4271-96-9

Usage

Uses

1. Used in Pharmaceutical Industry:
1,2-Dimethyl-1,4,5,6-tetrahydropyrimidine is used as a reagent for the synthesis of pyrantel derivatives, which possess nematocidal activity. These derivatives are essential in the development of drugs and treatments targeting nematodes, or roundworms, which are parasites that can cause various diseases in humans and animals.
2. Used in Chemical Research:
1,2-Dimethyl-1,4,5,6-tetrahydropyrimidine is also used as a reactant in the preparation of hapten antibodies that evoke terpenoid cyclization. Terpenoids are a large and diverse class of organic compounds that play a crucial role in the biochemistry of plants and animals. The cyclization of terpenoids is an essential process in the synthesis of various natural products, and 1,2-Dimethyl-1,4,5,6-tetrahydropyrimidine plays a vital role in facilitating this process.

InChI:InChI=1/C6H12N2/c1-6-7-4-3-5-8(6)2/h3-5H2,1-2H3

Synthetic route

1,2-dimethyl-hexahydro-pyrimidine (61327-70-6) → 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9)

Conditions	Yield
With oxygen; gold In acetonitrile at 60℃; under 760.051 Torr; for 40h;	97%

acetonitrile (75-05-8) + N-Methyl-1,3-propanediamine (6291-84-5) → 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9)

Conditions	Yield
With thioacetamide at 90 - 110℃; for 6h; Temperature; Reagent/catalyst; Large scale;	96%
Stage #1: acetonitrile; N-Methyl-1,3-propanediamine With zinc(II) chloride for 24h; Inert atmosphere; Reflux; Stage #2: Inert atmosphere;	45%

N-[3-(methylamino)propyl]acetamide (56125-48-5) → 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9)

Conditions	Yield
With PPE at 80℃; for 2h; Temperature; Microwave irradiation;	94.42%

ethyl acetimidate hydrochloride (2208-07-3) + N-Methyl-1,3-propanediamine (6291-84-5) → 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9)

Conditions	Yield
at 125℃; for 15h; Yield given;

N,N-dimethylacetamide dimethyl acetal (18871-66-4) + N-Methyl-1,3-propanediamine (6291-84-5) → 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9)

Conditions	Yield
In neat (no solvent) at 80℃; for 1h;	5.33 g

1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine hydroiodide

Conditions	Yield
With hydrogen iodide In 1,4-dioxane; water at 0 - 20℃; for 12h;	100%

1-isothiocyanato-4-vinylbenzene (1520-20-3) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → C15H19N3S

Conditions	Yield
In tetrahydrofuran at 0 - 20℃; for 12h; Schlenk technique; Inert atmosphere;	97%

3-bromobenzoyl chloride (1711-09-7) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-[1-(3-bromobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-bromophenyl)propane-1,3-dione (1228685-35-5)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	89%

1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) + 3-fluorobenzoyl chloride (1711-07-5) → 2-[1-(3-fluorobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-fluorophenyl)propane-1,3-dione (1228685-32-2)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	88%

4-fluorobenzoyl chloride (403-43-0) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-[1-(4-fluorobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(4-fluorophenyl)propane-1,3-dione (1228685-31-1)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	84%

4-methoxy-benzoyl chloride (100-07-2) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-[1-(4-methoxybenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(4-methoxyphenyl)propane-1,3-dione (1228685-29-7)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	83%

benzoyl chloride (98-88-4) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-(1-benzoyl-3-methyltetrahydropyrimidin-2(1H)-ylidene)-1,3-diphenylpropane-1,3-dione

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	82%
With triethylamine In tetrahydrofuran Inert atmosphere;

4-methyl-benzoyl chloride (874-60-2) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-[1-methyl-3-(4-methylbenzoyl)tetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(4-methylphenyl)propane-1,3-dione (1228685-30-0)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	82%

4-chloro-benzoyl chloride (122-01-0) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-[1-(4-chlorobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(4-chlorophenyl)propane-1,3-dione (1228685-28-6)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	80%

m-Chlorobenzoyl chloride (618-46-2) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-[1-(3-chlorobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-chlorophenyl)propane-1,3-dione (1228685-34-4)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	79%

para-fluorophenyl isocyanate (1195-45-5) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → N,7-bis(4-fluorophenyl)-1-methyl-6,8-dioxo-2,3,4,6,7,8-hexahydro-1H-pyrimido[1,6-a]pyrimidine-9-carboxamide (1227407-98-8)

Conditions	Yield
In acetonitrile at 20℃; Inert atmosphere; Reflux;	76%

1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) + 3-Methylbenzoyl chloride (1711-06-4) → 2-[1-methyl-3-(3-methylbenzoyl)tetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-methylphenyl)propane-1,3-dione (1228685-36-6)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	74%

p-Tolylisocyanate (622-58-2) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 1-methyl-6,8-dioxo-N,7-di-p-tolyl-2,3,4,6,7,8-hexahydro-1H-pyrimido[1,6-a]pyrimidine-9-carboxamide (1227407-96-6)

