WANG Wuwei, CHEN Jie, HE Jia
In the quality study of paliperidone, five related substances were prepared and their structures were confirmed by MS, 1H NMR, and 13C NMR. These substances were paliperidone N-oxide(D), 3-[2-[4-(6- fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl]ethyl]-2-methyl-7,8-dihydro-4H-pyrido[1,2-a]pyrimidin-4,9(6H)-
dione(E), 3-(2-hydroxyethyl)-9-hydroxy-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one(F), 3-[2-[4-[(2,4-difluorophenyl)(hydroxyimino)methyl]piperidin-1-yl]ethyl]-9-hydroxy-2-methyl-6,7,8,9-tetrahydro- 4H-pyrido[1,2-a]pyrimidin-4-one(G), and 3-[2-[4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl]ethyl]-9-hydroxy-2- methyl-4H-pyrido[1,2-a]pyrimidin-4-one(H).