Synthesis of carboxylic acid derivatives of 2-pyrazolines

2-Pyrazolines 7- 12 bearing a carboxylic acid ester or a carboxamide side- chain have been prepared by treatment of the appropriate chalcone derivatives 2- 6 with hydrazine hydrate or phenylhydrazine in hot acetic acid. 1-( 2- Carboxyphenyl)- 2- pyrazolines 24- 30 and 1-( 4-carboxyphenyl)- 2- pyrazolines 31- 41 were synthesized by the reaction of chalcones with ( 2-carboxyphenyl) hydrazine and ( 4- carboxyphenyl) hydrazine in hot acetic acid. Structures of all new compounds have been elucidated by microanalyses, H-1-, C-13- NMR and IR spectroscopic measurements.