Month: February 2021

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. 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, A new synthetic method of this compound is introduced below., Recommanded Product: 5-Methylpyrazine-2-carboxylic acid

5-methyl-2-pyrazinecarboxylic acid (122 mg, 0.88 mmol),CDI (143 mg, 0.88 mmol),DMAP (108 mg, 0.88 mmol)Was dissolved in anhydrous dichloromethane (10 mL)Nitrogen protection, the reaction at room temperature for 2 hours.Betulin amine (200 mg, 0.44 mmol) was added to the above reaction solution to continue the reaction for 8 hours.After completion of the TLC detection reaction, the solvent was removed under reduced pressure,The mixture was extracted with H2O (30 mL) and extracted with ethyl acetate (20 mL ¡Á 3). The combined organic phases were dried over anhydrous Na2SO4, concentrated and purified by silica gel column chromatography(DCM: MeOH = 20: 1) to give a white solid (205 mg, 81%).

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; East China Normal University; Qiu Wenwei; Yi Zhengfang; Liu Mingyao; Cui Haiwei; He Yuan; Wang Jinhua; Yang Lianfang; Gao Cheng; (22 pag.)CN104744549; (2017); B;,
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 71257-38-0 as follows. category: Pyrazines

Stage 1, Method B. Diisopropylethylamine (12.15 mmole) and di-tert-butyl dicarbonate (8.9 mmole) were added to a solution of the correspondingly 1-substituted 1,2,3,4- tetrahydropyrrolo [1, 2-a] pyrazine (8.1 mmole) in DCM. The reaction mixture was stirred for 16 hours at 25C. The organic phase was then washed with sodium carbonate solution, water and saturated NaCl solution, dried over sodium sulfate and concentrated by evaporation. The crude product was purified by column chromatography (silica gel, ethyl acetate/DCM, 99:1)

According to the analysis of related databases, 71257-38-0, the application of this compound in the production field has become more and more popular.

Reference:
Patent; GRUeNENTHAL GMBH; WO2009/90055; (2009); 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. 77112-53-9, name is Imidazo[1,2-a]pyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., SDS of cas: 77112-53-9

Ethyl bromopyruvate (2.153 g, 11.04 mmol) was added to a solution of 3-aminopyrazine (1 g, 10.51 mmol) in DME (10 mL) and the mixture was stirred continuously at 20-35 C. for 2 h. The reaction mixture was filtered and the solid which precipitated out was dried well, dissolved in EtOH (10 mL) and stirred under reflux for 2 h. This reaction mixture was then concentrated under reduced pressure to obtain a crude residue. The residue was diluted with aqueous sodium bicarbonate solution, and extracted with chloroform. The organic layer separated was washed with water and then with brine solution; dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford the crude product. The crude product was further purified by column chromatography (using Silica gel 60-120 mesh and 60% EtOAc in Hexane as eluent) to afford 450 mg of the title compound the as a yellow solid. MS (ESI): m/z 192 (M+H).

According to the analysis of related databases, 77112-53-9, the application of this compound in the production field has become more and more popular.

Reference:
Patent; DR. REDDY’S LABORATORIES LTD.; Sasmal, Pradip Kumar; Ahmed, Shahadat; Prabhu, Ganesh; Tehim, Ashok; Paradkar, Vidyadhar; Dattatreya, Marahanakuli Prasanna; Mavinahalli, Nanjegowda Jagadeesh; US2015/5280; (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. 27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., Application In Synthesis of 3-Chloropyrazine-2-carboxylic acid

3-Chloropyrazine-2-carboxylic acid (2.97 g, 18.73 mmol, 1 eq.) was dissolved in tetrahydrofuran (75 mL). The solution was stirred in an ice bath and triethylamine (5.2 mL, 37.5 mmol, 2 eq.) was added followed by addition of methyl chloroformate (1.74 mL, 22.5 mmol, 1.2 eq.) dropwise. After 30 m, the reaction was filtered and the solid rinsed with more tetrahydrofuran (10 mL). The tetrahydyofuran solution was stirred in an ice bath and a suspension of sodium borohydride (1.4 g, 37.5 mmol, 2 eq.) in water (3 mL) was added. After 1 h, a saturated aqueous ammonium chloride solution (100 mL) was added to the reaction and the mixture was extracted with ethyl acetate (2 x 100 mL). The combined organic phases were washed with a saturated aqueous sodium chloride solution (25 mL) and dried over sodium sulfate. After filtration and evaporation, the residue was purified by silica gel chromatography (5 – 70% ethyl acetate/hexanes) to give (3-chloropyrazin-2-yl)methanol (0.84 g, 31%) as a faintly colored oil.

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 27398-39-6.

Reference:
Patent; GLOBAL BLOOD THERAPEUTICS, INC.; LI, Zhe; HARRIS, Jason, R.; DUFU, Kobina, N.; GENG, Xin; SINHA, Uma; (101 pag.)WO2016/160755; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 4858-85-9, name is 2,3-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 4858-85-9, HPLC of Formula: C4H2Cl2N2

Similar to as described in General Procedure A, 2,3-dichloropyrazine was reacted with2-methoxyethan-1-amine to give the title compound (4 g, 79%) as a white solid. LC-MS (ES, mlz):189 [M+H]+. To a solution of nitrogen-containing nucleophile (1 eq.) and cesium carbonate (3.0 eq.) in N,N-dimethylformamide (2 mL/mmol) was added 2-haloheterocycle (1.1 eq.). The reaction washeated to 100 C and stirred at this temperature for 2 hours. The reaction was then cooled to room temperature and acidified to pH = 1 with 10 % aqueous HCl solution if product contains a carboxylic acid, or diluted with water if neutral. The solution was extracted with twice with dichloromethane. The organic layers were combined, dried with sodium sulfate and concentrated under vacuum. The crude material was either used directly in subsequent reactions or purified byflash chromatography.

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; F. HOFFMANN-LA ROCHE AG; GENENTECH, INC.; BLAQUIERE, Nicole; BURCH, Jason; CASTANEDO, Georgette; FENG, Jianwen A.; HU, Baihua; LIN, Xingyu; STABEN, Steven; WU, Guosheng; YUEN, Po-wai; WO2015/25026; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 63744-22-9, A common heterocyclic compound, 63744-22-9, name is 6,8-Dibromoimidazo[1,2-a]pyrazine, molecular formula is C6H3Br2N3, 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.

General procedure: 6,8-dibromoimidazo[1,2-a]pyrazine (6, 1.86 g, 6.72 mmol) was added to asolution of 3a-3c, 5a-5e (5.6 mmol), DIPEA (1.4 mL, 8.4 mmol) inisopropanol (60 mL), stirred at 85 C for 8 h, and then the solvent wasevaporated to dryness. The crude product was purified by columnchromatography to obtain the desired intermediates 7a, 11a-11 g.

The synthetic route of 63744-22-9 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Fan, Yan; Huang, Zhi; Li, Yao; Qin, Zhongxiang; Wang, Cheng; Wang, Tianqi; Wang, Xin; Xiang, Rong; Yang, Shengyong; Bioorganic Chemistry; vol. 95; (2020);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 56423-63-3, 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. 56423-63-3 name is 2-Bromopyrazine, 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.

Into a 25-mL round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed 2-chloro-5-[[4-methyl-6-(methylarnino)pyrimidin-2-yl]amino]benzarnide (100 mg, 0.34 mmol, 1.00 equiv), Xantphos (8 mg, 0.07 mmol, 0.20 equiv), Pd2(dba)3 (7 mg, 0.03 mmol, 0.10 equiv), Cs2C03 (200 mg, 0.68 mmol, 2.00 equiv), DMSO (5 raL), 2-bromopyrazine (55 mg, 0.35 mmol, 1 .00 equiv). The resulting solution was stirred for 8 h at 80 C in an oil bath . The solids were fi ltered out. The crude product was purified by Prep-HPLC with the following conditions (2-AnalyseHPLC-SHIMADZU(HPLC-10)): Column, XB ridge Shield RP 18 OBD Column, 30* 150mm,5um; mobile phase, Wateri 1 OMMOL/L NH4HC03) and ACN (25.0% ACN up to 45.0% in 7 min); Detector, UV 254220nm. This resulted in 15.2 mg (12%) of the title compound as a white solid.

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

Reference:
Patent; EPIZYME, INC.; CAMPBELL, John Emmerson; DUNCAN, Kenneth William; MILLS, James Edward John; MUNCHHOF, Michael John; (202 pag.)WO2019/79485; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 25710-18-3,Some common heterocyclic compound, 25710-18-3, name is 2,3-Dichloropyrido[2,3-b]pyrazine, molecular formula is C7H3Cl2N3, 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.

A mixture of 2,3-dichloropyrido[2,3-b]pyrazine (Intermediate F step 2) (5 g, 25 mmol), p- tolylboronic acid (4.08 g, 30.0 mmol), tricyclohexylphosphine (1 .682 g, 6.00 mmol), and cesium carbonate (16.29 g, 50.0 mmol) in dry dioxane (60ml) was degassed by bubbling nitrogen through (x3). Tris(dibenzylideneacetone)dipalladium (0) (2.289 g, 2.5 mmol) was added and the reaction mixture was degassed by bubbling nitrogen through (x3). The resulting mixture was stirred at 70 ¡ãC for 16 hours and at room temperature for 2 days. The mixture was diluted with water and EtOAc and filtered through Celite.(R).(filter material). The phases were separated and the aqueous extracted with EtOAc The combined organic extracts were washed with brine, dried over MgS04 and concentrated in vacuo. The crude product was purified bychromatography on silica eluting with 0-2percent THF/DCM to give a mixture of the mono and bis arylated products. The materials were re-purified by chromatography on silica eluting with 0-2percent THF/DCM] to afford the title compound;LCMS; Rt 1 .13 mins MS m/z 256/258 [M+H]+ Method 2minl_C_v003

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2,3-Dichloropyrido[2,3-b]pyrazine, its application will become more common.

Reference:
Patent; NOVARTIS AG; CHARLTON, Steven, John; LEBLANC, Catherine; MCKEOWN, Stephen, Carl; WO2012/7539; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 19745-07-4, These common heterocyclic compound, 19745-07-4, name is 2,5-Dichloropyrazine, 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 solution of 2,5-dichloropyrazine (2.91 mmole) in 1,2-dimethoxyethane (9 mL), was added 4-(phenoxyphenyl)lboronic acid (3.49 mmole) and tetrakis(triphenylphosphine)palladium (0.145 mmole) followed by 2M Na2CO3 (3 mL). The resulting mixture was heated at 85 C for 2 hours. The reaction mixture was diluted with ethyl acetate and filtered through celite. The organic extract was dried over Na2SO4 and evaporated in vacuo. The crude product was purifed by biotage chromatography and then with prep TLC eluting with 5percent ethyl acetate and hexane mixture to give 2-chloro-5-(4-phenoxyphenyl)pyrazine.

Statistics shows that 2,5-Dichloropyrazine is playing an increasingly important role. we look forward to future research findings about 19745-07-4.

Reference:
Patent; Gilead Palo Alto, Inc.; US2011/21521; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 5049-61-6, A common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, molecular formula is C4H5N3, 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.

EXAMPLE 41A 5-Bromo-pyrazin-2-ylamine To the solution of 2-aminopyrazine (Aldrich, 4.75 g, 50 mmol) in anhydrous MeCN (Aldrich, 50 mL) was slowly added the solution of N-bromosuccinimide (Aldrich, 8.90 g, 50 mmol) in MeCN (anhydrous, 50 mL) at 0-10 C. The reaction mixture was then stirred at ambient temperature and quenched with saturated Na2S2O3 (5.0 mL). The mixture was concentrated and the residue was extracted with EtOAc (3*50 mL). The combined extracts were concentrated and the title compound was purified by chromatography (SiO2, EtOAc/hexane=1/1, v. Rf=0.50). 1H NMR (300 MHz, CDCl3) delta 7.77 (d, J=1.36 Hz, 1H), 8.09 (d, J=1.36 Hz, 1H) ppm; m/z 174 (M+H)+, 174 (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; Ji, Jianguo; Li, Tao; Lynch, Christopher L.; Gopalakrishnan, Murali; US2008/45539; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem