Pyrazines

These common heterocyclic compound, 122-05-4, name is Pyrazine-2,5-dicarboxylic acid, 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: Pyrazine-2,5-dicarboxylic acid

Dimethyl Pyrazine-2,5-dicarboxylate (83). Hydrogen chloride gas was bubbled (approx. 5 min) into a stirred suspension of 82 (0.5 g, 2.97 mmol) in methanol (25 ml) and the mixture refluxed for 4 hours. Solvent was evaporated under reduced pressure and the residual solid dissolved in chloroform. The chloroform solution was washed with 10% sodium carbonate solution and water, dried (MgSO4) and evaporated under reduced pressure. Solid obtained was recrystallized from methanol to afford 0.42 g (72.2%) of colorless needles mp 167-169 C. [lit. Spoerri, P. E. and Erickson, A. J. Amer. Chem. Soc. 1938, 60, 400-402, mp 168-169 C. (sealed capillary)]; IR (KBr) cm-1 1720 (ester); NMR (CDCl3, 90 MHz) delta 4.09 (s, 6H, CO2 CH3), 9.40 (s, 2H, aromatic). Anal. calcd. for C8 H8 N2 O4: C, 48.98; H, 4.11; N, 14.28. Found: C, 48.89; H, 4.33; N, 14.12.

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

Reference:
Patent; The Ohio State University; US4871736; (1989); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 6164-79-0, name is Methyl 2-pyrazinecarboxylate, 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. Computed Properties of C6H6N2O2

A solution of the product of Example 83A (6.91 g, 50 mmol) in THF (Aldrich, anhydrous, 150 mL) was cooled down to -78° C. and a solution of LiAlH4 (Aldrich, 1.898 g, 50.0 mmol) in THF (50 mL) was added slowly via an additional funnel. The mixture was stirred at -78° C. under N2 for 1 hour, and then it was then carefully and slowly quenched with HOAc (Aldrich, 10 mL) at -70° C. The mixture was slowly warmed up to ambient temperature and stirred for 10 hours. After being concentrated, the residue was stirred with HCl (2N, 15 mL) in CH2Cl2 (300 mL) for 20 minutes and then filtered through diatomaceous earth to remove solid inorganic salt. The organic filtrate solution was concentrated and the residue was dissolved in EtOAc (100 mL) and filtered through diatomaceous earth again. The organic filtrate solution was concentrated to give the titled compound. 1H NMR (300 MHz, DMSO-d6) delta 8.91 (dd, 1H), 8.94 (d, 1H), 9.12 (d, J=1.6 Hz, 1H), 10.08 (s, 1H) ppm; MS (DCI/NH3) m/z 109 (M+H)+.

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

Reference:
Patent; ABBOTT LABORATORIES; US2009/306096; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 87486-34-8,Some common heterocyclic compound, 87486-34-8, name is 3,5-Dibromo-1-methylpyrazin-2(1H)-one, molecular formula is C5H4Br2N2O, 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.

Example 109c 5-Bromo-3-(l-cyclopropyl-lH-pyrazol-4-ylamino)-l-methylpyrazin- -one 109cCGIPHARM60WOA 100-mL three-neck round-bottomed flask equipped with a reflux condenser, magnetic stirrer and nitrogen inlet was charged with 109b (378 mg, 3.07 mmol), 3,5- dibromo-l-methylpyrazin-2(lH)-one (906 mg, 3.38 mmol), cesium carbonate (3.00 g, 9.21 mmol), and 1,4-dioxane (45 mL). After bubbling nitrogen through the resulting suspension for 30 min, Xantphos (151 mg, 0.261 mmol) and tris(dibenzylidene-acetone)dipalladium(0) (141 mg, 0.154 mmol) were added, and the reaction mixture was heated at reflux for 3 h. After this time, the mixture was cooled to room tempera-ture and diluted with ethyl acetate (150 mL) and water (30 mL). The organic layer was separated, and the aqueous layer was extracted with ethyl acetate (3 x 45 mL). The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography (silica, 0percent to 10percent methanol/methylene chloride) to afford a 28percent yield (266 mg) of 109c as an off-white solid: mp 228-230 °C; ]H NMR (300 MHz, DMSO-i3/4) delta 9.90 (s, 1H), 8.06 (s, 1H), 7.69 (s, 1H), 7.21 (s, 1H), 3.70 (m, 1H), 3.41 (s, 3H), 0.96 (m, 4H); MS (ESI+) m/z 310.0 (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 3,5-Dibromo-1-methylpyrazin-2(1H)-one, its application will become more common.

