A PROCESS FOR PREPARING ERDOSTEINE

摘要

A process for preparing erdosteine is provided, which reduces the preparation costs by inhibiting formation of by-products by performing the total process in two-phase solution comprising basic solution and organic solvents, and improves purity and yield by minimizing decomposition of a lactone ring. The process for preparing erdosteine represented by formula (I) comprises the steps of: reacting D,L-homocysteine thiolactone hydrochloric acid salt of formula (II) with chloroacetyl chloride of formula (III) to prepare 3-chloroacetamido-2-oxo-tetrahydrothiopen of formula (IV); and reacting the compound of formula (IV) with thioglyconic acid of formula (V), wherein the total process is performed in two-phase solution comprising basic solution and organic solvents at -10 to 20 deg. C for 2 to 3 hours; the base in the basic solution is one or more selected from sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate; and the organic solvent is one or more selected from acetone, ethylacetate, methylene chloride and chloroform.