Pyrazines

875781-43-4, These common heterocyclic compound, 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

Step 1 To a partial suspension of 2-bromo-5H-pyrrolo[2,3-b]pyrazine (5.0 g, 25.2 mmol) in 1,4-dioxane (100 mL) was added 2.0 M aqueous NaOH (25 mL, 50.0 mmol) and 37% aqueous formaldehyde (19 mL, 252 mmol). The dark homogenous reaction mixture was stirred at room temperature overnight. The organics were evaporated under reduced pressure. The aqueous layer was neutralized with 1.0 M HCl and extracted with EtOAc (2*). The combined organics were concentrated to afford 2.6 g of an orange solid. Upon standing, a thick brown precipitate formed in the aqueous layer. The precipitate was collected by filtration and dried. The brown solid was extracted with hot 10% MeOH/EtOAC (3*200 mL). The extracts were combined and evaporated to provide an additional 3.05 g of orange solid. Overall yield was 5.65 g (87%) of (2-bromo-7-hydroxymethyl-pyrrolo[2,3-b]pyrazin-5-yl)-methanol.

Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 875781-43-4.

Reference:
Patent; Hendricks, Robert Than; Hermann, Johannes; Kondru, Rama; Lou, Yan; Lynch, Stephen M.; Owens, Timothy D.; Soth, Michael; US2011/230462; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

55557-52-3, The chemical industry reduces the impact on the environment during synthesis 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, I believe this compound will play a more active role in future production and life.

Into a vessel containing 50 mL ethanol was added 1.0 g of 3-chloropyrazine-2- carbonitrile (Exp-5-g22, 7.2 mmol), 1.1 g PMBNHNH2 (7.3 mmol) and 1.9 g K2C03 (14.2 mmol). The reaction mixture thus provided was heated to reflux and refluxing was continued for 6 hours, then the mixture was cooled to ambient temperature, filtered and the solid was washed sequentially with 10 mL H20 and 10 mL of methanol and dried yielding 1.0 g Exp-5-g23 (calculated yield 56%).

The chemical industry reduces the impact on the environment during synthesis 3-Chloropyrazine-2-carbonitrile. I believe this compound will play a more active role in future production and life.

Reference:
Patent; MERCK SHARP & DOHME CORP.; LIVERTON, Nigel; JONES, Philip; LEI, Zhiyu; LIU, Fuqing; LUO, Yunfu; DONG, Jingchao; SOLL, Richard; WO2013/63100; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below. 33332-25-1

Step 1Compound (67) (10 g) was suspended in water (35 ml) and 2 mol/L-aqueous solution of sodium hydroxide (34.8 ml) was added and the mixture was stirred at room temperature for 4.5 hours. 2 mol/L-hydrochloric acid (34.8 ml) was added to neutralize and stirred at room temperature overnight. The precipitated insoluble material was collected by filtration, washed with water and dried under reduced pressure to afford Compound (68) (3.47 g).1H-NMR (DMSO-d6) delta 8.93 (1H, s), 9.03 (1H, s).

In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 33332-25-1, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; SHIONOGI & CO., LTD.; US2012/15961; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-25-1, The chemical industry reduces the impact on the environment during synthesis 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, I believe this compound will play a more active role in future production and life.

Example 24 5-{[3-(Cyclopropylmethyl)-2,3,4,5-tetrahydro-1 H-3-benzazepin-7-yl]oxy)-N-methyl-2- pyrazinecarboxamide (E24) Step 1: 1,1-Dimethylethyl 7-({5-[(methyloxy)carbonyl]-2-pyrazinyl}oxy)-1,2,4,5- tetrahydro-3H-3-benzazepine-3-carboxylate; 1,1-Dimethylethyl 7-hydroxy-1,2,4,5-tetrahydro-3H-3-benzazepine-3-carboxylate (Description 3 of WO 02/40471) (40 g, 0.15 mole) was dissolved in dry dimethylformamide (200 ml) and treated with sodium hydride (60% in mineral oil, 6.4 g, 0.16 mole). The mixture was stirred at room temperature for 1 hour and then cooled in ice. Methyl 5-chloro- 2-pyrazinecarboxylate (31.2 g, 0.18 mole) was added and the mixture stirred at room temperature for 18 hours. The mixture was poured into ice/water and the resulting solid collected by filtration. This was dissolved in ethyl acetate, dried (sodium sulphate) and evaporated under reduced pressure. The residue was purified by column chromatography eluting with ethyl acetate/pentane (1:2) to afford the title compound ?H NMR (CDCl3) No. 8.84 (H, s), 8.48 (H, s), 7.18 (H, m), 6.94 (2H, m), 4.01 (3H, s), 3.58 (4H, m), 2.92 (4H, m), 1.49 (9H, s)..

