G. Menozzi, P. Schenone, L. Mosti
Jul 1, 1993
Citations
0
Influential Citations
21
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Lithium aluminum hydride reduction of 5-substituted or unsubstituted ethyl or methyl 1-aryl-1H-pyrazole-4-carboxylates gave, generally in excellent yields, 5-substituted or unsubstituted 1-aryl-1H-pyrazole-4-methanols which afforded the corresponding 1-aryl-4-(bromomethyl)-1H-pyrazoles with hydrobromic acid in acetic acid solution. These crude intermediates gave by reaction with potassium cyanide in dimethylsulfoxide solution 1-aryl-1H-pyrazole-4-acetonitriles only in the case of 5-unsubstituted compounds, otherwise mixtures of 5-substituted 1-aryl-1H-pyrazole-4-acetonitriles and 4-methyl-1-phenyl-1H-pyrazole-3-carbonitriles were generally obtained. Acetonitriles IIIa,b,i,l gave in excellent yields the corresponding 1-aryl-1H-pyrazole-4-acetic acids Va,b,i,l by alkaline hydrolysis. Compounds Vb,i,l showed in the writhing test appreciable analgesic properties, associated with low acute toxicity; moreover, compound VI exhibited a statistically significant antiinflammatory activity in the carrageenan-induced edema assay.