The 1H–pyrazole-3-carboxylic acid 2 and its remarkably stable acid chlorides 3 can easily be converted into the
corresponding carbohydrazide, ester or amide derivatives 4, 6 and 7, respectively, from reaction with alcohols or Nnucleophiles.
The acid chloride (3) was also converted easily into the new derivatives consisting of 5-phenyl-1H-pyrazole
8a,b. The cyclocondensation reactions of 2 with some hydrazines led to the formation of pyrazolo[3,4-d ]pyradizinone 5
derivative. The nitrile derivative 9 was obtained by dehydration of 7a,b in a mixture of SOCl2 and DMF. The thermal decomposition
of 4-Benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid 2b leads to the formation of [1-(4-
nitrophenyl)-5-phenyl-1H-pyrazole-4-yl] phenylmethanone 10) It has been demonstrated that with the variation in reaction
conditions, the reaction changes and leads to different products. The structures of these newly synthesized compounds
were determined from the FT-IR, 1H and 13C NMR spectroscopic data and elemental analyses.
Keywords: 2, 3-Furandione, Pyrazole-3-carboxylic acid, Cyclic oxalyl compounds, Pyrazole-3-carboxylic acid chloride, Pyrazolo[
Rights & PermissionsPrintExport