Month: February 2021

Application of 59489-71-3,Some common heterocyclic compound, 59489-71-3, name is 2-Amino-5-bromopyrazine, molecular formula is C4H4BrN3, 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.

A. 5-vinylpyrazin-2-amine; To a mixture of 5-bromopyrazin-2-amine (1.0 g, 5.78 mmol) and vinyltri-n-butyltin (2.01 g, 6.36 mmol) in DMF(19 mL) were added LiCl (269 mg, 6.36 mmol) and DIEA (1.1 mL, 6.36 mmol). After degassing for 20 minutes, Pd(PPh3)4 (400 mg, 0.35mmol) was added to the reaction mixture. And then the mixture was refluxed for 4 hours under Ar atmosphere. The reaction mixture was cooled to room temperature and stirred with a 10% aqueous solution of potassium fluoride for 1 hour. The resulting solution was filtered through a pad of celite and washed with ethyl acetated. The aqueous layer was separated and extracted with ethyl acetate. The combined organic layer was dried over MgS04 and concentrated under reduced pressure. The crude product was purified by flash column chromatography (30% to 50% Ethyl acetate/Hexane) to afford title product (540 mg, 77% yield). MS m/z : 122 [M+l].

The synthetic route of 59489-71-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; DANA-FARBER CANCER INSTITUTE, INC.; GRAY, Nathanael, S.; WO2011/90738; (2011); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 33332-29-5, The chemical industry reduces the impact on the environment during synthesis 33332-29-5, name is 2-Amino-5-chloropyrazine, I believe this compound will play a more active role in future production and life.

Intermediate 22 5-Methoxypyrazin-2-amine [0242] To a solution of 5-chloropyrazin-2-amine (0.2 g, 1.54 mmol) in MeOH (3 mL) was added Cu powder (0.13 g, 2.07 mmol), followed by a solution of sodium methoxide in MeOH (0.38 mL, 1.75 mmol). The reaction mixture was stirred at 150 C. in a sealed tube for 24 h. The reaction mixture was then filtered through Celite, and the filtrate was concentrated in vacuo. The crude product obtained was purified by column chromatography (silica: 100-200 mesh, MeOH: DCM 2-3%) to afford the title compound (0.13 g, 67%). LCMS (ES+) 126 (M+H)+, RT 1.06 minutes (method 1).

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, 2-Amino-5-chloropyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Brookings, Daniel Christopher; Ford, Daniel James; Franklin, Richard Jeremy; Ghawalkar, Anant Ramrao; Kulisa, Claire Louise; Neuss, Judi Charlotte; Reuberson, James Thomas; US2014/315885; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 89123-58-0, name is 5-Bromopyrazine-2,3-diamine, 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 89123-58-0, Recommanded Product: 89123-58-0

(b) Add Compound II (7.8 g, 41.3 mmol, 1 eq) to a 250 mL vial.80 mL of DMF (ie, N,N-dimethylformamide) was added under constant stirring to dissolve Compound II.Triethyl orthoformate (7.34 g, 49.5 mmol, 1.2 eq) was added dropwiseAnd 20ml formic acid (about 1 drop / sec),Heating under reflux conditions for 24 h under nitrogen protection (at this time, TLC detection is basically free of raw materials);Unscrew the solvent and dissolve in methanol.Purification by silica gel column chromatography gave 5 g of compound III.

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

Reference:
Patent; Suzhou Derivative Biological Technology Co., Ltd.; Liu Ke; (6 pag.)CN108395436; (2018); 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. 33332-28-4, name is 2-Amino-6-chloropyrazine, This compound has unique chemical properties. The synthetic route is as follows., Recommanded Product: 2-Amino-6-chloropyrazine

Step 1: 2-amino-6-methoxypyrazine. To a stirred solution of methanol (89 muL; 2.2 mmol) in dioxane (1 mL) was added sodium hydride (53 mg; 2.2 mmol). After stirring for 30 minutes, 2-amino-6-chloropyrazine (258 mg; 2.0 mmol) was added and the reaction was heated to 90 C. After stirring for 12 hours, the reaction was cooled to room temperature, diluted with 30 mL of ethyl acetate and washed with aqueous 10% sodium carbonate (1*30 mL), and brine (30 mL), then dried (MgSO4), and filtered. The crude product was purified using the Biotage 12i cartridge eluding with hexane and ethyl acetate (3:1) to yield a white solid (11% yield).

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 33332-28-4.

Reference:
Patent; Keegan, Kathleen S.; Kesicki, Edward A.; Gaudino, John Joseph; Cook, Adam Wade; Cowen, Scott Douglas; Burgess, Laurence Edward; US2003/69284; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 33332-28-4, A common heterocyclic compound, 33332-28-4, name is 2-Amino-6-chloropyrazine, molecular formula is C4H4ClN3, 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.

The starting 2-amino-5-bromo-6-chloropyrazine was obtained as follows: A solution of 2-amino-6-chloropyrazine (5.0 g) and N-bromosuccinimide (13.9 g) in chloroform (200 ml) was heated under reflux for 2 hours. Insoluble material was removed by filtration and the filtrate was concentrated by evaporation. The residue was purified by flash chromatography on silica gel, eluding with dichloromethane, to give 2-amino-5-bromo-6-chloropyrazine (1.5 g); m.p. 120-122 C.; mass spectrum (+ve CI): 208 (M+H)+.

The synthetic route of 33332-28-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Zeneca Limited; US5861401; (1999); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 5049-61-6, 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. 5049-61-6, name is Pyrazin-2-amine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

To a solution of the compound 2-aminopyrazine (3.8 g, 40.00 mmol) in dimethyl sulfoxide (30 mL) and water (2 mL) was added N-bromosuccinimide (17.80 g, 0.10) in an ice bath. Mol). After stirring at room temperature for 4 hours, the reaction was poured into ice water (250 mL). Extract with ethyl acetate (50 mL¡Á4). Combine the organic phases, filter, and wash the filtrate with 5% sodium carbonate solution (200 mL) and saturated aqueous sodium chloride solution (50 mL), dry over anhydrous sodium sulfate, and concentrate. The residue is subjected to silica gel column chromatography. Purification by chromatography (petroleum ether/ethyl acetate=5:1) gave compound 56-b (4.10 g, 41%).

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

Reference:
Patent; SHANGHAI KAIHUI TECHNOLOGY DEVELOPMENT CO;LTD; XU, ZUSHENG; Kaihui Science And Technology Development (Shanghai) Co., Ltd.; Xu Zusheng; (100 pag.)CN103304571; (2018); B;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 123-32-0,Some common heterocyclic compound, 123-32-0, name is 2,5-Dimethylpyrazine, molecular formula is C6H8N2, 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.

General procedure: A 25 mL Schlenk tube equipped with a magneticstirring bar was charged with2,6-lutidine (0.75 mmol, 3equiv.), p-nitro-benzaldehyde(0.25 mmol), dioxane/water(1:1, 1ml) and [Hmim][H2PO4](1equiv.).The tube was sealed and heated at 100 for 24h. Aftercompletion of the reaction, the resulting solution was extracted with ether (3¡Á10 ml). The organic layer was dried with anhydrous Na2SO4,and concentrated under vacuum. The residue was chromatographed on a silica gelcolumn eluted with a mixture of petroleum ether and ethyl acetate (1:1) to givepure products (92%).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2,5-Dimethylpyrazine, its application will become more common.

Reference:
Article; Zhang, Xue-Yan; Dong, Dao-Qing; Yue, Tao; Hao, Shuang-Hong; Wang, Zu-Li; Tetrahedron Letters; vol. 55; 40; (2014); p. 5462 – 5464;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 98-97-5, name is Pyrazine-2-carboxylic acid belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. Formula: C5H4N2O2

To pyrazinecarboxylic acid (5.80 g, 46.5 mmol) in dichloromethane (100 mL) was added oxalyl chloride (5.10 mL, 60.4 mmol) followed by catalytic DMF. The reaction mixture was stirred at 23C for 6 h. Methanol (30 mL) was then added, and the mixture was stirred for an additional 30 min. The reaction mixture was concentrated in vacuo. The residue was taken up in EtOAc (200 mL), and washed with sat. NaHCO3 (aq) (1X100 mL) and brine (1X100mL). The organic layer was dried (MgSO4), and concentrated in vacuo to provide 3.38 g (53%) of methyl pyrazine-2-carboxylate which was used without further purification in the next step.1H NMR (400 MHz, CDCl3): d ppm 9.34 (d, 1H), 8.79 (d, 1H), 8.74 (dd, 1H), 4.06 (s, 3H); LCMS (Method A): tR= 0.48 min, m/z 139.3 (M+H)+.

The synthetic route of 98-97-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; VENENUM BIODESIGN LLC; LETOURNEAU, Jeffrey J; COLE, Andrew G; MARINELLI, Brett A; QUINTERO, Jorge G; (329 pag.)WO2017/214359; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 4774-14-5, 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. 4774-14-5, name is 2,6-Dichloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

A solution of compound 8 4500 g, 302 mol) in conc. aq. NH3 (3.0 L) was stirred at135C overnight in a 10 L sealed pressure vessel. TLC and LC/MS showed completeconversion of the starting material. The reaction mixture was cooled to roomtemperature and filtered to afford a white solid. The solid was washed with water (200mL x 3), and then dried to afford compound 9 (312 g, 80% yield) as a solid.1HNMR (400 MHz, DMSO-d6): 7,82 (s, 1 H), 712 (s, 1 H), 6.93 (s, 2H). MS Calcd.:129 MS Found: 130 ([M+Hj).

The synthetic route of 2,6-Dichloropyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; H. LUNDBECK A/S; SVENSTRUP, Niels; WEN, Kate; WANG, Yazhou; (78 pag.)WO2017/5786; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 5521-55-1, These common heterocyclic compound, 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, 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.

In methanol (15 ml), 5-methylpyrazine-2-carboxylic acid (manufactured by Tokyo Kasei Kogyo Co., Ltd.) (1.25 g) was dissolved. Then, the solution was added with WSCI hydrochloride (2.59 g) and N,N-dimethylaminopyridine (1.65 g) in this order, followed by stirring at room temperature for 3 hours. The reaction solution was added with water and then extracted with chloroform. The organic layer was washed with saturated saline solution and then dried with anhydrous sodium sulfate. The solvent was distilled off and the resulting crude product was then purified through silica gel column chromatography (chloroform/methanol). The purified product was dissolved in ethanol (15 ml) and THF (8 ml) and added with calcium chloride (1.11 g). After that, the reaction solution was cooled to 0C and then gradually added with sodium borohydride (757 mg), followed by stirring at room temperature for 19 hours. The reaction solution was added with a 1 mol/l citric acid solution (40 ml), followed by extraction with ethyl acetate. The organic layer was washed with saturated saline solution and then dried with anhydrous sodium sulfate, followed by distilling the solvent off. The residue was dissolved in chloroform (10 ml) and then added with manganese dioxide (chemically processed product) (2.2 g), followed by stirring at room temperature for 1 hour. After completion of the reaction, the catalyst was filtrated out through Celite and the solvent was then distilled off. The crude product obtained was purified through silica gel column chromatography (chloroform/methanol), thereby obtaining the subject compound (35.9 mg) as a colorless oily substance.

The synthetic route of 5521-55-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Kureha Chemical Industry Co., Ltd.; EP1550657; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem