Synthesis, Cyclization and Nucleophilic Substitution Reactions of Substituted Pyrazole Carboxylic Acid

Substituted pyrazole carboxylic acid 2a-b derivatives, obtained from 2,3-furandione 1 and benzaldehyde hydrazone 11a-b was converted via reactions of its acid chloride 3a-b. The corresponding ester 6a-b, urea 7a-b, and amide derivatives 4a-b, 8a-b were obtained from the reaction of the acyl chloride of the pyrazole carboxylic acid with various alcohols, urea, and amines. Additionally, the corresponding nitrile derivatives 5 were obtained by extracting water from the amide derivatives (SOCl2 / DMF). Furthermore, cyclization reactions of substituted pyrazole carboxylic acid derivatives using hydrazine were investigated 9 and reaction of 2b decarboxylation product 10.