STRUCTURE OF 3-(2-[4-(6-FLUORO-1,2-BENZISOXAZOL-3-YL)PIPERIDINO]ETHYL)-6,7,8,9-TETRAHYDRO-2-METHYL-4H-PYRIDO-[1,2-A]PYRIMIDIN-4-ONE (RISPERIDONE)

The benzisoxazole and pyrimidine moieties are essentially planar and the dihedral angle between these planes is 5.6 (1)-degrees. The piperidine ring is in a slightly distorted chair conformation, while the tetrahydropyridine moiety shows a half-chair conformation. The crystal stucture is stabilized by a hydrogen bond between the H atom on position 4 of the benzisoxazole and the O atom of the pyrimidinone of a translated (x, y-1, z) molecule [C...O = 3.372 (7), H...O = 2.327 angstrom, C-H...O = 161.6-degrees].