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. 4430-75-5, name is Octahydro-2H-pyrido[1,2-a]pyrazine, A new synthetic method of this compound is introduced below., Safety of Octahydro-2H-pyrido[1,2-a]pyrazine

General procedure: A mixture ofdifferent fluoro substituted 2-nitrobenzoate (1.5 mmol) and various amines (7.5 mmol) in DMF (3 mL) was stirred atroom temperature for 2 h. The reaction mixture was diluted with water and extracted with ethyl acetate. The organic phase was washed with water and brine. After dried by sodium sulfate and concentration, the residue was purified by chromatography on silica gel to give as yellowish solid.

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; Fan, Jun; Dai, Yang; Shao, Jingwei; Peng, Xia; Wang, Chen; Cao, Sufen; Zhao, Bin; Ai, Jing; Geng, Meiyu; Duan, Wenhu; Bioorganic and Medicinal Chemistry Letters; vol. 26; 11; (2016); p. 2594 – 2599;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 16298-03-6, name is Methyl 2-aminopyrazine-3-carboxylate, 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 16298-03-6, Computed Properties of C6H7N3O2

Bromine (3.91 g, 24.46 mmol) was added dropwise to a stirred mixture of 3- aminopyrazine-2-carboxylic acid methyl ester (1.27 g, 8.29 mmol) and hydrobromic acid (4.70 mL, 41.5 mmol) at 00C. A solution of sodium nitrite (1.44 g, 20.9 mmol) in water (6 mL) was then added dropwise. The reaction mixture was stirred for 15 min, brought to pH 8 with NaHCO3 (saturated, aqueous), and extracted with ethyl acetate (80 mL) and chloroform (50 mL). The combined organics were dried over MgSO4 and concentrated in vacuoto give 1.13 g (63percent) of an orange oil which solidified on standing.

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, Methyl 2-aminopyrazine-3-carboxylate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; BAYER PHARMACEUTICALS CORPORATION; WO2006/121588; (2006); A2;; ; Patent; BAYER PHARMACEUTICALS CORPORATION; WO2006/121860; (2006); A2;; ; Patent; BAYER PHARMACEUTICALS CORPORATION; WO2006/121904; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 5521-58-4, 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. 5521-58-4, name is 5-Methylpyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows.

CH2Cl2 (6OmL) and DMF (0.08mL, 1.064mmol, 1.2 eq) were cooled to -100C and oxalylchloride slowly added (0.09mL, 0.465mol, 1.2 eq). After stirring for 15min the reaction mixture was cooled to -300C and (2R)-2-(4-cyclopropanesulfonylphenyl)-3- (tetrahydropyran-4-yl)propionic acid (Preparation 8, 0.300g, 0.886mmol, 1.0 eq) was added. The reaction was stirred at -300C for 45min then pyridine (1.395mol, 0.3ImL in ImL CH2Cl2, 4.5eq) and the amine (4.43mmol, 5.0eq) were slowly added in parallel at -400C. The reaction mixture was stirred for 15min then the ice bath removed. The reaction mixture was stirred for 2h until it reached rt. The solvent was removed under partial vacuum and the crude mixture dissolved in EtOAc (1OmL) and aqueous HCl (1.5mL). The layers were separated and the aqueous phase extracted with EtOAc (5mL). The organic fractions were combined and washed with H2O (1OmL), saturated aqueous NaHCtheta3 (2 x 10 mL), water (5mL) and brine (5mL) and dried (Mg2SOzi). Purification was by flash chromatography (EtOAc :heptane, 2:1) and/or recrystallisation.

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

Reference:
Patent; Prosidion Ltd; WO2007/51845; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 4774-14-5, 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 4774-14-5 as follows.

2,6-Dichloropyrazine (2.0 g, 13.4 mmol) was dissolved in 13 mL of DMSO. Dimethylamine hydrochloride (1.31g, 16.08 mmol) and DIPEA (5.2 mL, 30 mmol) were sequentially added thereto, and the mixture was stirred at roomtemperature for 24 hours. The reaction solution was diluted with water, extracted with EtOAc and purified by columnchromatography to obtain the title compound (1.82 g, 86 percent). 1H-NMR (CDCl3) delta 7.87 (1H, s), 7.77 (1H, s), 3.13 (6H, s)

According to the analysis of related databases, 4774-14-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; LG Chem, Ltd.; KIM, Young Kwan; PARK, Sang Yun; JOO, Hyun Woo; CHOI, Eun Sil; PAEK, Seung Yup; KANG, Seung Wan; KIM, Byung Gyu; LEE, Chang Seok; KIM, Sung Wook; LEE, Sang Dae; (369 pag.)EP3239143; (2017); A2;,
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. 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, it is a common compound, a new synthetic route is introduced below. Product Details of 767340-03-4

Into a 500 ML flask were charged chloro (1, 5-cyclooctadiene) rhodium (I) dimer { [Rh (cod) Cl] 2} (292 mg, 1.18 mmol) and (R, S) t-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 2-4 (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 C for 13 h. Assay yield was determined by HPLC 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 H3P04 solution (0.5 M, 95 mL). After separation of the layers, 3N NAOH (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 C). The hot toluene solution was then allowed to cool to 0 C slowly (5-10 h). The crystals were isolated by filtration (13 g, yield 72%, 98-99% ee); m. p. 114. 1-115. 7 C. 1H NMR (300 MHz, CD3CN) : 8 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) : 8 171.8, 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, 7CL= 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 synthetic route of 767340-03-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MERCK & CO., INC.; WO2005/30127; (2005); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 6966-01-4,Some common heterocyclic compound, 6966-01-4, name is Methyl 3-amino-6-bromopyrazine-2-carboxylate, molecular formula is C6H6BrN3O2, 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 methyl 3-amino-6-bromopyrazine-2-carboxylate (100 mg, 0.43 mmol) in MeOH (5 mL) was added 2 mL of NaOH aqueous solution (5 N). After being stirred at 50C for 4 h, the mixture was cooled and acidified with 1 M HCl to a pH of 2. The precipitate was collected by filtration and washed with water to afford the product of 3-amino-6- bromopyrazine-2-carboxylic acid (90 mg, yield: 96%). XH-NMR (DMSO-ifc, 400 MHz) delta 8.38 (s, 1H), 7.51-7.56 (m, 2H). MS (M+H)+: 218 / 220.

