Synthesis of some new benzimidazolecarboxamides and evaluation of their antimicrobial activity.

A series of 1,2-disubstituted benzimidazole-5(6)-carboxamides was prepared and evaluated in vitro for antimicrobial activity against Staphyloccus aureus, Escherichia coli and Candida albicans. The precursor benzimidazolecarboxylic acids 4a-c and 9a-c were prepared via oxidative condensation of diaminobenzoic acids with aldehydes and via several steps over the 2(1H)-benzimidazolones, respectively. All acids were converted to their acyl chlorides with SOCl2, then amidified with several N,N'-dialkylaminoethyl derivatives. Compounds 8a-c, 20 and 22 exhibited the best activity.