz, 1H), 6.59 (dd, J = 8.6, 3.0 Hz, 1H), 4.12 (q, J = 7.1 Hz, 2H), 3.44 (s, 2H), 3.18 (septet, J = 6.9 Hz, 1H), 1.20 (t, J = 7.1 Hz, 3H), 1.13 (d, J = 6.9 Hz, 6H). ESI-TOF-MS (-) calcd for C20H21ClNO5 (M-H)- 390.12, found 390.10. Purity (HPLC-UV): 99% (tR=10.8 min).

1,3-Dichloro-2-(4-methoxyphenoxy)-5-nitrobenzene (4k).

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The title compound was synthesized from 1,3-dichloro-2-fluoro-5-nitrobenzene and 4-methoxyphenol following the general procedure A to give the desired product as a white powder (15.2 g, 97 %). 1H NMR (600 MHz, CDCl3) δ 8.30 (s, 2H), 6.84 (dd, J=6.6, 1.2 Hz, 2H), 6.77 (dd, J = 6.6, 1.2 Hz, 1H), 3.78 (s, 3H).

4-(2,6-Dichloro-4-nitrophenoxy)phenol (5k).

The title compound was synthesized from 4k following the general procedure B to give the desired product (7.5 g, 63%) as a yellowish powder. 1H NMR (400 MHz, DMSO-d6) δ 9.28 (s, 1H), 8.50 (s, 2H), 6.72 (s, 4H).

4-(4-Amino-2, 6-dichlorophenoxy) phenol (6k).

The title compound was synthesized from 5k following the general procedure C to give the desired product (6.4 g, quant) as an off-white solid. 1H NMR (400 MHz, DMSO-d6) δ 9.05 (s, 1H), 6.69 (s, 2H), 6.67 (d, J = 13.8 Hz, 2H), 6.58 (d, J = 9.1 Hz, 2H), 5.73 (s, 2H).

Ethyl 3-((3, 5-dichloro-4-(4-hydroxyphenoxy) phenyl) amino)-3-oxopropanoate (1k).

The title compound was synthesized from 6k following the general procedure D to give the desired product (3.89 g, 76%) as a white powder; mp 150.8-151.6 °C; 1H NMR (600 MHz, CDCl3) δ 9.51 (s, 1H), 7.67 (s, 2H), 6.83 – 6.62 (m, 4H), 4.58 (s, 1H), 4.28 (q, J = 7.1 Hz, 2H), 3.49 (s, 2H), 1.34 (t, J = 7.2 Hz, 3H). 13C NMR (151 MHz, DMSO- d6) δ 167.1, 164.5, 152.6, 149.3, 142.3, 136.8, 128.7, 119.3, 115.9, 115.3, 60.6, 43.6, 13.9. ESI-TOF-MS (-) calcd for C17H14Cl2NO5 (M-H)- 382.03 found 383.05. Purity (HPLC-UV): 95% (tR=9.7 min). 3-Bromo-4-methoxyphenol (2l).

The title compound was synthesized as described previously with slight modifications.10 To a DCM solution of 3-bromo-4-methoxybenzaldehyde (2 g, 9.3 mmol) was added m-CPBA (3.2 g,

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18.5 mmol, 2 equiv) at rt, then heated to 40 °C, and stirred overnight. After cooling to rt, aqueous sodium thiosulfate solution was added followed by saturated NaHCO3aq, then the DCM layer was separated, and the aqueous layer was extracted with DCM. The DCM layer was combined and washed with a solution of saturated Na2S2O3, saturated NaHCO3 aqueous solution, and brine, dried over MgSO4, filtered and concentrated in vacuo. To this was added 50 mL ethanol followed by sodium ethoxide (21% in ethanol, 3.47 mL) at rt, then the solution was refluxed for 14 h then cooled and concentrated. Purification by flash column chromatography gave the desired compound as a white powder (630 mg, 33%). 1H NMR (600 MHz, CDCl3) δ 7.08 (d, J = 2.8 Hz, 1H), 6.81 – 6.68 (m, 2H), 4.81 (s, 1H), 3.84 (s, 3H).

2-(3-Bromo-4-methoxyphenoxy)-1, 3-dichloro-5-nitrobenzene (4l).

The title compound was synthesized from 2l and 1,3-dichloro-2-fluoro-5-nitrobenzene following the general procedure A to give the desired product (2.06 g, quant). 1H NMR (600 MHz, CDCl3) δ 8.31 (s, 2H), 7.08 (d, J = 3.0 Hz, 1H), 6.84 (d, J = 9.0 Hz, 1H), 6.76 (dd, J = 9.0, 3.0 Hz, 1H), 3.87 (s, 3H).

2-Bromo-4-(2,6-dichloro-4-nitrophenoxy)phenol (5l).

The title compound was synthesized from 4l following the general procedure B to give the desired product as a yellowish solid (2.0 g, quant). 1H NMR (600 MHz, CDCl3) δ 8.31 (s, 2H), 6.99 (s, 1H), 6.96 (d, J=3.0 Hz, 1H), 6.75 (dd, J = 9.0, 2.0 Hz, 1H), 5.34 (s, 1H).

4-(4-Amino-2,6-dichlorophenoxy)-2-bromophenol (6l).

The title compound was synthesized from 5l following the general procedure C to give the desired product (195 mg, 85%) as a yellowish solid. 1H NMR (600 MHz, DMSO-d6) δ 9.90 (s, 1H), 6.88 (d, J = 8.9 Hz, 1H), 6.84 (d, J = 3.0 Hz, 1H), 6.69 (s, 2H), 6.66 (dd, J = 8.9, 3.1 Hz, 1H), 5.65 (s, 2H).

Ethyl 3-((4-(3-bromo-4-hydroxyphenoxy)-3, 5-dichlorophenyl) amino)-3-oxopropanoate (1l).

S30

The title compound was synthesized from 6l following the general procedure D to give the desired product as an off-white powder (42 mg, 40%); mp 140-142 °C; 1H NMR (600 MHz, CDCl3) δ 9.55 (s, 1H), 7.69 (s, 2H), 6.95 – 6.93 (m, 2H), 6.75 (dd, J = 9.0, 3.0 Hz, 1H), 5.25 (s, 1H), 4.28 (q, J = 7.1 Hz, 2H), 3.49 (s, 2H), 1.34 (t, J = 7.2 Hz, 3H). ESI-TOF-MS (-) calcd for C17H13BrCl2NO5 (M-H)- 459.94 found 459.94. Purity (HPLC-UV): >99% (tR=10.6 min).

4-Methoxyphenyl 4-methylbenzenesulfonate.

The title compound was synthesized as described previously with slight modifications.11 To a THF solution of 4-methoxyphenol (4.97 g, 40 mmol) was added p-toluenesulfonyl chloride (7.63 g, 40 mmol, 1 equiv) and pyridine (3.22 mL, 40 mmol, 1 equiv) at rt, and stirred overnight. To this was added water and MTBE and the organic layer was separated, and the aqueous layer was extracted with MTBE. The organic layer was combined and washed with NaHCO3, dried over MgSO4, filtered and concentrated in vacuo to give a title compound (6.04 g, 21.7 mmol, 54%). 1H NMR (600 MHz, CDCl3) δ 7.69 (d, J = 8.3 Hz, 2H), 7.30 (d, J = 7.9 Hz, 2H), 6.88 (d, J = 9.2 Hz, 2H), 6.77 (d, J = 9.2 Hz, 2H), 3.77 (s, 3H), 2.45 (s, 3H).

3-Iodo-4-methoxyphenyl 4-methylbenzenesulfonate.

The title compound was synthesized as described previously with slight modifications.11 To a tetrachloromethane (5 mL) solution of compound (4.37 g, 15.7 mmol) was added water (6 mL), iodine (3.17 g, 25.0 mmol), iodic acid (1.10 g, 6.3 mmol), sulfuric acid (1 mL), and acetic acid (12 mL) at rt, and the solution was refluxed overnight. After cooling to rt, to this was added MTBE and water, and the organic layer was separated, and the aqueous layer was extracted with MTBE. The organic layer was combined and washed with aqueous sodium thiosulfate solution 4 times, 1 M NaOH aqueous solution twice, water and brine, then dried over MgSO4, filtered and concentrated in vacuo to give a title compound (5.59 g, 13.8 mmol, 88%). 1H NMR (600 MHz, CDCl3) δ 7.69 (d, J = 8.3 Hz, 2H), 7.36 – 7.34 (m, 3H), 6.95 (dd, J = 8.9, 2.8 Hz, 1H), 6.68 (d, J = 9.0 Hz, 1H), 3.83 (s, 3H), 2.46 (s, 3H).

3-Iodo-4-methoxyphenol (2m).

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The title compound was synthesized as described previously with slight modifications.11 To a t-BuOH solution of 3-iodo-4-methoxyphenyl 4-methylbenzenesulfonate (5.59 g, 13.8 mmol) was added 20% NaOH aqueous solution (20 mL) at rt, then refluxed overnight. After cooling to rt, MTBE and aqueous 1 M HCl solution was added and the organic layer was separated. The aqueous layer was extracted with MTBE. The organic layer was combined and washed with water and brine, dried over MgSO4, filtered and concentrated in vacuo to give a title compound (2.85 g, 11.4 mmol, 82%). 1H NMR (600 MHz, CDCl3) δ 7.30 (d, J = 2.9 Hz, 1H), 6.81 (dd, J = 8.8, 2.9 Hz, 1H), 6.72 (d, J=8.8 Hz, 1H), 4.49 (s, 1H), 3.82 (s, 3H).

1, 3-Dichloro-2-(3-iodo-4-methoxyphenoxy)-5-nitrobenzene (4m).

The title compound was synthesized from 2m and 1,3-dichloro-2-fluoro-5-nitrobenzene following the general procedure A to give the desired product (10.3 g, 64%). 1H NMR (300 MHz, CDCl3) δ 8.31 (s, 2H), 7.27 (m, 1H), 6.82 – 6.72 (m, 2H), 3.85 (s, 3H).

4-(2, 6-Dichloro-4-nitrophenoxy)-2-iodophenol (5m).

The title compound was synthesized from 4m following the general procedure B to give the desired product (3.9 g, 80%) as a brownish solid. 1H NMR (600 MHz, CDCl3) δ 8.31 (s, 2H), 7.12 (d, J=3.0 Hz, 1H), 6.93 (d, J = 8.9 Hz, 1H), 6.78 (dd, J = 8.9, 3.0 Hz, 1H), 5.16 (s, 1H).

4-(4-Amino-2, 6-dichlorophenoxy)-2-iodophenol (6m).

The title compound was synthesized from 5m following the general procedure C to give the desired product (4 g, quant) as a dark brown solid. 1H NMR (600 MHz, DMSO-d6) δ 9.97 (s, 1H), 7.01 (d, J = 3.0 Hz, 1H), 6.80 (d, J = 8.9 Hz, 1H), 6.69 (s, 2H), 6.67 (dd, J = 8.9, 3.2 Hz, 1H), 5.64 (s, 2H).