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-amino-6-bromopyrazine-2-carboxylate, its application will become more common.

Reference:
Patent; MERCK SHARP & DOHME CORP.; DAI, Xing; LIU, Hong; PALANI, Anandan; HE, Shuwen; NARGUND, Ravi; XIAO, Dong; ZORN, Nicolas; DANG, Qun; MCCOMAS, Casey, C.; PENG, Xuanjia; LI, Peng; SOLL, Richard; WO2014/209727; (2014); 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. COA of Formula: C6H6N2O2

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-78C keeping the reaction temperature below-72C. On completion of addition the reaction mixture was left to stir at-78C 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, 100%). This was immediately dissolved in chloroform (200ml) cooled to 0C 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, 31%) as a solid. NMR (DMSO-d6) : 8.15 (s, 1H), 8.62 (dd, 2H), 8. 99 (s, 1H).

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

Synthetic Route of 95-89-6, 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. 95-89-6, name is 3-Chloro-2,5-dimethylpyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

EXAMPLE 26; 2,5-Dimethyl-3-(5-methyl-3-phenyl-isoxazol-4-ylethynyl)-pyrazine; As described for example 11c, 4-ethynyl-5-methyl-3-phenyl-isoxazole (66 mg, 0.36 mmol) was converted [using 3-iodo-2,5-dimethyl-pyrazine (prepared from 3-chloro-2,5-dimethyl-pyrazine according to J. Med. Chem. (19) 490, 1976) instead of 2-chloro-4-iodopyridine] to the title compound (SiO2, heptane:ethyl acetate=95:5 to 0:100, 89 mg, 85%) which was obtained as a white solid. MS: m/e=290.1 [M+H]+.

The synthetic route of 3-Chloro-2,5-dimethylpyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Buettelmann, Bernd; Knust, Henner; Thomas, Andrew; US2007/287739; (2007); 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. 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, This compound has unique chemical properties. The synthetic route is as follows., Product Details of 113305-94-5

Palladium (II) acetate (39 mg, 0.17 mmol) was added to (+/-)-2,2″-bis(diphenylphosphino)- 1 ,1″-binaphthalene (321 mg, 0.51 mmol) in DMF/toluene (1/1 15 mL) and the resulting mixture was degassed under a stream of nitrogen gas for 10 min. 2-Amino-5- cyanopyrazine (210 mg, 1.7 mmol), sodium ferf-butoxide (250 mg, 2.6 mmol) and tert- butyl 3-((2-bromo-5-nitropyridin-4-yiamino)methyl)piperidine-1-carboxylate (713 mg, 1.7 mmol) were added and the mixture was degassed for a further 5 minutes then heated at 150 C for 30 min using microwave irradiation. The mixture was concentrated in vacuo and water and ethyl acetate were added. The aqueous phase was extracted three times with ethyl acetate. The combined organic phases were dried (Na2SO4) and concentrated. The residue was purified by flash column chromatography on silica, eluting with a gradient of ethyl acetate in hexane, 10 – 100% over 50 min. The fractions containing the product contaminated with 2-amino-5-cyanopyrazine were combined, evaporated and repurified by silica column chromatography, eluting with a gradient of ethyl acetate in hexane, 10 – 50% over 45 min. Tert-butyl 3-((2-(5-cyanopyrazin-2-ylamino)-5-nitropyridin- 4-ylamino)methyl)piperidine-1-carboxylate was obtained as a yellow solid (265 mg, 34%).LCMS (1): Rt = 2.38 min; m/z (ESI+) 455 (MH+). 62

According to the analysis of related databases, 113305-94-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; CANCER RESEARCH TECHNOLOGY LIMITED; WO2009/44162; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 108-50-9, 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. 108-50-9, name is 2,6-Dimethylpyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

First, a synthesis method of an intermediate, 2-chloro-3,5-dimethylpyrazine is described. 7.12 g of 2,6-dimethylpyrazine and 6.5 mL of dimethylformamide (abbreviation : DMF) were put in a three-neck flask equiiped with a drop funnel and a thermometer, and the inside was refluxed under a nitrogen atmosphere. 6.7 mL of sulfuric chloride was put in a drop funnel and the reaction container was soaked in an ice bath. While the reaction solution was being stirred, the sulfuric chloride was dropped in such a way that the temperature of the solution be kept 45 C +/- 5 C. After that, water was added after it was confirmed that the temperature of the solution was 40 0C or lower. After it was confirmed again that the temperature of the solution was 40 0C or lower, an aqueous sodium hydroxide was added and the pH of the solution was adjusted to 7 to 8. This solution was subjected to steam distillation. The obtained solution was subjected to extraction using dichloromethane to separate an organic layer. The organic layer obtained was dried with magnesium sulfate. After the drying, the solution was filtrated. After the solvent of this solution was distilled off, the obtained residue was distilled under reduced pressure, so that an objective intermediate was obtained (clear and colorless liquid, yield of 36 %).

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, 2,6-Dimethylpyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; SEMICONDUCTOR ENERGY LABORATORY CO., LTD.; WO2008/149828; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem