A Clean, Benign, Energy Efficient One-Pot Multicomponent Synthesis and Bio-evaluation of Novel [1,2,4]Triazolo[1,5-a]quinolines

Abstract

In present work, a series of novel [1,2,4]triazolo[1,5-a]quinoline derivatives (HP-101-110) have been synthesized using multi-component reaction at room temperature in the presence of ammonium chloride as mild, cost effective green catalyst along with water as eco-friendly green solvent. The synthesis of 1,2,4-triazolo[1,5-a]quinolines (HP-101-110) was achieved by two step process. In first step, diversified Hantzsch pyridine reaction of an appropriate aromatic aldehyde, malononitrile, dimedone and benz hydrazide using ethanol as a solvent gives N-(2-amino-3-cyano-7,7-dimethyl-5-oxo-4-phenyl-5,6,7,8- tetrahydro-quinolin-1(4H)-yl)-4-hydroxybenzamide derivatives. In the second step, synthesis of the final product 2-(4-hydroxyphenyl)-8,8-dimethyl-6-oxo-5-phenyl-6,7,8,9-tetrahydro[1,2,4]triazolo[1,5- a]-quinoline-4-carbonitriles was achieved by the intramolecular cyclization of step 1 product.The structure of all the synthesized compounds (HP101-110) has been elucidated by FT-IR, 1H & 13C NMR, mass spectral data and elemental analyses.