Reference:
Patent; GILEAD CONNECTICUT, INC.; GENENTECH, INC.; CURRIE, Kevin S.; WANG, Xiaojing; YOUNG, Wendy B.; WO2012/31004; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

1057216-55-3, name is 2-Chloro-5-iodopyrazine, 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. SDS of cas: 1057216-55-3

Intermediate 31 (350 mg, 1.05 mmol), 2-chloro-5-iodopyrazine (252 mg, 1.05 mmol), 2M aqueous sodium carbonate solution (1.58 mL, 3.16 mmol) and anhydrous DMSO (5 mL) were charged to a sealed tube. The mixture was degassed by bubbling with nitrogen for 5 minutes before the addition of tetrakis(triphenylphosphine)20 palladium(0) (61 mg, 0.05 mmol). The reaction mixture was sealed under nitrogen andstirred at 110C for 1 h. The mixture was diluted with water (40 mL) and extracted with EtOAc (3 x 20 mL). The organic phase was washed with saturated aqueous sodium bicarbonate solution (2 x 10 mL) followed by brine (10 mL), then dried over sodium sulfate and concentrated under vacuum. The residue was purified by FCC, eluting with17-80% EtOAc in heptane, to afford the title compound (285 mg, 54% at 80% purity) as an off white solid. oH (500 MHz, CDC13) 8.73-8.64 (m, 2H), 8.63-8.59 (m, 1H), 7.92 (s, 2H), 7.33-7.27 (m, 1H), 7.17 (d, J8.2 Hz, 1H), 7.15-7.07 (m, 1H), 7.00 (d, J6.6 Hz, 1H),6.67 (t, J73.5 Hz, 1H), 4.36 (s, 2H), 2.60 (s, 3H). Method C HPLC-MS: MH+ m/z 401,

The synthetic route of 1057216-55-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; UCB PHARMA S.A.; BENTLEY, Jonathan Mark; BROOKINGS, Daniel Christopher; BROWN, Julien Alistair; CAIN, Thomas Paul; CHOVATIA, Praful Tulshi; FOLEY, Anne Marie; GALLIMORE, Ellen Olivia; GLEAVE, Laura Jane; HEIFETZ, Alexander; HORSLEY, Helen Tracey; HUTCHINGS, Martin Clive; JACKSON, Victoria Elizabeth; JOHNSON, James Andrew; JOHNSTONE, Craig; KROEPLIEN, Boris; LECOMTE, Fabien Claude; LEIGH, Deborah; LOWE, Martin Alexander; MADDEN, James; PORTER, John Robert; QUINCEY, Joanna Rachel; REED, Laura Claire; REUBERSON, James Thomas; RICHARDSON, Anthony John; RICHARDSON, Sarah Emily; SELBY, Matthew Duncan; SHAW, Michael Alan; ZHU, Zhaoning; WO2014/9295; (2014); A1;,
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. 56423-63-3, name is 2-Bromopyrazine, A new synthetic method of this compound is introduced below., name: 2-Bromopyrazine

n-BuLi (25.4 ml_, 63.5 mmol, 2.5 M in hexane) was added drop wise to a -78 C solution of 2-bromopyrazine (10.1 g, 63.5 mmol) in toluene (150 ml_) under N2. After 10 min at -78 C, a solution of N-cyclobutylidene-2-methylpropane-2-sulfinamide (Preparation 50, 10.0 g, 57.71 mmol) in toluene (50 ml_) was added slowly. The resulting dark red solution was stirred for 1 hr at -78 C. The reaction was quenched by the addition of sat. NH4CI solution (10 ml_) and the reaction mixture dried (MgS04), filtered and concentrated in vacuo to give a brown oil. The crude product was purified by column chromatography on silica gel eluting with pet. Ether: EtOAc (100:0 to 0: 100) to MeOH: EtOAc (9:91 ) to afford the title compound as a yellow oil, 4.0 g, 27%. 1H NMR (400 MHz, CDCI3): delta 1 .21 (s, 9H), 1.86-1 .96 (m, 1 H), 2.08-2.19 (m, 1 H), 2.58-2.78 (m, 4H), 3.62-3.75 (br s, 1 H), 8.49 (d, 1 H), 8.56 (dd, 1 H), 8.80 (d, 1 H). LCMS m/z = 254 [M+H]+

The synthetic route of 56423-63-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PFIZER INC.; CASIMIRO-GARCIA, Agustin; STROHBACH, Joseph Walter; HEPWORTH, David; LOVERING, Frank Eldridge; CHOI, Chulho; ALLAIS, Christophe Philippe; WRIGHT, Stephen Wayne; (213 pag.)WO2018/11681; (2018); 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. 6863-73-6, name is 3-Chloropyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows., Recommanded Product: 6863-73-6

Example A3 8-Chloro-imidazo[1,2-a]pyrazine Bromoacetaldehyde diethyl acetal (17.4 ml, 115.8 mmol) was added dropwise to a 48% aqueous solution of hydrobromic acid (4.45 ml, 38.6 mmol) at RT. The mixture was stirred at reflux temperature for 2 h. and then poured onto a suspension of sodium hydrogen carbonate (74.5 g, 0.88 mol) in isopropanol (220 ml). The mixture was stirred for a further 30 min. and then filtered off. 3-Chloro-pyrazin-2-ylamine (5 g, 38.6 mmol) was added to the filtrate and the mixture was stirred at 85 C. for 4 h. The solvent was evaporated in vacuo and the crude product suspended in a saturated solution of sodium hydrogen carbonate and extracted with DCM. The organic layer was dried (Na2SO4), filtered and the solvents evaporated in vacuo. The crude product was precipitated from Et2O to yield intermediate 3 (4.1 g, 70%) as a brown solid which was used in the next step without further purification.