Ethyl 3-((3,5-dichloro-4-(4-hydroxy-3-iodophenoxy)phenyl)amino)-3-oxopropanoate (1m).

S32

The title compound was synthesized from 6m following the general procedure D to give the desired product (303 mg, 49%) as an off-white amorphous powder; 1H NMR (600 MHz, CDCl3) δ 9.55 (s, 1H), 7.69 (s, 2H), 7.10 (d, J = 2.9 Hz, 1H), 6.91 (d, J = 8.9 Hz, 1H), 6.77 (dd, J = 8.9, 2.9 Hz, 1H), 5.03 (s, 1H), 4.28 (q, J = 7.1 Hz, 2H), 3.49 (s, 2H), 1.34 (t, J = 7.1 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 167.0, 164.6, 152.3, 149.5, 141.8, 137.1, 128.5, 124.2, 119.4, 115.6, 115.1, 84.3, 60.6, 43.6, 13.9. ESI-TOF-MS (-) calcd for C17H13Cl2INO5 (M-H)- 507.93 found 507.91. Purity (HPLC-UV): 96% (tR=10.8 min).

1,3-Dichloro-2-(4-methoxy-3-(trifluoromethyl)phenoxy)-5-nitrobenzene (4n).

The title compound was synthesized from 4-methoxy-3-(trifluoromethyl)phenol and 1,3-dichloro-2-fluoro-5-nitrobenzene following the general procedure A to give the desired product (828 mg, 83%) as a white powder. 1H NMR (600 MHz, CDCl3) δ 8.32 (s, 2H), 7.11 (d, J = 3.0 Hz, 1H), 6.96 – 6.93 (m, 2H), 3.89 (s, 3H).

4-(2,6-Dichloro-4-nitrophenoxy)-2-(trifluoromethyl)phenol (5n).

The title compound was synthesized from 4n following the general procedure B with a modification that boron tribromide solution was added dropwise at -78 °C, to give the desired product (300 mg, 89%) as an off-white solid. 1H NMR (600 MHz, CDCl3) δ 8.32 (s, 2H), 7.02 (d, J = 3.2 Hz, 1H), 6.95 – 6.84 (m, 2H), 5.74 (bs, 1H).

4-(4-Amino-2,6-dichlorophenoxy)-2-(trifluoromethyl)phenol (6n).

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The title compound was synthesized from 5n following the general procedure C to give the desired product (250 mg, 91%) as a black solid. 1H NMR (600 MHz, DMSO-d6) δ 10.26 (s, 1H), 6.99 – 6.95 (m, 1H), 6.95 – 6.88 (m, 1H), 6.85 (d, J = 3.0 Hz, 1H), 6.70 (s, 2H), 5.67 (s, 2H).

Ethyl 3-((3, 5-dichloro-4-(4-hydroxy-3-(trifluoromethyl) phenoxy) phenyl) amino)-3-

oxopropanoate (1n).

The title compound was synthesized from 6n following the general procedure D to give the desired product (45 mg, 29%); mp 131-133 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.59 (s, 1H), 10.35 (s, 1H), 7.80 (s, 2H), 6.98 (d, J = 9.5 Hz, 1H), 6.94 (m, 2H), 4.13 (q, J = 7.0 Hz, 2H), 3.49 (s, 2H), 1.21 (t, J = 7.1 Hz, 3H). ESI-TOF-MS (-) calcd for C18H13Cl2F3NO5 (M-H)- 450.02 found 450.01. Purity (HPLC-UV): 97% (tR=10.9 min).

Ethyl 3-((3,5-dichloro-4-(4-hydroxy-3-((trimethylsilyl)ethynyl)phenoxy)phenyl)amino)-3-

oxopropanoate.

To a toluene:TEA (50 mL: 25 mL) solution of compound 1m (1 g, 1.96 mmol) was added TMS acetylene (5 mL, 35 mmol, 18 equiv), PdCl2(PPh3)2 (84 mg, 120 µmol, 6.1 mol%), and CuI (32 mg, 169 µmol, 8.6 mol%) and stirred overnight at rt. The target compound was purified by column chromatography to give a crude product (500 mg, 1.04 mmol, 53%), which was used for the next step without further purification. 1H NMR (400 MHz, CDCl3) δ 9.53 (s, 1H), 7.68 (s, 2H), 6.90 – 6.81 (m, 2H), 6.70 (s, 1H), 5.63 (s, 1H), 4.28 (q, J = 7.1 Hz, 3H), 3.49 (s, 2H), 1.34 (t, J = 7.1 Hz, 3H), 0.26 (s, 9H).

Ethyl 3-((3, 5-dichloro-4-(3-ethynyl-4-hydroxyphenoxy) phenyl) amino)-3-oxopropanoate (1p).

To an ice-cold EtOH solution of ethyl 3-((3,5-dichloro-4-(4-hydroxy-3-((trimethylsilyl)ethynyl)phenoxy)phenyl)amino)-3-oxopropanoate (450 mg, 0.938 mmol) was added potassium fluoride (272 mg, 4.69 mmol, 5 equiv), warmed to rt, and stirred 5 h. The target compound was purified by column chromatography to give the desired compound as an off-white powder (200 mg, 52%); mp 135.5-135.9 °C; 1H NMR (600 MHz, CDCl3) δ 9.53 (s, 1H),

S34

7.68 (s, 2H), 6.88 (d, J = 9.0 Hz, 1H), 6.84 (dd, J = 9.1, 3.0 Hz, 1H), 6.77 (d, J = 3.0 Hz, 1H), 5.55 (s, 1H), 4.28 (q, J = 7.1 Hz, 2H), 3.49 (s, 2H), 3.44 (s, 1H), 1.34 (t, J = 7.2, 3H). ESI-TOF-MS (-) calcd for C19H14Cl2NO5 (M-H)- 406.03 found 406.02. Purity (HPLC-UV): 96% (tR=10.1 min).

