Synthesis of 4-amino-3-(4′-benzyloxyphenyl)-5-mercapto-1,2,4-triazole and its derivatives

4-Amino-3-(4'-benzyloxyphenyl)-5-mercapto-1,2,4-triazole (1) was prepared by treating 4-benzyloxy benzoyl hydrazine successively with alcoholic potassium hydroxide-carbon disulphide and hydrazine hydrate, which on reaction with hydrazine hydrate, carbon disulphide, benzoic acid, benzoin, phenacyl bromide, phenyl isothiocyanate, formic acid, chloroacetyl chloride and benzaldehyde gave 3-(4'-benzyloxyphenyl)-4-amino-5-hydrazino-1,2,4-triazole (2), 3-(4'-benzyloxyphenyl)-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazole-6-(5H) thione (3), 3-(4'-benzyloxyphenyl)-6-phenyl-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazole (4), 3-(4'-benzyloxyphenyl)-6,7-diphenyl-5H-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazine (5), 6-phenyl-3-(4'-benzyloxyphenyl)-7H-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazine (6), 3-(4'-benzyloxyphenyl)-6-aminophenyl-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazole (7), 3-(4'-benzyloxyphenyl)-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazole (8), 3(4'-benzyloxyphenyl)-7H-1,2,4-triazolo [3,4-b] [1,3,4] -thiadiazine 6(5H)-one (9) and 6-phenyl-5,6-dihydro-3-(4'-benzyloxyphenyl)-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazole (10) respectively.