Novel selective biocatalytic deacetylation studies on dihydropyrimidinones

Five racemic ethyl 4-(3/4-acetoxyphenyl)-6-methyl-3,4-dihydropyrimidin-2-one-5-carboxylates have been synthesized by acetylation of corresponding hydroxy analogues, which in turn have been synthesized under microwave condition by multi-component Biginelli cyclocondensation of ethyl acetoacetate, urea and the corresponding hydroxybenzaldehydes in the presence of ferric chloride. These dihydropyrimidinones have been subjected to biocatalytic resolution using acetoxyl group on the phenyl ring as remote handle; Novozyme®-435, an immobilized lipase from Candida antarctica in THF:DIPE has been found to catalyze the deacetylation reactions in an enantioselective fashion.