AN INFRARED SPECTROSCOPIC STUDY OF SOME SUBSTITUTED 1,3-THIAZOLIDIN-4-ONES

The infra-red spectra of a series of 2,3-diaryl-1,3-thiazolidin-4-ones were measured and the majority of the absorption bands assigned. The value of the carbonyl stretching frequency was related to the availabi lity of the lone pair on the nitrogen atom of the thiazolidinone ring. The effects of S-oxidation of these compounds on their spectra were e xamined. The spectra of 3-benzyl-2-phenyl-1,3-thiazolidin-4-one, 3-but yl-2-phenyl-1,3-thiazolidin-4-one, 5-methyl-2,3-diphenyl-1,3-thiazolid in-4-one and 3-phenyl-2-thioxo-1,3-thiazolidin-4-one were also investi gated.