Abstract:The process of preparing 3-methylthiazolidine-thione-2 by N-methyl-monoethanolamine and carbon disulfide was subjected to research. The optimum conditions were found out by orthogonal experiment. Qualitative analysis and quantitative analysis of the thus synthesized product were carried out by use of the melting-point instrument, infrared spectrometer and high-performance liquid chromatography. The results showed that the optimum conditions for preparing 3-Methylthiazolidine-thione-2 were as follows: the drop-wise adding temperature was at 75 ℃, the reaction temperature at 125℃, the reaction time 2.5 h, the molar ratio of N-methyl-monoethanolamine and Carbon disulfide 1∶2.4. Under the optimum conditions, the yield rate of 3-Methylthiazolidine-thione-2 was 87.4%, the infrared spectrogram of the product conformed to the standard sample, with the purity quotient reaching up to 98.67%.