Efficient green synthesis of N'-benzylidene-2-(2-fluorobiphenyl) propanehydrazides: Crystal structure and anti-oxidant potential

Abstract

For the synthesis of N'-benzylidene-2-(2-fluorobiphenyl)propanehydrazides, 2-(2-fluorobiphenyl-4-yl)propanoic acid was esterified to methyl 2-(2-fluorobiphenyl-4-yl)propanoate under microwave irradiation followed by hydrazinolysis. This hydrazide was then reacted in an ultrasonic bath with different benzaldehydes to afford a series of N'-benzylidene-2-(2-fluorobiphenyl)propanehydrazides. Comparison of both the conventional and ultrasound assisted reactions indicates a significant reduction in reaction times and improvement in yields. Besides chemical characterisation and X-ray crystallography, all the synthesised compounds were evaluated for their anti-oxidant potential (total anti-oxidant activity, ferric reducing antioxidant power and total phenolic content) and most of them were found to have useful potential for pharmaceutical applications especially derivative bearing 2-hydroxy substituents.