An efficient, solvent-free microwave-assisted synthesis and antimicrobial screening of 1,6-dihydropyrimidine analogues

A series of compounds 4-(4-(4-aminophenyl)-6-(aryl)-1,6-dihydropyrimidin-2-ylthio)butanenitriles 5a – l were synthesised by the reaction of allyl cyanide 4 with 3a – l . Compounds 3a – l were prepared from reaction between various chalcones 1a – l and thiourea in presence of catalytic amount of potassium hydroxide. Compounds 3a – l , and 5a – l were prepared by classical as well as MWI methods. Structures of the compounds were characterized by IR, 1 H NMR, 13 C NMR and mass spectral data. The newly synthesized compounds 5a – l were screened for their antimicrobial activity against different strains of bacteria and fungi using serial broth dilution method. Compounds 5e , 5g and 5k were found to be most active with MIC of 25 μg/mL against selected bacterial strains , while compound 5d , 5f , 5j and 5k were found to be most active with MIC 50 μg/mL against selected fungal strains.