Synthesis and biological evaluation of some new aryl pyrazol-3-one derivatives as potential hypoglycemic agents

Abstract

Several new aryl substituted pyrazol-3-one 3 derivatives were prepared by the reaction of substituted phenyl hydrazine 1 with diethylethoxymethylene malonate (DEEM) 2. The compounds were synthesized by Michael addition reaction, which is a nucleophilic addition of enolate anions to the carbon-carbon double bond of α,β-unsaturated carboxylic acid derivatives. All the compounds were characterized by UV, IR and NMR spectroscopy and tested for hypoglycemic activity on alloxan induced diabetic rats. Among the tested compounds ethyl-2-para nitrophenyl-2,3-dihydro-1H-pyrazol-3-one-4-carboxylate 3c and ethyl-2-meta nitrophenyl-2,3-dihydro-1H-pyrazol-3-one-4-carboxylate 3d are identified as potent hypoglycemic agents and their activities are comparable with the standard drug metformin.