Category: Pyrazines

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. 27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., 27398-39-6

102901 To a solution of 3-chloropyrazine-2-carboxylic acid (2.0 g, 12.70 mmol, 1.0 eq.) andTEA (3.50 mL, 25.40 mmol, 2.0 eq.) in THF (50 mL) was added methyl chloroformate (1.2 mL,15.20 mmol, 1.2 eq.) atO ¡ãC. The mixture was stirred at 0¡ãC for 10 mm and filtered. To thisfiltrate was added a suspension of NaBH4 (0.97 g, 25.40 mmol, 2 eq.) in water (1.0 mL) at 0 ¡ãC. The mixture was stirred at 0 ¡ãC for 1 h, quenched with NH4C1 (aq) solution, and extracted with EtOAc twice. The combined organic layers were dried over Na2SO4, concentrated, and purified on silica gel using a mixture of EtOAc and hexanes as eluent to give (3-chloropyrazin-2- yl)methanol (400 mg, 22percent) as a white solid. 1H NMR (400 MHz, MeOD) 8.58 (d,J 2.5 Hz,1H), 8.38 (d,J= 2.5 Hz, 1H), 4.84 (s, 2H). LRMS (M+H+) m/z 145.1.

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; GLOBAL BLOOD THERAPEUTICS, INC.; CYTOKINETICS, INC.; THE REGENTS OF THE UNIVERSITY OF CALIFORNIA; METCALF, Brian; CHUANG, Chihyuan; WARRINGTON, Jeffrey; PAULVANNAN, Kumar; JACOBSON, Matthew P.; HUA, Lan; MORGAN, Bradley; WO2013/102145; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

36070-80-1, 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. 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

Step 1: 5-chloro-N-[(lR)-2,2,2-trifluoro-l-methylethyl]pyrazine-2-carboxamideN,N-Diisopropylethylamine (1.3 mL, 7.5 mmol) was added to a mixture of 5- chloropyrazine-2-carboxylic acid (0.40 g, 2.5 mmol) (Matrix, Cat.No.: 054028), N,N,N’,N’-tetramethyl-0-(7-azabenzotriazol- 1 -yl)uronium hexafluorophosphate (1.0 g, 2.8 mmol) and (2R)-l, l,l-trifluoropropan-2-amine hydrochloride (0.38 g, 2.5 mmol) in methylene chloride (10 mL). The reaction mixture was stirred at room temperature overnight. The reaction mixture was worked up with saturated aqueous aHC03, and extracted with ethyl acetate (3x 20 mL). The combined organic layers were washed with brine, dried over MgS04, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography on a silica gel column with ethyl acetate in hexanes (0-20%) to afford the desired product (0.64 g,76%). LCMS (M+H) +: m/z = 253.9/255.9.

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

Reference:
Patent; INCYTE CORPORATION; YAO, Wenqing; BURNS, David M.; ZHUO, Jincong; WO2012/177606; (2012); 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. 27398-39-6 name is 3-Chloropyrazine-2-carboxylic acid, 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. 27398-39-6

[00142] A mixture of 19 (1.50 g, 9.49 mmols, 1.0 eq), 1-(4-fluorophenyl)ethanamine (2.64 g, 19.0 mmols, 2.0 eq) and K2C03 (3.93 g, 28.5 mmols, 3.0 eq) in NMP (30 mL) was degassed, purged with nitrogen, and stirred at 140 ¡ãC for 16 hours. The mixture was diluted with ethyl acetate (100 mL) and washed with 2 N aqueous HC1 (30 mL x 3). The organic layer was dried over Na2SO4, filtered, and concentrated, the residue was purified by recrystallization (Petroleum ether/ethyl acetate) to give the desired product 20 (2.00 g, 7.66 mmols, 80.6percent) as a white solid.[00143] LCMS: ESI-MS: m/z: 262.2 [M+H1 RT = 1.87 mm. (Method A).

