63234-80-0

Usage

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

• 41078-70-0 3-(2-chloro-ethyl)-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 
• 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 

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 academic research and scientific papers

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.

Derisking the Cu-Mediated 18F-Fluorination of Heterocyclic Positron Emission Tomography Radioligands

Molecules labeled with fluorine-18 (18F) are used in positron emission tomography to visualize, characterize and measure biological processes in the body. Despite recent advances in the incorporation of 18F onto arenes, the development of general and efficient approaches to label radioligands necessary for drug discovery programs remains a significant task. This full account describes a derisking approach toward the radiosynthesis of heterocyclic positron emission tomography (PET) radioligands using the copper-mediated 18F-fluorination of aryl boron reagents with 18F-fluoride as a model reaction. This approach is based on a study examining how the presence of heterocycles commonly used in drug development affects the efficiency of 18F-fluorination for a representative aryl boron reagent, and on the labeling of more than 50 (hetero)aryl boronic esters. This set of data allows for the application of this derisking strategy to the successful radiosynthesis of seven structurally complex pharmaceutically relevant heterocycle-containing molecules.

Synthesis of 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a] pyrimidin-4-one derivatives as antibacterial agents

A series of novel 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H- pyrido[1,2-a]pyrimidin-4-one aliphatic/ aromatic/ heterocyclic amine derivatives were synthesized in good yield. The synthesized compounds were characterized by 1H-NMR, FTIR and elemental analysis. All the synthesized compounds were screened for their in vitro antibacterial activity by agar well diffusion and micro dilution method against standard strains of Gram-Positive (Bacillus Subtilis MTCC 121 and Staphylococcus epidermidis 435), and Gram-negative (Xanthomonas Campestris 7903 and Pseudomonas aeruginosa MTCC 7908) bacteria. Compounds with substituted heterocyclic piperazine moiety showed good activity. In particular, compound 6i showed two fold better activity compared to the standard drug Strepyomycin sulphate.

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.

A PROCESS FOR THE PREPARATION OF RISPERIDONE

The present invention relates to an improved process for the preparation of Risperidone of formula (I) by condensing 6-fluoro-3- (4-piperidinyl)-l, 2- benzisoxazole with 3-(2-chloroethyl)-6, 7, 8, 9-tetrahydro-2-methyl-4H-pyrido [1,2-a] pyrimidin-4-one in water and water immiscible solvents under basic conditions in the presence of a catalyst. This invention also relates to a method for purification of crude Risperidone by removing an impurity specifically named as 9-hydroxy Risperidone to undetectable level using acid chlorides and an organic base in a suitable solvent.

METHOD FOR PREPARING RISPERIDONE

Risperidone is prepared in a high yield by reacting 2,4-difluorophenyl(4-piperidinyl)methanone oxime hydrochloride and 3-(2-chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one in an aqueous alkali hydroxide solution having an alkali hydroxide concentration in the range of 20 to 40%.