4-Amino-3-[2-benzo(b)furyl]-5-mercapto-1,2,4-triazole was synthesized by the reactions of 2-benzo(b)furoyl hydrazine with CS₂ and next hydrazine under microwave irradiation. Treatment of the resulting 4-amino-5-mercapto-1,2,4-triazole with aromatic carboxylic acids (or aryloxyacetic acids), α-bromoacetophenones and aromatic aldehydes under microwave irradiation yielded the corresponding 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles, 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines and 4-arylideneamino-5- mercapto-1,2,4-triazole in good to moderate yields, respectively. The structures of all these new compounds were confirmed by elemental analyses, IR, ¹H NMR and MS spectra.

Key words: microwave irradiation, 4-arylideneamino-5-mercapto-1,2,4-triazole, 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole, 1,2,4-triazolo[3,4-b]-1,3,4- thiadiazine, synthesis