Pyrazines

274-79-3, A common compound: 274-79-3, name is Imidazo[1,2-a]pyrazine, 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.

Step 1 The indole obtained [1,2-A] pyrazine (10g, 0.08mmol) was dissolved in 100mL of ethylene glycol monomethyl ether, was added 5% palladium on carbon (2G), quickly replaced with hydrogen three times, at room temperature (20-25 ) The reaction was stirred, TLC detection reaction process, the reaction is complete after 30 hours, suction filtered through celite pad, and the filtrate was concentrated by rotary evaporation and purified by column chromatography by chromatography to give 5,6,7,8- hydrogen-imidazo [1,2-A] pyrazine 7g, the the yield of about 68%

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, Imidazo[1,2-a]pyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; shanghai bide pharmatech co. ltd; LI, JINFEI; HUANG, LIANGFU; LI, XINLING; WANG, MINGXIA; (5 pag.)CN103864799; (2016); B;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

873-42-7, Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 873-42-7, name is 2-Amino-3,5-dichloropyrazine, A new synthetic method of this compound is introduced below.

Similar procedure to step 3 of the example 18 was followed to arrive at compound 255 with LC-MS [M+H] -m/z 388.

If you are interested in these compounds, you can also browse my other articles.Thank you for taking the time to read this article. I hope you enjoyed it.

Reference:
Patent; FUJIAN HAIXI PHARMACEUTICALS CO., LTD; FENG, Yan; WANG, Ruyong; LI, Junqing; ZHENG, Jianjia; LIAN, Xin; GONG, Xuan; FU, Yueli; KANG, Xinshan; (144 pag.)WO2019/174601; (2019); 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.

The starting compound 3-chloropyrazine-2-carboxamide was prepared via partial hydrolysis of the nitrile group of 3-chloropyrazine-2-carbonitrile (Fluorochem, Co., Hadfield, Derbyshire, UK). A mixture of concentrated (30%) hydrogen peroxide (29 mL) and water (195 mL) was prepared and alkalinized with an 8% (w/v) solution of sodium hydroxide to obtain a solution with pH 9. The carbonitrile (104 mmol) was then added portionwise into the heated (50 C) mixture over a period of 30 min. The whole mass was stirred for an additional 2.5 h at 55 C while the pH was periodically monitored and alternatively adjusted to the value of 9 by adding a few drops of 8% NaOH solution. The reaction mixture was cooled in a fridge to initiate crystallization. The crude product was recrystallized from ethanol [27]. The yield of this reaction was approximately 80%.

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:
Article; Jandourek, Ondrej; Tauchman, Marek; Paterova, Pavla; Konecna, Klara; Navratilova, Lucie; Kubicek, Vladimir; Holas, Ondrej; Zitko, Jan; Dolezal, Martin; Molecules; vol. 22; 2; (2017);,
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Pyrazine | C4H4N2 – PubChem

A common compound: 6705-33-5, name is Pyrazin-2-ylmethanol, 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. 6705-33-5

Step 1 (2-Chloromethyl)pyrazine To a stirred solution of (2-hydroxymethyl)pyrazine (Maury et al. (1982) Bull. Soc. Chim. Belg. 91, 153-162) (0.40 g, 3.6 mmol) in CH2 Cl2 (40 mL) at 0 C. was added thionyl chloride (1.6 g, 13 mmol), dropwise. The mixture was stirred for 18 h at ambient temperature then concentrated under reduced pressure. The residue was partitioned between saturated NaHCO3 (20 mL) and CH2 Cl2 (25 mL). The organic layer was removed and the aqueous phase extracted further with CH2 Cl2 (3*25 mL). The combined organic extracts were dried (MgSO4), filtered, and concentrated under reduced pressure. The resulting oil was purified by flash column chromatography, eluding with hexanes; 30% EtOAc, to give the title compound: 1 H NMR (400 MHz, CDCl3) delta 8.76 (s, 1H), 8.58-8.54 (m, 2H), 4.72 (s, 2H) ppm. The compound was converted to its hydrochloride salt for storage.

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, 6705-33-5, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Merck & Co., Inc.; US5939439; (1999); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., 36070-80-1

[0109] At 0C, a solution of oxalyl chloride (2.52 g, 0.02 mol) in dichloromethane (10 mL) is dripped dropwise into asuspension of 5-chloropyrazine-2-carboxylic acid (1.56 g, 0.01 mol) and N,N-dimethyl formamide (1 drop) in dichloromethane(100 mL). After being stirred overnight at room temperature, the reaction mixture is evaporated under vacuum,and the trace amount of oxalyl chloride is removed twice by additional dichloromethane (100 mL) azeotropic mixture togive compound (4-2) (1.77 g, 100%).

If you are interested in these compounds, you can also browse my other articles.Thank you for taking the time to read this article. I hope you enjoyed it.

Reference:
Patent; Hangzhou Bensheng Pharmaceutical Co., Ltd.; XU, Rongzhen; XIE, Fuwen; LAI, Hongxi; RONG, Frank; EP2615092; (2013); 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.

To a solution of rert-hutyl 4-(ir,4-4-hydroxycyclohexyioxy)piperidine-i -carboxylate (W0201 1127051) (4 g, 13.36 mmol) in THF (10 mL) was added 1 M potassium tert-butoxide solution in THF (16.03 mL, 16.03 mmol) at 0 E/ under nitroger. After stirring for 10 mm, asolution of 3-chioropyrazine-2–earbonitrile (2.051 g, 14.70 mmoi) in THF (6 mL) was added. The reaction mixture was slowly warmed to room temperatuw and stirred for I Ii. The mixture was quenched with water and 1 N HC1 (aq) and extracted with EtOAc. The organic layer was washed with brine, dried with anhydrousMgSO,, fihered, and concentrated under reducedpressure. The residue was purified by silica gel column chromatography to afford the titlecompound (4.80 g, 11.9 mmoi, 89,3%), Exact mass calculated for C21H30N404: 402.2, fOundLCMS m/z =403.2 [M¡ÀHf; ?H NMR (CDCI1, 400 MHz) S ppm 1.46 (s, 9H), 1.46-1.58 (m,4Fl). 1.65-1.72 (m, 2H), 1.75-1.82 (in, 21-1). 1.96-2.05 (in. 2H). 2.10-2.18 (m, 2H), 3.05-3.12(m, ZR), 3.52-3.58 (m, 21-i). 3.73-3.82 (m. 21-1), 5.18-5.25 (m, Hi), 8.22 (d, J= 2.5 Hz, 11-i).8.29 (d, .J= 2,5 Hz. 11-I).

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; ARENA PHARMACEUTICALS, INC.; THE UNIVERSITY OF COPENHAGEN; JONES, Robert M.; SCHWARTZ, Thue Walter; KRISTENSEN, Line Vildbrad; MADSEN, Torben Andreas Nygaard; WO2014/74700; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, Adding a certain compound to certain chemical reactions, such as: 5049-61-6, name is Pyrazin-2-amine, belongs to Pyrazines compound, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound 5049-61-6.

EXAMPLE 1A 5-bromo-2-pyrazinamine A 0 C. solution of 2-aminopyrazine (15.0 g, 157 mmol) in dichloromethane (900 mL) was treated with N-bromosuccinimide (28.2 g, 159 mmol), stirred for 3.5 hours, and filtered through diatomaceous earth (Celite). The filtrate was treated with silica gel (300 g) and concentrated. The concentrate was purified by flash column chromatography with 30% ethyl acetate/hexanes to provide 22.09 g (81.5%) of the desired product. MS (APCI(+)) m/z 174 (M+H)+; 1H NMR (300 MHz, CDCl3) delta 8.09 (d, J=1.4 Hz, 1H), 7.77 (d, J=1.7 Hz, 1H), 4.30-4.78 (br s, 2H).

According to the analysis of related databases, 5049-61-6, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Li, Goaquan; Li, Qun; Li, Tongmei; Lin, Nan-Horng; Mantei, Robert A.; Sham, Hing L.; Wang, Gary T.; US2004/34038; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

4858-85-9, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 4858-85-9, name is 2,3-Dichloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

2,3-Dichloropyrazine A-1 (15 g; 100.68 mmol) and hydrazine hydrate 65% (15.509 ml; 201.37 mmol) are dissolved in 45 ml ethanol and stirred for 1 h at 80 C. While cooling down, a precipitate is formed. It is slurred up with a small amount of water and filtered off. It is washed with water and then dried to afford the product. Yield: 93% (13.6 g; 94.07 mmol) HPLC-MS: (M+H)+=145/147; tRet=0.34 min; method FECB5

The synthetic route of 4858-85-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ENGELHARDT, Harald; US2015/133447; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, molecular formula is C6H5ClN2O2, 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. 33332-25-1.

A mixture of methyl 5-chloropyrazine-2-carboxy- late (1.72 g, 10 mmol), tert-butyl piperazine-1-carboxylate (3.72 g, 20 mmol) and DIPEA (3.87 g, 30 mmol) in 1 ,4-dioxane (20 mE) was stirred at 1000 C. for overnight. The mixture was concentrated to get a residue, which was purified by silica gel to get compound (3.06 g, 95%).

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

Reference:
Patent; Regenacy Pharmaceuticals, LLC; van Duzer, John H.; Mazitschek, Ralph; (123 pag.)US2018/141923; (2018); 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. 486460-21-3 name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine, 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. 486460-21-3

The resulting product is dissolved in tetrahydrofuran (200 ml) and the solution is added in about 90 minutes to a solution obtained dissolving chloroacetyl chloride (28.6 g, 253 mmol) in tetrahydrofuran (200 ml), under N2 atmosphere and under stirring. The solution is left under stirring at 25C for 1 h. After completion of the reaction, a 25% NaOH solution (80 g) is added, the phases are separated and the aqueous phase is extracted with 2×100 ml of tetrahydrofuran. The solvent is concentrated under reduced pressure to obtain 160 g of a crude, which is added with methyl-tert-butyl ether (220 ml) and the solution is heated under reflux of the solvent mixture. The solution is cooled to 10C under strong stirring for 3h. The product (56.1 g, 209 mmol, 89% yield) is a white solid.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine, and friends who are interested can also refer to it.

Reference:
Patent; Dipharma Francis S.r.l.; EP2270009; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem