Synthesis of 4-amino-2,6-diaryl-5-cyanopyrimidines as antimicrobial agents

This article describes an efficient and facile synthesis of 11 2,4,6-trisubstituted 5-cyanopyrimidines starting from meta- and para-substituted 2-cyanocinnamonitriles and arylamidines. The synthesized heterocycles, 3a–k, were characterized by infrared (IR), 1H NMR, 13C NMR, and mass spectral data. The probable mechanism of formation of the title compounds employing 2-cyanocinnamonitriles and arylamidines in the presence of a base was clarified. A preliminary screening of the antibacterial tests clearly showed that 4 out of 11 pyrimidines, 3a, 3e, 3f, and 3k, were effective against bacteria Staphyloccus aureus, Bacillus subtillis, and Pseudomonas aeruginosa. Further, the minimum inhibitory concentration (MIC) against the bacteria has been determined.