Improved Synthesis of 3-(α , α-diphenyl –α- hydroxymethyl)- 4-amino 1,2,4-triazoline-5-thione and Facile Route to 3,6-Disubstituted 1,2,4-triazolo [3,4-b][1,3,4] thiadiazoles(*)

The reaction of thiocarbohydrazide (1) with benzilic acid (2) at the melting temperature (160-170 C) allows an improved preparation of 3-(,-diphenyl--hydroxymethyl)-4-amino-1,2,4-triazoline-5-thione (3).
The compound (3) reacts easily with suitable carboxylic acids in presence of phosphorous oxychloride to afford 1,2,4-triazolo [3,4-b] [1,3,4] thiadiazole ring systems (4a-g). The synthesized products were confirmed by physical and spectral methods.