The synthesis and reactions of novel pyrazole derivatives by 4-phenylcarbonyl-5-phenyl-2,3-dihydro-2,3-furandione reacted with some hydrazones

We report some novel pyrazole derivatives taking 4-phenylcarbonyl-5-phenyl-2,3-dihydro-2,3-furandione, 1. For this, 4-phenylcarbonyl-5-phenyl-2,3-dihydro-2,3-furandione, 1 was reacted with benzaldehyde(2-or 4-fluorophenyl)hydrazone to give 4-benzoyl-1-(2-or 4-fluorophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid 2a,b. Pyrazol derivative containing 2-fluorophenyl group 2a was converted into carboxylic chloride derivative 3a by thionyl chloride and then the compound 4a was obtained from reaction ammonia with compound 3a. In the next step, 4-benzoyl-1-(2-fluorophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid 2a was reacted with MeOH/H2SO4, EtOH/H2SO4, 2-nitrophenylhydrazine and 3-nitrophenylydrazine to give 5a,b and 6a,b pyrazol derivatives, respectively. The structures regarding all compounds synthesized were determined by the IR, NMR and elemental analysis method.