Abstract: IR and NMR spectra of some 2-aryl-thiazolidine-4-carboxyli acids and MS spectra oftwo of them have been recorded. As indicated by IR, the 2-aryl-thiazolidine-4-carboxylicocids in solid state mainly exist in the zwitterion form. These compounds are rather stableand a considerable similarity among them in cleavage were found in MS spectra. The NMRspectra revealed the existence of diasteroisomers for these compounds and the influence ofthe substituents on the electron density of the carbon atoms of the benzere ring is muchgreater than on that of the thiazolidine ring.

Key words: 2-Substituted-thiazolidine-4-carboxylic acid, Infrared spectrum, Nuclear magnetic resonance spectrum, Mass spectrum