Solid-phase combinatorial synthesis of 1,4-benzoxazin-3(4H)-one and 1,4-benzothiazin-3(4H)-one derivatives

Abstract

The first solid-phase synthesis of 1,4-benzothiazin-3(4H)-ones and 1,4-benzoxazin-3(4H)-ones is reported. Alkylation of the immobilized 4-hydroxy-3-nitrobenzamide (2a) and 3-nitro-4-sulfanylbenzamide (2b), followed by reduction and cyclization gave 4. Further alkylation and acylation in the presence of sodium hydride followed by TFA cleavage gave the desired 1,4-benzothiazin-3(4H)-ones and 1,4-benzoxazin-3(4H)-ones. © 2001 Elsevier Science Ltd.