Electrochemical oxidation of 3-amino-4,5-dihydro-1-phenylpyrazole

Abstract

The electrochemical oxidation of 3-amino-4,5-dihydro-1-phenylpyrazole in acetonitrile has been examined. One reversible oxidation wave was observed between the potentials –0.6 and 0.9 V versus s.c.e. Controlled potential electrolysis indicated the formation of a persistent red radical-cation which decayed to give mainly the dimeric species 3-amino-4,5-dihydro-1-[4′-(3-amino-4,5-dihydropyrazol-1-yl)biphenyl-4-yl]pyrazole plus a small amount of 3-amino-1-phenylpyrazole. Kinetic studies using visible light spectroscopy and e.s.r. were made in conjunction with the usual electrochemical techniques.