Reactions of 1,3-Diphenyl-2-pyrazolin-5-one and 4-Amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one. Synthesis of Some New Pyrazoles and Pyrazolones

Abstract

1,3-Diphenyl-2-pyrazolin-5-one 1 was converted to 5-azido-4-formylpyrazolone 3 which is used as the key starting compounds of some new pyrazole derivatives 4-9. Also, 4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one 10 is coupled with some diazonium salts to give coloured products 11, and reacted with isocyanates and isothiocyanates to give pyrazolylurea and thiourea derivatives which are then reacted with organohalogen compounds under PTC conditions to give 13,14 while with some active methylene compounds yielded 15 via Michael 1,4-addition reaction.