63234-80-0

Basic information

• Product Name: 3-(2-Chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one
• Synonyms: 3-(2-CHLOROETHYL)-2-METHYL-6,7,8,9-TETRAHYDRO-4H-PYRIDO[1,2-A]PYRIMIDIN-4-ONE;3-(2-CHLORO-ETHYL)-2-METHYL-6,7,8,9-TETRAHYDRO-PYRIDO[1,2-A]PYRIMIDIN-4-ONE;3-(2-CHLOROETHYL)-6,7,8,9-TETRAHYDRO-2-METHYL-4H-PYRIDINO[1,2-A]PYRIMIDINE-4-ONE;3-(2-CHLOROETHYL)-6,7,8,9-TETRAHYDRO-2-METHYL-4H-PYRIDO(1,2A)PYRIMIDINE-4-ONE;3-(2-CHLOROETHYL)-6,7,8,9-TETRAHYDRO-2-METHYL-4H-PYRLDO[1,2-A]PYRIMDIN-4-ONE;3-2(2-chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-alpha]pyrimnidin-4-one;3-(2-Chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]-pyrididine-4-one (intermediate of Risperidone);3-2(2-CHLOROETHYL)-6,7,8,9-TETRAHYDRO-2-METHYL-4H-PYRIDO[1,2-A]PYRIMDIN-4-ONE
• CAS NO: 63234-80-0
• Molecular Formula: C₁₁H₁₅ClN₂O
• Molecular Weight: 226.7
• EINECS: 1592732-453-0
• Product Categories: (intermediate of Risperidone);Nucleotides and Nucleosides;Bases & Related Reagents;Intermediates & Fine Chemicals;Nucleotides;Pharmaceuticals;Intermediates
• Mol File: 63234-80-0.mol
• Article Data: 7

Chemical Properties

• Melting Point: 68.5-69.5 °C
• Boiling Point: 337 °C
• Flash Point: 157 °C
• Appearance: White solid
• Density: 1.30
• Vapor Pressure: 0.000111mmHg at 25°C
• Refractive Index: 1.611
• Storage Temp.: -20°C Freezer
• Solubility: Chloroform (Slightly), Methanol (Slightly)
• PKA: 3.58±0.70(Predicted)
• CAS DataBase Reference: 3-(2-Chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one(CAS DataBase Reference)
• NIST Chemistry Reference: 3-(2-Chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one(63234-80-0)
• EPA Substance Registry System: 3-(2-Chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one(63234-80-0)

Safety Data

• Hazard Codes: T
• Statements: 25
• Safety Statements: 45
• HazardClass: IRRITANT
• Hazardous Substances Data: 63234-80-0(Hazardous Substances Data)

Usage

Chemical Properties

White Solid

Uses

3-(2-Chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (Risperidone EP Impurity L) is an intermediate in the synthesis of Risperidone (R525000), which is a combined serotonin (5-HT2) and dopamine (D2) receptor antagonist.

InChI:InChI=1/C11H15ClN2O/c1-8-9(5-6-12)11(15)14-7-3-2-4-10(14)13-8/h2-7H2,1H3

Synthetic route

3-(2-chloro-ethyl)-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one (41078-70-0) → 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0)

Conditions	Yield
With hydrogenchloride; hydrogen; palladium In water at 20℃; under 1810.07 Torr; for 8h;	90%
With hydrogenchloride; palladium on activated charcoal; hydrogen In water at 30 - 40℃; under 1500.15 Torr; Temperature; Reagent/catalyst;	90%
With palladium on activated charcoal; hydrogen In ethanol under 760.051 Torr; for 20h;	47%
With palladium 10% on activated carbon; hydrogen In methanol	4.6 g
With palladium 10% on activated carbon; hydrogen In methanol

3-(2-chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one monohydrochloride → 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0)

Conditions	Yield
With sodium carbonate; potassium iodide In water; 4-methyl-2-pentanone Product distribution / selectivity;

2-aminopyridine (504-29-0) → 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0)

Conditions	Yield
Multi-step reaction with 3 steps 1: toluene-4-sulfonic acid / toluene / Reflux 2: trichlorophosphate / 1 h / Reflux 3: palladium 10% on activated carbon; hydrogen / methanol View Scheme
Multi-step reaction with 3 steps 1: toluene-4-sulfonic acid / toluene / 12 h / Reflux; Dean-Stark 2: trichlorophosphate / 1 h / Reflux 3: hydrogen; palladium 10% on activated carbon / methanol View Scheme
Multi-step reaction with 2 steps 1: trichlorophosphate / toluene / 6 h / Reflux 2: palladium on activated charcoal; hydrogen / ethanol / 20 h / 760.05 Torr View Scheme

3-acetyl-2-oxo-4,5-dihydrofuran (517-23-7) → 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0)

Conditions	Yield
Multi-step reaction with 3 steps 1: toluene-4-sulfonic acid / toluene / Reflux 2: trichlorophosphate / 1 h / Reflux 3: palladium 10% on activated carbon; hydrogen / methanol View Scheme
Multi-step reaction with 3 steps 1: toluene-4-sulfonic acid / toluene / 12 h / Reflux; Dean-Stark 2: trichlorophosphate / 1 h / Reflux 3: hydrogen; palladium 10% on activated carbon / methanol View Scheme
Multi-step reaction with 2 steps 1: trichlorophosphate / toluene / 6 h / Reflux 2: palladium on activated charcoal; hydrogen / ethanol / 20 h / 760.05 Torr View Scheme

3-(1-(pyridin-2-ylamino)ethylidene)dihydrofuran-2-(3H)-one (380634-63-9) → 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0)

Conditions	Yield
Multi-step reaction with 2 steps 1: trichlorophosphate / 1 h / Reflux 2: palladium 10% on activated carbon; hydrogen / methanol View Scheme
Multi-step reaction with 2 steps 1: trichlorophosphate / 1 h / Reflux 2: hydrogen; palladium 10% on activated carbon / methanol View Scheme

C11H11ClN2O*ClH → 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0)

Conditions	Yield
With palladium 10% on activated carbon; hydrogen In methanol; dichloromethane

sodium cyanide (773837-37-9) + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → C12H15N3O

Conditions	Yield
at 20℃; for 5h;	100%

(4-bromo-1-methyl-1H-pyrazol-3-yl)piperazin-1-ylmethanone hydrochloride + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → 3-{2-[4-(4-bromo-1-methyl-1H-pyrazole-3-carbonyl)piperazin-1-yl]ethyl}-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (1235992-87-6)

Conditions	Yield
With potassium carbonate In acetonitrile at 150℃; for 0.333333h; Microwave irradiation;	99%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazole hydrochloride (84163-13-3) → Risperidone (106266-06-2)

Conditions	Yield
With sodium carbonate In water at 110 - 120℃; for 0.666667h; Product distribution / selectivity;	93.2%
With sodium carbonate; potassium iodide In N,N-dimethyl-formamide at 80℃; for 10h; Temperature;	76.9%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 6-fluoro-3-(4-piperidinyl)benzo[d]isoxazole (84163-77-9) → Risperidone (106266-06-2)

Conditions	Yield
With sodium carbonate In methanol at 73 - 75℃; for 4 - 4.5h; Product distribution / selectivity;	92.8%
With N-ethyl-N,N-diisopropylamine In methanol at 45 - 50℃; for 70 - 100h; Product distribution / selectivity;	77.8%
With sodium carbonate In water at 85 - 90℃; for 4h;	73%
With potassium iodide; sodium carbonate In water; isopropyl alcohol

piperidine (110-89-4) + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → 2-methyl-3-(2-(piperidin-1-yl)ethyl)-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate; potassium iodide In acetonitrile at 80℃; for 8h;	91%
With potassium carbonate; potassium iodide In acetonitrile for 17h; Inert atmosphere; Reflux;	0.05 g

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + diphenylmethylpiperazine (841-77-0) → 3-(2-(4-benzhydrylpiperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	88%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → C11H14ClN3O2 (1204248-71-4)

Conditions	Yield
With isopentyl nitrite In butan-1-ol at 85 - 90℃; for 1.5h;	86%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + N-phenylphenylene-1,4-diamine (101-54-2) → 3-(2-((4-aminophenyl)(phenyl)amino)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	85%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 2-Amino-6-ethoxybenzothiazole (94-45-1) → 3-(2-(6-ethoxybenzo[d]thiazol-2-ylamino)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	84%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + Cyclopentamine (1003-03-8) → 3-(2-(cyclopentylamino)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	83%

TETRAHYDROFURFURYLAMINE (4795-29-3) + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → 2-methyl-3-(2-((tetrahydrofuran-2-yl)methylamino)ethyl)-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	82%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 6-fluoro-3-(4-piperidinyl)benzo[d]isoxazole (84163-77-9) → 3-(2-(4-(5-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	80%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + cyclohexylamine (108-91-8) → 3-(2-(cyclohexylamino)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	80%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 7-(4-bromobutyl)-1,8a-dihydroquinoline-2(3H)-one → 3-(2-(7-(4-bromobutyl)-2-oxo-2,3-dihydroquinolin-1(8aH)-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	80%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 1-(o-fluorophenyl)piperazine (1011-15-0) → 3-(2-(4-(2-fluorophenyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	78%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 1-(3,4-diethoxybenzyl)-5,6-diethoxyisoindoline → 3-(2-(1-(3,4-diethoxybenzyl)-5,6-diethoxyisoindolin-2-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	78%

6-bromo-3-(piperidin-4-yl)benzo[d]isoxazole + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → 3-(2-(4-(6-bromobenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With sodium carbonate In methanol at 70℃; for 13h;	78%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + para-fluorobenzylamine (140-75-0) → 3-(2-(4-fluorobenzylamino)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	77%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + hexan-1-amine (111-26-2) → 3-(2-(hexylamino)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	76%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + N,N-dimethyl-formamide (68-12-2, 33513-42-7) → C12H15ClN2O2 (1160611-32-4)

Conditions	Yield
Stage #1: N,N-dimethyl-formamide With trichlorophosphate at -2 - 0℃; for 1.75h; Stage #2: 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one In N,N-dimethyl-formamide at -1 - 80℃; for 195h;	75%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + benzyl-methyl-amine (103-67-3) → 3-(2-(benzyl(methyl)amino)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	75%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 2-methylimidazole (693-98-1) → 2-methyl-3-(2-(2-methyl-1H-imidazol-1-yl)ethyl)-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	75%

2-thiazolylamine (96-50-4) + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → 2-methyl-3-(2-(thiazol-2-ylamino)ethyl)-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	73%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + N-Benzylethanolamine (104-63-2) → 3-(2-(benzyl(2-hydroxyethyl)amino) ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	73%

Indole-3-carboxaldehyde (487-89-8) + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → 1-(2-(2-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-3-yl)ethyl)-1H-indole-3-carbaldehyde

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	73%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + 4-diphenylhydroxymethylpiperazine → 3-(2-(4-(hydroxydiphenylmethyl) piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	68%

aminoethylpiperazine (140-31-8) + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → 3-(2-(4-(2-aminoethyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	68%

3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) + furan-2-ylmethanamine (617-89-0) → 3-(2-(furan-2-ylmethylamino)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 8h;	66%

1-(benzo[b]thiophen-4-yl)piperazine hydrochloride + 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (63234-80-0) → 3-(2-(4-(benzo[b]thiophen-4-yl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Conditions	Yield
With potassium carbonate; potassium iodide In acetonitrile at 85℃;	55%

Upstream product

• 380634-63-9 3-(1-(pyridin-2-ylamino)ethylidene)dihydrofuran-2-(3H)-one 
• 517-23-7 3-acetyl-2-oxo-4,5-dihydrofuran 
• 504-29-0 2-aminopyridine 
• 93076-03-0 3-(2-chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one monohydrochloride 
• 41078-70-0 3-(2-chloro-ethyl)-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 

Downstream Products

• 106266-06-2 Risperidone 
• 1345732-45-7 3-(2-(4-(4-tert-butylphenylsulfonyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-46-8 3-(2-(4-(phenylsulfonyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-48-0 2-methyl-3-(2-(4-tosylpiperazin-1-yl)ethyl)-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-49-1 3-(2-(4-(2-fluorobenzoyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-50-4 3-(2-(4-(3-bromobenzoyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-51-5 3-(2-(4-(3-methoxybenzoyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-52-6 3-(2-(4-(2,4-dichlorobenzoyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-53-7 3-(2-(4-(3,5-dinitrobenzoyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-54-8 3-(2-(4-(4-tert-butylbenzoyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-42-4 3-(2-(4-(2,5-dichlorophenylsulfonyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-43-5 3-(2-(4-(4-chlorophenylsulfonyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 1345732-44-6 3-(2-(4-(2-nitrophenylsulfonyl)piperazin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 
• 106266-11-9 3-(2-(4-(6-hydroxybenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one 

Relevant articles and documents

A method for preparing risperidone chloro

The invention discloses a method for preparing risperidone chloro, the risperidone [...] shown in structural formula II, the method comprises the following steps: a) the 2 - aminopyridine, α - acetyl - γ - butyrolactone in toluene is added, after mixing, drop added to the phosphorus oxychloride or phosphorus oxychloride in toluene solution, during the dropping control phosphorus oxychloride at a temperature between 75 - 110 °C, the completion of the dropping, thermal insulation obtained through the reaction of intermediate III 2 - methyl - 3 - (2 - chloro ethyl) - pyrido [1, 2 - a] pyrimidine - 4 - one; b) in the step a) the obtained intermediate III 2 - methyl - 3 - (2 - chloro ethyl) - pyrido [1, 2 - a] pyrimidine - 4 - one is dissolved in hydrochloric acid solution, adding palladium-carbon, the pressure of 0.20 ± 0.05 mpa the hydrogenation is carried out under the conditions of the reaction, the solution is neutralized, extraction to obtain 2 - methyl - 3 - (2 - chloroethyl) - 6, 7, 8, 9 - tetrahydro-pyrido [1, 2 - a] pyrimidine - 4 - one. The method by changing the way the reaction material, and thereby the conversion, the intermediate (III) of the yield can be up to 80 - 85%; optimize the post treatment process, and is favorable for industrial production.

Preparation of 3-(2-Chloroethyl)-6,7,8,9-tetrahydro-9-hydroxy-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one, a Key Intermediate for the Synthesis of Paliperidone

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Synthesis of 2-methyl-3-(2-(piperazin-1-yl)ethyl)-6,7,8,9-tetrahydro- 4hpyrido[1,2-a]pyrimidin-4-one derivatives as antimicrobial agents

A series of novel 2-methyl-3-(2-(piperazin-1-yl)ethyl)-6,7,8,9-tetrahydro- 4H-pyrido[1,2-a]pyrimidin-4-one sulfonamide and carboxamide derivatives were synthesized in good yield. The synthesized compounds were characterized by 1H-NMR, FTIR and elemental analysis. All the synthesised compounds were screened for their in vitro antimicrobial activity by agar well diffusion and micro dilution method against standard strains of Gram-positive (Bacillus subtilis MTCC 121, Staphylococcus epidermidis 435), and Gram-negative (Xanthomonas campestris 7903 and Pseudomonas aeruginosa MTCC 7908) bacteria. Compound 7a and compound 8d with dichloro substitution among sulphonamide and carboxamide series respectively showed potent inhibitory activity.