Pyrazine-2-substituted carboxamide derivatives : synthesis, antimicrobial and leuconostoc mesenteroides growth inhibition activity

Condensation of pyrazine-2,3-dicarboxylic acid anhydride with aminoaceto- phenones gave the corresponding N-(acetylphenyl)pyrazine-2-carboxamide. Their reac- tions with some electrophilic (carbonyl group, bromine) and nucleophilic (malononitrile, hydrazine) reagents are discussed. N-(3-(2,2-Dicyano-1-methylethenyl)phenyl)pyra- zine-2-carboxamide underwent Michael addition reaction with an activated double bond yielding 3-amino-5-aryl-3'-(pyrazine-2-carboxamido)biphenyl-2,4-dicarbonitrile deriva- tives and 2-imino-4-(3-(pyrazine-2-carboxamido)phenyl)-6-(4-methoxyphenyl)cyclo- hexa-3,5-diene-1,1,3-tricarbonitrile. The structures of the newly synthesized com- pounds were confirmed by their IR, 1 HN MR, 13 C 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. Keywords: pyrazine-2,3-dicarboxylic acid anhydride, N-(acetylphenyl)-pyrazine-2-car- boxamide, {((pyrazine-2-carboxamido)phenyl)ethylidene}hydrazine, 3-amino-5-ar- yl-3'-(pyrazine-2-carboxamido)biphenyl-2,4-dicarbonitrile, Leuconostoc sp. gro- wth inhibition.