Pyrazines

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 274-79-3 as follows. Quality Control of Imidazo[1,2-a]pyrazine

Step 2 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine Imidazo[1,2-a]pyrazine 4b (500 mg, 4.20 mmol) was dissolved in 5 mL of 2-methoxyethanol, followed by addition of platinum dioxide (100 mg, 0.36 mmol), and the reactor was purged with hydrogen for three times. After stirring for 12 hours, the reaction mixture was filtered. The filtrate was concentrated under reduced pressure to obtain 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine 4c (200 mg, yield 38.7%) as a yellow oil. MS m/z (ESI): 124.1 [M+1]

According to the analysis of related databases, 274-79-3, the application of this compound in the production field has become more and more popular.

Reference:
Patent; JIANGSU HANSOH PHARMACEUTICAL CO., LTD.; Tang, Peng Cho; Li, Xin; Li, Xiangqin; Chen, Yang; Wang, Bin; Zhu, Zhe; US2013/131068; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 939412-86-9, 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. 939412-86-9, name is (3-Chloropyrazin-2-yl)methanamine hydrochloride, This compound has unique chemical properties. The synthetic route is as follows.

To a solution of 59 (3-chloropyrazin-2-yl)methanamine hydrochloride 1a (0.9 g, 5.0 mmol) and 32 N,N-dimethyl formamide (0.02 mL) in 25 dichloromethane (20 mL) at room temperature, was added dropwise a solution of 60 benzyl 3-(chlorocarbonyl)azetidine-1-carboxylate (1.3 g, 5.0 mmol) in dichloromethane (5.0 mL) at room temperature. The resulting mixture was stirred at room temperature for 10 min. The reaction mixture was quenched with saturated 33 sodium bicarbonate solution (30 mL) and the organic phase was separated. The aqueous phase was extracted with dichloromethane (30 mL×2). The combined organic phase was washed with saturated brine (30 mL×2), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under vacuum and the residue was purified by flash column chromatography (20:1 dichloromethane/methanol) to provide 61 benzyl-3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)azetidine-1-carboxylate 2a (1.20 g, 3.7 mmol, yellow oil). Yield: 75%.1H NMR (400 MHz, CDCl3) delta8.43 (d, J=2.4 Hz, 1H), 8.34 (d, J=2.4 Hz, 1H), 7.35-7.27 (m, 5H), 6.91 (bs, 1H), 5.10 (s, 2H), 4.71 (d, J=4.4 Hz, 2H), 4.27-4.19 (m, 4H), 3.40 (dd, J=6.0 & 6.0 Hz, 1H).

The chemical industry reduces the impact on the environment during synthesis (3-Chloropyrazin-2-yl)methanamine hydrochloride. I believe this compound will play a more active role in future production and life.

Reference:
Patent; GUANGZHOU INNOCARE PHARMA TECH CO., LTD.; KONG, Norman Xianglong; ZHOU, Chao; CHEN, Xiangyang; US2019/177333; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 313339-92-3,Some common heterocyclic compound, 313339-92-3, name is 3,5-Dichloropyrazine-2-carbonitrile, molecular formula is C5HCl2N3, 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 3,5-dichloropyrazine-2-carbonitrile (100 mg, 0.578 mmol), phenylboronic acid (0.635 mmol, 77.5 mg, 1.1 equiv), [1,1?- bis(diphenylphosphino)ferrocene]dichloropalladium(II) (0.029 mmol, 5 mol%) in degassed dioxane/water 4:1 (6 mL) was sodium carbonate (0.635 mmol, 1.1 equiv) and the reaction mixture was stirred for 4h under nitrogen at 100oC. Once complete, the reaction was diluted with EtOAc and water. The organic phase was separated and aqueous layer was extracted twice with EtOAc, dried over magnesium sulfate, filtered and concentrated under reduced pressure to give product: ESI-MS (m/z): 215.1

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-Dichloropyrazine-2-carbonitrile, its application will become more common.

Reference:
Patent; CASE WESTERN RESERVE UNIVERSITY; BOARD OF REGENTS, THE UNIVERSITY OF TEXAS SYSTEM; MARKOWITZ, Sanford; ANTCZAK, Monika; READY, Joseph; ZHANG, Youngyou; (332 pag.)WO2018/218251; (2018); A1;,
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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. 123-32-0, name is 2,5-Dimethylpyrazine, This compound has unique chemical properties. The synthetic route is as follows., Product Details of 123-32-0

Preparation (benzo [d] [1,3] dioxol-5-yl) (3,6-dimethyl-2-yl) methanone, comprising the steps of : (1) 2,5-dimethyl pyrazine take 0.2mmol, 3,4- methylenedioxy-benzoyl acid 0.4mmol, 0.02 mmol silver phosphate, potassium persulfate 0.4mmol 5mL reaction tube was placed, was added 1.4mL of dichloromethane, 0.6 mL of distilled water was added, and the reaction mixture was placed in a 5mL tube and placed in an oil bath at 40 heated, reaction 24h, cooled to room temperature to obtain a reaction solution;(2) The step (1) the resulting reaction mixture was directly concentrated to give a concentrate, the concentrate with petroleum ether / dichloromethane = 1/2 (v / v) as the developing solvent, separation by thin layer chromatography to give 37mg target The product, in 72% yield.