2-(2-Bromo-4-methoxyphenoxy)-1,3-dichloro-5-nitrobenzene (4q).

The title compound was synthesized from 2-bromo-4-methoxyphenol and 1,3-dichloro-2-fluoro-5-nitrobenzene following the general procedure A to give the desired product as a yellowish powder (800 mg, 76%). 1H NMR (600 MHz, CDCl3) δ 8.30 (s, 2H), 7.21 (d, J = 2.9 Hz, 1H), 6.71 (dd, J = 9.0, 2.9 Hz, 1H), 6.37 (d, J = 9.0 Hz, 1H), 3.78 (s, 3H).

3-Bromo-4-(2,6-dichloro-4-nitrophenoxy)phenol (5q).

The title compound was synthesized from 4q following the general procedure B to give the desired product as a brown oil (761 mg, 99%). 1H NMR (600 MHz, CDCl3) δ 8.30 (s, 2H), 7.18 (d, J = 2.9 Hz, 1H), 6.66 (dd, J = 8.9, 2.9 Hz, 1H), 6.33 (d, J = 8.9 Hz, 1H), 4.95 (s, 1H).

4-(4-Amino-2,6-dichlorophenoxy)-3-bromophenol (6q).

The title compound was synthesized from 5q following the general procedure C to give the desired product as a yellowish solid (738 mg, quant). 1H NMR (600 MHz, DMSO-d6) δ 9.49 (s, 1H), 7.02 (d, J = 2.8 Hz, 1H), 6.69 (s, 2H), 6.64 (dd, J = 8.9, 2.8 Hz, 1H), 6.30 (d, J = 8.9 Hz, 1H), 5.65 (s, 2H).

Ethyl 3-((4-(2-bromo-4-hydroxyphenoxy)-3, 5-dichlorophenyl) amino)-3-oxopropanoate (1q).

S35

The title compound was synthesized from 6q following the general procedure D to give the desired product as a white powder (49 mg, 46%); mp 147.5-148.3 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.56 (s, 1H), 9.57 (s, 1H), 7.78 (s, 2H), 7.04 (d, J = 2.8 Hz, 1H), 6.62 (dd, J = 8.9, 2.9 Hz, 1H), 6.33 (d, J = 8.9 Hz, 1H), 4.11 (q, J = 7.1 Hz, 2H), 3.47 (s, 2H), 1.19 (t, J = 7.1 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 167.2, 164.8, 153.3, 145.7, 142.1, 137.3, 128.4, 128.4, 119.7, 119.4, 115.3, 114.8, 110.2, 60.8, 43.7, 14.0. ESI-TOF-MS (-) calcd for C17H13BrCl2NO5 (M-H)- 459.94, found 459.94. Purity (HPLC-UV): 99% (tR=10.5 min).

N-(3, 5-Dichloro-4-(4-hydroxy-3-iodophenoxy) phenyl) propionamide (7).

The title compound was synthesized from 6m and propionyl chloride following the general procedure D to give the desired product (2.58 g, 75%) as an off-white solid. IR (neat) 3313, 3086 (broad), 1661, 1590, 1529, 1467 cm-1; 1H NMR (600 MHz, DMSO-d6) δ 10.24 (s, 1H), 10.05 (s, 1H), 7.82 (s, 2H), 7.07 (d, J = 3.0 Hz, 1H), 6.81 (d, J = 8.9 Hz, 1H), 6.70 (dd, J = 8.9, 3.0 Hz, 1H), 2.35 (q, J = 7.5 Hz, 2H), 1.09 (t, J = 7.5 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 172.6, 152.3, 149.6, 141.2, 137.9, 128.4, 124.1, 119.2, 115.7, 115.2, 84.4, 29.6, 9.4.

5-(4-Amino-2,6-dichlorophenoxy)-[1,1'-biphenyl]-2-ol.

The title compound was synthesized from compound 6m following the general procedure E from 4-(4-amino-2,6-dichlorophenoxy)-2-iodophenol to give the desired product as a yellowish powder (131 mg, 50%). 1H NMR (600 MHz, Methanol-d4) δ 7.49 – 7.47 (m, 2H), 7.37 – 7.35 (m, 2H), 7.30 – 7.23 (m, 1H), 6.80 (d, J = 8.8 Hz, 1H), 6.74 (s, 2H), 6.65 (d, J = 3.1 Hz, 1H), 6.59 (dd, J = 8.8, 3.0 Hz, 1H).

N-(3, 5-dichloro-4-((6-hydroxy-[1,1'-biphenyl]-3-yl)oxy)phenyl)propionamide (8a).

The title compound was synthesized from 5-(4-amino-2,6-dichlorophenoxy)-[1,1'-biphenyl]-2-ol and propionyl chloride following the general procedure D from 5-(4-amino-2, 6-dichlorophenoxy)-[1,1'-biphenyl]-2-ol to give the desired product as a white crystals (48 mg,

S36

58%); mp 164.4-165.6 °C; IR (neat) 3296, 3171 (broad), 1662, 1590, 1532, 1466 cm-1; 1H NMR (600 MHz, DMSO-d6) δ 10.21 (s, 1H), 9.35 (s, 1H), 7.82 (s, 2H), 7.48 – 7.47 (m, 2H), 7.38 (dd, J = 8.3, 7.0 Hz, 2H), 7.30 – 7.28 (m, 1H), 6.88 (d, J = 8.8 Hz, 1H), 6.67 – 6.63 (m, 2H), 2.34 (q, J = 7.5 Hz, 2H), 1.09 (t, J = 7.5 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 172.6, 149.6, 149.6, 141.5, 137.9, 137.7, 128.9, 128.6, 128.4, 128.0, 126.8, 119.1, 116.9, 115.9, 114.4, 29.6, 9.4. ESI-TOF-MS (-) calcd for C21H16Cl2NO3 (M-H)- 400.06, found 400.04. Purity (HPLC-UV): 99% (tR=11.3 min).

5'-(2, 6-Dichloro-4-propionamidophenoxy)-2'-hydroxy-[1, 1’-biphenyl]-4-carboxylic acid (8b).

The title compound was synthesized from 7 and 4-carboxyphenylboronic acid following the general procedure E to give the desired product (12 mg, 15%) as a yellowish powder; mp 228-230 °C; 1H NMR (600 MHz, Acetone-d6) δ 11.20 (s, 1H), 9.37 (s, 1H), 8.40 (s, 1H), 8.06 (d, J = 8.6 Hz, 2H), 7.88 (s, 2H), 7.72 – 7.70 (m, 2H), 6.99 (d, J = 8.8 Hz, 1H), 6.87 (d, J = 3.1 Hz, 1H), 6.75 (dd, J = 8.8, 3.1 Hz, 1H), 2.41 (q, J = 7.5 Hz, 2H), 1.15 (t, J = 7.5 Hz, 3H). 444.06 (444.05) Purity (HPLC-UV): 96% (tR=9.86 min) ESI-TOF-MS (-) calcd for C22H16Cl2NO5 (M-H)- 444.05. Found 444.05.

5'-(2,6-Dichloro-4-propionamidophenoxy)-2'-hydroxy-[1,1'-biphenyl]-4-carboxamide (8c). See main text.

5'-(2,6-Dichloro-4-propionamidophenoxy)-2'-hydroxy-[1,1'-biphenyl]-3-carboxamide (8d).

The title compound was synthesized from 7 and 3-aminocarbonylphenylboronic acid following the general procedure E to give the desired product as an off-white powder (23 mg, 29%); mp 136.3-140.5°C; 1H NMR (600 MHz, Acetone-d6) δ 9.36 (s, 1H), 8.25 (s, 1H), 8.11 (s, 1H), 7.88 (m, 3H), 7.72 (d, J = 7.8 Hz, 1H), 7.50 – 7.47 (m, 2H), 6.96 (m, 1H), 6.88 (s, 1H), 6.68 (dd, J = 8.8, 3.1 Hz, 1H), 6.61 (s, 1H), 2.40 (q, J = 7.5 Hz, 2H), 1.15 (t, J = 7.5 Hz, 3H). δ ESI-TOF-MS (-) calcd for C22H17Cl2N2O4 (M-H)- 443.06 found 443.07. Purity (HPLC-UV): 98% (tR=9.0 min).

N-(3,5-dichloro-4-((4'-cyano-6-hydroxy-[1,1'-biphenyl]-3-yl)oxy)phenyl)propionamide (8e).

S37

The title compound was synthesized from 7 and 4-cyanophenylboronic acid following the general procedure E to give the desired product as an off-white powder (30 mg, 40%); mp 231.6-232.0 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.22 (s, 1H), 9.67 (s, 1H), 7.85 – 7.83 (m, 4H), 7.71 – 7.70 (m, 2H), 6.92 (d, J = 8.9 Hz, 1H), 6.78 (d, J = 3.2 Hz, 1H), 6.70 (dd, J = 8.9, 3.1 Hz, 1H), 2.34 (q, J = 7.5 Hz, 2H), 1.09 (t, J = 7.5 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 173.0, 150.3, 150.1, 143.1, 141.8, 138.2, 132.4, 130.3, 129.0, 126.9, 119.6, 119.4, 117.7, 116.3, 116.2, 109.8, 30.0, 9.9. ESI-TOF-MS (-) calcd for C22H15Cl2N2O3 (M-H)- 425.05 found 425.04. Purity (HPLC-UV): 97% (tR=11.1 min).

N-(3,5-dichloro-4-((3'-cyano-6-hydroxy-[1,1'-biphenyl]-3-yl)oxy)phenyl)propionamide (8f).

The title compound was synthesized from 7 and 3-cyanophenylboronic acid following the general procedure E to give the desired product as an off-white powder (37 mg, 87%); mp 211.6-212.8 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.22 (s, 1H), 9.62 (s, 1H), 7.95 (s, 1H), 7.82 (s, 3H), 7.76 – 7.75 (m, 1H), 7.60 (t, J = 7.8 Hz, 1H), 6.91 (d, J = 8.9 Hz, 1H), 6.84 (d, J = 3.1 Hz, 1H), 6.65 (dd, J = 8.8, 3.1 Hz, 1H), 2.35 (q, J = 7.5 Hz, 2H), 1.09 (t, J = 7.5 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 172.6, 149.7, 149.7, 141.4, 138.8, 137.7, 133.8, 132.5, 130.6, 129.4, 128.6, 126.2, 119.1, 118.9, 117.1, 116.1, 115.2, 111.2, 29.6, 9.4. ESI-TOF-MS (-) calcd for C22H15Cl2N2O3 (M-H)- 425.05 found 425.05. Purity (HPLC-UV): 98% (tR=11.1 min).

5'-(2,6-Dichloro-4-propionamidophenoxy)-2'-hydroxy-N-methyl-[1,1'-biphenyl]-4-carboxamide

(8g).

The title compound was synthesized from 7 and 4-(N-methylaminocarbonyl)phenylboronic acid following the general procedure E to give the desired product as an off-white powder (25 mg, 31%); mp 161.3-165.2°C; 1H NMR (600 MHz, DMSO-d6) δ 10.22 (s, 1H), 9.47 (s, 1H), 8.42 (q, J = 4.5 Hz, 1H), 7.83 (d, J = 8.6 Hz, 4H), 7.57 (d, J=8.4 Hz, 2H), 6.89 (d, J = 8.9 Hz, 1H), 6.76

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(d, J = 3.2 Hz, 1H), 6.63 (dd, J = 8.9, 3.2 Hz, 1H), 2.79 (d, J = 4.5 Hz, 3H), 2.34 (q, J = 7.5 Hz, 2H), 1.09 (t, J = 7.5 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 172.6, 166.4, 149.7, 149.6, 141.5, 140.4, 137.7, 132.9, 128.8, 128.6, 127.6, 126.8, 119.1, 117.0, 116.0, 114.8, 29.6, 26.3, 9.4. ESI-TOF-MS (-) calcd for C23H19Cl2N2O4 (M-H)- 457.08. Found 457.08. Purity (HPLC-UV): 97% (tR=9.40 min).

1-(4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)urea.

B

HNH2N

O

O

O

The title compound was synthesized as described previously with slight modifications.12 To an ice-cold DCM solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (150 mg, 685 µmol) was added in one-portion chlorosulfonyl isocyanate (84 µL, 754 µmol, 1.1 equiv) and stirred 1 h. Water was added and stirred 2 h. To this reaction mixture was added DCM and water, the DCM layer was separated, and the aqueous layer was extracted with DCM. The DCM layer was combined and washed with brine, dried over MgSO4, filtered and concentrated in vacuo. Flash column chromatography eluting with DCM:MeOH (50:1) gave the title compound (100 mg, 56%). 1H NMR (600 MHz, CDCl3) δ 7.72 (d, J = 8.5 Hz, 2H), 7.41 (s, 1H), 7.30 (d, J = 8.6 Hz, 2H), 5.05 (s, 2H), 1.33 (s, 12H).

N-(3,5-dichloro-4-((6-hydroxy-4'-ureido-[1,1'-biphenyl]-3-yl)oxy)phenyl)propionamide (8h).

To a DME solution of compound 7 (80 mg, 177 µmol, 1.0 equiv) were added Pd(PPh3)4 (10 mg, 8.7 µmol, 0.05 equiv), an aqueous solution of Na2CO3 (400 mg in 1 mL H2O), and 1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)urea (55.5 mg, 212 µmol, 1.2 equiv) in 1 mL ethanol. This solution was stirred at 71 °C overnight. After cooling to rt, ethyl acetate and 1 M HClaq were added and extracted 4 times with ethyl acetate. The organic layer was combined and washed with brine, dried over MgSO4, filtered and concentrated in vacuo. The target compound was purified by column chromatography (DCM->DCM:MeOH=30:1), and recrystallized from acetone/DCM/hexane to give the desired product as an off-white powder (11 mg, 14%). TLC Rf=0.25 (DCM:MeOH=30:1); mp 162.0-162.9 °C; IR (neat) 3600-3000 (broad), 1664, 1590, 1535, 1464 cm-1; 1H NMR (600 MHz, DMSO-d6) δ 10.21 (s, 1H), 9.25 (s, 1H), 8.55 (s, 1H), 7.82 (s, 2H), 7.40 (d, J = 8.7 Hz, 2H), 7.35 (d, J = 8.7 Hz, 2H), 6.84 (d, J = 8.8 Hz, 1H), 6.66 (d, J = 3.2 Hz, 1H), 6.56 (dd, J = 8.8, 3.2 Hz, 1H), 5.84 (s, 2H), 2.34 (q, J = 7.5 Hz, 2H), 1.09 (t, J = 7.5 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 173.0, 156.4, 150.0, 150.0, 142.0, 139.9, 138.1, 131.0, 129.6, 129.1, 128.8, 119.6, 117.7, 117.2, 116.0, 114.0, 30.0, 9.9. HRMS (+) calcd for

S39

C22H20Cl2N3O4+ (M-H)+ 460.0825. Found 460.0828. Purity (HPLC-UV): 97% (tR=9.11 min).

Anal. C 58.46, H 4.61, N 9.06%, calcd for C22H19Cl2N3O4·0.2C6H14, C 58.35, H 4.60, N 8.80%.

N-(4-(4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) phenyl) acetamide.

B

HN

O

O

O

To a MTBE solution of 4-aminophenylboronic acid pinacol ester (100 mg, 457 µmol) was added saturated NaHCO3 aqueous solution, and then to this was added dropwise acetyl chloride (71.7 mg, 914 µmol, 2 equiv) at 0 °C, and stirred for 3 h at rt. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The organic layer was combined and washed with saturated NaHCO3 aqueous solution, 1 M HCl aqueous solution, brine, dried over MgSO4, filtered and concentrated in vacuo. The title compound was recrystallized from DCM to give the desired product as a white powder (88 mg, 74%). 1H NMR (600 MHz, CDCl3) δ 7.76 (d, J = 8.0 Hz, 2H), 7.51 (d, J = 8.0 Hz, 2H), 7.18 (s, 1H), 2.18 (s, 3H), 1.34 (s, 12H).

N-(4-((4'-acetamido-6-hydroxy-[1, 1’-biphenyl]-3-yl) oxy)-3, 5-dichlorophenyl) propionamide

(8i).

The title compound was synthesized from 7 and N-(4-(4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) phenyl) acetamide following the general procedure E to give the desired product as an off-white powder (11 mg, 14%); mp 146.8-147.4 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.21 (s, 1H), 9.97 (s, 1H), 9.29 (s, 1H), 7.82 (s, 2H), 7.58 – 7.56 (m, 2H), 7.43 – 7.41 (m, 2H), 6.85 (d, J = 8.8 Hz, 1H), 6.69 (d, J = 3.1 Hz, 1H), 6.57 (dd, J = 8.8, 3.2 Hz, 1H), 2.34 (q, J = 7.5 Hz, 2H), 2.05 (s, 3H), 1.09 (t, J = 7.5 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 172.6, 168.2, 149.6 (2 carbons overlapped), 141.6, 138.1, 137.6, 132.4, 129.2, 128.6, 128.2, 119.1, 118.6, 116.8, 115.8, 113.9, 29.6, 24.0, 9.4. ESI-TOF-MS (-) calcd for C23H19Cl2N2O4 (M-H)-

457.08. Found 457.09. Purity (HPLC-UV): 99% (tR=9.4 min).

N-(4-((4'-acetyl-6-hydroxy-[1, 1’-biphenyl]-3-yl) oxy)-3, 5-dichlorophenyl) propionamide (8j).

S40

To a DME solution of compound 7 (80 mg, 177 µmol, 1.0 equiv) were added Pd(PPh3)4 (10 mg, 8.7 µmol, 0.05 equiv), aqueous solution of Na2CO3 (400 mg in 1 mL H2O), and 4-acetylphenylboronic acid (35 mg, 212 µmol, 1.2 equiv) in 1 mL ethanol. This solution was stirred at 71 °C overnight. After cooling to rt, ethyl acetate and 1 M HClaq were added and extracted 4 times with ethyl acetate. The organic layer was combined and washed with brine, dried over MgSO4, filtered and concentrated in vacuo. The target compound was purified by column chromatography (DCM-> DCM:EtOAc=10:1), and recrystallized from acetone/DCM/hexane to give the desired product as an off-white powder (10 mg, 13%). TLC Rf=0.3 (DCM:EtOAc=10:1); mp 190.0-193.8 °C; IR (neat) 3311, 3236 (broad), 1667, 1585, 1529, 1466 cm-1; 1H NMR (600 MHz, DMSO-d6) δ 10.22 (s, 1H), 9.56 (s, 1H), 7.98 – 7.96 (m, 2H), 7.83 (s, 2H), 7.65 – 7.64 (m, 2H), 6.91 (d, J = 8.8 Hz, 1H), 6.76 (d, J = 3.2 Hz, 1H), 6.68 (dd, J = 8.9, 3.2 Hz, 1H), 2.59 (s, 3H), 2.34 (q, J = 7.5 Hz, 2H), 1.09 (t, J = 7.5 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 197.5, 172.6, 149.8, 149.6, 142.6, 141.4, 137.7, 135.1, 129.2, 128.6, 128.0, 127.2, 119.1, 117.2, 115.9, 115.2, 29.6, 26.7, 9.4. HRMS (+) calcd for C23H20Cl2NO4

+ (M-H)+ 444.0764. Found 444.0757. Purity (HPLC-UV): >99% (tR=10.8 min). Anal. C 62.42, H 4.46, N 3.23%, calcd for C23H19Cl2NO4, C 62.17, H 4.31, N 3.15%.

N-(3, 5-dichloro-4-((6-hydroxy-4'-sulfamoyl-[1,1'-biphenyl]-3-yl)oxy)phenyl)propionamide (8k).

The title compound was synthesized from 7 and 4-sulfamoylbenzeneboronic acid following the general procedure E to give the desired product as an off-white powder (8 mg, 9%); mp 143-144 °C; 1H NMR (600 MHz, DMSO-d6) δ 10.22 (s, 1H), 9.57 (s, 1H), 7.83 – 7.82 (m, 4H), 7.68 – 7.67 (m, 2H), 7.35 (s, 2H), 6.91 (d, J = 8.9 Hz, 1H), 6.79 (d, J = 3.2 Hz, 1H), 6.65 (dd, J = 8.9, 3.2 Hz, 1H), 2.35 (q, J = 7.5 Hz, 2H), 1.09 (t, J = 7.6 Hz, 3H). 13C NMR (151 MHz, DMSO-d6) δ 173.0, 150.2, 150.1, 142.8, 141.9, 141.7, 138.2, 129.9, 129.0, 127.5, 125.9, 119.6, 117.5, 116.6, 115.5, 30.0, 9.9. ESI-TOF-MS (-) calcd for C21H17Cl2N2O5S (M-H)- 479.03. Found 479.04. Purity (HPLC-UV): 95% (tR=9.64 min).

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References

1. Singh, L.; Pressly, B.; Mengeling, B. J.; Fettinger, J. C.; Furlow, J. D.; Lein, P. J.; Wulff, H.; Singh, V., Chasing the elusive benzofuran impurity of the THR antagonist NH-3: Synthesis, isotope labeling, and biological activity. J. Org. Chem. 2016, 81 (5), 1870-1876. 2. Diederichs, K.; Karplus, P. A., Improved R-factors for diffraction data analysis in macromolecular crystallography. Nat. Struct. Mol. Biol. 1997, 4 (4), 269-275. 3. Morisseau, C.; Newman, J. W.; Wheelock, C. E.; Hill III, T.; Morin, D.; Buckpitt, A. R.; Hammock, B. D., Development of metabolically stable inhibitors of mammalian microsomal epoxide hydrolase. Chem. Res. Toxicol. 2008, 21 (4), 951-957. 4. Morisseau, C.; Bernay, M.; Escaich, A.; Sanborn, J. R.; Lango, J.; Hammock, B. D., Development of fluorescent substrates for microsomal epoxide hydrolase and application to inhibition studies. Anal. Biochem. 2011, 414 (1), 154-162. 5. (a) Beetham, J. K.; Tian, T. G.; Hammock, B. D., cDNA cloning and expression of a soluble epoxide hydrolase from human liver. Arch. Biochem. Biophys. 1993, 305 (1), 197-201; (b) Wixtrom, R. N.; Silva, M. H.; Hammock, B. D., Affinity purification of cytosolic epoxide hydrolase using derivatized epoxy-activated Sepharose gels. Anal. Biochem. 1988, 169 (1), 71-80. 6. Borhan, B.; Mebrahtu, T.; Nazarian, S.; Kurth, M. J.; Hammock, B. D., Improved radiolabeled substrates for soluble epoxide hydrolase. Anal. Biochem. 1995, 231 (1), 188-200. 7. Kim, I. H.; Nishi, K.; Kasagami, T.; Morisseau, C.; Liu, J.-Y.; Tsai, H. J.; Hammock, B. D., Biologically active ester derivatives as potent inhibitors of the soluble epoxide hydrolase. Bioorg. Med. Chem. Lett. 2012, 22 (18), 5889-5892. 8. Ulu, A.; Appt, S.; Morisseau, C.; Hwang, S. H.; Jones, P. D.; Rose, T. E.; Dong, H.; Lango, J.; Yang, J.; Tsai, H. J.; Miyabe, C.; Fortenbach, C.; Adams, M. R.; Hammock, B. D., Pharmacokinetics and in vivo potency of soluble epoxide hydrolase inhibitors in cynomolgus monkeys. Br. J. Pharmacol. 2012, 165 (5), 1401-1412. 9. Chidambaram, R.; Kant, J.; Weaver, R. E., Jr.; Yu, J.; Ghosh, A. Process for the preparation of aniline-derived thyroid receptor ligands with improved safety and economy. WO03039456 (A2) May 15, 2003. 10. Vacondio, F.; Silva, C.; Lodola, A.; Fioni, A.; Rivara, S.; Duranti, A.; Tontini, A.; Sanchini, S.; Clapper, J. R.; Piomelli, D.; Mor, M.; Tarzia, G., Structure–property relationships of a class of carbamate-based fatty acid amide hydrolase (FAAH) inhibitors: Chemical and biological stability. ChemMedChem 2009, 4 (9), 1495-1504. 11. Yamaguchi, Y.; Matsubara, Y.; Ochi, T.; Wakamiya, T.; Yoshida, Z., How the π conjugation length affects the fluorescence emission efficiency. J. Am. Chem. Soc. 2008, 130 (42), 13867-13869. 12. Luo, L.; Parrish, C. A.; Nevins, N.; McNulty, D. E.; Chaudhari, A. M.; Carson, J. D.; Sudakin, V.; Shaw, A. N.; Lehr, R.; Zhao, H.; Sweitzer, S.; Lad, L.; Wood, K. W.; Sakowicz, R.; Annan, R. S.; Huang, P. S.; Jackson, J. R.; Dhanak, D.; Copeland, R. A.; Auger, K. R., ATP-competitive inhibitors of the mitotic kinesin KSP that function via an allosteric mechanism. Nat.

Chem. Biol. 2007, 3 (11), 722-726.

S42

Compound SMILES Cif IC50 (m Thyroid hormone EC50 (nM)

1a CC(C)C1=C( 2.6 0.43 EE}0.146a CC(C)C1=C( 9.7

5a CC(C)C1=C( 10.3

1b CC(C)C1=C( 8.8

1c CC(C)C1=C( 7.5 7.0 EE}2.11d CC(C)C1=C( 6.7

1e CC(C)C1=C( 3.2

1f CC(C)C1=C( 5.5

1g CC(C)C1=CC>50

1h CC(C)C1=C(>25

1i CC(C)C1=C( 3.8

1j CC(C)C1=C( 11.6

1k ClC1=CC(NC>50

1l ClC1=CC(NC 4.9

1m ClC1=CC(NC 3.8

1n ClC1=CC(NC 3

1p ClC1=CC(NC 2.9

1q ClC1=CC(NC 29.3

8a OC1=CC=C( 1.4

8b OC1=CC=C( 10.5

8c OC1=CC=C( 0.35 >10000

8d OC1=CC=C( 0.46

8e OC1=CC=C( 11.9

8f OC1=CC=C( 0.58

8g OC1=CC=C( 1.7

8h OC1=CC=C( 0.29 >10000

8i OC1=CC=C( 15.6

8j OC1=CC=C( 0.35 >10000

8k OC1=CC=C( 2