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

Reference:
Patent; ALPHARMAGEN, LLC; PUTMAN, David, G.; DASSE, Olivier; HOGENKAMP, Derk; (154 pag.)WO2016/144792; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 6164-79-0, name is Methyl 2-pyrazinecarboxylate, molecular formula is C6H6N2O2, 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. 6164-79-0

a 2-Hydroxymethylpyrazine To methyl 2-pyrazinecarboxylate (1.80 g) in THF (60 ml) was added diisobutylaluminium hydride (1 M solution in THF; 39 ml) at -78 C. with stirring. The solution was allowed to warm to room temperature, and stirred for 24 h. The reaction was quenched with solid tartaric acid, then aqueous sodium potassium tartrate, and stirred for 30 min at room temperature. Saturated aqueous sodium hydrogen carbonate was added until the pH of the solution was >7. The solution was washed with ethyl acetate (3*200 ml), and the organic layers combined, washed with saturated sodium chloride solution (1*200 ml), dried (magnesium sulfate) and concentrated in vacuo. The residue was purified by flash chromatography (silica gel, eluent =5% methanol in dichloromethane) to yield 2-hydroxymethylpyrazine as a dark brown oil (0.16 g). 1H NMR (250 MHz, CDCs) delta3.42 (1 H, br s), 4.85 (2 H, s), 8.55 (2 H, m), 8.68 (1 H, s); MS (ES+) m/e 111 [MH+].

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 6164-79-0, its application will become more common.

Reference:
Patent; Merck Sharp & Dohme Limited; US6255305; (2001); B1;,
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. 123-32-0 name is 2,5-Dimethylpyrazine, 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. 123-32-0

54 g (498 mmol) of 2,5-dimethylpyrazine (manufactured by Tokyo Chemical Industry Co., Ltd.) and 224 g (2.02 mol) of selenium dioxide were added to 840 ml of a mixed solution of pyridine and water (mixing mass ratio: 20/1) And the mixture was heated under reflux for 48 hours. The reaction solution was cooled to ambient temperature and filtered, and the filtration residue was washed with a mixed solution of pyridine and water (mixing mass ratio: 20/1), the filtrate and the washing solution were combined and the liquid was distilled off to obtain a solid It was.The resulting solid was dispersed in 2 M dimethylamine aqueous solution used as an extraction solvent, and residual solids were removed from the extract by filtration. By distilling off the solvent from the extract, 71 g (yield 85%) of 2,5-pyrazinedicarboxylic acid (3) was obtained.

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

Reference:
Patent; IHI Corporation; Waseda University; Sato, Yutaka; Kanomata, Norihiro; Yuchi, Takeshi; (19 pag.)JP2018/140981; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6164-79-0, These common heterocyclic compound, 6164-79-0, name is Methyl 2-pyrazinecarboxylate, 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.

Method 54; Pvrazine-2-carboxaldehyde oxime A IN solution of lithium aluminium hydride in THF (73. 8ml, 73.8mmol) was added to a suspension of methyl pyrazine-2-carboxylate (20g, 145mmol) in anhydrous THF (300. 0ml) at-78¡ãC keeping the reaction temperature below-72¡ãC. On completion of addition the reaction mixture was left to stir at-78¡ãC for a further 20 minutes and then quenched with glacial acetic acid (20. 0ml). The resulting mixture was warmed to room temperature and the volatiles removed by evaporation. The residue was dissolved in 3N hydrochloric acid (116ml) and extracted with DCM. The extracts were combined, washed with saturated aqueous sodium hydrogen carbonate solution and the solvent evaporated. The residue was purified by chromatography on silica gel eluting with DCM/diethylether (100: 0 then 80: 20 and then 0: 100) to give pyrazine-2-carboxaldehyde (15.67g, 100percent). This was immediately dissolved in chloroform (200ml) cooled to 0¡ãC and hydroxylamine mono-hydrochloride (11. 02g, 159. 5mmol) and triethylamine (24. 2ml, 117. 4mmol) were added. The reaction mixture was then stirred at ambient temperature for 0.5 hour, and the solvent removed by evaporation. The residue suspended in diethylether (500ml) and the insolubles removed by filtration. The filtrate was evaporated and the residue purified by chromatography eluting with DCM/diethylether (100: 0 then 80: 20 and then 0: 100) to give the title compound (5. 5g, 31percent) as a solid. NMR (DMSO-d6) : 8.15 (s, 1H), 8.62 (dd, 2H), 8. 99 (s, 1H).

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 6164-79-0.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2005/40159; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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 274-79-3 as follows. 274-79-3

To a solution of imidazo[1,2-a]pyrazine (intermediate C) (2.8 g, 23.5 mmol) in AcOH (acetic acid) (200 ml) was added bromine (6 ml, 5 eq.) via addition funnel, with the reaction flask protected from light. After addition, the flask was sealed. The mixture was stirred at rt for 24 hr., 6 ml (5 eq.) of additional Br2 was added to the reaction mixture, which was further stirred at rt for 48 hr. The mixture was evaporated to remove Br2 and acetic acid, and the residue was dissolved in 10% IPA/DCM, washed with sat. Na2CO3 (300 ml). The organics were combined, dried and concentrated to afford 5.9 g (yield 97%) of 3,5-dibromo-imidazo[1,2-a]pyrazine. 1H-NMR (400 MHz, DMSO-d6) delta 9.05 (s, 1H), 8.09 (s, 1H), 7.99 (s, 1H). MS m/z 278 [M++1].

