Category: Pyrazines

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

The chemical industry reduces the impact on the environment during synthesis 1458-01-1, name is Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, I believe this compound will play a more active role in future production and life. 1458-01-1

A mixture of methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (100 g; 494 mmol), methanol (1 I) and NaOH (6 mol/l in water; 240 mL; 1 .44 mol) is refluxed for 3 h. The mixture is allowed to cool to r.t. and then neutralized by addition of hydrochloric acid (6 mol/l in water; approx. 240 mL). Water (200 mL) is added. The precipitate formed is filtered off with suction, washed with water and dried at 60¡ãC. Yield: 99.6 g (107percent of theory). C5H5ClN4O2. ESI Mass spectrum: m/z = 189 [M+H]+; m/z = 187 [M-H]-.

The chemical industry reduces the impact on the environment during synthesis 1458-01-1. I believe this compound will play a more active role in future production and life.

Reference:
Patent; BOEHRINGER INGELHEIM INTERNATIONAL GMBH; HECKEL, Armin; BLUM, Andreas; HAMPRECHT, Dieter; KLEY, Joerg; WO2013/92674; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 23611-75-8, name is Methyl 6-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. 23611-75-8.

Add methyl 6-chloropyrazine-2-carboxylate (20. 0 g, 116 mmol) in THF (1 00 mL) to methylmagnesium bromide (3.0 mol/L) in diethyl ether (120 g, 348 mmol, 3.0 mol/L) at 0 C and the mixture is stirred at this temperature for 2 h. The reaction is quenched with 1.0HCl solution (100 mL) and extracted with EtOAc (100 mL x 3). The combined organic layers are washed with brine (100 mL), dried over anhydrous sodium sulfate, concentrated to afford a yellow oil. The yellow oil is purified by column chromatography on silica gel eluting with 0-30% EA in PE to afford title compound (3.80 g, 18.0%) as brown oil. LCMS (m/z): 5 172.8 [M+H]

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 6-chloropyrazine-2-carboxylate, its application will become more common.

Reference:
Patent; ELI LILLY AND COMPANY; LILLY CHINA RESEARCH AND DEVELOPMENT CO., LTD.; MA, Tianwei; WU, Liang; ZHANG, Xuejun; (109 pag.)WO2019/41340; (2019); A1;,
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. 15707-23-0, name is 2-Ethyl-3-methylpyrazine, This compound has unique chemical properties. The synthetic route is as follows., 15707-23-0

[0239] A mixture of 2-methyl-3-ethylpyrazine (1.0 g, 8.19mmol), selenium dioxide (1.8 g, 16.38 mmol), and diatomaceous earth (1.8 g) in dioxane (20ml) was refluxed for overnight. The mixture was allowed to cool to room temperature. The solid material was removed by filtration through diatomaceous earth. The solvent was evaporated under reduced pressure. The crude product was washed with water (3 x 10 ml), extracted with ethyl acetate (3 x 20 ml), dried with Na2S04 and concentrated. The crude product was used directly for the next step reaction without purification. LC/MS = 137 [M+l].

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; MERCK SHARP & DOHME CORP.; KUANG, Rongze; TING, Pauline; ALI, Amjad; WU, Heping; BERLIN, Michael; STAMFORD, Andrew; WANG, Hongwu; ZHOU, Gang; KIM, David; DENG, Qiaolin; LIM, Yeon-Hee; YU, Younong; (201 pag.)WO2016/81290; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

19745-07-4, 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. 19745-07-4, name is 2,5-Dichloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

To a stirred solution of Intermediate 2 (0.2 g, 0.74 mmol) in DMF (5 mL,), TEA (0.5 mL,, 3.70 mmol) and 2,5-dichloro pyrazine (0.11 g, 0.74mmol) was added and stirred at 120¡ãC for 2 h. The reaction mixture was concentrated under vacuum and the resulting crude product was dissolved in DCM. It was washed with water, dried over anhydrous Na2SO4, and concentrated under vacuum. The crude product was purified by flash chromatography to afford the title compound (brown oil). 1H NMR (400 MHz, DMSO-d6): delta 8.23 (s, 1H), 7.81 (s, 1H), 6.88 (d, J = 1.2 Hz, 1H), 6.84 (d, J = 8.0 Hz, 1H), 6.74 (dd, J = 1.6, 8.0 Hz, 1H), 5.97 (s, 2H), 3.54-3.52 (m, 4H), 3.39-3.37 (m, 1H), 2.45-2.44 (m, 2H), 2.39-2.37 (m, 2H), 1.27 (d, J = 6.4Hz, 3H). LCMS: (Method A) 347.0 (M+H), Rt. 3.03 min, 97.9percent (Max). HPLC: (Method A) Rt. 3.05 min, 97.6percent (Max).

The synthetic route of 19745-07-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ASCENEURON SA; QUATTROPANI, Anna; KULKARNI, Santosh S.; GIRI, Awadut Gajendra; (243 pag.)WO2016/30443; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

55557-52-3, 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. 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, This compound has unique chemical properties. The synthetic route is as follows.

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 4.5h. 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, CDC13) 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).

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; N.V. ORGANON; FOLMER, Brigitte, Johanna, Bernita; MAN, de, Adrianus, Petrus, Antonius; GERNETTE, Elisabeth, Sophia; CORTE REAL GONCALVES AZEVEDO, Rita; IBRAHIM, Hemen; WO2011/147764; (2011); 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. 5521-58-4 name is 5-Methylpyrazin-2-amine, 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. 5521-58-4

To a flask fitted with overhead stirrer, condenser, thermometer and nitrogen line was added 3-{[5-(azetidin-1-ylcarbonyl)pyrazin-2-yl]oxy}-5-[(1S)-2-methoxy-1-methylethoxy]benzoic acid (1.0 eq), and acetonitrile (10 vols) followed by pyridine (3 eq) under a nitrogen atmosphere. Thionyl chloride (1.2 eq) as a solution in acetonitrile (0.225 vols) was added slowly, drop-wise via syringe pump over at least 2 hours. 5-Methylpyrazin-2-amine (1.2 eq) was added to the mixture as a solid. After 2.5 hours the reaction was quenched by adding toluene (10 vols) and 1.0M sodium carbonate solution (2.5 eq). The layers were separated. The organic layer was retained in the flask, then 1.0M hydrochloric acid (1.94 eq) was added. The mixture was agitated for 15 minutes then separated. The organic layer was washed with two aliquots of water (5 vols) then the solvent was removed on the rotary evaporator. Toluene (5 vols) was added to the residue, and warmed to 45 C. Isohexane (1.7 vols) was added, the mixture was seeded, and allowed to cool to ambient temperature overnight. The mixture was cooled to 0 C. for 4 hours, and then cooled to -10 C. for 3 hours. The solid was isolated by filtration then washed with iso-hexane (2.5 vols). After drying in the vacuum oven at 40 C. overnight, the desired product was obtained as a solid (corrected yield 85%).

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

Reference:
Patent; AstraZeneca AB; US2010/210841; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6164-79-0, Name is Methyl 2-pyrazinecarboxylate, 6164-79-0, 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.

Methyl 3-oxo-3-(pyrazin-2-yl)propanoate: To a stirred solution of sodium methoxide (25% in MeOH, 27.54 mL, 72.4 mmol, 1 eq) in 90 mL of toluene at 110 C. in a 3-neck flask attached with a mechanical stirrer, condenser and dropping funnel was added a solution of methylpyrazine-2-carboxylate (10 g, 72.4 mmol, 1 eq) in 115 mL of methyl acetate, dropwise, over a period of ?35-40 min. A yellow precipitate was formed. Stirring was continued at 110 C. for 3 hrs. The reaction was cooled and the yellow precipitate was filtered and washed with a small quantity of toluene. This solid was taken into 200 mL of saturated ammonium chloride and 400 mL of EtOAc. The aqueous layer was extracted twice with EtOAc. The combined organic layers were dried over magnesium sulfate, filtered and evaporated to give 6.52 g (50%) of methyl 3-oxo-3-(pyrazin-2-yl)propanoate as a yellow solid.

Statistics shows that Methyl 2-pyrazinecarboxylate is playing an increasingly important role. we look forward to future research findings about 6164-79-0.

Reference:
Patent; Hoffmann-La Roche Inc; Bhagirath, Niala; Brameld, Kenneth Albert; Kennedy-Smith, Joshua; US2013/90334; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, 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. 27398-39-6

To a solution of 3-chloropyrazine-2-carboxylic acid (100 mg, 0.63 mmol) in DCM/MeOH (2 mL : 0.2 mL) was added TMSCH1?2 (0.47 mL, 0.95 mmol) at RT and the resulting mixture was stirred at RT for 2 h. Acetic acid (0.2 mL) was added and the mixture was diluted with water (2 mL) and extracted with DCM (4 mL x 3). The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated in vacuo to give the title compound. LRMS m/z (M+H) 173.0 found, 173.0 required.

Statistics shows that 27398-39-6 is playing an increasingly important role. we look forward to future research findings about 3-Chloropyrazine-2-carboxylic acid.

Reference:
Patent; MERCK SHARP & DOHME CORP.; KIM, Ronald; KUDUK, Scott, D.; LIVERTON, Nigel; ZHUO, Gang; (97 pag.)WO2016/100157; (2016); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

13301-04-7,Some common heterocyclic compound, 13301-04-7, name is Methyl 3,6-dibromopyrazine-2-carboxylate, molecular formula is C6H4Br2N2O2, 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 solution of LiOH (121 mg, 5.07 mmol) in water (1 mL) was slowly added to a solution the pyrazine ester (500 mg, 1.67 mmol) in 1:1 THF/water (8 mL) at 0 C. After stirring at 0 C. for 45 min. The solvent was removed under reduced pressure. The residue was dissolved in a mixture of DCM and 1N aq. HCl. The organic layer was separated and the aqueous extracted twice with DCM. The combined organic extracts were dried (Na2SO4), filtered and concentrated to afford 350 mg (74%) of a cream colored solid. MS m/z (ES): 282 (M+H)+.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 3,6-dibromopyrazine-2-carboxylate, its application will become more common.

Reference:
Patent; de Vicente Fidalgo, Javier; Hermann, Johannes Cornelius; Lemoine, Remy; Li, Hongju; Lovey, Allen John; Sjogren, Eric Brian; Soth, Michael; US2011/59118; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem