Synthesis of isomeric 3-phenyl-5-(pyridyImethylene)-2-thiohydantoins and their S-methylated derivatives.Molecular and crystal structures of (5Z)-3-phenyl-5-(pyridin-2-ylmethylene)-2-thiohydantoin and (5Z)-2-methyIthio-3-phenyl-5-(pyridin-2-ylmethylen

摘要

Three procedures were used for the synthesis of alpha-,beta-,and gamma-pyridyl-substituted (5Z)-3-phenyl-5-(pyridylmethylene)-2-thiohydantoins:the reaction of 2-thiohydantoin with the corresponding aldehyde in AcOH in the presence of AcONa,the two-step one-pot synthesis with the use of the same starting compounds,and three-component condensation of aryl isothiocyanate,glycine,and aldehyde in AcOH.Alkylation of the resulting thiohydantoins with iodomethane in the presence of a base afforded the corresponding S-methylated derivatives,viz.,2-methylthio-3-phenyl-5-(pyridylmethylene)-3,5-dihydro-4H-imidazol-4-ones.The structures of (5Z)3-phenyl-5-(pyridin-2-ylmethylene)-2-thioxoimidazolin-4-one and (5Z)-2-methylthio-3-phenyl-5-(pyridin-2-ylmethylene)-3,5-dihydro-4H-imidazol-4-one were established by X-ray diffraction analysis.