Pyrazines

Electric Literature 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

622392-04-5, name is 2-Bromo-5-iodopyrazine, belongs to pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. Quality Control of 2-Bromo-5-iodopyrazine

Preparation of compound 22a: 2-(2,2-difluoroethoxy)-5-iodopyrazineTo a solution of 2,2-difluoroethanol (0.74 g, 8.7 mmol) in THF (5OmL) at room temperature was added sodium butoxide (1.13 g, 11.4 mmol) and stirred for 15 min. The reaction mixture was cooled to 0 0C and a solution of 2-bromo-5-iodopyrazine (2.5 g, 8.7 mmol) in THF (50 ml_) was added slowly over 5 min. The reaction mixture was allowed to warm to room temperature and stirred for 16 h. The mixture was diluted with ethyl acetate and washed with sat. NH4CI. The organic layer was dried over MgSO4, filtered and concentrated which gave the title compound 22a (2.3 g, 90%).

The synthetic route of 622392-04-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PFIZER INC.; NINKOVIC, Sacha; BRAGANZA, John Frederick; COLLINS, Michael Raymond; KATH, John Charles; LI, Hui; RICHTER, Daniel Tyler; WO2010/16005; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 622392-04-5, name is 2-Bromo-5-iodopyrazine, A new synthetic method of this compound is introduced below., Formula: C4H2BrIN2

Step 1: N-1-(5-Iodo-pyrazin-2-yl)-2-methyl-propane-1,2-diamine To a solution of 2-bromo-5-iodopyrazine (CAS 622392-04-5) (250 mg, 878 mmol) in 0.7 ml of pyridine, was added 2-methylpropane-1,2-diamine (116 mg, 138 mul, 1.32 mmol, 1.5 equiv.) at room temperature. The colorless solution was stirred for 16 hours at 100 C. The reaction mixture was cooled and concentrated in vacuo. The crude material was used directly in the next step.

The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.

Reference:
Patent; Green, Luke; Guba, Wolfgang; Jaeschke, Georg; Jolidon, Synese; Lindemann, Lothar; Ricci, Antonio; Rueher, Daniel; Stadler, Heinz; Vieira, Eric; US2011/251169; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 850349-42-7, 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. 850349-42-7, name is Methyl imidazo[1,2-a]pyrazine-8-carboxylate, This compound has unique chemical properties. The synthetic route is as follows.

PREPARATIVE EXAMPLE 10; Commercially available Imidazo[l,2-a]pyrazine-8-carboxylic acid methyl ester (337 mg) was dissolved in 1,4-dioxane (25 ml) and H2O (58 ml) and treated with 1 M NaOH (2.4 ml). The mixture was stirred at room temperature for 45 Min and the solvents evaporated to afford the crude title compound (MH+ = 164).

The chemical industry reduces the impact on the environment during synthesis Methyl imidazo[1,2-a]pyrazine-8-carboxylate. I believe this compound will play a more active role in future production and life.

Reference:
Patent; ALANTOS PHARMACEUTICALS HOLDING, INC.; WO2008/63669; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 54608-52-5,Some common heterocyclic compound, 54608-52-5, name is 2-Hydrazinopyrazine, molecular formula is C4H6N4, 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.

Synthesis of (Z)-3-(3-(4-chloro-3,5-bis(trifluoromethyl)phenyl)-lH-l ,2,4-triazol-l- yl)-N’-(pyrazin-2-yl)acrylohydrazide: In a 50-mL, 3-necked, round-bottomed flask charged with a solution of (Z)-3-(3-(4- chloro-3,5-bis(trifluoromethyl)phenyl)-lH-l,2,4-triazol-l-yl)acrylic acid (0.8 g) in 1 : 1 EtOAc:THF (20 mL). The solution was cooled to -70 C and treated sequentially with 2- hydrazinopyrazine (0.275 g, 1.2 eq.), T3P (50% in EtOAc; 2.5 mL, 2.0 eq.) and DIPEA (1.44 mL, 4.0 eq.), added dropwise. The clear reaction mixture was stirred at -60C for 1 h before being concentrated under reduced pressure (25 C, 20 mm Hg) to afford crude compound. Purification by column chromatography using (60/120 mesh Si02, elution with 3-4% MeOH in CH2C12) afforded 0.30 g (yield: 30%) (Z)-3-(3-(4-chloro-3,5-bis(trifluoromethyl)phenyl)- lH-l ,2,4-triazol-l-yl)-N’-(pyrazin-2-yl)acrylohydrazide. 1H NMR (400 MHz, DMSO-d6) delta = 10.53 (s, 1H), 9.58 (s, 1H), 9.11 (s, 1H), 8.47 (s, 1H), 8.32 (s, 1H), 8.13 (s, 1H), 8.06 (s, 1H), 7.97 (s, 1H), 7.52-7.55 (d, J = 10.4 Hz, 1H), 6.08-6.1 1 (d, J = 10.4 Hz, 1H); LCMS for CnHnClFe yO [M+H]+ 478.76 found 478.1 (RT 2.64 min, purity: 100%).

The synthetic route of 54608-52-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; KARYOPHARM THERAPEUTICS, INC.; SANDANAYAKA, Vincent, P.; SHACHAM, Sharon; MCCAULEY, Dilara; SHECHTER, Sharon; WO2013/19548; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

875781-43-4, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 875781-43-4 as follows.

Step 4: Synthesis of 2-Bromo-7-iodo-5H-pyrrolo[2,3-b]pyrazine.[0285] To a solution of 2-Bromo-5H-pyrrolo[2,3-b]pyrazine (258 mg, 1.3 mmol) inacetone (5 ml) was added Af-iodosuccinimide (324 mg, 1.44 mmol) in one portion. Thereaction mixture was stirred at room temperature for 45 minutes. The resulting precipitatewas filtered off, washed with a minimal amount of acetone, and dried in vacuum to give thetitle compound as a light brown solid ^-NMR (500 MHz, d6-DMSO) £12.81 (s br, 1H),8.40 (s, 1H), 8.19 (d, 3.0Hz, 1H). MS: m/z 323.8/325.8 [MH+].

According to the analysis of related databases, 875781-43-4, the application of this compound in the production field has become more and more popular.

Reference:
Patent; SGX PHARMACEUTICALS, INC.; WO2006/15124; (2006); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 768-05-8, A common heterocyclic compound, 768-05-8, name is Pyrazinoic acid hydrazide, molecular formula is C5H6N4O, 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 a dried RB flask, KOH (1.42 g, 25.33 mmol) was suspended in ethanol (50 mL) atambient temperature. Then pyrazine-2-carbohydrazide6a (5 g, 36.19 mmol) was added and reaction mass was cooled.Carbon disulfide (2.4 mL, 39.81 mmol)was added dropwise and the resulting mixture was refluxed for 12 h. Thereaction progress was monitored by TLC and after completion of the reactionsolvent was distilled under vacuum. The reaction pH was adjusted to 6.0-7.0 by adding4N HCl. The precipitated solid was collected by filtration, washed with water(50 mL) and dried to give white solid compound 7a. Yield: 5.71 g, 87 %; 1HNMR (CDCl3, 400 MHz, delta inppm): 14.817 (s, 1H, -SH), 9.193 (bs, 1H, Ar-H), 8.793 (s, 1H, Ar-H), 8.764 (s,1H, Ar-H); 13C NMR (100 MHz, CDCl3) delta (ppm): 168.7, 164.2, 152.6, 147.7, 145.4, 143.5; ESI-MS (m/z)= 181.1 (M+H)+; calculated for C6H4N4OS;C, 39.99; H, 2.24; N, 31.09; S, 17.80. Found: C, 39.97; H, 2.25; N, 31.05; S,17.84.

The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.

Reference:
Article; Reddyrajula, Rajkumar; Dalimba, Udayakumar; Bioorganic and Medicinal Chemistry Letters; vol. 30; 2; (2020);,
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. 6863-74-7, name is 6-Chloropyrazine-2-carbonitrile belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. 6863-74-7

A mixture of tert-butyl ((1R,4R,7R)-2-(1-(azetidin-3-ylmethyl)-2-(1- (cyclopropylmethyl)-1H-pyrrolo[2,3-b]pyridin-2-yl)-7-methoxy-1H-benzo[d]imidazole- 5-carbonyl)-2-azabicyclo[2.2.1]heptan-7-yl)carbamate (15 mg, 0.024 mmol), 6- chloropyrazine-2-carbonitrile (3.34 mg, 0.024 mmol), cesium carbonate (15.62 mg, 0.048 mmol), BINAP (0.746 mg, 1.199 mmol) and Pd2(dba)3 (1.098 mg, 1.199 mmol) in degassed dioxane (1.0 mL) under nitrogen in a seal vial was stirred at 90C for 18 hour. The mixture was diluted with EtOAc (5 mL) and was washed with a solution of aqueous saturated sodium bicarbonate (5 mL). The organic layer was dried over sodium sulfate and concentrated to give crude tert-butyl ((1R,4R,7R)-2-(1-(azetidin-3-ylmethyl)-2-(1- (cyclopropylmethyl)-1H-pyrrolo[2,3-b]pyridin-2-yl)-7-methoxy-1H-benzo[d]imidazole- 5-carbonyl)-2-azabicyclo[2.2.1]heptan-7-yl)carbamate (15 mg, 0.024 mmol). Material was used as is in next reaction.

The synthetic route of 6863-74-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; BRISTOL-MYERS SQUIBB COMPANY; NGU, Khehyong; (435 pag.)WO2020/33514; (2020); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 74290-67-8, 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. 74290-67-8 name is 2-Amino-5-bromo-3-methylpyrazine, 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.

a) 3-(N-(3-((5-amino-6-methylpyrazin-2-yl)ethynyl)-2,4-difluorophenyl)sulfamoyl)-5-chloro-2-methoxybenzyl Acetate A mixture of 5-chloro-3-(N-(3-ethynyl-2,4-difluorophenyl)sulfamoyl)-2-methoxybenzyl acetate (200 mg), dichlorobis(tricyclohexylphosphine)palladium(II) (34.3 mg), DIPEA (2 mL), copper(I) iodide (17.7 mg), 5-bromo-3-methylpyrazin-2-amine (114 mg) and DMSO (2 mL) was stirred under microwave irradiation at 100 C. for 1 hr. After cooling to room temperature, the reaction mixture was diluted with water and extracted with ethyl acetate. The obtained organic layer was washed with saturated brine, dried over magnesium sulfate and concentrated to give a residue. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give the title compound (216 mg). MS: [M+H]+ 537.0.

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

Reference:
Patent; Takeda Pharmaceutical Company Limited; FUJIMOTO, Jun; LIU, Xin; KURASAWA, Osamu; TAKAGI, Terufumi; CARY, Douglas Robert; BANNO, Hiroshi; ASANO, Yasutomi; KOJIMA, Takuto; (159 pag.)US2019/169166; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

14508-49-7, name is 2-Chloropyrazine, belongs to pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. Recommanded Product: 14508-49-7

A mixture of CHLOROPYRAZINE (9.6 g, 83.3 MMOL) and hydrogen peroxide solution (30%, 16 mi) in glacial acetic acid (26 ml) was heated at 70 C for 18 hours. The mixture was allowed to cool to room temperature, poured into water (250 ml) and extracted with DICHLOROMETHANE (3 x 100 ML). The DICHLOROMETHANE extracts were combined, washed with saturated sodium bicarbonate solution (2 x 70 ML), water (3 x 100 ML) and brine (100 ml). The organic portion was dried under sodium sulfate and evaporated in vacuo to give a white solid which was recrystallised from absolute ethanol to give the title compound (0.45 g). ‘H NMR (CDCI3) 8.27-8. 26 (1H, d), 8.15 (1 H, S), 8.03-8. 02 (1 H, dd).

The synthetic route of 14508-49-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GLAXO GROUP LIMITED; WO2004/56369; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem