Patent ID: 7915412

Claim:
A process for preparing paliperidone comprising a) combining 3-(2-chloroethyl)-6,7,8,9-tetrahydro-9-hydroxy-2-methyl-4H-pyrido[1,2-a]-pyrimidin-4-one (CMHTP) or salt thereof, 6-fluoro-3-(4-piperidinyl)-1,2-benisoxazole (FBIP) or salt thereof, an inorganic base, and a first solvent to obtain a suspension; b) heating the suspension to obtain a reaction mixture; c) cooling the reaction mixture; d) filtering the cooled reaction mixture of step c) to obtain a solid; e) adding a second solvent to the solid of step d) to obtain a slurry; and f) filtering the slurry to obtain paliperidone.