An Efficacious Protocol for 4-Substituted 3,4-Dihydropyrimidinones: Synthesis and Calcium Channel Binding Studies

Ethyl 1,2-dihydro-1,6-dimethyl/6-methyl-2-oxopyrimidine-5-carboxylates react with C-nucleophiles as well as the anion of the enantiopure chiral auxiliary (1R,2S,5R)-(–)-methyl (S)-p-toluenesulfinate to afford 4-substituted and enantiopure congeners of medicinally potent Biginelli dihydropyrimidinones. The calcium channel blocking activity of some of the compounds was evaluated and compared with nifedipine for their ability to relax a membrane depolarization-induced contraction.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)