1998 protection, deprotection

protection, deprotectionO 0345

36 - 103Simultaneous Deprotection and Purification of Boc-Amines on IonicResin Capture. — Deprotection of a series of Boc-protected amines is car-ried out in the presence of the strongly acidic ion-exchange resin Amberlyst 15.The amine-bound resin thus formed is treated with excess methanolic ammoniato give the pure amines. No additional purification steps are required. Bothprimary and secondary aliphatic substrates are deprotected efficiently within1 day; other functional groups do not interfere with the process. Aromaticamines [cf. (VII)] react slowly. The utility of the methodology shown is furtherdemonstrated by 2 sequences which mimic solution phase parallel synthesis. Theproducts (XI) and (XIII) are obtained with excellent purity. — (LIU, Y.-S.;ZHAO, C.; BERGBREITER, D. E.; ROMO, D.; J. Org. Chem. 63 (1998) 10,3471-3473; Dep. Chem., Tex. A&M Univ., College Station, TX 77843, USA; EN)

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