INTERMEDIATE FOR PREPARING LEVOSULPIRIDE AND PREPARATION METHOD THEREOF

摘要

PURPOSE: Provided are an intermediate for preparing levosulpiride and a preparation method thereof, thereby preparing levosulpiride in higher yield and purity. CONSTITUTION: An intermediate represented by the formula (IV) for preparing levosulpiride of the formula (I) is provided, wherein R1 and R2 are independently hydrogen, C1-C4 lower alkyl or phenyl; R3 is phenyl derivative of the formula (VIII) or naphthyl derivative of the formula (IX); and X is hydrogen or halogen, provided that the formula (IV) may be racemic body, (S) body and (R) body because it contains chiral carbon(*). A method for preparing an intermediate of the formula (IV) for preparing levosulpiride comprises reducing a compound of the formula (III) with a reducing agent, wherein R1 and R2 are independently hydrogen, C1-C4 lower alkyl or phenyl; R3 is phenyl derivative of the formula (VIII) or naphthyl derivative of the formula (IX); and X is hydrogen or halogen.