Abstract
Condensation of pyrazine-2,3-dicarboxylic acid anhydride with aminoacetophenones gave the corresponding N-(acetylphenyl)pyrazine-2-carboxamide. Their reactions with some electrophilic (carbonyl group, bromine) and nucleophilic (malononitrile, hydrazine) reagents are discussed. N-[3-(2,2-Dicyano-1-methylethenyl)phenyl]pyrazine-2-carboxamide underwent Michael addition reaction with an activated double bond yielding 3-amino-5-aryl-3'-(pyrazine-2-carboxamido)biphenyl-2,4-dicarbonitrile derivatives and 2-imino-4-(3-(pyrazine-2-carboxamido)phenyl)-6-(4-methoxyphenyl)cyclohexa-3,5-diene-1,1,3-tricarbonitrile. The structures of the newly synthesized compounds were confirmed by their IR, H-1 NMR, C-13 NMR and mass-spectra data. Antimicrobial acitivites and Leuconostoc sp. growth inhibition of the newly synthesized compounds were studied and some of these were found to exhibit a pronounced effect.