Synthesis and in vitro microbiological evaluation of novel 4-aryl-5-isopropoxycarbonyl-6-methyl-3,4-dihydropyrimidinones

Seven 4-aryl-5-isopropoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2(1H)-ones 4a–g and 4-phenyl-5-isopropoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2(1H)-thione 4h have been synthesized by a one-pot cyclocondensation of aldehydes, isopropyl acetoacetate and urea/thiourea in ethanol by using strontium chloride hexahydrate as the catalyst. All the compounds were screened for their antibacterial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella typhi and antifungal activity against Candida albicans, Aspergillus flavus, Rhizopus and Mucor. Compounds 4b, 4c, 4f, 4g exhibited excellent in vitro antibacterial activity against Staphylococcus aureus, Salmonella typhi and Pseudomonas aeruginosa and potent in vitro antifungal activity against Candida albicans, Rhizopus and Mucor. Compound 4f with a nitro group at the para position of the 4-aryl group and 4g with a fluorine at the para position of the 4-aryl group showed more activity than the standard drugs.

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