risperidone and its Impurities
Risperidone is mainly used for the treatment of schizophrenia, bipolar disorder, and irritability associated with autism. It is available as a generic medication. It is sold under the brand name Risperdal.Reference standards of Risperidone API,and its pharmacopeial, non pharmacopeial impurities, and stable isotopes are listed below.


Risperidone - Impurity I
3-[2-(4-{4-Fluoro-2-[4-(6-fluoro-benzo[d]isoxazol-3-yl)-piperidin-1-yl]-benzoyl}-piperidin-1-yl)-ethyl]-2-methyl-6,7,8,9-tetrahydro-pyrido[1,2-a]pyrimidin-4-one
Catalogue No.:PA 18 13090
CAS :
1329796-66-8
Molecular Formula : C35H39F2N5O3
Molecular Weight : 615.71


Risperidone - Impurity J
3-{2-[4-({4-Fluoro-2-[4-(6-fluoro-benzo[d]isoxazol-3-yl)-piperidin-1-yl]-phenyl}-hydroxyimino-methyl)-piperidin-1-yl]-ethyl}-2-methyl-6,7,8,9-tetrahydro-pyrido[1,2-a]pyrimidin-4-one
Catalogue No.:PA 18 13100
CAS :
1346606-24-3
Molecular Formula : C35H40F2N6O3
Molecular Weight : 630.73


Risperidone Related Compound G (3-{2-[4-(4-Fluoro-2-hydroxybenzoyl)piperidin-1-yl]ethyl}-2-methyl-6 (1604756)
Risperidone Related Compound G (3-{2-[4-(4-Fluoro-2-hydroxybenzoyl)piperidin-1-yl]ethyl}-2-methyl-6 (1604756)
Catalogue No.:PA USP1604756
CAS :
152542-00-2
Molecular Formula : NA
Molecular Weight : NA

![3-(2-(4-(6-(2-(6-Fluorobenzo[d]isoxazol-3-yl)piper PA 18 0131010](https://www.pharmaffiliates.com/pimages/PA180131010.jpg)
3-(2-(4-(6-(2-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)benzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one
3-(2-(4-(6-(2-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)benzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one
Catalogue No.:PA 18 0131010
CAS :
NA
Molecular Formula : C35H39FN6O3
Molecular Weight : 610.73


3-(2-(4-(4-Fluoro-2-hydroxybenzoyl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one Hydrochloride
3-(2-(4-(4-Fluoro-2-hydroxybenzoyl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one Hydrochloride
Catalogue No.:PA 18 0131013
CAS :
2469195-84-2
Molecular Formula : C23H29ClFN3O3
Molecular Weight : 449.95

![4-(6-Fluorobenzo[d]isoxazol-3-yl)-1,1-bis(2-(2-met PA 18 0131017](https://www.pharmaffiliates.com/pimages/PA180131017.jpg)
4-(6-Fluorobenzo[d]isoxazol-3-yl)-1,1-bis(2-(2-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-3-yl)ethyl)piperidin-1-ium Chloride
4-(6-Fluorobenzo[d]isoxazol-3-yl)-1,1-bis(2-(2-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-3-yl)ethyl)piperidin-1-ium Chloride
Catalogue No.:PA 18 0131017
CAS :
NA
Molecular Formula : C34H42ClFN6O3
Molecular Weight : 637.2

![(E)-3-(2-(4-((4-Fluoro-2-(4-(6-fluorobenzo[d]isoxa PA 18 0131023](https://www.pharmaffiliates.com/pimages/PA180131023.jpg)
(E)-3-(2-(4-((4-Fluoro-2-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)phenyl)(hydroxyimino)methyl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one
(E)-3-(2-(4-((4-Fluoro-2-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)phenyl)(hydroxyimino)methyl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one
Catalogue No.:PA 18 0131023
CAS :
NA
Molecular Formula : C35H40F2N6O3
Molecular Weight : 630.74


6-Fluoro-3-[1-bis-[2-(methyl-6,7,8,9-tetrahydropyridol[1,2,a]pyrimidin-4-one-3-yl)ethyl]piperidinium]benzisoxazole Iodide
6-Fluoro-3-[1-bis-[2-(methyl-6,7,8,9-tetrahydropyridol[1,2,a]pyrimidin-4-one-3-yl)ethyl]piperidinium]benzisoxazole Iodide
Catalogue No.:PA 18 0131025
CAS :
NA
Molecular Formula : C34H42FIN6O3
Molecular Weight : 728.65