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 6863-73-6.

Reference:
Patent; Janssen Pharmaceutica NV; US2012/329792; (2012); 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. 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, This compound has unique chemical properties. The synthetic route is as follows., Application In Synthesis of Methyl 5-chloropyrazine-2-carboxylate

Preparative Example 1. EPO A round bottomed flask was charged with methyl 2-chloropyrazine-5-carboxylate (Lonza, 25.9 g, 145 mmol), 2-S-ethyl piperazine (prepared as per Williams et al J. Med. Chem 1996, 39, 1345, 85% active, 28.0 g, 208 mmol), cesium carbonate (Aldrich, 11O g, 338 mmol) and 1 ,4 dioxane (400 ml). The resulting suspension was stirred at room temperature for 18 hours and then filtered. The solid was washed with ethyl acetate (3X400 ml). The combined organic solutions were concentrated on a rotary evaporator to remove the solvent. The residue was purified by flash chromatography on silica gel using 5% to 10% methanol in dichloromethane as an eluent to provide A3 as a white solid (28.0 g, 77%).

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 33332-25-1.

Reference:
Patent; SCHERING CORPORATION; PHARMACOPEIA DRUG DISCOVERY, INC.; WO2006/88837; (2006); A2;,
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. 274-79-3, name is Imidazo[1,2-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., name: Imidazo[1,2-a]pyrazine

Imidazo[1,2-a]pyrazine (7.2 g, 60.44 mmol) was dissolved in 2-methoxyethanol (100 ml). Platinum(IV) oxide (1.2 g, 5.13 mmol) was added, and the mixture was stirred overnight at room temperature, under a hydrogen atmosphere of 4 bar, in an autoclave. The reaction mixture was flooded with nitrogen, filtered over Celite, concentrated and coevaporated with toluene. Purification was carried out by column chromatography dichloromethane/7 N ammonia in methanol 95:5). Yield: 5.7 g (76%)

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 274-79-3.

Reference:
Patent; Gruenenthal GmbH; US2008/153843; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 1458-01-1, name is Methyl 3,5-diamino-6-chloropyrazine-2-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 1458-01-1, Recommanded Product: 1458-01-1

(b) A mixture of 2.0 g (10.0 mmol) of methyl 3,5-diamino-6-chloropyrazine-2-carboxylate and 13.5 g (22.6 mmol) of ethylene diamine was allowed to stand for 3 days at ambient temperature. The excess amine was evaporated and the residue was crystallized from ethanol. There was obtained 1.38 g (5.9 mmol, 59percent) of 3,5-diamino-6-chloro-N-(2-aminoethyl)pyrazine-2-carboxamide: mp 173°-174° C. Analysis calculated for C7 H11 ClN6 O: C, 36.45: N, 4.81; N, 36.44; Found: C, 36.50; N, 4.71; N, 36.22

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, and friends who are interested can also refer to it.

Reference:
Patent; ICI Americas Inc.; US4906633; (1990); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 24241-18-7, These common heterocyclic compound, 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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 stirred suspension of 2-amino-3,5-dibrompyrazine (427 g, 1688mmol) in water (6.4 L) / THF (482 mL), at rt was added bromacetaldehyde-diethylacetal (998 g, 5065 mmol) in one portion. After stirring under reflux for 4 h, the clear orange solution was stirred for an additional 15 h at rt. The suspension was filtered, and the remaining solid was washed with MeOH (2 L) and dried in vaccuo at 60 C to yield 6,8-dibromo-imidazo[1 ,2-a]pyrazine as an off-white solid (500 g, 107% with residual MeOH): 1H-NMR (300 MHz, d6-DMSO): delta =9.02 (s, 1 H), 8.23 (d, 1 H), 7.89 (d, 1 H) ppm. UPLC-MS: RT = 0.80 min; m/z 277.9 [MH+]; required MW = 276.9.

Statistics shows that 2-Amino-3,5-dibromopyrazine is playing an increasingly important role. we look forward to future research findings about 24241-18-7.

Reference:
Patent; BAYER PHARMA AKTIENGESELLSCHAFT; SIEMEISTER, Gerhard; BADER, Benjamin; WENGNER, Antje, Margret; MUMBERG, Dominik; KOPPITZ, Marcus; KLAR, Ulrich; KROEMER, Guido; VITALE, Ilio; JEMAA, Mohamed; WO2014/20041; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem