Month: September 2021

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

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. 32587-10-3, name is 3-Aminopyrazine-2-carboxamide, A new synthetic method of this compound is introduced below., Quality Control of 3-Aminopyrazine-2-carboxamide

To a stirred solution of 3-aminopyrazine-2-carboxamide (1 g, 7.24 mmol, prepared according to International Patent Application Publication No. W0201 1054922) and NaOAc (200mg, 2.44 mmol) in HOAc (15 mE) was added Br2 (0.45 mE) dropwise at 0C for 1 hour, and then it was stirred at 50C for 8 hours. After the mixing, it was poured into ice-water and filtrated, the crude product of 3-amino-6-bromopyrazine-2-carboxamide as brown solid (1.5 g, yield: 95%) was obtained. ?H-NMR (DMSO-d6, 400 MHz) 8.30 (s, 1H), 7.93 (s, 2H), 7.66 (s, 2H). MS (M+H):217/219.

The synthetic route of 32587-10-3 has been constantly updated, and we look forward to future research findings.

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; WO2014/205593; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 642459-03-8,Some common heterocyclic compound, 642459-03-8, name is 6-Chloro-N-phenylpyrazin-2-amine, molecular formula is C10H8ClN3, 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 36 36A. Preparation of Phenyl- [6- (2. 2, 2-triiluoroethoxy-pyrazm-2-yl]-amine To sodium hydride (50 mg, 1.25 mmol of a 60% dispersion in oil, 1.5 equiv) in DMSO (1 ml) was added a solution of 2, 2, 2-trifluoroethanol (90 1ll, 1.25 mmol, 1.5 equiv) in DMSO (1 ml). The mixture was stirred 15 minutes and 6-chloro- (pyrazin- 2-yl) -phenyl-amine (171 mg, 0.833 mmol, 1 equiv) was added as a solution in DMSO (1 ml). The mixture was heated to 80C for 3 days. The title compound was purified by flash chromatography on silica (19 g, Si02), eluted with 25% ethyl acetate-petrol, to afford 110 mg (49%) ; LCMS 3.95 min, [M+H]”270.; 36B. Preparation of (6-Methylsulfanyl-pyrazin-2-yl)-phenyl-amine The title compound was obtained as a side product of the method of 36A and was isolated as a minor fraction of the reaction products following flash chromatography on silica (19 g, Si02), eluting with 25% ethyl acetate-petrol, to afford 3 mg (1%); LCMS 2.76 min, m/z [M+H] + 218.

The synthetic route of 642459-03-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ASTEX TECHNOLOGY LIMITED; WO2004/4730; (2004); 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. 22047-25-2, name is Acetylpyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. name: Acetylpyrazine

The synthetic procedure used in this preparation is outlined below in Scheme D. To a solution of 1-pyrazin-2-yl-ethanone (2.0 g, 15.85 mmol) and ammonium acetate (19.337 g, 158.5 mmol) in methanol (50 mL) was added sodium cyanoborohydride (0.7 g, 11.1 mmol) in one portion. The reaction mixture was stirred overnight at room temperature. After removal of methanol, water (20 mL) was added to the residue and the resulting solution was basified by addition of sodium hydroxide to pH=13. The aqueous solution was extracted with dicholromethane and the combined organic phase was dried over sodium sulfate. Removal of the solvent under reduced pressure afforded 14.62 g of 1-pyrazin-2-yl-ethylamine, yield: 75%. MS (M+H)=124.

The synthetic route of 22047-25-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Broka, Chris Allen; Hawley, Ronald Charles; US2010/324056; (2010); 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. 14508-49-7, name is 2-Chloropyrazine, A new synthetic method of this compound is introduced below., Safety of 2-Chloropyrazine

[Referential Example 33] 2-Hydrazinopyrazine; [Show Image] Hydrazine monohydrate (21.80 g) was added to a solution of 2-chloropyrazine (10.44 g) in ethanol (65 ml) at room temperature, and the mixture was heated under reflux for 17 hours. After cooling with air, the reaction solvent was evaporated under reduced pressure, and benzene was added to the residue, then the insoluble content was’ removed by decantation. After evaporation of the benzene solution under reduced pressure, hexane was added to the resulting solid, and the product was collected by filtration to give the title compound (4.67 g, 47%). 1H-NMR (400 MHz, CDCl3)delta: 7.89 (1H, d, J = 2.7 Hz), 7.99-8.05 (1H, m), 8.20 (1H, d, J = 1.5 Hz). ESI-MSm/z: 111 (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; DAIICHI PHARMACEUTICAL CO., LTD.; EP1698626; (2006); 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. 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, A new synthetic method of this compound is introduced below., 113305-94-5

Synthesis 1C (S)-tert-Butyl 2-((2-(5-cyanopyrazin-2-ylamino)-5-(trifluoromethyl)pyridin-4-carboxylate S)-tert-Butyl 2-((2-chloro-5-(trifluoromethyl)pyridin-4-ylamino)methyl)morpholine-4- carboxylate (4.67 g, 1 1.8 mmol), 2-amino-5-cyanopyrazine (1.98 g, 16.5 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.86 g, 0.94 mmol), rac-2,2′- bis(diphenylphosphino)-1 ,1 ‘-binaphthyl (0.54 g, 0.87 mmol) and caesium carbonate (7.69 g, 23.6 mmol) were suspended in anhydrous dioxane (108 ml_) under argon. Argon was bubbled through the mixture for 30 minutes, after which the suspension was heated to 100C for 29 hours. The reaction mixture was cooled and diluted with dichloromethane, then absorbed onto silica gel. The pre-absorbed silica gel was added to a 340 g KP-Sil SNAP column which had been equilibrated with 20% ethyl acetate in hexane. Column chromatography, eluting with a gradient of 20-35% ethyl acetate in hexane, gave partially purified material as an orange gum. This was further purified by column chromatography, eluting with 20% ethyl acetate in dichloromethane, to give the title compound as a light tan powder (3.28 g, 58%). H NMR (500 MHz, CDCI3) delta 1.49 (9H, s), 2.73-2.86 (1 H, m), 2.94-3.07 (1 H, m), 3.26- 3.31 (1 H, m), 3.38-3.43 (1 H, m), 3.57-3.61 (1 H, m), 3.70-3.75 (1 H, m), 3.83-4.08 (3H, m), 5.31 (1 H, broad s), 7.12 (1 H, s), 8.13 (1 H, s), 8.23 (1 H, s), 8.57 (1 H, s), 8.87 (1 H, s). LC- MS (Agilent 4 min) Rt 2.90 min; m/z (ESI) 480 [MH+].

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; CANCER RESEARCH TECHNOLOGY LIMITED; COLLINS, Ian; MATTHEWS, Thomas Peter; FARIA DA FONSECA MCHARDY, Tatiana; OSBORNE, James; LAINCHBURY, Michael; WALTON, Michael Ian; GARRETT, Michelle Dawn; WO2013/171470; (2013); 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 14508-49-7 as follows. COA of Formula: C4H3ClN2

Step 1 To a solution of chloropyrazine (11.5 g, 0.1 mmol) in absolute ethanol (50 ml) was added anhydrous hydrazine (16 ml, 0.5 mmol) and the reaction mixture was refluxed for 3 h. The organics were removed in vacuo and the residue was extracted with benzene to give hydrazinopyrazine (4.2 g).

According to the analysis of related databases, 14508-49-7, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Syntex (U.S.A.) LLC; US6316464; (2001); B1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem