Synonyms: Risperidone cis-N-Oxide, 3-[2-[cis-4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-oxido-1-piperidinyl]ethyl]-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one (ACI), 4H-Pyrido[1,2-a]pyrimidin-4-one, 3-[2-[cis-4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-oxido-1-piperidinyl]ethyl]-6,7,8,9-tetrahydro-2-methyl- (ACI)