Novel Rearrangement of 5-Arylazo-2-thiohydantoin Derivatives with Alkali and Aromatic Amines

Abstract

Abstract 5-Arylazo-2-thiohydantoin derivatives (2a,c) were cleaved and rearranged by aqueous sodium hydroxide to give the corresponding 1-aryl-⊿2-1,2,4-trazole-5-imino-3-carboxylic acids (3a-c). 3 a was decarboxylated to 1-phenyl-⊿2 -1,2,4-triazoline-5-imine (5). Hydrolysis of 5-arylazo-1-phenyl-2-thiohydantoins (6a-c) behaved in different manner affording 1-aryl-4-phenyl-⊿2 -1,2,4-triazoline-5-thione-3-carboxylic acids (7a-c). Fusing (2a-c) with aromatic amines at high temperature gave the corresponding anilides (8a-h). Treatment of 5-arylidene-2-thiohydantoin derivatives (9a-c) with hydrazine hydrate gave colourless products of thioureido cinnamic acid hydrazide derivatives (10a-c), while refluxing 5-arylidene-2-methylmercaptohydantoin (11a-d) with hydrazine hydrate and/or benzo-phenone hydrazone gave the corresponding glycocyamidine derivatives (12a-g).