Pyrazines

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, name: 5-Bromopyrazine-2,3-diamine

(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

These common heterocyclic compound, 23611-75-8, name is Methyl 6-chloropyrazine-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. Quality Control of Methyl 6-chloropyrazine-2-carboxylate

Methyl 6-(chloropyrazine)-2-carboxylate (13) (2g, 0.0115mmol) was dissolved in 80mL of 87 DMSO. 88 Sodium azide (3g, 0.0463mmol) and 39 triphenylphosphene (4.6g, 0.1738mmol) were added and refluxed at 120C for 4h. 20mL of 1N 89 HCl was added and the reaction was continued at 120C for 2h. The mixture was cooled and neutralized by aqueous NaHCO3 solution and 131 product was extracted in ethyl acetate, dried with Na2SO4 which was then concentrated and dried with n-pentane to get 1.4g of compound 14 as yellow solid (yield 82.4%). 1H NMR (400MHz, DMSO-d6) delta 8.28-8.27 (m, 1H), 8.07 (s, 1H), 6.90 (s, 2H), 3.84 (s, 3H). C6H7N3O2 [M]: 153.14; MS (ESI) m/z: [M+H]+: 154.05

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

Reference:
Article; Trivedi, Prakruti; Adhikari, Nilanjan; Amin, Sk. Abdul; Jha, Tarun; Ghosh, Balaram; European Journal of Pharmaceutical Sciences; vol. 124; (2018); p. 165 – 181;,
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Pyrazine | C4H4N2 – PubChem

Related Products of 221136-66-9, 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. 221136-66-9, name is Ethyl 2-(3-bromo-6-methyl-2-oxopyrazin-1(2H)-yl)acetate, This compound has unique chemical properties. The synthetic route is as follows.

Example 8 r3-(2,2-Difluoro-2-phenyl-ethylamino)-6-methyl-2-oxo-2H-pyrazin-1-vn- acetic acid ethyl ester(3-Bromo-6-methyl-2-oxo-2H-pyrazin-1 -yl)-acetic acid ethyl ester was reacted with 2,2-difluoro-2-phenyl-ethylamine in the presence of a base, at elevated temperature, to yield the title compound as shown in the Scheme above. Table 5 below lists the reagent amounts, base and temperature combinations applied to this reaction, as well as yield.

The chemical industry reduces the impact on the environment during synthesis Ethyl 2-(3-bromo-6-methyl-2-oxopyrazin-1(2H)-yl)acetate. I believe this compound will play a more active role in future production and life.

Reference:
Patent; JANSSEN PHARMACEUTICA, N.V.; WO2007/146553; (2007); A2;,
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. 13301-04-7, name is Methyl 3,6-dibromopyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., Product Details of 13301-04-7

To a solution of methyl 2,5-dibromo pyrazine carboxylate (40g, 135mmol) in toluene (300ml) were dropwise added K2CO3 (28g, 202mmol) and N-ethyl-N- cyclohexylamine (35g, 270mmol). The reaction mixture was refluxed at 120C for 3 with stirring, and then cooled to room temperature. After extraction with ethyl acetate, the organic layer thus formed was washed with 2N HCI and further with water. Then, the organic layer was dried over anhydrous magnesium sulfate, filtered and concentrated in a vacuum to afford the title compound (46g, 99%). 1H NMR (400MHz, CDCI3) 8.15 (s, 1 H), 3.92 (s, 3H), 3.50 (, 3H), 1.81 (m, 4H), 1.66 (m, 2H), 1.57 (m, 2H), 1.28 (m 2H), 1.12 (t, 3H).

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; DONG-A ST CO.,LTD; PARK, Jang Hyun; SONG, Seung Hyun; CHUNG, Han Kook; KIM, Heung Jae; LEE, Ji Hye; JANG, Byeong Jun; KIM, Eun Jung; JUNG, Hae Hum; RYU, Chae Lim; HWANG, Jae-Sung; LEE, Hyung Ki; KANG, Kyung Koo; KIM, Soon Hoe; WO2014/157994; (2014); A1;,
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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. 19847-12-2, name is Pyrazinecarbonitrile, This compound has unique chemical properties. The synthetic route is as follows., Application In Synthesis of Pyrazinecarbonitrile

2-Cyanopyrazine (1.0g, 9.5mmol) was dissolved in dry methanol (50mL) with stirring at room temperature. Metallic sodium (0.12g, 5.2mmol) was added and the mixture refluxed for 2h. The clear yellow solution of the in situ iminoester was brought to neutral pH with glacial acetic acid resulting in a clear orange solution. 2-(Hydoxyimino)-propanehydrazone [14,15] (1.1g, 9.3mmol) was added and the resulting solution refluxed for 1h, and stirred at room temperature overnight. The white solid formed was separated by suction filtration and washed with methanol and diethylether (Yield: 1.85g, 90%). 1H NMR (300MHz, DMSO-d6, 298K) delta (ppm) 11.72 (s, 1H, N-OH), 10.03 (s, 1H, NH), 9.27 (d, 1H, CH(pyz)), 8.70 (d, 1H, CH(pyz)), 8.64 (dd, 1H, CH(pyz)), 6.99 (s, 2H, NH2), 1.95 (s, 3H, CH3). 13C{1H} NMR (75.4MHz, DMSO-d6, 298K) delta (ppm) 160.52 (C=O), 150.66, 146.14 (C=N), 146.04 (C(pyz)), 145.01, 142.86, 142.72 (CH(pyz)), 10.20 (CH3). Selected IR data (cm-1): 3247 br (nu N-H), 1650 s (nu C=O), 1621 s, (nu C=N), 1045 s (nu N-Ooxime). M. pt. 240-242C.

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 19847-12-2.

Reference:
Article; Drover, Marcus W.; Tandon, Santokh S.; Anwar, Muhammad U.; Shuvaev, Konstantin V.; Dawe, Louise N.; Collins, Julie L.; Thompson, Laurence K.; Polyhedron; vol. 68; (2014); p. 94 – 102;,
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Pyrazine | C4H4N2 – PubChem

Electric Literature of 19847-12-2, 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. 19847-12-2, name is Pyrazinecarbonitrile belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

(1) preparing a format reagent,Add magnesium, anhydrous polarity to a nitrogen-protected pressure vesselSolvent tetrahydrofuran and elemental iodine, then add methyl chloride to the pressure vessel and stir.After the pressure vessel is heated to 60 C and stirring is continued for 2 hours, a format reagent is prepared;Metal magnesium is newly formed magnesium, and the molar ratio of magnesium metal to chloromethane acid is 1:1.1;The content of elemental iodine is 0.21% × metal magnesium weight; the reaction equation is as follows:(2)Addition reaction, adding 2-cyanopyrazine and tetrahydrofuran to the reactor and heating the reactor to50 C, then add catalysisThe cuprous chloride and the reagents of the above format are then refluxed and condensed.After the end, the remaining part of the reactor is an intermediate product, wherein the addition reaction time is 14h;The molar ratio of 2-cyanopyrazine to the format reagent S1 is1:1.05; the content of cuprous chloride is 2.1% metal magnesium weight;(3)Hydrolyzing, adding water to the remaining intermediate product of the above reactor,The pH of the solution in the reactor was adjusted to 1 with dilute sulfuric acid, and then stirred for 12 hours.Adjusting the pH of the solution in the reactor to neutral with a saturated aqueous solution of sodium carbonate;Finally extracted with toluene three times;(4)After the treatment, the toluene extract is desolvated, and the solid after desolvation is dissolved by heating with ethanol.Add activated carbon, continue heating and reflux for 10 min, and filter.The filtrate was cooled to 5 C to obtain a white solid P1; then the white solid P1 was recrystallized from ethanol.Produced a white solid P2,Drying gives 2-acetylpyrazine;The purity of 2-acetylpyrazine was 98.4%, and the yield of 2-acetylpyrazine was 69%.The reagent polar solvents, elemental iodine, 2-cyanopyrazine, tetrahydrofuran toluene and ethanol were all analytically pure.

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, Pyrazinecarbonitrile, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Henan Weiyuan Biological Technology Co., Ltd.; Xuan Bingwu; Xing Xiaodong; Xuan Fuxing; (8 pag.)CN109796416; (2019); 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. 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., Recommanded Product: 875781-43-4

General procedure: 2-Bromo-5H-pyrrolo[3,2-b]pyrazine(4; 0.471 g,2.39 mmol), 4-pyridylboronic acid (0.58 g, 4.72 mmol), dichloro 1,1′-bis(diphenylphosphino)ferrocenepalladium (II) dichloromethane adduct (0.097 g, 0.12 mmol), acetonitrile(3 mL) and 1M sodium carbonate (3 mL) were placed in a 10 mL CEM microwavevial. The vial was capped and irradiated in a CEM microwave reactor for 30minutes at 150 C.Water (3 mL) and ethyl acetate (9 mL) were added the layers were partitioned. Theaqueous layer was extracted with ethyl acetate (2 x 10 mL). The combined organicextracts were washed with saturated sodium chloride (5 mL), dried over MgSO4and concentrated under reduced pressure. The residue was purified by preparativereverse phase HPLC to give 2-(pyridin-4-yl)-5H-pyrrolo[2,3-b]pyrazine(14; 0.28 g,60%) as an off white solid: 1H NMR (400 MHz, DMSO-d6) delta 12.24 (s, 1H), 9.00(s, 1H), 8.69 (dd, J = 4.5, 1.6 Hz, 2H), 8.12 (dd, J = 4.5, 1.6Hz, 2H), 7.98 (d, J = 3.6 Hz, 1H), 6.74 (d, J = 3.6 Hz, 1H); ESMSm/z 197.1 (M+1).

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 875781-43-4.

Reference:
Article; Burdick, Daniel J.; Wang, Shumei; Heise, Christopher; Pan, Borlan; Drummond, Jake; Yin, Jianping; Goeser, Lauren; Magnuson, Steven; Blaney, Jeff; Moffat, John; Wang, Weiru; Chen, Huifen; Bioorganic and Medicinal Chemistry Letters; vol. 25; 21; (2015); p. 4728 – 4732;,
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Pyrazine | C4H4N2 – PubChem

767340-03-4, name is (2Z)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-yl]-1-(2,4,5-trifluorophenyl)but-2-en-2-amine, 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. 767340-03-4

Into a 500 ml flask were charged chloro(l,5-cyclooctadiene)rhodium(I) dimer {[Rh(cod)Cl]2}(292 mg, 1.18 mmol) and (R,S) f-butyl Josiphos (708 mg, 1.3 mmol) under a nitrogen atmosphere. Degassed MeOH was then added (200 mL) and the mixture was stirred at room temperature for 1 h. Into a 4 L hydrogenator was charged the enamine amide 2Lambda (118 g, 0.29 mol) along with MeOH (1 L). The slurry was degassed. The catalyst solution was then transferred to the hydrogenator under nitrogen. After degassing three times, the enamine amide was hydrogenated under 200 psi hydrogen gas at 50 0C for 13 h. Assay yield was determined by EtaPLC to be 93% and optical purity to be 94% ee.The optical purity was further enhanced in the following manner. The methanol solution from the hydrogenation reaction (18 g in 180 mL MeOH) was concentrated and switched to methyl t- butyl ether (MTBE) (45 mL). Into this solution was added aqueous Eta3PO4 solution (0.5 M, 95 mL).After separation of the layers, 3NNaOH (35 mL) was added to the water layer, which was then extracted with MTBE (180 mL + 100 mL). The MTBE solution was concentrated and solvent switched to hot toluene (180 mL, about 75 0C). The hot toluene solution was then allowed to cool to 0 0C slowly (5 – 10 h). The crystals were isolated by filtration (13 g, yield 72%, 98 – 99% ee); m.p. 114.1 – 115.7 0C. lH NMR (300 MHz, CD3CN): delta 7.26 (m), 7.08 (m), 4.90 (s), 4.89 (s), 4.14 (m), 3.95 (m), 3.40 (m), 2.68(m), 2.49 (m), 1.40 (bs).Compound 2-5 exists as amide bond rotamers. Unless indicated, the major and minor rotamers are grouped together since the carbon-13 signals are not well resolved: 13c NMR (CD3CN): delta 171.8, 157.4 (ddd , JCF = 242.4, 9.2, 2.5 Hz), 152.2 (major), 151.8 (minor), 149.3(ddd; JCF = 246.7, 14.2, 12.9 Hz), 147.4 (ddd, JCF = 241.2, 12.3, 3.7 Hz), 144.2 (q, JCF = 38.8 Hz), 124.6 (ddd , JCF = 18.5, 5.9, 4.0 Hz), 120.4 (dd , JCF = 19.1, 6.2 Hz), 119.8 (q, JCF = 268.9 Hz), 106.2 (dd , JCF = 29.5, 20.9 Hz), 50.1, 44.8, 44.3 (minor), 43.2 (minor), 42.4, 41.6 (minor), 41.4, 39.6, 38.5 (minor), 36.9. The crystalline free base 2^ can also be isolated as follows:(a) The reaction mixture upon completion of the hydrogenation step is charged with 25 wt% of Ecosorb C-941. The mixture is stirred under nitrogen for one h and then filtered. The cake is washed with 2L/kg of methanol. Recovery of free base is about 95% and optical purity about 95% ee.(b) The freebase solution in methanol is concentrated to 3.5-4.0 L/kg volume (based on free base charge) and then solvent-switched into isopropanol (IPA) to final volume of 3.0 L/kg IPA.(c) The slurry is heated to 40 0C and aged 1 h at 4O0C and then cooled to 25 0C over 2 h. EPO (d) Heptane (7L/kg) is charged over 7 h and the slurry stirred for 12 h at 22-250C. The supernatant concentration before filtering is 10-12 mg/g.(e) The slurry is filtered and the solid washed with 30% IPA/heptane (2L/kg).(f) The solid is dried in a vacuum oven at 40 0C. (g) The optical purity of the free base is about 99% ee.

Statistics shows that 767340-03-4 is playing an increasingly important role. we look forward to future research findings about (2Z)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-yl]-1-(2,4,5-trifluorophenyl)but-2-en-2-amine.

Reference:
Patent; MERCK & CO., INC.; WO2006/33848; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 33332-29-5, name is 2-Amino-5-chloropyrazine, molecular formula is C4H4ClN3, 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. HPLC of Formula: C4H4ClN3

General procedure: 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 150C 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).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 33332-29-5, its application will become more common.

Reference:
Patent; UCB PHARMA S.A.; KATHOLIEKE UNIVERSITEIT LEUVEN, K.U.LEUVEN R&D; BROOKINGS, Daniel Christopher; FORD, Daniel James; FRANKLIN, Richard Jeremy; GHAWALKAR, Anant Ramrao; KULISA, Claire Louise; NEUSS, Judi Charlotte; REUBERSON, James Thomas; WO2013/68458; (2013); A1;,
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Pyrazine | C4H4N2 – PubChem

Electric Literature of 1379338-74-5, A common heterocyclic compound, 1379338-74-5, name is 5,7-Dichloropyrido[3,4-b]pyrazine, molecular formula is C7H3Cl2N3, 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 mixture of (9H-fluoren-9-yl)methyl hexahydropyrrolo[3,4-b]pyrrole-1(2H)-carboxylate (100 mg, 0.5 mmol) and 5,7-dichloropyrido[4,3-b]pyrazine (600 mg, 1.8 mmol) in dioxane was stirred at 0 C. for 30 minutes and then at room temperature for 4 hours. The mixture was concentrated, and the residue was purified by chromatography to give the title compound. MS (m/z): 498 (M+H)+.

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; HUTCHISON MEDIPHARMA LIMITED; Su, Wei-Guo; Deng, Wei; Ji, Jianguo; US2014/121200; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem