Sarita Khandelwal, Anshu Rajawat and Mahendra Kumar Pages 51 - 58 ( 8 )
Structurally diverse unsymmetrically annulated 1,4-dihydropyridines have been synthesized by L-proline catalyzed four-component domino protocol involving the reaction of 2-aminobenzothiazole, thiophene-2-carbaldehyde and carbonyl compounds in ethanol. The utilization of L-proline in the multicomponent reaction will make the present protocol attractive for synthesis of 1,4-dihydropyridines in terms of reaction efficiency, atom-economy and environmental safety.
2-aminobenzothiazole, 1, 4-dihydropyridines, chromenoindenopyridines, chromenoquinolines, indenoquinolines, Knoevenagel condensation, medicinally privileged heterocycles, Michael addition, multicomponent reaction, organocatalysis, L-proline, pyranoquinolines.
Department of Chemistry, University of Rajasthan, Jaipur, 302004, India.