Category: Pyrazines

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. 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, A new synthetic method of this compound is introduced below., 875781-43-4

Step 1. 2-Bromo-5-trityl-5H-pyrrolo[2,3-b]pyrazine. At 40 C., a solution of 2-bromo-5H-pyrrolo[2,3-b]pyrazine (725 mg, 3.66 mmol) and cesium carbonate (3250 mg, 9.95 mmol) in DMF (20.0 mL) was treated with trityl chloride (925 mg, 3.32 mmol). After 2 hours, the reaction mixture was cooled to ambient temperature and poured onto water (150 mL). The mixture was filtered and the filter cake was triturated with water (250 mL) for 1 hour. The solid was isolated and recrystallized from hot ethanol to afford 2-bromo-5-trityl-5H-pyrrolo[2,3-b]pyrazine (750 mg, 52%) as a colorless crystalline solid. LC/MS (M+H) 440.16.

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; Thorarensen, Atli; Brown, Matthew Frank; Casimiro-Garcia, Agustin; Che, Ye; Coe, Jotham Wadsworth; Flanagan, Mark Edward; Gilbert, Adam Matthew; Hayward, Matthew Merrill; Langille, Jonathan David; Montgomery, Justin Ian; Telliez, Jean-Baptiste; Unwalla, Rayomand Jal; US2015/158864; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6705-33-5, The chemical industry reduces the impact on the environment during synthesis 6705-33-5, name is Pyrazin-2-ylmethanol, I believe this compound will play a more active role in future production and life.

To a solution of pyrazin-2-ylmethanol (550 mg, 5 mmol, 1 equiv) and triethylamine (1.52 mL, 11 mmol, 2.2 equiv) in DCM (15 mL) was added MsCl (1.26 g, 11 mmol, 2.2 equiv) dropwise. The resulting mixture was stirred at room temperature for 2 hours. The reaction mixture was diluted with water and extracted with DCM (3*50 mL). The combined organic phase were dried over MgSCL and concentrated in vacuo to afford the title compound pyrazin-2-ylmethyl methanesulfonate as a yellow solid which was used for the next step without any further purification (940 mg crude). LC-MS: m/z 189.0 (M+H)+

The chemical industry reduces the impact on the environment during synthesis Pyrazin-2-ylmethanol. I believe this compound will play a more active role in future production and life.

Reference:
Patent; ANNAPURNA BIO INC.; TANG, Haifeng; BOYCE, Sarah; HANSON, Michael; NIE, Zhe; (213 pag.)WO2019/169193; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

113305-94-5, The chemical industry reduces the impact on the environment during synthesis 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, I believe this compound will play a more active role in future production and life.

To a stirred mixture of 5-aminopyrazine-2-carbonitrile (131 mg, 1.09 mmol) in THF (8 mL) was slowly added sodium hydride (73 mg, 1.82 mmol) below 15 C. The resulting mixture was stirred at room temperature for 1 hour and compound 207 (302 mg, 0.91 mmol) was added. The reaction mixture was then stirred at 60 C for 4 hours, quenched with ice-water, and extracted with ethyl acetate. The organic layer was dried over Na2504 and concentrated to afford the title compound 208 (280 mg, crude) as a yellow solid.

The chemical industry reduces the impact on the environment during synthesis 113305-94-5. I believe this compound will play a more active role in future production and life.

Reference:
Patent; PHARMAENGINE, INC.; CAI, Xiong; QIAN, Changgeng; WANG, Yanong Daniel; (98 pag.)WO2017/132928; (2017); 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. 55557-52-3 name is 3-Chloropyrazine-2-carbonitrile, 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. 55557-52-3

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 4.5 h. 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, CDCl3) 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).

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

Reference:
Patent; Folmer, Brigitte Johanna Bernita; Man, de Adrianus Petrus Antonius; Gernette, Elisabeth Sophia; Corte Real Goncalves Azevedo, Rita; Ibrahim, Hemen; US2013/79341; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

486460-20-2, A common heterocyclic compound, 486460-20-2, name is 3-(Trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyrazine, molecular formula is C6H3F3N4, 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.

To a solution of 3-(trifluoromethyl)[1,2,4]triazolo[4,3-a]pyrazine (1.60 g) in metanol (20 mL) was added a catalytic amount of Pd/C. The suspension was stirred under H2 for 5 h, and then filtered. The filtrate was concentrated in vacuo to give a residue, which was used for next step without further purification.

The synthetic route of 3-(Trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SUNSHINE LAKE PHARMA CO., LTD.; Zhang, Jiancun; Zhang, Yingjun; Zhang, Weihong; Liu, Bing; Zhang, Jiquan; Liu, Jinlei; Zhang, Lu; US2014/228361; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5900-13-0, The chemical industry reduces the impact on the environment during synthesis 5900-13-0, name is 5-Bromo-3-methoxypyrazin-2-amine, I believe this compound will play a more active role in future production and life.

Toa stirred suspension of sodium hydride (60%, 196 mg, 4.9 mmol) and THF (10 mL)at 0C, under N2, was added 5-bromo-3-methoxypyrazin-2-amine (1.00g, 4.9 mmol) in one portion. This was stirred at 0C for 30 min before theaddition of 3,5-dichlorobenzene-l- sulfonyl chloride (120 mg, 0.49 mmol) in oneportion. The reaction was allowed to warm to room temperature and stirred for 2hrs. The reaction was acidified to pH 2 with 2 M HC1, diluted with water (100mL) and extracted with EtOAc (100 ml x 3). The combined organic extracts werewashed with water (100 ml), brine (100 ml), dried ( a2S04), filtered andconcentrated to give the crude product as a brown oil, which was purified usingsilica chromatography (eluent 12% to 50% EtOAc in heptane) to give the titlecompound as a white solid (866 mg, 39%); m z=411.7, 413.6 (MH)+

The chemical industry reduces the impact on the environment during synthesis 5-Bromo-3-methoxypyrazin-2-amine. I believe this compound will play a more active role in future production and life.

Reference:
Patent; ACTIVE BIOTECH AB; FRITZSON, Ingela; LIBERG, David; EAST, Stephen; MACKINNON, Colin; PREVOST, Natacha; WO2014/184234; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5521-58-4, A common heterocyclic compound, 5521-58-4, name is 5-Methylpyrazin-2-amine, molecular formula is C5H7N3, 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.

Oxalyl chloride (2.1 mL, 24.0 mmol) was added to a solution of 3-[(l-methylethyl)oxy]-5- [(phenylmethyl)oxy]benzoic acid (5.72 g, 20.0 mmol) in DCM (100 mL) and the mixture stirred at ambient RT for 4 hours. The mixture was evaporated in vacuo to a residue, which was taken up in DCM (25 mL) and added to a stirred mixture of 2-amino-5-methylpyrazine (2.29 g, 21.0 mmol) and pyridine (1.94 mL, 24.0 mmol) in DCM (100 mL) at 50C – 1O0C. The mixture was stirred at RT for 18 hours, the DCM evaporated in vacuo to a residue, which was partitioned between water (50 mL) and ethyl acetate (150 mL). The organic layer was washed with brine, dried (MgSO4) and evaporated to a residue which was chromatographed on silica, eluting with 30% ethyl acetate in isohexane, and crystallised from ethyl acetate / isohexane to give the desired compound (5.52 g). 1R NuMR delta (CDCl3): 1.3 (d, 6H), 2.5 (s, 3H), 4.5 (m, IH), 5.0 (s, 2H), 6.6 (s, IH), 6.95 (s, IH), 7.0 (s, IH), 7.35 (m, 5H), 8.05 (s, IH), 8.3 (s, IH) and 9.5 (s, IH). m/z 378 (M+H)+.

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

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2007/7041; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 6966-01-4, name is Methyl 3-amino-6-bromopyrazine-2-carboxylate, 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. 6966-01-4

Step 2 : 3-amino-6-bromopyrazine-2-carboxylic acid[00211] A mixture of methyl 3-amino-6-bromo-pyrazine-2-carboxylate (3 g, 12.93 mmol) and lithium hydroxide (1.548 g, 64.65 mmol) in MeOH (11.74 mL) and H2O (11.74 mL) was heated to 90 0C for 2 hours. The reaction mixture was allowed to cool, neutralised with HCl and diluted with water, and the resultant precipitate collected by filtration (2.2 g, 78% Yield). 1H NMR (400.0 MHz, DMSO) 7.57 (br s, 2H) and 8.39 (s, IH), 13.41 (br s, IH) ppm.

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 6966-01-4.

Reference:
Patent; VERTEX PHARMACEUTICALS INCORPORATED; CHARRIER, Jean-damien; DURRANT, Steven; KAY, David; O’DONNELL, Michael; KNEGTEL, Ronald; MACCORMICK, Somhairle; PINDER, Joanne; VIRANI, Anisa; YOUNG, Stephen; BINCH, Hayley; CLEVELAND, Thomas; FANNING, Lev, T.d.; HURLEY, Dennis; JOSHI, Pramod; SHETH, Urvi; SILINA, Alina; WO2010/54398; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-25-1, The chemical industry reduces the impact on the environment during synthesis 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, I believe this compound will play a more active role in future production and life.

Example 24 5-{[3-(Cyclopropylmethyl)-2,3,4,5-tetrahydro-1 H-3-benzazepin-7-yl]oxy)-N-methyl-2- pyrazinecarboxamide (E24) Step 1: 1,1-Dimethylethyl 7-({5-[(methyloxy)carbonyl]-2-pyrazinyl}oxy)-1,2,4,5- tetrahydro-3H-3-benzazepine-3-carboxylate; 1,1-Dimethylethyl 7-hydroxy-1,2,4,5-tetrahydro-3H-3-benzazepine-3-carboxylate (Description 3 of WO 02/40471) (40 g, 0.15 mole) was dissolved in dry dimethylformamide (200 ml) and treated with sodium hydride (60% in mineral oil, 6.4 g, 0.16 mole). The mixture was stirred at room temperature for 1 hour and then cooled in ice. Methyl 5-chloro- 2-pyrazinecarboxylate (31.2 g, 0.18 mole) was added and the mixture stirred at room temperature for 18 hours. The mixture was poured into ice/water and the resulting solid collected by filtration. This was dissolved in ethyl acetate, dried (sodium sulphate) and evaporated under reduced pressure. The residue was purified by column chromatography eluting with ethyl acetate/pentane (1:2) to afford the title compound ?H NMR (CDCl3) No. 8.84 (H, s), 8.48 (H, s), 7.18 (H, m), 6.94 (2H, m), 4.01 (3H, s), 3.58 (4H, m), 2.92 (4H, m), 1.49 (9H, s)..

The chemical industry reduces the impact on the environment during synthesis Methyl 5-chloropyrazine-2-carboxylate. I believe this compound will play a more active role in future production and life.

Reference:
Patent; GLAXO GROUP LIMITED; WO2005/97778; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, 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. 33332-25-1

Step 1Compound (67) (10 g) was suspended in water (35 ml) and 2 mol/L-aqueous solution of sodium hydroxide (34.8 ml) was added and the mixture was stirred at room temperature for 4.5 hours. 2 mol/L-hydrochloric acid (34.8 ml) was added to neutralize and stirred at room temperature overnight. The precipitated insoluble material was collected by filtration, washed with water and dried under reduced pressure to afford Compound (68) (3.47 g).1H-NMR (DMSO-d6) delta 8.93 (1H, s), 9.03 (1H, s).

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, 33332-25-1, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; SHIONOGI & CO., LTD.; US2012/15961; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem