3-[2-[4-(2-Fluoro-4-hydroxybenzoyl)piperidin-1-yl]ethyl]-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one ;

3-(2-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one ; CAS # 108855-18-1 ;

3-(2-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-7-hydroxy-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one ; CAS # 147663-04-5 ;

(E)-2-(3-(2-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-4-oxo-7,8-dihydro-4H-pyrido[1,2-a]pyrimidin-9(6H)-ylidene)acetic acid ;

3-(2-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2,9-dimethyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one ; CAS # 138271-01-9 ;

Paliperidone 9-Oxo Impurity ; 3-[2-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]ethyl]-7,8-dihydro-2-methyl-4H-pyrido[1,2-a]pyrimidine-4,9(6H)-dione ; CAS # 1189516-65-1 ;

CAS # 106266-06-2 ;

(Z)-2-(3-(2-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-4-oxo-7,8-dihydro-4H-pyrido[1,2-a]pyrimidin-9(6H)-ylidene)acetic acid ;

(Z)-2-(3-(2-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-4-oxo-7,8-dihydro-4H-pyrido[1,2-a]pyrimidin-9(6H)-ylidene)acetic acid ;

4-[4-Fluoro-2-[4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidin-1-yl] benzoyl]-N-acetylpiperidine ;

(1s,4r)-3-(4-Fluoro-2-hydroxyphenyl)-1-(2-(2-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-3-yl)ethyl)-1,2-diazabicyclo[2.2.2]oct-2-en-1-ium Iodide ;

3-[2-[4-(2-Hydroxybenzoyl)piperidin-1-yl]ethyl]-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one ;

4-(2,4-Difluorobenzoyl)-N-acetylpiperidine ; CAS # 84162-82-3 ;

4-(2,4-Difluorobenzoyl)-piperidine HCl ; CAS # 106266-04-0 (HCl) ; 84162-86-7 (Base) ;

Risperidone BP Impurity A ; Risperidone E-Oxime ; CAS # 691007-09-7 ;

Risperidone BP Impurity B ; Risperidone Z-Oxime ; CAS # 132961-05-8 ;

Risperidone BP Impurity C ; 9-Hydroxy Risperidone ; Paliperidone ; CAS # 144598-75-4 ;

Risperidone BP Impurity D ; Risperidone 5-Fluoro Isomer ; CAS # 1199589-74-6 ;

Risperidone BP Impurity E ; 6-Methyl Risperidone ; 2,6-Dimethyl Risperidone ; CAS # 1346602-28-5 ;

Risperidone BP Impurity F ; Risperidone Carboxylate Impurity ; CAS # 1346603-86-8 ;

Risperidone BP Impurity H ; 3-[2-[4-(2,4-Difluorobenzoyl)piperidin-1-yl]ethyl]-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one ; CAS # 158697-67-7 ;

Risperidone BP Impurity I ; 3-[2-[4-[4-Fluoro-2-[4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidin-1-yl]benzoyl]piperidin-1-yl]ethyl]-2-methyl-6,7,8,9-tetrahydro-4H- pyrido[1,2-a]pyrimidin-4-one ; CAS # 1329796-66-8 ;

Risperidone BP Impurity J ; 3-[2-[4-[(Z)-(4-Fluoro-2-[4-(6-fluoro-1,2-benzisoxazol-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 ; CAS # 1346606-24-3 ;

Risperidone BP Impurity K ; Desfluoro Risperidone ; CAS # 106266-09-5 ;

Risperidone Chloroethyl Impurity ; CAS # 63234-80-0 ;

3-(2-Chloroethyl)-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one hydrochloride ; CAS # 93076-03-0 ;

Risperidone Amine Impurity (HCl Salt) ; Paliperidone USP RC B ; CAS # 84163-13-3 (HCl salt) ; 84163-77-9 (base);

3-Ethyl-2-methyl-6,7,8,9-tetrahydro-4H-pyrido-(1,2-a)-pyrimidin-4-one ; CAS # 70381-58-7 ;

3-(2-Hydroxyethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido-(1,2-a)-pyrimidin-4-one ; CAS # 66698-27-9 ;

3-(2-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2,7-dimethyl-4H-pyrido[1,2-a]pyrimidin-4-one ; CAS # 106266-08-4 ;

3-[2-[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 ; CAS # 832747-55-4 ;

4-[4-Fluoro-2-[4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidin-1-yl] benzoyl]-piperidine ;

(Z)-(2,6-Difluorophenyl)(piperidin-4-yl)methanone oxime ; CAS # 691007-05-3 ;

6-Desfluoro 6-Hydroxy Risperidone ; 3-(2-(4-(6-Hydroxybenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one ; CAS # 106266-11-9 ;

6-Desfluoro 6-Methoxy Risperidone ; 6,7,8,9-Tetrahydro-3-[2-[4-(6-methoxy-1,2-benzisoxazol-3-yl)-1-piperidinyl]ethyl]-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one ; CAS # 1246817-15-1 ;

(E)-(2,4-Difluorophenyl)(piperidin-4-yl)methanone oxime ; CAS # 691007-07-5 ;

Ethyl 4-(chlorocarbonyl)piperidine-1-carboxylate ; CAS # 146801-00-5 ;

3-Ethyl-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one ; CAS # 16867-31-5 ;

3-(2-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-7-methoxy-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one ; CAS # 130049-83-1 ;

3-(2-(4-(6-Fluorobenzo[d]oxazol-2-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one ; CAS # 1005191-81-0 ;

1-(4-(5-Fluoro-2-hydroxybenzoyl)piperidin-1-yl)ethanone ; CAS # 84162-84-5 ;

(E)-3-(2-(4-((4-Fluoro-2-hydroxyphenyl)(hydroxyimino)methyl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one ; CAS # 1391062-47-7 ;

5-Fluoro-3-(piperidin-4-yl)benzo[d]isoxazole ; CAS # 84163-64-4 ;

5-Fluoro-3-(piperidin-4-yl)benzo[d]isoxazole hydrochloride ; CAS # 84163-16-6 ;

1-(4-(4-Fluorobenzoyl)piperidin-1-yl)ethanone ; CAS # 25519-77-1 ;

Benzyl 4-(6-methoxybenzo[d]isoxazol-3-yl)piperidine-1-carboxylate ; CAS # 84163-07-5 ;

(E)-Benzyl 4-((2-hydroxy-4-methoxyphenyl)(hydroxyimino)methyl)piperidine-1-carboxylate ; CAS # 84163-47-3 ;

(Z)-Benzyl 4-((2-hydroxy-4-methoxyphenyl)(hydroxyimino)methyl)piperidine-1-carboxylate ; CAS # 84163-00-8 ;

(E)-2-(5-Methoxy)phenol 4-(N-benzyloxycarbonyl)piperidinyl-methanone O-acetyl oxime ; CAS # 84163-48-4 ;

(2-Hydroxy-4-methoxyphenyl)(piperidin-4-yl)methanone ; CAS # 64671-19-8 ;

(2-Hydroxy-4-methoxyphenyl)(piperidin-4-yl)methanone hydrochloride ; CAS # 84162-88-9 ;

Methyl 1-nitrosopiperidine-4-carboxylate ; CAS # 13458-55-4 ;

1-(Ethoxycarbonyl)piperidine-4-carboxylic acid ; CAS # 118133-15-6 ;

4-(6-Fluorobenzo[d]isoxazol-3-yl)-1-(2-(2-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-3-yl)ethyl)piperidine 1-oxide ; CAS # 1894509-66-0 ;

3-(2-Iodoethyl)-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one ; CAS # 885706-66-1 ;

2-Methyl-3-vinyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one ; CAS # 832747-59-8 ;

3-[2-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]ethyl]-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one N-oxide ; CAS # 1301724-91-3 ;

3-[2-[4-(6-Fluoro-1,2-benzisoxazol-3-yl-2-oxido)-1-piperidinyl]ethyl]-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one ; CAS # 1391053-34-1 ;

(E)-1-Acetyl-N-(acetyloxy)-α-(5-fluoro-2-hydroxyphenyl)-4-piperidinemethanimine ; CAS # 84163-52-0 ;

(E)-1-(4-((5-Fluoro-2-hydroxyphenyl)(hydroxyimino)methyl)piperidin-1-yl)ethanone ; CAS # 84162-97-0 ;

1-(4-(2-Hydroxy-4-methoxybenzoyl)piperidin-1-yl)ethanone ; CAS # 64671-18-7 ;

3-(2-Chloroethyl)-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one ; CAS # 41078-70-0 ;

3-(2-Chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one N-oxide ; CAS # 1797131-18-0 ;

Risperidone 2-Hydroxybenzoyl Impurity ; 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 ; CAS # 152542-00-2 (free base) ;