LaCl3.7H20: An efficient catalyst for one-pot multi-component Synthesis of 1,4-polyhydroquinoline derivatives through unsymmetrical Hantzsch Reaction

An efficient one-pot multi component synthesis of 1, 4-Polyhydroquinoline derivatives through unsymmetrical Hantzsch reaction using lanthanum chloride heptahydrate (LaCl3.7H2O) from an aromatic aldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a nitrogen precursor in ethanol at room temperature is described. In the present work, we report lanthanum chloride heptahydrate remarkably non-toxic in nature and ease of handling, we explored the utility of lanthanum chloride heptahydrate as a catalyst for the synthesis of 1, 4-polyhydroquinoline derivatives. We newly report p-N, N-dimethylamino-cinnamaldehyde and m-chlorobenzaldehyde for the synthesis of 1, 4-Polyhydroquinoline derivatives through unsymmetrical Hantzsch reaction and the products were characterized by IR and ^1HNMR spectroscopic methods.