Conditions	Yield
In acetonitrile at 20℃; Inert atmosphere; Reflux;	74%

phenyl isocyanate (103-71-9) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 1-methyl-6,8-dioxo-N,7-diphenyl-2,3,4,6,7,8-hexahydro-1H-pyrimido[1,6-a]pyrimidine-9-carboxamide (1227407-95-5)

Conditions	Yield
In acetonitrile at 20℃; Inert atmosphere; Reflux;	71%

n-octyne (629-05-0) + carbon monoxide (201230-82-2) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 7-hexyl-1,8a-dimethyl-1,2,3,4-tetrahydropyrrolo[1,2-a]pyriamidin-6(8aH)-one (1418740-37-0)

Conditions	Yield
With 2,2'-azobis(isobutyronitrile); tri-n-butyl-tin hydride In benzene at 80℃; under 60804.1 Torr; for 6h; Pauson-Khand Annulation; Autoclave;	64%

4-Methoxyphenyl isocyanate (5416-93-3) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → N,7-bis(4-methoxyphenyl)-1-methyl-6,8-dioxo-2,3,4,6,7,8-hexahydro-1H-pyrimido[1,6-a]pyrimidine-9-carboxamide (1227407-97-7)

Conditions	Yield
In acetonitrile at 20℃; Inert atmosphere; Reflux;	63%

m-anisoyl chloride (1711-05-3) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-[1-(3-methoxybenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-methoxyphenyl)propane-1,3-dione (1228685-33-3)

Conditions	Yield
With triethylamine In tetrahydrofuran at 20℃; Inert atmosphere; Reflux;	61%

carbon monoxide (201230-82-2) + 5-hexyn-1-yl acetate (68274-83-9) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 7-(4-acetoxy)butyl-1,8a-dimethyl-1,2,3,4-tetrahydropyrrolo[1,2-a]pyriamidin-6(8aH)-one (1418740-39-2)

Conditions	Yield
With 2,2'-azobis(isobutyronitrile); tri-n-butyl-tin hydride In benzene at 80℃; under 60804.1 Torr; for 6h; Pauson-Khand Annulation; Autoclave;	61%

2-formylbenzo[b]furan (4265-16-1) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) + formic acid ethyl ester (109-94-4) → 1-methyl-2-<(2-benzofuryl)vinyl>-1,4,5,6-tetrahydropyrimidine formate

Conditions	Yield
With lithium fluoride at 50℃; for 18h;	52%

1,4-diphenyl-1,3-butadiyne (886-66-8) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → N-(2-(3,6-diphenylpyridin-2-yl)ethyl)-N-methylacetamide

Conditions	Yield
With carbon dioxide; water; caesium carbonate In acetonitrile at 80℃; for 48h; Reagent/catalyst; Schlenk technique;	45%

3,4,5-trimethoxy-benzaldehyde (86-81-7) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) + formic acid ethyl ester (109-94-4) → 1-methyl-2-<2-(3,4,5-trimethoxyphenyl)vinyl>-1,4,5,6-tetrahydropyrimidine formate

Conditions	Yield
With lithium fluoride at 50℃; for 18h;	42%

2-Thiophenecarbonyl chloride (5271-67-0) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 2-(1-Methyl-tetrahydro-pyrimidin-2-ylidene)-1,3-di-thiophen-2-yl-propane-1,3-dione

Conditions	Yield
With triethylamine In acetonitrile Ambient temperature;	40.5%

piperonal (120-57-0) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) + formic acid ethyl ester (109-94-4) → 1-methyl-2-<2-(3,4-methylenedioxyphenyl)vinyl>-1,4,5,6-tetrahydropyrimidine formate

Conditions	Yield
With lithium fluoride at 50℃; for 18h;	40%

1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) + 4-chloro-3-nitro-benzoyl chloride (38818-50-7) → 1,3-Bis-(4-chloro-3-nitro-phenyl)-2-(1-methyl-tetrahydro-pyrimidin-2-ylidene)-propane-1,3-dione

Conditions	Yield
With triethylamine In acetonitrile Ambient temperature;	40%

3-methyl-2-thiophenecarboxaldehdye (5834-16-2) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 1-methyl-2-<(3-methyl)thio-2-thenoyl methylene>hexahydropyrimidine (83467-08-7)

Conditions	Yield
With sulfur In xylene Heating; 5-8 h;	37.8%

2-furancarbonyl chloride (527-69-5) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 1,3-Di-furan-2-yl-2-(1-methyl-tetrahydro-pyrimidin-2-ylidene)-propane-1,3-dione

Conditions	Yield
With triethylamine In acetonitrile Ambient temperature;	37%

thiophene-2-carbaldehyde (98-03-3) + 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (4271-96-9) → 1-methyl-2-(thio-2-thenoyl methylene)hexahydropyrimidine (83467-07-6)

Conditions	Yield
With sulfur In xylene Heating; 5-8 h;	36.8%

Upstream product

• 2208-07-3 ethyl acetimidate hydrochloride 
• 6291-84-5 N-Methyl-1,3-propanediamine 
• 61327-70-6 1,2-dimethyl-hexahydro-pyrimidine 
• 75-05-8 acetonitrile 
• 56125-48-5 N-[3-(methylamino)propyl]acetamide 
• 18871-66-4 N,N-dimethylacetamide dimethyl acetal 

Downstream Products

• 83467-06-5 1-methyl-2-(4-nitrothiobenzoyl methylene)hexahydropyrimidine 
• 83467-03-2 1-methyl-2-(thiobenzoyl methylene)hexahydropyrimidine 
• 83467-05-4 1-methyl-2-(4-methoxythiobenzoyl methylene)hexahydropyrimidine 
• 81841-05-6 2-(1-Methyl-tetrahydro-pyrimidin-2-ylidene)-1,3-bis-(4-nitro-phenyl)-propane-1,3-dione 
• 124927-56-6 2-(4-chlorobenzoylmethylene)-1-methylhexahydropyrimidine 
• 124927-52-2 2-(benzoylmethylene)-1-methylhexahydropyrimidine 
• 1228685-35-5 2-[1-(3-bromobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-bromophenyl)propane-1,3-dione 
• 1228685-34-4 2-[1-(3-chlorobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-chlorophenyl)propane-1,3-dione 
• 1228685-33-3 2-[1-(3-methoxybenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-methoxyphenyl)propane-1,3-dione 
• 1228685-30-0 2-[1-methyl-3-(4-methylbenzoyl)tetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(4-methylphenyl)propane-1,3-dione 
• 1228685-28-6 2-[1-(4-chlorobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(4-chlorophenyl)propane-1,3-dione 
• 1228685-29-7 2-[1-(4-methoxybenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(4-methoxyphenyl)propane-1,3-dione 
• 1228685-32-2 2-[1-(3-fluorobenzoyl)-3-methyltetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-fluorophenyl)propane-1,3-dione 
• 1228685-36-6 2-[1-methyl-3-(3-methylbenzoyl)tetrahydropyrimidin-2(1H)-ylidene]-1,3-bis(3-methylphenyl)propane-1,3-dione 

Relevant academic research and scientific papers

Economical synthetic method 1, 2 - dimethyl -1, 4, 5, 6 - tetrahydropyrimidine (by machine translation)

1, 2 - Dimethyl -1, 4, 5, 6 - tetrahydropyrimidine synthesis methods greatly shorten the reaction time N - methylenediamine and acetonitrile by adding thioacetamide or hydrogen sulfide as catalyst, obtain high yield in a short reaction time, and greatly improve the economical. (by machine translation)

Synthesis method of 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine

The invention discloses a synthesis method of 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine. A novel route is chosen, reactions are efficiently and quickly carried out under the assistance of microwaves,and the product yield is high. The synthesis method has the advantages of simple reaction route, easy operation, short reaction time, and high yield.

Cyclic and linear amidine catalysts for the efficient synthesis of cyclic trithiocarbonates from carbon disulfide and episulfides under mild conditions

Cyclic and linear amidines effectively catalyzed the reaction of carbon disulfide and episulfides under mild conditions, such as ordinary pressure and ambient temperature, to give the corresponding cyclic trithiocarbonates in high yields.

Push-pull alkenes by reacting N,N′-dimethyl cyclic ketene N,N′-acetals with isocyanates: synthesis, structures, and reactivities

N,N′-Dimethyl cyclic ketene N,N′-acetals react with two or three equivalents of isocyanates to generate tetrasubstituted push-pull alkene derivatives in one-pot sequential reactions. X-ray crystallography showed significant elongations and out of plane distorsions of the polarized carbon-carbon double bonds.

Non-nanogold catalyzed aerobic oxidation of secondary amines to imines

Bulk gold powder (～103 nm particle size) is a highly active catalyst for the oxidative dehydrogenation of secondary amines to imines under the mild conditions of 1 atm O2 and 60-100°C. The Royal Society of Chemistry.

Process for the preparation of 4-nitrodiphenylamines

The invention relates to a process for the preparation of 4-nitrodiphenylamines by the reaction of halogenonitrobenzenes with primary aromatic amines in the presence of copper or a copper compound, a neutralizing agent and a cyclic diaza compound.