According to the analysis of related databases, 274-79-3, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Sugen, Inc.; US2004/220189; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, 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. 55557-52-3

1-[3-(3-Chloro-phenyl)-acryloyl]-piperazine-2-carboxylic acid methyl ester (1.6 g, 5.18 mmol) was mixed with 3-chloro-pyrazine-2-carbonitrile (0.868 g, 6.22 mmol) and triethylamine (1.05 g, 10.36 mmol) in acetonitrile at 90 C. overnight. The reaction mixture was quenched water and extracted with dichloromethane. The product was purified by column chromatography with 50% ethyl acetate in hexanes to give 4-[3-(3-chloro-phenyl)-acryloyl]-3′-cyano-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl-3-carboxylic acid methyl ester (white solid, 1.5 g, 70.3%).

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 55557-52-3.

Reference:
Patent; AstraZeneca AB; NPS PHARMACEUTICALS; US2007/49578; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

875781-43-4, 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. 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, This compound has unique chemical properties. The synthetic route is as follows.

Step 5: Synthesis of 2-Bromo-7-iodo-5-(toluene-4-suIfonyl)-5H-pyrroIo[2,3-b]pyrazine.[0286] To a suspension of 2-Bromo-7-iodo-5H-pyrrolo[2,3-b]pyrazine (290 mg, 0.895mmol) in THF (5 ml) was added NaH (60%, 43 mg, 1.08 mmol) in one portion at 0 C.The resulting mixture was stirred for 20 minutes before a ‘solution of para-toluenesulfonylchloride (188mg, 0.98 mmol) in THF (2 mL) was added. The reaction mixture was thenstirred at room temperature for 3 hours. Solvents were removed and the resulting darkbrown residue washed with aqueous KOH, water and dried to afford the title compound(423 mg, 99% yield) as a light brown solid. .H-NMR (500 MHz, Patent; SGX PHARMACEUTICALS, INC.; WO2006/15124; (2006); A2;,
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. 23229-25-6, name is 2,6-Dibromopyrazine, This compound has unique chemical properties. The synthetic route is as follows., 23229-25-6

the molar ratio of Sodiummethoxide and dibromopyrazine is 5:1 placed into three-necked flask with astirrer and a thermometer, added 500ml of Distilled water, start the mixer andwith speed of 200r / min it was stirredfor 10min; After the mixing the mixture was placed at reflux apparatus , heatedup to 60 C, refluxed for 2h, , the collected reflux liquid was put into abeaker then placed in an ice-water bath , at 4 C under ice the precipitatewas allowed to stand for 2h, filtered toobtain precipitate and spare after rotary evaporation drying; The massconcentration of concentrated sulfuric acid is 98% and after drying as mentioned above the precipitatemass ratio is 12: 1 were mixed andtogether poured into a beaker of 500mL, after stirred with a glass rod for10min placed on the shaker and Oscillating reaction for 2 h ,then againadded 50mL of nitric acid solution with a mass concentration of 95% , continues to oscillate the reaction for 20minto obtain a mixed solution; The ratio of the mixed liquid and ammonia water is1:5, the ammonia water was poured into the above mentioned mixed solution, placedthe reaction solution on a magnetic stirrer, with speed of 600r / min it was stirred for 10s , afterwards reduce speed to200r / min and continue to stir for 30min. After completion of the stirring,400ml of anhydrous ethanol added into the mixture solution, placed intoultrasonic vibration device, ultrasonic vibration reaction for 1h, thentransferred to a distillation apparatus, heated to 60 C, ethanol was removedby distillation,for drying used vacuum freeze-drying machine and after crushingof solid particles; Take 1g of the above mentioned solid particles and put into100ml of beaker , added 15ml of glacial acetic acid and 10ml of hydrogenperoxide with a mass concentration of 30%, water bath warmed to 40 C, andafter the 6hrs of reaction filtrated to obtain precipitate and dried to obtain 2,6-diamino-3,5-dinitro-1-oxidepyrazine.

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; Changzhou University; CHEN, Xing-quan; (5 pag.)CN105399690; (2016); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem