A PROCESS FOR THE PREPARATION OF RISPERIDONE

摘要

The present invention relates to an improved process for the preparation of Risperidone of formula (I) by condensing 6-fluoro-3- (4-piperidinyl)-l, 2- benzisoxazole with 3-(2-chloroethyl)-6, 7, 8, 9-tetrahydro-2-methyl-4H-pyrido [1,2-a] pyrimidin-4-one in water and water immiscible solvents under basic conditions in the presence of a catalyst. This invention also relates to a method for purification of crude Risperidone by removing an impurity specifically named as 9-hydroxy Risperidone to undetectable level using acid chlorides and an organic base in a suitable solvent.