A simple and efficient approach for synthesis of 1,4-dihydro-pyridines using nano-crystalline solid acid catalyst
A simple highly versatile and efficient synthesis of various 1,4-dihydropyridines in the condensation of aromatic aldehydes with β-dicarbonyl compounds and ammonium acetate in the presence of nano-sulfated zirconia, nano-structured ZnO, nano-γ-alumina and nano-ZSM-5 zeolites, as catalyst in the ethanol at moderate temperature is presented. The advantages of method are short reaction times and milder conditions and easy work-up. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of efficiency.
KEY WORDS: Nano-sulfated zirconia, Nano-sized ZnO, Nano-γ-alumina, Nano-ZSM-5 zeolites, Green synthesis, 1,4-Dihydropyridines
Bull. Chem. Soc. Ethiop. 2013, 27(3), 427-437.