Research Article Synthesis, Characterization, and ...downloads.hindawi.com/archive/2013/370626.pdf · -thiadiazole--amine has been synthesized by single step reaction. A series of

Hindawi Publishing CorporationOrganic Chemistry InternationalVolume 2013 Article ID 370626 7 pageshttpdxdoiorg1011552013370626

Research ArticleSynthesis Characterization and BiologicalActivity of 5-Phenyl-134-thiadiazole-2-amine IncorporatedAzo Dye Derivatives

Chinnagiri T Keerthi Kumar1 Jathi Keshavayya1 Tantry N Rajesh1

Sanehalli K Peethambar2 and Angadi R Shoukat Ali1

1 Department of Studies and Research in Chemistry School of Chemical Sciences Kuvempu UniversityJnana Sahyadri Shankaraghatta Karnataka 577451 India

2Department of Biochemistry Kuvempu University Jnana Sahyadri Shankaraghatta Karnataka 577451 India

Correspondence should be addressed to Jathi Keshavayya jkeshavayyagmailcom

Received 30 April 2013 Revised 25 June 2013 Accepted 27 June 2013

Academic Editor Ashraf Aly Shehata

Copyright copy 2013 Chinnagiri T Keerthi Kumar et al This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

5-Phenyl-134-thiadiazole-2-amine has been synthesized by single step reaction A series of heterocyclic azodyes were syn-thesized by diazotisation of 5-phenyl-134-thiadiazole-2-amine by nitrosyl sulphuric acid followed by coupling with differentcoupling compounds such as 8-hydroxyquinoline 26-diaminopyridine 2-naphthol NN-dimethyl aniline resorcinol and 46-dihydroxypyrimidine The dyes were characterized by UV-Vis IR 1H-NMR 13C NMR and elemental analysis The synthesizedcompounds were also screened for biological activity

1 Introduction

Azo dyes are themost widely used class of colouringmaterialsbecause of their massive applications in various fields ofscience and technology [1ndash3] The azo dyes are synthesizedby diazotization of aromatic amines and coupling reagentwhich include one or more azo groups (ndashN=Nndash) attached toone or more aromatic moieties (Karci et al [4]) These dyesplay a major role in textile printing leather papermakingdrug (Torres et al [5]) and food industries (Yousefi et al [6])Heterocyclic azo dyes have wide applications as high level-dying agents in the dyestuff industries (Hallas and Choi [7])It has been known that the activity of azo linkage increaseswith the incorporation of suitable heterocyclic moiety Theincreasing usage of these dyes in electronic industry such ascolorimetric sensors nonlinear optical (NLO) devices andliquid crystalline displays (LCDs) used as potential sensi-tizers for photodynamic therapy (PDT) has attracted muchattention (Demirbas et al [8]) Nowadays much attentionhas been focused on 134-thiadiazole derivatives as a very

important class of nitrogen-containing aromatic heterocycliccompounds due to their diverse biological activities such asantitumor [9 10] antibacterial [11 12] anti-inflammatoryantimycotic (Fernandez et al [13]) and powerful antifungalagents (Waring and Hallas [14]) In contrast 134-thiadiazolederivatives exhibits a broad spectrum of biocidal activitiespossibly due to the presence of toxophoric-N-C-S moiety(Mavrova et al [15])

With these objects in view and also work carried outin our lab on this class of azo dyes [16 17] we nowfocus on synthesis and screening for antimicrobial andantioxidant activities of 5-phenyl-134-thiadiazole-2-aminecontaining azo group in their structure 5-phenyl-134-thiadiazole-2-amine was synthesized by single step reactionand it was transformed to its corresponding diazoniumsalt by diazotization reaction and was further coupledwith various coupling agents (8-hydroxy quinoline 26-diaminopyridine NN-dimethyl aniline 2-naphthol resor-cinol and 46-dihydroxypyrimidine) under suitable experi-mental reaction

2 Organic Chemistry International

H2N

H2N

+

+

NH2NH2

NH2

NH2

1

R = 2d =

2(andashf)

R = 2b =

3(andashf)

R = 2a =

1

R = 2c =

R = 2f =R = 2e =

POCl3

90∘C

(i) Nitrosylsulfuric acid

(ii) Coupling

S

NH

N

OH

N

N

OH

OH

OH

N

NHO

OH

N

S

N

N

S

N

O

OH

N

S

N

N

NR

Scheme 1

2 Materials and Measurements

All the starting materials were obtained from Merck andwere used without further purification Melting points weremeasured using standard melting point apparatus fromSunder Industrial Products (India) and were uncorrectedThe UV-Visible absorption spectra were recorded in DMSOwith a SHIMADZU UV-1800 spectrometer at concentrationrange of 10minus4M IR spectra were recorded in the regionof 4000 cmminus1 to 400 cmminus1 on an FT-IR-Alpha Bruker IRspectrometer in KBr pellets The 1H-and 13C-NMR spectrawere recorded in DMSO-d6 at 500MHz using AV500-High Resolution Multinuclear FT-NMR Spectrometer withtetramethylsilane as internal standard

3 Experimental

31 Synthesis of 5-Phenyl-134-thiadiazol-2-amine (1) Ben-zoic acid (01mol) and thiosemicarbazide (01mol) in phos-phorous oxychloride (30mL) were refluxed gently for 30minand cooled followed by careful addition of water (90mL)The separated solid was filtered and suspended in waterand basified with aqueous potassium hydroxide followed byfiltration drying and crystallization from mixture of DMFand ethanol (9 1) to obtain colourless solidwith 65 yield IR[(KBr) 120592maxcm

minus1] 3087 (aromatic CndashH) 1613 (C=N) cmminus11H-NMR (DMSO-d6) 72ndash75 (m 5H) 51 (s 2H) 13C-NMR(DMSO-d6 ppm) 1539 (CndashO) 1304 (CndashN) 1746 (C=N)1508 (CndashN) LC-MS (119898119911) 1772 anal calcd for C

8H7N3S

C5422 H398 N2371 found C5419 H395 N2269

32 General Procedure for Preparation of Dye 3(andashf) 5-Phenyl-134-thiadiazole-2-amine (20 times 10minus3mol) was dis-solved in hot glacial acetic acidpropionic acid mixture (2 160mL) and was rapidly cooled in an icesalt bath to minus5∘CThe liquorwas then added in portions during 30min to a coldsolution of nitrosyl sulphuric acid (prepared from sodiumnitrite (015 g) and concentrated sulphuric acid (3mL) at50∘C) The mixture was stirred for an additional 2 hrs at0∘C Excess nitrous acid was destroyed by addition of ureaThe resulting diazonium salt was cooled in saltice mixtureAfter diazotization was complete the diazo liquor was slowlyadded to vigorously stirred solution of coupling component(20 times 10minus3mol) in potassium hydroxide (20 times 10minus3mol)and water (2mL) The solution was stirred at 0ndash5∘C for 2 hAfter 2 h the pH of the reaction mixture was maintainedat 4ndash6 by the simultaneous addition of saturated sodiumcarbonate solution The mixture was stirred for one day atroom temperature After one day the resulting solid wasfiltered washed with cold water and dried

The general scheme for the syntheses is given inScheme 1

33 Preparation of 5-[(5-Phenyl-134-thiadiazol-2-yl)diazen-yl]quinolin-8-ol [3a] The dye was obtained from 5-phenyl-134-thiadiazol-2-amine and 8-hydroxy quinoline as browncrystals (yield 46 mp 218) IR [(KBr) 120592maxcm

minus1] 3553ndash3312 (broad ndashOH group) 3063 (aromatic CndashH) 1573 (C=N)1530 (N=N) cmminus1 1H-NMR (DMSO-d6) 89 (d 1H)86 (d 1H) 79 (t 2H) 680 (d 1H) 72ndash75 (m 5H)

Organic Chemistry International 3

51 (s 1H) 13C-NMR (DMSO-d6 ppm) 1539 (CndashO) 1304(CndashN) 1746 (C=N) 1508 (CndashN quinoline) anal calcd forC17H11N5OS C6125 H333 N2101 found C6122 H331

N2099

34 Preparation of 3-[(5-Phenyl-134-thiadiazol-2-yl)diazen-yl]pyridine-26-diamine [3b] This dye was prepared from 5-phenyl-134-thiadiazol-2-amine and 26-diamino pyridine aswine red crystals (yield 57mp 178) IR [(KBr) 120592maxcm

minus1]absorptions bands at 3335 cmminus1 3063 (aromatic CndashH) 1580(C=N) 1631 cmminus1 (NndashH aromatic) 1490 cmminus1 (N=N)1H-NMR (DMSO-d6) 722ndash748 (m 5H) 77 (d 1H) 62 (d1H) 42 (s 4H)13C-NMR (DMSO-d6 ppm) 1586 (C=Npyridine) 1569 (CndashN) 1755 (C=N thiadiazole) anal calcdfor C

13H11N7S C5251 H373 N3297 found C5249

H370 N3294

35 Preparation of NN-dimethyl-4-[(5-phenyl-134-thiadia-zol-2-yl)diazenyl]aniline [3c] This dye was synthesizedfrom 5-phenyl-134-thiadiazol-2-amine and NN-dimethylaniline as dark red crystals (yield 71 mp 191) IR [(KBr)120592maxcm

minus1] 3056 (aromatic CndashH) 2940 (aliphatic CndashH)1562 (C=N) cmminus1 1496 (N=N) cmminus1 1H-NMR (DMSO-d6) 285 (d 6H) 72 (d 2H) 68 (d 2H) 725ndash76 (m 5H)13C-NMR (DMSO-d6 ppm) 409 (CH

3) 1502 (CndashN) 1759

(C=N Thiadiazole) 1501 (CndashN aniline) 1191 (CndashN Azo)anal calcd for C

16H15N5S C6211 H489 N2264 found

C6209 H487 N2261

36 Preparation of 1-[(5-Phenyl-134-thiadiazol-2-yl)diazen-yl]naphthalen-2-ol [3d] This dye was obtained from 5-phenyl-134-thiadiazol-2-amine and 2-naphthol as brick redcrystals (yield 66 mp 182) IR [(KBr) 120592maxcm

minus1] 3439ndash3397 (broad ndashOH group) 3031 (aromatic CndashH) 1550 (C=N)cmminus1 1475 (N=N) cmminus1 1H-NMR (DMSO-d6) 71 (d 1H)75-76 (d 3H) 72ndash74 (m 7H) 141 (s 1H) 13C-NMR (DMSO-d6ppm) 1629 (CndashO) 1232 (CndashN) 1758 (C=N) anal calcdfor C18H12N4OS C6504 H364 N1686 found C6501

H361 N1682

37 Preparation of 4-[(5-Phenyl-134-thiadiazol-2-yl)diazen-yl]benzene-13-diol [3e] This dye was prepared from 5-phenyl-134-thiadiazol-2-amine and resorcinol as red crys-tals (yield 61 mp 182) IR [(KBr) 120592maxcm

minus1] 3421ndash3385(broad OndashH group) 3031 (aromatic CndashH) 1557 (C=N) cmminus11510 (N=N) cmminus1 1H-NMR (DMSO-d6) 71ndash75 (m 5H) 52(s 2H) 62 (d 1H) 64 (s 1H) 69 (s 1H) 13C-NMR (DMSO-d6 ppm) 1629 (CndashO) 1232 (CndashN) 1758 (C=N) anal calcdfor C14H10N4O2S C5637 H338 N1878 found C5633

H334 N1882

38 Preparation of 5-[(5-Phenyl-134-thiadiazol-2-yl)diazen-yl]pyrimidine-46-diol [3f] This dye was synthesised from5-phenyl-134-thiadiazol-2-amine and 46-dihydroxy pyrim-idine as orange crystals (yield 61 mp 182) IR [(KBr)120592maxcm

minus1] 3438ndash3391 (broad OndashH group) 3031 (aromaticCndashH) 1564 (C=N) cmminus1 1527 (N=N) cmminus1 1H-NMR

(DMSO-d6) 51 (d 2H) 72ndash75 (d 5H) 76 (d 1H) 13C-NMR(DMSO-d6 ppm) 1629 (CndashO) 1232 (CndashN) 1758 (C=N)anal calcd for C

12H8N6O2S C4800 H269 N2799 found

C4797 H267 N2796

4 Biological Activity

41 Bacterial and Fungal Strains The following bacteriaand fungi were used for the experiment Bacteria Staphy-lococcus aureus ATCC 25923 Escherichia coli ATCC 25922and Pseudomonas aeruginosa ATCC 27853 All bacterialstrains were maintained on nutrient agar medium at 37∘CFungi Aspergillus flavus Chrysosporium keratinophilum andCandida albicans MTCC 227 are used in this study Thesecultures are obtained from the Department of MicrobiologyKuvempu University All fungi strains were maintained onpotato dextrose agar (PDA) at 25∘C

42 Antibacterial and Antifungal Activities The antimicro-bial activity of newly synthesized compounds was evaluatedusing agar disc diffusion assay [18 19] Briefly a 24-hourold culture of bacteria and 48-hour old culture of fungiwere mixed with sterile physiological saline (09) andthe turbidity was adjusted to the standard inoculum ofMacFarland scale 05 (106 colony forming units (CFU) permL) Petri plates containing 20mL of Mueller Hinton agarand Sabouraud-dextrose agar were used for antibacterialand antifungal activities The inoculums were spread on thesurface of the solidified media and Whatman No 1 filterpaper discs (5mm in diameter) impregnated with the testcompound (20120583Ldisc) were placed on the solidified mediaStreptomycin (5mgdisc) and fluconazole (5mgdisc) wereused as positive controls for bacteria and fungi respectivelyalong with DMSOdisc as negative control Zone of inhibitionwas recorded in millimeters after incubating bacterial strainsat 37∘C (24 hr) and fungal strains at 25∘C (72 hr) Tests wereperformed in triplicate and the valueswere expressed asmeanplusmn SD [18 20 21]

43 Minimal Inhibitory Concentrations (MIC) The in vitrodetermination of the minimum inhibitory concentration(MIC) against selected bacterial strains was carried outusing serial dilution method (Table 4) The agar dilutionsusceptibility test was performed based on the reportedmethod by Shridhar [22] to determine the MIC of the syn-thesized compounds The test compounds 3(andashf) dissolvedin sterilized 5 DMSO (400mgmL concentration) weretaken as standard stock A series of twofold dilutions ofeach compound in the final concentrations of 400 300200 100 50 25 13 and 7mgmL were prepared in nutri-ent agar for bacteria After solidification the plates werespotted with 100120583L of overnight grown bacterial culturesapproximately containing 1 times 104 CFUmL The test wascarried out in triplicate The plates of bacterial culture wereincubated at 37∘C for 18ndash24 h After incubation the MIC wasdetermined


Table 1 Yield melting point 120582max molar absorptivity (120576) molecular formula and solubility data of dye 3(andashf)

Dye Yield () MP (∘C) 120582max in nm Log 120576 Molecular formula Mol wt Solubility3a 46 216ndash218 490 42 C17H11N5OS 33336 AcetoneEthanolDMFDMSO3b 57 169ndash171 488 451 C13H11N7S 29733 AcetoneEthanolDMFDMSO3c 71 189ndash191 512 402 C16H15N5S 30938 AcetoneEthanolDMFDMSO3d 66 179ndash182 525 458 C18H12N4OS 33237 AcetoneEthanolDMFDMSO3e 61 192ndash194 509 417 C14H10N4O2S 29831 AcetoneEthanolDMFDMSO3f 54 202ndash204 498 43 C12H8N6O2S 30029 AcetoneDMSO EthanolDMF

44 Antioxidant Activity

441 DPPH Activity The antioxidant capacity of newlysynthesised compounds was determined by the reportedmethod of Blois [23]with suitablemodificationsThe reactionmixture contained 3mL of 01mM DPPH in 95 methanoland 100 120583L of solution of different organic compounds fromthe stock solution (1mgmL) and final volume was made upto 4mL with 95 ethanol The mixture was kept at roomtemperature for 20min in the dark and then the absorbancewas recorded at 517 nm The 95 methanol was used as acontrol The scavenging activity of DPPH radicals () wascalculated by the following equation

of inhibition

=

(abs of the control minus abs of the test sample)abs of the control

times 100

(1)

442 Metal Chelating Activity The metal chelating proper-ties of newly synthesised compounds were determind usingreported the procedure by Dinis [24] Briefly 100 120583L ofnewly synthesised compounds in methanol was added to asolution of 2mM FeCl

2(005mL) The reaction was initiated

by adding 5mM ferrozine (02mL) and the mixture wasshaken vigorously and kept at room temperature for 10minAfter the mixture had reached equilibrium the absorbanceof the solution was then measured spectrophotometrically at562 nm All the tests and analyses were run in triplicate Thepercentage of inhibition of ferrozine-Fe2+ complex formationis given by the following equation

inhibition () = [(119860cont minus 119860 test)

119860cont] times 100 (2)

where 119860cont is the absorbance of the control and 119860 test is theabsorbance of the test samplestandard

5 Result and Discussion

51 Synthesis and Characterization As shown in Scheme 1the hetarylazo dyes 3(andashf)were prepared through the diazoti-zation of 5-phenyl-134-thiadiazol-2-amine and coupledwithdifferent coupling components such as 8-hydroxyquinoline26-diamino pyridine NN dimethyl aniline 2-naphtholresorcinol and 46-dihydroxypyrimidine The synthesized

dyes were characterized by FT-IR UV-Vis 1H-NMR 13C-NMR and elemental analysis

The infrared spectra of all the dyes (inKBr) were recordedin the region of 4000 cmminus1 to 400 cmminus1 For the dyes 3a 3d3e and 3f a broad band has appeared at the region 3500ndash3200which confirms the presence of hydroxyl group (ndashOH)Thesedyes 3(andashf) are showed 1517ndash1535 cmminus1 for (N=N) azo groupThe 120592max values at 3085ndash3005 cmminus1 (aromatic CndashH) and at2986ndash2851 cmminus1 (aliphatic CndashH) were also observed

The 1H-NMR spectra were recorded in DMSO-d6 in dye3c singlet at 285 ppm for ndash(CH

3)2group of NN-dimethyl

aniline amultiplet from 720 to 750 ppm for aromatic protons(Ar-H) In dyes 3(andashf) the signals within the range of 725ndash76 ppm are attributable to aromatic protons on the 5-phenyl134-thiadiazole The signal of the four protons on the twoamino groups of dye (3b) was not clearly observed in 1H-NMR spectrum of dye (3b) because they were acidic hydro-gen atoms which could exchange with deuterium atoms ofsolvent (Pavia et al [25])

These dyes were in good yield and these are soluble inacetone DMF and DMSO Absorption spectra of the azodyes 3(andashf) were recorded in DMSO at a concentration of10minus4mol Lminus1 Due to 120587-120587lowast electronic transition in azo group

the absorption maxima of the dyes 3(andashf) lie in the rangeof 485 to 528 with the marginal variation The results aresummarized in Table 1 and Figure 1

511 Antimicrobial Effect The capacity of antimicrobialactivity of the six newly synthesized compounds against six(3 bacteria and 3 fungi) human pathogenic microorganismswere assessed both qualitatively and quantitatively by thepresence or the absence of inhibition zone and MIC valueswith standard drugs (streptomycin and fluconazole) Theresults of antibacterial activities of the extracts are shownin Table 2 The result shows that the synthetized compoundsshowed lower antimicrobial activities than thoes of standardThe compounds 3a (50 25 50 of MIC) 3b (100 50 50of MIC) and 3f (100 100 100 of MIC) show good andcomparable activity than that of standard According to Scor-zoni [26] the compounds show an MIC less than 75120583gmLconsidered to have strong antimicrobial activity from 75to 150120583gmL the activity is considered as moderate from150 to 250 120583gmL the antimicrobial activity was weak andover 250120583gmL the compounds were considered as inactiveTherefore in the present work all synthesized compoundspossessed strong moderate and weak activities against all


Table 2 In vitro antibacterial activities of the compounds 3(andashf)

Sl noEscherichia coli Staphylococcus aureus Pseudomonas aeruginosa

Diameter of zone of inhibition (mm)Conc in mgmL 1 05 1 05 1 05

1 Control 00 00 002 Standard streptomycin 16 plusmn 02 10 plusmn 03 15 plusmn 04 10 plusmn 05 16 plusmn 03 13 plusmn 06

3 3a 13 plusmn 05 10 plusmn 07 14 plusmn 06 12 plusmn 03 10 plusmn 05 08 plusmn 05

4 3b 12 plusmn 04 09 plusmn 06 12 plusmn 04 10 plusmn 05 13 plusmn 03 11 plusmn 02

5 3c 04 plusmn 02 01 plusmn 02 02 plusmn 05 00 03 plusmn 03 01 plusmn 01

6 3d 08 plusmn 04 06 plusmn 05 09 plusmn 06 07 plusmn 03 08 plusmn 02 05 plusmn 07

7 3e 06 plusmn 06 04 plusmn 02 08 plusmn 07 05 plusmn 03 07 plusmn 02 05 plusmn 05

8 3f 10 plusmn 06 07 plusmn 02 11 plusmn 08 08 plusmn 02 10 plusmn 01 07 plusmn 03

test bacteria Although a comparable antibacterial activitywas exhibited by few compounds these compounds failedto show a good response to antifungal activity and thecompound 3c does not show any antimicrobial property

512 Antioxidant Activity The DPPH radical scavengingactivity is a widely used method to evaluate the antioxidantcapacity of newly synthetized compounds due to its shorttime reaction compared to other methods The ability todonate hydrogen or electron to the DPPH radicals is thoughtto be the reason for the antioxidant property of organiccompounds (Baumann et al [27]) The DPPH radicals easilyexpcept the electron or hydrogen atom from the organicmolecules to form stable diamagnetic molecules Soares et al[28] The DPPH lose its colour and the absorbance of theDPPH also decreases which is read at 517 nm Scavengingeffects of newly synthesised compounds 3a 3b and 3f showgood and comparable value to standard (Figure 2) on theother hand remaining compounds are showing moderatescavenging activity when compared to standard BHT How-ever the scavenging effects of BHT are higher than of allnewly synthesized compounds

513 Metal Chelating Activity The ferrozine can bind to Fe2+ions quantitatively to form stable complexes In the pres-ence of chelating agents like organic compounds and plantextracts the complex formation is disrupted which resultsin the destabilization of complex and results in decreases inthe red colour of complex Measurement of the decrease inthe colour allows us to estimate the chelating property of theorganic compounds or coexisting chelator (Yamaguchi [29])In the present work the organic compounds and standarddestabilize the complex of ferrous and ferrozine suggestingthat they have a chelating capacity The metal like ironcan stimulate the lipid peroxidation by the Fenton reactionand it also stimulates the peroxidation by decomposinglipid hydroperoxides into peroxyl and alkoxyl free radicalsthat can themselves abstract hydrogen and perpetuate thechain reaction of lipid peroxidation (Halliwell [30]) Thecompounds 3a 3b and 3f shows good activity than the othercompounds indicates the capacity of these compounds to

300 400 500 6000

1

2

3

Abso

rban

ce

Wavelength

3a 3b 3c

3d 3e 3f

Figure 1 Absorption spectra of dyes 3(andashf) in DMSO

3a 3b 3d 3e 3f BHT0

102030405060708090

100

Inhi

bitio

n (

)

Organic compounds

Figure 2 DPPH radical scavenging activity

destabilize the complex between the ferrozine and Fe2+ ionsBut the remaining compounds fail to chelate the metal ionsas compared to standard


Table 3 In vitro antifungal activities of the compounds 3(andashf)

Sl no Aspergillus flavus Chrysosporium keratinophilum Candida albicansDiameter of zone of inhibition (mm)

Conc in mgmL 1 05 1 05 1 051 Control 00 00 002 Standard flucanazole 18 plusmn 05 15 plusmn 03 16 plusmn 07 14 plusmn 02 23 plusmn 08 20 plusmn 03



5 3c 04 plusmn 03 02 plusmn 02 05 plusmn 03 03 plusmn 06 03 plusmn 03 02 plusmn 01




Table 4 Minimum inhibitory concentration compounds 3(andashf)

Sl no Compounds Concentration in 120583gmLEscherichia

coliStaphylococcus

aureusPseudomonasaeruginosa

1 3a 50 25 502 3b 100 50 503 3c 400 mdash 4004 3d 200 200 2005 3e 400 200 2006 3f 100 100 100

3a 3b 3d 3e 3f EDTA0

10

20

30

40

50

60

70

80

90

100

Inhi

bitio

n (

)

Organic compounds

Figure 3 Metal chelating activity

514 Biological Activity See Tables 2 and 3

515 Antioxidant Activity See Figures 2 and 3

6 Conclusions

In this work 6 new heterocyclic azo dyes were synthesized bya classical method of diazotizing coupling This investigationproposes a convenient economical cheaper and useful

method for the synthesis of 5-phenyl-134-thiadiazole-azodyes coupled with quinoline which are biologically activemolecules possessing antimicrobial and in vitro antioxidantproperties These new classes of heterocycles exhibit signifi-cant antimicrobial and antioxidant activities 134-Thiadiazolazo dye coupled with 8-hydroxy quinoline showed higheractive antioxidant capacity than 134-thiadiazol azo dye cou-pled with naphthol The preliminary antimicrobial activitystudies revealed that the azo dye having 134-thiadiazolemoiety exhibited a potential antimicrobial activity Hence itcan be concluded that this new class of compounds certainlyholds a greater promise in discovering a potent antimicrobialand antioxidant agent

References

[1] M Dakiky and I Nemcova ldquoAggregation of oo1015840-dihydroxy azodyes III Effect of cationic anionic and non-ionic surfactantson the electronic spectra of 2-hydroxy-5-nitrophenylazo-4-[3-methyl-1-(4

10158401015840

-sulfophenyl)-5-pyrazolone]rdquo Dyes and Pigmentsvol 44 no 3 pp 181ndash193 2000

[2] A Navarro and F Sanz ldquoDye aggregation in solution study ofCI direct red IrdquoDyes and Pigments vol 40 no 2-3 pp 131ndash1391999

[3] J Tao G Mao and L Daehne ldquoAsymmetrical molecularaggregation in spherulitic dye filmsrdquo Journal of the AmericanChemical Society vol 121 no 14 pp 3475ndash3485 1999

[4] F Karci I Sener and H Deligoz ldquoAzocalixarenes 2 synthesischaracterization and investigation of the absorption spectra ofazocalix[6]arenes containing chromogenic groupsrdquo Dyes andPigments vol 62 no 2 pp 131ndash140 2004

[5] E Torres I Bustos-Jaimes and S Le Borgne ldquoPotential use ofoxidative enzymes for the detoxification of organic pollutantsrdquoApplied Catalysis B vol 46 no 1 pp 1ndash15 2003

[6] H Yousefi A Yahyazadeh M Reza Yazdanbakhsh et al ldquoSyn-thesis spectral features and biological activity of some novelhetarylazo dyes derived from 6-amino-13-dimethyluracilrdquoJournal of Molecular Structure vol 1015 pp 27ndash32 2012

[7] G Hallas and J-H Choi ldquoSynthesis and properties of novelaziridinyl azo dyes from 2-aminothiophenesmdashpart 2 appli-cation of some disperse dyes to polyester fibresrdquo Dyes andPigments vol 40 no 2-3 pp 119ndash129 1999

[8] A Demirbas D Sahin N Demirbas and S A Karaoglu ldquoSyn-thesis of some new 134-thiadiazol-2-ylmethyl-124-triazole


derivatives and investigation of their antimicrobial activitiesrdquoEuropean Journal of Medicinal Chemistry vol 44 no 7 pp2896ndash2903 2009

[9] K S Bhat B Poojary D J Prasad P Naik and B S HollaldquoSynthesis and antitumor activity studies of some new fused124-triazole derivatives carrying 24-dichloro-5-fluorophenylmoietyrdquo European Journal of Medicinal Chemistry vol 44 no12 pp 5066ndash5070 2009

[10] G B Bagihalli P G Avaji S A Patil and P S Badami ldquoSynthe-sis spectral characterization in vitro antibacterial antifungaland cytotoxic activities of Co(II) Ni(II) and Cu(II) complexeswith 124-triazole Schiff basesrdquo European Journal of MedicinalChemistry vol 43 no 12 pp 2639ndash2649 2008

[11] Z H Chohan S H Sumrra M H Youssoufi and T B HaddaldquoMetal based biologically active compounds design synthesisand antibacterialantifungalcytotoxic properties of triazole-derived Schiff bases and their oxovanadium(IV) complexesrdquoEuropean Journal of Medicinal Chemistry vol 45 no 7 pp2739ndash2747 2010

[12] K Zamani K Faghihi T Tofighi and M R ShariatzadehldquoSynthesis and antimicrobial activity of some pyridyl and naph-thyl substituted 124-triazole and 134-thiadiazole derivativesrdquoTurkish Journal of Chemistry vol 28 no 1 pp 95ndash100 2004

[13] E R Fernandez J L Manzano J J Benito R Hermosa EMonte and J J Criado ldquoThiourea triazole and thiadiazinecompounds and their metal complexes as antifungal agentsrdquoJournal of Inorganic Biochemistry vol 99 no 8 pp 1558ndash15722005

[14] D R Waring and G Hallas The Chemistry and Applications ofDyes Plenum Press New York NY USA 1990

[15] A T Mavrova D Wesselinova Y A Tsenov and P DenkovaldquoSynthesis cytotoxicity and effects of some 124-triazole and134-thiadiazole derivatives on immunocompetent cellsrdquo Euro-pean Journal of Medicinal Chemistry vol 44 no 1 pp 63ndash692009

[16] C T Keerthi Kumar J Keshavayya T Rajesh and S KPeethambar ldquoSynthesis characterization and biological activityof heterocyclic azo dyes derived from 2-aminobenzothiozolerdquoInternational Journal of Pharmacy and Pharmaceutical Sciencesvol 5 no 1 pp 296ndash301 2013

[17] AH Shridhar J KeshavayyaH JoyHoskeri andR A ShoukatAli ldquoSynthesis of some novel bis 134-oxadiazole fused azodye derivatives as potent antimicrobial agentsrdquo InternationalResearch Journal of Pure amp Applied Chemistry vol 3 pp 119ndash129 2011

[18] B A Arthington-Skaggs M Motley D W Warnock and CJ Morrison ldquoComparative evaluation of PASCO and NationalCommittee for Clinical Laboratory Standards M27-A brothmicrodilution methods for antifungal drug susceptibility test-ing of yeastsrdquo Journal of Clinical Microbiology vol 38 no 6 pp2254ndash2260 2000

[19] L Rocha A Marston O Potterat M A C Kaplan H Stoeckli-Evans and K Hostettmann ldquoAntibacterial phloroglucinols andflavonoids fromHypericum brasilienserdquo Phytochemistry vol 40no 5 pp 1447ndash1452 1995

[20] J D MacLowry M J Jaqua and S T Selepak ldquoDetailedmethodology and implementation of a semiautomated serialdilution microtechnique for antimicrobial susceptibility test-ingrdquo Applied Microbiology vol 20 no 1 pp 46ndash53 1970

[21] A Portillo R Vila B Freixa et al ldquoAntifungal activity ofParaguayan plants used in traditional medicinerdquo Journal ofEthnopharmacology vol 76 no 1 pp 93ndash98 2001

[22] A H Shridhar J Keshavayya S K Peethambar and H JoyHoskeri ldquoSynthesis and biological activities of Bis alkyl 134-oxadiazole incorporated azo dye derivativesrdquo Arabian Journalof Chemistry 2012

[23] M S Blois ldquoAntioxidant determinations by the use of a stablefree radicalrdquo Nature vol 181 pp 1199ndash1200 1958

[24] T C P Dinis V M C Madeira and L M Almeida ldquoActionof phenolic derivatives (acetaminophen salicylate and 5-aminosalicylate) as inhibitors of membrane lipid peroxidationand as peroxyl radical scavengersrdquo Archives of Biochemistry andBiophysics vol 315 no 1 pp 161ndash169 1994

[25] D L Pavia G M Lampman and G S Kriz Introduction toSpectroscopy Bellingham Wash USA 1996

[26] L Scorzoni T Benaducci A M F Almeida D H S Silva VS Bolzani and M J S Mendes-Giannini ldquoComparative studyof disk diffusion and microdilution methods for evaluationof antifungal activity of natural compounds against medicalyeasts Candida spp and Cryptococcus sprdquo Revista de CienciasFarmaceuticas Basica e Aplicada vol 28 no 1 pp 25ndash34 2007

[27] J Baumann G Wurm and V Bruchhausen ldquoProstaglandinsynthetase inhibiting and O

2-radical scavenging properties of

some flavonoids and related phenolic compoundsrdquo Naunyn-Schmiedebergrsquos Archives of Pharmacology vol 27 p 308 2002

[28] J R Soares T C P Dinis A P Cunha and L M AlmeidaldquoAntioxidant activities of some extracts of Thymus zygisrdquo FreeRadical Research vol 26 no 5 pp 469ndash478 1997

[29] F Yamaguchi T Ariga Y Yoshimura and H NakazawaldquoAntioxidative and anti-glycation activity of garcinol fromGarcinia indica fruit rindrdquo Journal of Agricultural and FoodChemistry vol 48 no 2 pp 180ndash185 2000

[30] B Halliwell ldquoReactive oxygen species in living systems sourcebiochemistry and role in human diseaserdquo American Journal ofMedicine vol 91 no 3 p 1422 1991

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


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Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

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Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


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Applied ChemistryJournal of



Theoretical ChemistryJournal of


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Spectroscopy

Analytical ChemistryInternational Journal of


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Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


H2N

H2N

+

+

NH2NH2

NH2

NH2

1

R = 2d =

2(andashf)

R = 2b =

3(andashf)

R = 2a =

1

R = 2c =

R = 2f =R = 2e =

POCl3

90∘C

(i) Nitrosylsulfuric acid

(ii) Coupling

S

NH

N

OH

N

N

OH

OH

OH

N

NHO

OH

N

S

N

N

S

N

O

OH

N

S

N

N

NR

Scheme 1

2 Materials and Measurements

All the starting materials were obtained from Merck andwere used without further purification Melting points weremeasured using standard melting point apparatus fromSunder Industrial Products (India) and were uncorrectedThe UV-Visible absorption spectra were recorded in DMSOwith a SHIMADZU UV-1800 spectrometer at concentrationrange of 10minus4M IR spectra were recorded in the regionof 4000 cmminus1 to 400 cmminus1 on an FT-IR-Alpha Bruker IRspectrometer in KBr pellets The 1H-and 13C-NMR spectrawere recorded in DMSO-d6 at 500MHz using AV500-High Resolution Multinuclear FT-NMR Spectrometer withtetramethylsilane as internal standard

3 Experimental

31 Synthesis of 5-Phenyl-134-thiadiazol-2-amine (1) Ben-zoic acid (01mol) and thiosemicarbazide (01mol) in phos-phorous oxychloride (30mL) were refluxed gently for 30minand cooled followed by careful addition of water (90mL)The separated solid was filtered and suspended in waterand basified with aqueous potassium hydroxide followed byfiltration drying and crystallization from mixture of DMFand ethanol (9 1) to obtain colourless solidwith 65 yield IR[(KBr) 120592maxcm

minus1] 3087 (aromatic CndashH) 1613 (C=N) cmminus11H-NMR (DMSO-d6) 72ndash75 (m 5H) 51 (s 2H) 13C-NMR(DMSO-d6 ppm) 1539 (CndashO) 1304 (CndashN) 1746 (C=N)1508 (CndashN) LC-MS (119898119911) 1772 anal calcd for C

8H7N3S

C5422 H398 N2371 found C5419 H395 N2269

32 General Procedure for Preparation of Dye 3(andashf) 5-Phenyl-134-thiadiazole-2-amine (20 times 10minus3mol) was dis-solved in hot glacial acetic acidpropionic acid mixture (2 160mL) and was rapidly cooled in an icesalt bath to minus5∘CThe liquorwas then added in portions during 30min to a coldsolution of nitrosyl sulphuric acid (prepared from sodiumnitrite (015 g) and concentrated sulphuric acid (3mL) at50∘C) The mixture was stirred for an additional 2 hrs at0∘C Excess nitrous acid was destroyed by addition of ureaThe resulting diazonium salt was cooled in saltice mixtureAfter diazotization was complete the diazo liquor was slowlyadded to vigorously stirred solution of coupling component(20 times 10minus3mol) in potassium hydroxide (20 times 10minus3mol)and water (2mL) The solution was stirred at 0ndash5∘C for 2 hAfter 2 h the pH of the reaction mixture was maintainedat 4ndash6 by the simultaneous addition of saturated sodiumcarbonate solution The mixture was stirred for one day atroom temperature After one day the resulting solid wasfiltered washed with cold water and dried

The general scheme for the syntheses is given inScheme 1

33 Preparation of 5-[(5-Phenyl-134-thiadiazol-2-yl)diazen-yl]quinolin-8-ol [3a] The dye was obtained from 5-phenyl-134-thiadiazol-2-amine and 8-hydroxy quinoline as browncrystals (yield 46 mp 218) IR [(KBr) 120592maxcm

minus1] 3553ndash3312 (broad ndashOH group) 3063 (aromatic CndashH) 1573 (C=N)1530 (N=N) cmminus1 1H-NMR (DMSO-d6) 89 (d 1H)86 (d 1H) 79 (t 2H) 680 (d 1H) 72ndash75 (m 5H)



N2099



13H11N7S C5251 H373 N3297 found C5249

H370 N3294



3) 1502 (CndashN) 1759


16H15N5S C6211 H489 N2264 found

C6209 H487 N2261



H361 N1682



H334 N1882




12H8N6O2S C4800 H269 N2799 found

C4797 H267 N2796










of inhibition

=


times 100

(1)





119860cont] times 100 (2)


























300 400 500 6000

1

2

3

Abso

rban

ce

Wavelength

3a 3b 3c

3d 3e 3f


3a 3b 3d 3e 3f BHT0

102030405060708090

100

Inhi

bitio

n (

)

Organic compounds















coliStaphylococcus


1 3a 50 25 502 3b 100 50 503 3c 400 mdash 4004 3d 200 200 2005 3e 400 200 2006 3f 100 100 100


10

20

30

40

50

60

70

80

90

100

Inhi

bitio

n (

)

Organic compounds




6 Conclusions



References


10158401015840












































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



N2099



13H11N7S C5251 H373 N3297 found C5249

H370 N3294



3) 1502 (CndashN) 1759


16H15N5S C6211 H489 N2264 found

C6209 H487 N2261



H361 N1682



H334 N1882




12H8N6O2S C4800 H269 N2799 found

C4797 H267 N2796










of inhibition

=


times 100

(1)





119860cont] times 100 (2)


























300 400 500 6000

1

2

3

Abso

rban

ce

Wavelength

3a 3b 3c

3d 3e 3f


3a 3b 3d 3e 3f BHT0

102030405060708090

100

Inhi

bitio

n (

)

Organic compounds















coliStaphylococcus


1 3a 50 25 502 3b 100 50 503 3c 400 mdash 4004 3d 200 200 2005 3e 400 200 2006 3f 100 100 100


10

20

30

40

50

60

70

80

90

100

Inhi

bitio

n (

)

Organic compounds




6 Conclusions



References


10158401015840












































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of






of inhibition

=


times 100

(1)





119860cont] times 100 (2)


























300 400 500 6000

1

2

3

Abso

rban

ce

Wavelength

3a 3b 3c

3d 3e 3f


3a 3b 3d 3e 3f BHT0

102030405060708090

100

Inhi

bitio

n (

)

Organic compounds















coliStaphylococcus


1 3a 50 25 502 3b 100 50 503 3c 400 mdash 4004 3d 200 200 2005 3e 400 200 2006 3f 100 100 100


10

20

30

40

50

60

70

80

90

100

Inhi

bitio

n (

)

Organic compounds




6 Conclusions



References


10158401015840












































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of















300 400 500 6000

1

2

3

Abso

rban

ce

Wavelength

3a 3b 3c

3d 3e 3f


3a 3b 3d 3e 3f BHT0

102030405060708090

100

Inhi

bitio

n (

)

Organic compounds















coliStaphylococcus


1 3a 50 25 502 3b 100 50 503 3c 400 mdash 4004 3d 200 200 2005 3e 400 200 2006 3f 100 100 100


10

20

30

40

50

60

70

80

90

100

Inhi

bitio

n (

)

Organic compounds




6 Conclusions



References


10158401015840












































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of













coliStaphylococcus


1 3a 50 25 502 3b 100 50 503 3c 400 mdash 4004 3d 200 200 2005 3e 400 200 2006 3f 100 100 100


10

20

30

40

50

60

70

80

90

100

Inhi

bitio

n (

)

Organic compounds




6 Conclusions



References


10158401015840












































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Documents

Research Article Synthesis, Characterization, and ...downloads.hindawi.com/archive/2013/370626.pdf · -thiadiazole--amine has been synthesized by single step reaction. A series of