The chemical industry reduces the impact on the environment during synthesis Methyl 5-chloropyrazine-2-carboxylate. I believe this compound will play a more active role in future production and life.

Reference:
Patent; GLAXO GROUP LIMITED; WO2005/97778; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 6966-01-4, name is Methyl 3-amino-6-bromopyrazine-2-carboxylate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 6966-01-4

Step 2 : 3-amino-6-bromopyrazine-2-carboxylic acid[00211] A mixture of methyl 3-amino-6-bromo-pyrazine-2-carboxylate (3 g, 12.93 mmol) and lithium hydroxide (1.548 g, 64.65 mmol) in MeOH (11.74 mL) and H2O (11.74 mL) was heated to 90 0C for 2 hours. The reaction mixture was allowed to cool, neutralised with HCl and diluted with water, and the resultant precipitate collected by filtration (2.2 g, 78% Yield). 1H NMR (400.0 MHz, DMSO) 7.57 (br s, 2H) and 8.39 (s, IH), 13.41 (br s, IH) ppm.

Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 6966-01-4.

Reference:
Patent; VERTEX PHARMACEUTICALS INCORPORATED; CHARRIER, Jean-damien; DURRANT, Steven; KAY, David; O’DONNELL, Michael; KNEGTEL, Ronald; MACCORMICK, Somhairle; PINDER, Joanne; VIRANI, Anisa; YOUNG, Stephen; BINCH, Hayley; CLEVELAND, Thomas; FANNING, Lev, T.d.; HURLEY, Dennis; JOSHI, Pramod; SHETH, Urvi; SILINA, Alina; WO2010/54398; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5521-58-4, A common heterocyclic compound, 5521-58-4, name is 5-Methylpyrazin-2-amine, molecular formula is C5H7N3, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

Oxalyl chloride (2.1 mL, 24.0 mmol) was added to a solution of 3-[(l-methylethyl)oxy]-5- [(phenylmethyl)oxy]benzoic acid (5.72 g, 20.0 mmol) in DCM (100 mL) and the mixture stirred at ambient RT for 4 hours. The mixture was evaporated in vacuo to a residue, which was taken up in DCM (25 mL) and added to a stirred mixture of 2-amino-5-methylpyrazine (2.29 g, 21.0 mmol) and pyridine (1.94 mL, 24.0 mmol) in DCM (100 mL) at 50C – 1O0C. The mixture was stirred at RT for 18 hours, the DCM evaporated in vacuo to a residue, which was partitioned between water (50 mL) and ethyl acetate (150 mL). The organic layer was washed with brine, dried (MgSO4) and evaporated to a residue which was chromatographed on silica, eluting with 30% ethyl acetate in isohexane, and crystallised from ethyl acetate / isohexane to give the desired compound (5.52 g). 1R NuMR delta (CDCl3): 1.3 (d, 6H), 2.5 (s, 3H), 4.5 (m, IH), 5.0 (s, 2H), 6.6 (s, IH), 6.95 (s, IH), 7.0 (s, IH), 7.35 (m, 5H), 8.05 (s, IH), 8.3 (s, IH) and 9.5 (s, IH). m/z 378 (M+H)+.

The synthetic route of 5-Methylpyrazin-2-amine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2007/7041; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5900-13-0, The chemical industry reduces the impact on the environment during synthesis 5900-13-0, name is 5-Bromo-3-methoxypyrazin-2-amine, I believe this compound will play a more active role in future production and life.

Toa stirred suspension of sodium hydride (60%, 196 mg, 4.9 mmol) and THF (10 mL)at 0C, under N2, was added 5-bromo-3-methoxypyrazin-2-amine (1.00g, 4.9 mmol) in one portion. This was stirred at 0C for 30 min before theaddition of 3,5-dichlorobenzene-l- sulfonyl chloride (120 mg, 0.49 mmol) in oneportion. The reaction was allowed to warm to room temperature and stirred for 2hrs. The reaction was acidified to pH 2 with 2 M HC1, diluted with water (100mL) and extracted with EtOAc (100 ml x 3). The combined organic extracts werewashed with water (100 ml), brine (100 ml), dried ( a2S04), filtered andconcentrated to give the crude product as a brown oil, which was purified usingsilica chromatography (eluent 12% to 50% EtOAc in heptane) to give the titlecompound as a white solid (866 mg, 39%); m z=411.7, 413.6 (MH)+

The chemical industry reduces the impact on the environment during synthesis 5-Bromo-3-methoxypyrazin-2-amine. I believe this compound will play a more active role in future production and life.

Reference:
Patent; ACTIVE BIOTECH AB; FRITZSON, Ingela; LIBERG, David; EAST, Stephen; MACKINNON, Colin; PREVOST, Natacha; WO2014/184234; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

486460-20-2, A common heterocyclic compound, 486460-20-2, name is 3-(Trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyrazine, molecular formula is C6H3F3N4, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

To a solution of 3-(trifluoromethyl)[1,2,4]triazolo[4,3-a]pyrazine (1.60 g) in metanol (20 mL) was added a catalytic amount of Pd/C. The suspension was stirred under H2 for 5 h, and then filtered. The filtrate was concentrated in vacuo to give a residue, which was used for next step without further purification.

The synthetic route of 3-(Trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SUNSHINE LAKE PHARMA CO., LTD.; Zhang, Jiancun; Zhang, Yingjun; Zhang, Weihong; Liu, Bing; Zhang, Jiquan; Liu, Jinlei; Zhang, Lu; US2014/228361; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 55557-52-3 name is 3-Chloropyrazine-2-carbonitrile, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below. 55557-52-3

Step 7: synthesis of Ethyl 7-aminothieno[2,3-b]pyrazine-6-carboxylate (7) A mixture of 3-chloropyrazine-2-carbonitrile (17.9 g, 128 mmol), sodium carbonate (17.7 g, 167 mmol) and ethyl-2-mercaptoacetate (18.4 mL, 167 mmol) in ethanol (120 mL) was heated to reflux for 4.5 h. Quenched with water (1.5 L) and stirred for 30 min. The resulting precipitate was collected and washed with water. The residue was dissolved in diethyl ether and a black precipitate was filtrated off. Ether was evaporated to give pure compound ethyl 7-aminothieno[2,3-b]pyrazine-6-carboxylate 7 (19.6 g, 68.5%). 1H-NMR (400 MHz, CDCl3) 1.42 (t, J=7.2 Hz, 3H), 4.40 (q, J=7.2 Hz, 2H), 6.19 (br s, 1H), 8.58 (d, J=2.2 Hz, 1H), 8.63 (d, J=2.2 Hz, 1H).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-Chloropyrazine-2-carbonitrile, and friends who are interested can also refer to it.

Reference:
Patent; Folmer, Brigitte Johanna Bernita; Man, de Adrianus Petrus Antonius; Gernette, Elisabeth Sophia; Corte Real Goncalves Azevedo, Rita; Ibrahim, Hemen; US2013/79341; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

41270-66-0, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 41270-66-0 name is 5-Chloro-2,3-diphenylpyrazine, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.

6 g of the compound of the formula (1), 7 g of isopropylamine and 5 mL of dimethyl sulfoxide were placed in a sealed pressure-resistant reaction vessel, and the mixture was heated to 90 C for 48 hours, and the reaction was completed. The reaction solution was cooled to 25 C, then 18 mL of ethanol was added, and the solution was dissolved at 80 C, then 24 mL of water was added dropwise over 1 h, a large amount of solid was precipitated, and the temperature was lowered to 25 C, stirred for 0.5 hour, and suction-filtered to obtain a solid.Drying at 80 C for 24 h under vacuum gave 6 g of the compound of formula (2) as a pale yellow solid.The yield was 92.3%.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5-Chloro-2,3-diphenylpyrazine, and friends who are interested can also refer to it.

Reference:
Patent; Dongguan Dongyangguang Pharmaceutical Research And Development Co., Ltd.; Liu Yongjun; Wang Zhongqing; Liao Shouzhu; Luo Zhonghua; (5 pag.)CN109422698; (2019); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem