Synthesis of 3-(benzimidazol-2-yl-amino)-1-(4-bromophenyl)-2-thioxopyrimidin4,6-dione analogs and their antimicrobial activity

Abstract

3-(Benzimidazol-2-yl-amino)-5-(substituted benzylidene)-1-(4-bromophenyl)-2-thioxopyrimidin-4,6-dione (4a-e) and 5-(2-substituted phenylhydrazono)-3-(benzimidazol-2-yl-amino)-1-(4-bromophenyl)-2-thioxopyrimidine-4,6-dione (5a-c) were synthesized in three steps. Reaction of 2-hydrazinobenzimidazole (1) with 4-bromophenyl isothiocyanate gave 1(benzimidazol-2-yl-amino)-4-(4-bromophenyl)thiosemicarbazide (2) which on cyclization with malonic acid in presence of acetyl chloride furnished 3-(benzimidazol-2-yl-amino)-1-(4-bromophenyl)-2-thioxopyrimidin-4,6-dione (3). Further, reaction of 3 with aryl aldehydes and diazonium salt of arylamines yielded desired compounds 4a-e and 5a-c in 52-72% yield. All the systhesized compounds have been characterized by spectral data's and they are screened for anti-microbial activity.