A Simple and Efficient Synthesis of Some Important Pyrazole Derivatives

The 1H-pyrazole-3-carboxylic acid was converted via reactions of its acid chloride 1a,b with amino acid, thiol and various amine derivatives into the corresponding amino acid ester derivatives 2a-d, 4-aroyl-1,5-diaryl-1H-pyrazol-3-carbotioates 3a-d, and pyrazole-3-carboxamides 6, 7 respectively, in good yields (35-85%). The structures of all new synthesized compounds were established by the 13C NMR, IR 1H NMR, IR spectroscopic data and elemental analysis. (author)