1. Yüzüncü Y?l University, Art and Science Faculty, Chemistry Department, 65080 VAN‐TURKEY;2. Yüzüncü Y?l University, Faculty of Education, Department of Sciences, 65080 VAN‐TURKEY;3. Celal Bayar University, Faculty of Arts and Sciences, Chemistry Department, Manisa‐TURKEY
Abstract:
1,5‐Diphenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid‐4‐ethyl ester 2 , obtained from the 4‐ethoxycarbonyl‐5‐phenyl‐2,3‐furandione 1 and N‐benzylidene‐N′‐phenyl hydrazine, was converted via reactions of its acid chloride 3 with various alcohols or N‐nucleophiles into the corresponding ester 5 or amide derivatives 6 , respectively. In addition, 2 was decarboxylated to give ethyl 1,5‐diphenylpyrazole‐4‐carboxylate 4 . Nitrile 7 derivative of 2 was also obtained by dehydration of 6a in a mixture of SOCl2 and DMF. While cyclocondensation reaction of 2 with hydrazine hydrate leads to the formation of pyrazolo3,4‐d]pyridazine‐4,7‐dione 8 , the reaction of 3 with anhydrous hydrazine provided a new bis pyrazole derivative 9 .
