One-pot three-component domino protocol for the synthesis of novel pyrano[2,3-d]pyrimidines as antimicrobial and anti-biofilm agents.

A simple and facile synthesis of a series of novel pyrano[2,3-d]pyrimidines has been achieved successfully via the one-pot three-component reaction of 2-amino-7-methyl-5-oxo-4-phenyl-4,5-dihydropyrano[4,3-b]pyran-3-carbonitriles, DMF-DMA and arylamines in the presence of 1-butyl-3-methylhydrogensulphate [Bmim]HSO4 ionic liquid. This method has several advantages such as high yields, clean reaction, simple methodology and short reaction times. The synthesized compounds were evaluated for their antimicrobial activity against Gram-positive, Gram-negative and different Candida strains. Among the derivatives screened, compounds 4c, 4d, 4h and 4l were found to be active against both bacterial and Candida strains with MIC values ranging from 3.9 to 31.2 μg mL(-1). In addition, compound 4l showed a good minimum bactericidal concentration, minimum fungicidal concentration and anti-biofilm activities. Furthermore, the mode of the antifungal action for the promising compound 4l was evaluated in C. albicans MTCC 1637 through an ergosterol biosynthesis inhibition process.