Synthetic methodology of isoxazole derivatives

Abstract

This thesis deals with the study of the synthetic method of isoxazole derivatives. Ethyl 3-aryl-5-methylisoxazole-4-carboxylate was synthesized from benzaldehyde in three steps via benzaldoxime with the yield of 37%. Other methods have also been screened, including the reaction of benzyl bromide and sodium nitrite to generate the reactive intermediate nitrile oxide, which then reacted with ethyl beta-pyrrolidinocrotonate; and the reaction of benzolyl chloride with hydroxylamine hydrochloride to yield benzohydroxamic acid, which then reacted with ethyl acetoacetate. However, the desired product, ethyl 3-aryl-5-methylisoxazole-4-carboxylate, could not be obtained from the latter two methods