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. 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., category: Pyrazines

Diisobutylaluminium hydride (1.0 M in toluene; 6.4 mL, 6.40 mmol) was added dropwise to a cooled solution of methyl 5-chloropyrazine-2-carboxylate (690 mg, 4.00 mmol) in THF (13.6 mL) at -55 C. The reaction was stirred under these conditions for 1 hour and then quenched by addition of saturated aqueous NH4C1 (25 mL) and EtOAc (25 mL). An emulsion formed and 2N aqueous HC1 was added to clear the emulsion (5 mL). The layers were separated, and the aqueous layer was extracted with EtOAc. The organic layerwas washed with saturated aqueous sodium chloride, dried over magnesium sulfate and concentrated under reduced pressure. The resulting residue was purified by flash silica chromatography, elution gradient 0 to 50% EtOAc in heptane. Product fractions were evaporated to dryness to afford 5-chloropyrazine-2-carbaldehyde (385 mg, 68%) as a beige solid. ?H NMR (500 MHz, CDC13, 27 C) 8.75 (1H, d), 8.96 (1H, d), 10.15 (1H, d).

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; ASTRAZENECA AB; SCOTT, James, Stewart; MOSS, Thomas, Andrew; YANG, Bin; VARNES, Jeffrey, Gilbert; O’DONOVAN, Daniel, Hillebrand; NISSINK, Johannes, Wilhelmus, Maria; HUGHES, Samantha, Jayne; BARLAAM, Bernard, Christophe; WU, Dedong; BROO, Dan, Anders; (224 pag.)WO2018/19793; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 4774-14-5, name is 2,6-Dichloropyrazine, 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 4774-14-5, Formula: C4H2Cl2N2

A solution of compound 8 (450.0 g, 3.02 mol) in cone. aq. NH3 (3.0 L) was stirred at 135°C overnight in a 10 L sealed pressure vessel. TLC and LC/MS showed complete conversion of the starting material. The reaction mixture was cooled to room temperature and filtered to afford a white solid. The solid was washed with water (200 mL x 3), and then dried to afford compound 9 (312 g, 80percent yield) as a solid. 1HNMR (400 MHz, DMSO- 6): delta 7.82 (s, 1 H), 7.12 (s, 1 H), 6.93 (s, 2H). MS Calcd.: 129 MS Found: 130 ([M+H]+).

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; IMARA, INC.; H. LUNDBECK A/S; SVENSTRUP, Niels; PARACHIKOVA, Anna I.; MCARTHUR, James; (133 pag.)WO2018/9424; (2018); 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 951626-95-2 as follows. 951626-95-2

To the solution of piperidine (25 mg, 0.29 mmol) in dry THF (5 mL) was added trimethylaluminium (0.14mL, 0.29 mmol) drop wise at -10C under nitrogen over a period of 10 min. This solution was allowed to stir at room temperature for 45 minutes. Further the reaction mixture was re-cooled to -10C and thereto was added a solution of compound 5a (50 mg, 0.22 mmol) in THF (2.5 mL) drop wise. The resulting reaction mixture was stirred at room temperature initially then refluxed for 18 h. Reaction mixture was cooled to room temperature and quenched with iso-propanol (IPA) followed by methanol and then with saturated Na2SO4 solution. The reaction mixture was filtered and the filtrate was evaporated to dryness. The crude material was purified by column chromatography on silica gel (100-200 mesh) using MeOH in DCM to give desired compound 6a (50 mg, 85%). MS (ES+) m/z: 249. 1H NMR (400 MHz, CDCl3) delta 7.13 (s, 1H), 6.14-6.28 (m, 1H), 4.43 (m, 2H), 3.77-3.85 (m, 2H), 3.68-3.74 (m, 4H), 1.51-1.76 (m, 6H)

According to the analysis of related databases, 951626-95-2, the application of this compound in the production field has become more and more popular.

Reference:
Article; Surase, Yogesh B.; Samby, Kirandeep; Amale, Sagar R.; Sood, Ruchi; Purnapatre, Kedar P.; Pareek, Pawan K.; Das, Biswajit; Nanda, Kamna; Kumar, Subodh; Verma, Ashwani K.; Bioorganic and Medicinal Chemistry Letters; vol. 27; 15; (2017); p. 3454 – 3459;,
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. 100047-56-1, name is 5-Bromo-3-methylpyrazin-2-ol, A new synthetic method of this compound is introduced below., HPLC of Formula: C5H5BrN2O

(ls,4s)-4-(l-Methylpiperidin-4-yloxy)cyclohexanol (1.2 g, 5.63 mmol) was dissolved inTHF (10 mL), 5-bromo-3-methylpyrazin-2-ol (1.170 g, 6.19 mmol) and triphenylphosphine (1.771 g, 6.75 mmol) were added, then cooled down in an ice -water bath. DIAD (1.329 ml, 6.75 mmol) was added dropwise under N2. The reaction mixture was slowly warmed to room temperature, stirred overnight, and concentrated. The residue was purified by preparative HPLC (15-80% CH3CN/H20 with 0.1 % TFA over 30 min) and column chromatography (5% methanol/ethyl acetate containing 1 % Et3N) to give the title compound (525 mg, 1.366 mmol, 24.3% yield). Exact mass calculated for Ci7H26BrN302: 383.1 , found: LCMS m/z = 384.2[M+H]+; lU NMR (400 MHz, CDC13) 5 ppm 1.45-1.62 (m, 4H), 1.65-1.75 (m, 2H), 1.91-2.05 (m, 4H), 2.05-2.15 (m, 2H), 2.39 (s, 3H), 2.36-2.42 (m, 2H), 2.42 (d, J = 0.7 Hz, 3H), 2.78-2.85 (m, 2H), 3.46-3.54 (m, 2H), 4.95-5.02 (m, 1H), 7.98 (d, J = 0.6 Hz, 1H).

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; ARENA PHARMACEUTICALS, INC.; JONES, Robert M.; HAN, Sangdon; BUZARD, Daniel J.; LEHMANN, Juerg; NARAYANAN, Sanju; YUE, Dawei; WO2011/127051; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

3149-28-8, Adding some certain compound to certain chemical reactions, such as: 3149-28-8, name is 2-Methoxypyrazine, 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 3149-28-8.

To a solution of 2-methoxypyrazine (5.0g, 45.4mmol), in 40ml of anhydrous THF was added tributyltin hydride (15.0mL, 54.9mmol) and the resulting solution stirred under nitrogen at 0C. Cyclohexylcarbonyl chloride (8.0mL, 59.8mmol) was added over 10min and stirring continued until reaction completion in 20min as determined by TLC (neutral alumina, EtOAc/hexanes (1/19, v/v)). A 1M solution of HCl in methanol (20.0mL) was then added to the reaction mixture that was stirred under nitrogen at 0C until reaction completion in 30min as determined by TLC (SiO2, EtOAc/hexanes (2/3, v/v). The reaction mixture was quenched with 50mL of water, extracted with ethyl acetate (3×50mL), washed with saturated sodium bicarbonate (10mL), and then dried over anhydrous Na2SO4. Purification by silica gel flash column chromatography (100% hexanes: to remove tin by-products, followed by methanol / dichloromethane 2-5%) afforded 4-cyclohexanecarbonyl-1,2-dihydro-2-pyrazinone 3 (8.9g, 94%) as a pale yellow solid (mp 160-163C dec).

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 3149-28-8.

Reference:
Article; Williams, Alfred L.; St. Hilaire, Valentine R.; Tetrahedron; vol. 73; 48; (2017); p. 6712 – 6717;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 68774-77-6, name is 8-Chloro[1,2,4]triazolo[4,3-a]pyrazine, 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 68774-77-6, HPLC of Formula: C5H3ClN4

A mixture of crude 4-methylbenzyl 4-(aminomethyl)-3,3-difluoropiperidine-1-carboxylate (600mg, 2.0 mmol), 8-chloro-[1,2,4]triazolo[4,3-a]pyrazine (360 mg, 2.0 mmol) and DIPEA (0.76 mL, 4.0 mmol) in butyl alcohol (10 mL) was heated at 130 C overnight. The mixture was allowed to cool to room temperature and concentrated under reduced pressure. The concentrate was purified by column chromatography over silica gel (100% ethyl acetate) to afford the title compound as a light gray powder (150 mg, 18%). MS (ESI) calcd for C20H22F2N602: 416.2; found: 417.3 [M+H]. 1H NMR (400MHz, CD3OD) 6 9.16 (s, 1H), 7.77 (d, J = 4.8 Hz, 1H), 7.29 (d, J = 4.8 Hz, 1H), 7.24 (d, J = 8.0 Hz, 2H), 7.17 (d, J = 8.0 Hz, 2H), 5.09 (s, 2H), 4.33 (br s, 1H), 4.19-4.15 (m, 1H), 4.05-3.95 (m, 1H), 3.72-3.58 (m, 1H), 3.25-2.90 (m, 2H), 2.67-2.51 (m,1H), 2.33 (s, 3H), 1.99-1.93 (m, 1H), 1.62-1.52 (m, 1H).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 8-Chloro[1,2,4]triazolo[4,3-a]pyrazine, and friends who are interested can also refer to it.

Reference:
Patent; RUGEN HOLDINGS (CAYMAN) LIMITED; SHAPIRO, Gideon; (246 pag.)WO2016/196513; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

274-79-3,Some common heterocyclic compound, 274-79-3, name is Imidazo[1,2-a]pyrazine, molecular formula is C6H5N3, 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.

Imidazo[1,2-a]pyrazine (420 mg, 3.53 mmol) was dissolved in acetonitrile (10 mL).N-bromosuccinimide (691 mg, 3.88 mmol) was added thereto, and the mixture was reacted at room temperature overnight.After the reaction is completed, a saturated sodium hydrogencarbonate solution is added thereto.Extract with dichloromethane, dry the organic phase with anhydrous sodium sulfate, filter, and then dry the solvent.The residue was purified by silica gel column chromatography to give a yellow solid,619mg.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Imidazo[1,2-a]pyrazine, its application will become more common.

Reference:
Patent; Shanghai Pharmaceutical Group Co., Ltd.; Wan Huixin; Li Chunli; Shi Chen; Liu Haiyan; Li Ping; Shen Jingkang; (50 pag.)CN104341425; (2018); B;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, 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. 5049-61-6 name is Pyrazin-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.

Preparation of 3,5-dibromopyrazin-2-amine Intermediate BA) [0322] To a stirred solution of aminopyrazine (8.21 g, 86.4 mmol) in anhydrous methylene chloride (215 mL) cooled to 0C was added N-bromosuccinimide (32.3 g, 181 mmol) in portions over a six hour period, during which time the temperature of the reaction was kept below 0C. The resulting mixture was stored at 4C overnight, after which it was stirred vigorously and quenched with H20 (100 mL). The organic layer was separated, after which it was washed with saturated aqueous NaHC03, washed with brine, dried over MgS04, filtered, and evaporated in vacuo to yield a residue that was triturated with 20% EtOAc in hexanes to yield the title compound (10.3 g, 47%) as a yellow/brown powder. 1H NMR (CDC13, 300MHz) delta 8.02 (s, 1H), 5.05 (bs, 2H); HPLC retention time: 1.99 minutes; MS ESI (m/z): 252.0/254.0/256.2 (M+l)+, calc. 251.

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

Reference:
Patent; UNIVERSITY OF ROCHESTER; GELBARD, Harris, A.; DEWHURST, Stephen; GOODFELLOW, Val, S.; WIEMANN, Torsten; RAVULA, Satheesh, Babu; LOWETH, Colin, J.; WO2011/149950; (2011); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 1458-01-1, name is Methyl 3,5-diamino-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. name: Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate

4-(4-Aminophenyl)ethylamidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride (83) A mixture of 1-H-pyrazolecarboxamidine hydrochloride (2.8 g, 19 mmol), 4-aminoethylaniline (1.3 mL, 9 mmol) and diisopropylethylamine (1.3 ml) were stirred in dry DMF (5 mL) under argon for 18 h. After this time, ether (30 ml) was added to produce a clear oil. The obtained oil (82) was washed with ether and dried under vacuum (40 mTorr) overnight. After drying 70 mg of oil was taken into dry methanol (3 mL) and 25percent NaOH (0.14 mL) was added. The reaction volume was decreased to 1.0 mL and 3,5-diamino-6-chloropyrazine-2 carboxylic acid methyl ester (0.1 g, 0.5 mmol) was added. The mixture was stirred at room temperature overnight. Another portion of 82 (0.1 g) was dissolved in methanol (1 mL), treated with 25percent NaOH (0.15 mL) and the resulting solution was added to the reaction mixture. The reaction mixture was stirred 3 h at reflux, then cooled to room temperature and the solvent was removed under reduced pressure. The residue was dissolved in a minimal volume of DMF and separated by preparative HPLC. The obtained fractions were analyzed by LC/MS. The fractions containing product with M+H=349 were collected and the solvent was removed under reduced pressure. The residue was dissolved in 10percent HCl and evaporated to dryness to produce 83 (23.5 mg, 11percent) as a yellow solid. 1H NMR (360 MHz, DMSO-d6) delta 2.91 (m, 2H), 3.59 (m, 2H), 7.31 (d, 2H), 7.42 (m, 4H), 9.02 (br s, 2H), 9.41 (br s., 1H), 10.56 (s, 1H). 13C NMR (90 MHz, DMSO-d6) 33.1, 42.0, 108.9, 119.6, 120.7, 129.9 (2 C), 131.0 (2 C), 153.1, 154.1, 155.8, 165.2. API MS m/z=349 [C14H17ClN8O+H]+.

The synthetic route of Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PARION SCIENCES, INC.; JOHNSON, Michael Ross; (49 pag.)US2015/376146; (2015); 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. 486424-37-7, name is 3-Amino-6-bromopyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., Recommanded Product: 3-Amino-6-bromopyrazine-2-carboxylic acid

-Amino-6-bromopyrazine-2-carboxylic acid (53.59 g, 0.229 mol) and 4-hydroxy-3-aminopyridine (33.64 g, 0.275 mol) were mixed in THF (500 mL) and triethyl amine (115.86 g, 1.145 mol) was added. The mixture was stirred at 25 for 10 min. The temperature was raised to 55 C. and T3P (218.90 g, 0.344 mol) was added. The mixture was stirred at 55 C. for 30 min. Water (150 mL) was added at 55 C. and the mixture was stirred for 2 h at 55 C. Solvents were distilled of until fractions at 55-80 C. was removed.Acetonitrile (500 mL) was added followed by water (350 mL) while maintaining the temperature at 75 C. The mixture was stirred for 2 h at 75 C. The solid was isolated by filtration. The solid was washed with water (250 mL) followed by acetonitrile (250 mL). The solid was dried under vacuum at 80 C. for 5 h to give the title compound (84.5%)1HNMR (400 MHz, DMSO-d6): 11.64 (s, 1H) 10.26 (s, 1H) 8.78 (s, 1H) 8.45 (s, 1H) 7.78 (s, 2H) 7.72 (d, 1H) 6.31 (d, 1H).MS (ESI+) m/z 310 [M+H]+

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 486424-37-7.

Reference:
Patent; ASTRAZENECA AB; US2011/118275; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem