Journal of heterocyclic chemistry

Condensed 1, 3??benzothiazinones. 1. Facile synthesis of 2??amino??1, 2, 4??triazolo [5, 1??b][1, 3]??benzothiazin??9??one

KC Liu, BJ Shih, JW Chern

Index: Liu, Kang-Chien; Shih, Bi-Jane; Chern, Ji-Wang Journal of Heterocyclic Chemistry, 1988 , vol. 25, p. 1215 - 1217

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Citation Number: 5

Abstract

Abstract Treating 2-mercaptobenzohydrazide (1a) with cyanogen bromide gave 3-amino-2- imino-3, 4-dihydro-2. H-1, 3-benzothiazin-4-one (2a). This compound underwent further cyclocondensation with a second molecule of cyanogen bromide or S-methylisothiourea sulfate to afford the biologically interesting 2-amino-1, 2, 4-triazolo-[5, 1-b][1, 3] benzothiazin- 9-one (3c). Compound 3c could also be prepared directly from 1a by treating with excess ...