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
2-aminobenzothiazole, 1, 4-dihydropyridines, chromenoindenopyridines, chromenoquinolines, indenoquinolines,
Knoevenagel condensation, medicinally privileged heterocycles, Michael addition, multicomponent reaction, organocatalysis,
Department of Chemistry, University of Rajasthan, Jaipur, 302004, India.