Synthesis of isoxazolyl oxadiazolines and thiazolidinones

摘要

4-(5-Methyl-3-isoxazolyl)-3,5-diaryl-DELTA~2-1,2,4-oxadiazolines have been prepared by benzonitrile oxide addition to 30-benzalamino-5-methyl isoxazoles. The Schiff bases have been obtained by the condensation of aromatic aldhydes with 3-amino-5-methyl isoxaole. The reaction between these Schiff bases and 2-mercaptopopanoic acid (thiolactic acid) in refluxing benzene, provides a mixture of distereomeric thiazoidinones. Similarly the condensation of 4-benzalamino-3-methyl-5-styrylisoxazoles with 2-mercaptopropanoic acid also led to the formation of a mixture of disasteromeric thiazolidinones. Attempts have been made to separate them by using column chromatography and their ratios determined through ~1 HNR data.