Abstract
Novel pyrazoles and isoxazoles were synthesized from the reaction of the carbanions of 1-aryl-2-(phenyl-sulphonyl)-ethanone with different hydrazonyl halides and 1-aryl-2-bromo-2-hydroximinoethanone in ethanol, respectively. Reactions were carried out under silent and ultrasonic conditions. In general, it was found that ultrasound irradiations enable some reactions to occur which could not be carried out under silent condition in addition to improvement in reaction times. The products were obtained in high yields and their structures were determined by elemental analyses, spectral data and X-ray diffraction. (C) 2008 Elsevier B V All rights reserved.