Preparation of 3- 2- 4 - ((6-fluoro-1,2-benzisoxazol-3-yl) -l-piperidinyl) -6,7,8,9-tetrahydro-9-hydroxy-2-methyl- 4H-pyrido 1,2 a -primidin-4-one (paliperidone) and paliperidone palmitate

摘要

Process for preparing palmitate ester of 3- (2-chloroethyl) -6,7,8,9-tetrahydro-2-methyl-9-hydroxy-4H-pyrido [1,2-a] pyrimidin-4-one of formula V * * ** Formula comprising the steps of: (i) combining 3- (2-chloroethyl) -6,7,8,9-tetrahydro-2-methyl-9-hydroxy-4H-pyrido [1,2-a] pyrimidin-4-one of formula IV with a fatty acid derivative in the presence of a pyridine derivative, at least one base and at least one organic solvent to obtain a reaction mixture and (ii) adding acid halide to a mixture of reaction obtained in step (i) and maintaining the mixture for a sufficient time to give the compound, palmitate ester of 3- (2-chloroethyl) -6,7,8,9-tetrahydro-2-methyl-9- hydroxy -4H-pyrido [1,2-a] pyrimidin-4-one of formula V: formula ** **