Regioselective One-pot transformation of 2'-hydroxy chalcones to 3,5-diphenylisoxazole via dehydrogenation of dihydroisoxazolines using Copper salt in DMF

A synthesis of series of 3, 5-diaryl isoxazoles has been described. The Cu salt in DMF with EDU base induces oxidative dehydrogenation of 2-(5-phenyl-4,5-dihydroisoxazol-3-yl) phenol results in the formation of 2-(5-phenylisoxazol-3-yl) phenol in excellent yields under mild reaction conditions. The present protocol contains cheap catalyst, easy workup, normal reaction conditions and high selectivity.