• Archives of Pharmacal Research
• /
• v.13 no.4
• /
• pp.351-354
• /
• 1990

2, 3-diphenyl-4-cyano-pyrrole-5-thione (4) was either by the reaction of benzoin (1) and cyanothioacetamide (3) followed by cyclization using AcOH/sodium acetate or by refluxing a mixture of benzoin (1) and cyanothioacethamide in pyridine to afford directly 4. Several new pyrrole and pyrazole derivatives were synthesised using 4 as synthon. The structure of the newly synthesised derivatives were based on celemental and spectral data studies. Methylation of the SH group in 4 afforded 5. Reaction of 4 with ethyl bromo acetate afforded (6). Treatment of (5) and (6) with hydrazine hydrate afforded the same pyrazole derivative (10) through the intermediate (9). Treatment of 6 with aniline and phenylhydrazine afforded the pyrrole derivatives 8a, b respectively. Treatment of 6 while dill HCI gave 2, 3-diphenyl-4-cyano-pyrrole-5-one (7). Treatment of 6 with $NH_3$/EtOH afforded the amidic derivatives (11) with treatment of 6 $NH_3$/ heat then acidification it gave the carboxylic derivatives (12).