New routes to aroylthiadiazolines and arylazothiazoles from phenylglyoxalyl bromide arylhydrazones and phenacyl thiocyanate

AS Shawali, AO Abdelhamid

Index: Shawali,A.S.; Abdelhamid,A.O. Journal of Heterocyclic Chemistry, 1976 , vol. 13, p. 45 - 49

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Citation Number: 22

Abstract

Abstract Reaction of phenylglyoxalyl bromide arylhydrazones (III) with thiourea in ethanol produces 2-amino-4-phenyl-5-arylazothiazoles (XI) instead of the expected 2-benzoyl-4-aryl- 5-imino-Δ 2− 1, 3, 4-thiadiazolines (V) obtained from III and potassium thiocyanate. Phenacyl thiocyanate (IV) couples with diazotized anilines to give V. The mechanisms of formation of V and XI from VI and III, respectively, are postulated. Nitrosation of V gives the ...