Regioselective synthesis of heterocycles and their biological activity

A simple, efficient solvent free and three-component approach for the synthesis of pyrazole based 1,2,4-triazolo[1,5-a]quinoline derivatives 10(a-l) has been developed by one-pot reaction of 1H-pyrazole-4-carbaldehyde 4(a-d), malononitrile and enaminones 7(a, b) in the presence of pyrrolidine-acetic acid as bifunctional catalyst under solvent free condition. Regioselectivity of reaction performed by different catalyst and higher regioselectivity is achieved by pyrrolidine-acetic acid. This new procedure gives an efficient method to design a fused tricyclic heterocycles containing 1,2,4-triazole analogues. We have using small amount of amphoteric catalyst like ammonium acetate, L-proline and mixture of pyrolidine with acetic acid to obtain 1,4-dihydroquinoline 9j as a byproduct and the salient features of this protocol is higher regioselectivity toward desired products 10(a-l). The structures of the title compounds were confirmed by FT-IR, 1H NMR, 13C NMR and mass spectrometry.

Autorentext

Dr. Haresh B. Patel did his M.Sc.(Analytical Chemistry) and PhD. under the guidance of Dr. Manish Patel Sir from S. P. University Vallabh Vidyanagar Gujarat, India. Now He is working as lecturer at L J Institute Applied Science Ahmadabad.