Synthesis of Cysteamine Hydrochloride by High Pressure Acidolysis of 2-Mercaptothiazoline

Abstract

The synthesis of cysteamine hydrochloride by high pressure acidolysis of 2-mercaptothiazoline was investigated and the result showed that the high pressure acidolysis can significantly increase the reaction rate as well as the product yield. Characterization by melting point, purity analysis, IR and ¹H NMR proved that the synthesized product is cysteamine hydrochloride with purity as high as 98.9 %. The reaction pressure and molar ratio between the reactants were demonstrated to have significant impacts on the product yield. The optimum conditions for the acidolysis reaction obtained via a group of orthogonal experiments are: reaction pressure, 0.3 MPa; mole ratio between 2-mercap-tothiazoline to HCl (20 wt %), 1:5; reaction time, 7 h. Under the optimum conditions, the yield of cysteamine hydrochloride can reach 95.6 %.