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 123-32-0.

Reference:
Patent; Henan Agricultural University; Wu Zhiyong; Zhao Mingqin; Li Yuan; (10 pag.)CN108101856; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 21279-62-9, name is 3-Chloropyrazine-2-carboxamide, molecular formula is C5H4ClN3O, 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. Safety of 3-Chloropyrazine-2-carboxamide

General procedure: Compounds 1-6 were prepared according to conventional organic synthesis methods. 3-Chloropyrazine-2-carboxamide (1.27 mmol) was dissolved in THF (20 mL) in a round bottom flask and after that treated with two equivalents of the corresponding benzylamine and an equimolar amount of triethylamine. The reaction was conducted with continuous stirring and heating (70 C) under reflux in an oil bath for 15 h. Compounds 7-15 were synthesised using a microwave reactor with a focused field. 3-Chloropyrazine-2-carboxamide (1.27 mmol) was put into a thick-walled tube together with the corresponding benzylamine (2.54 mmol), pyridine (1.27 mmol), methanol (approx. 5 mL) and a magnetic stir bar and then sealed with a special cap. The reaction parameters were set according to the previously published paper as follows-140 C, 30 min, 200 W [29]. Reaction progress was checked by TLC (hexane:ethyl acetate-1:1). Regardless of the synthesis method used,all reaction mixtures were adsorbed on silica and subjected to preparative flash chromatography (hexane and ethyl acetate, gradient elution, detection wavelengths 260 nm and 280 nm). Products were recrystallized from ethanol or ethanol and water if necessary. All final substances were chemically characterized (1H-NMR, 13C-NMR, IR, melting point and elemental analysis).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 21279-62-9, its application will become more common.

Reference:
Article; Jandourek, Ondrej; Tauchman, Marek; Paterova, Pavla; Konecna, Klara; Navratilova, Lucie; Kubicek, Vladimir; Holas, Ondrej; Zitko, Jan; Dolezal, Martin; Molecules; vol. 22; 2; (2017);,
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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. 13924-95-3, name is Methyl 5-hydroxypyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., Recommanded Product: 13924-95-3

Step 1: (0546) To 5-hydroxypyrazine-2-carboxylic acid methyl ester (2.0 g, 13 mmol) in a glass tube reaction vessel in DMF (26 mL) was added potassium carbonate (5.3 g, 39 mmol) and sodium 2-chloro-2,2-difluroacetate (4.0 g, 26 mmol). The reaction vessel was capped and warmed to 100 C. The reaction was stirred for 30 minutes and cooled to room temperature. The reaction was filtered washing with EtOAc. The filtrate was concentrated in vacuo. The residue was taken up into EtOAc and washed with brine. The organic layer was dried (MgSO4), filtered, and concentrated in vacuo. The residue was purified by silica gel chromatography (0-40% EtOAc/hex) to give methy-5-(difluoromethoxy)pyrazine-2-carboxylate (0.09 g, 0.46 mmol) (0.40 g, 20%).

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; MERCK SHARP & DOHME CORP.; Scott, Jack D.; Stamford, Andrew W.; Gilbert, Eric J.; Cumming, Jared N.; Iserloh, Ulrich; Misiaszek, Jeffrey A.; Li, Guoqing; US2015/307465; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 74290-65-6, A common heterocyclic compound, 74290-65-6, name is 3-Bromo-5-methylpyrazin-2-amine, molecular formula is C5H6BrN3, 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.

3-Bromo-5-methylpyrazin-2-amine (7.64 g, 40.6 mmol), triethylamine (12.3 g, 122mmol), cuprous iodide (0.77 g, 4.06 mmol) and palladium(II)bis(triphenylphosphine) dichloride(2.85 g, 4.06 mmol) were dissolved in tetrahydrofuran (150 mL). The mixture was stirred at rt,then trimethylsilylacetylene (8.00 mL, 56.9 mmol) was added dropwise slowly to the mixture.The resulting mixture was continued to stir for 4 h.The reaction mixture was diluted with ethylacetate (50 mL). The mixture was filtered. The filtrate was concentrated in vacuo, and theresidue was purified by silica gel column chromatography (PE/EtOAc (v/v) = 3011) to give thetitle compound as a light yellow solid (7 .0 g, 84 % ).MS (ESI, pos. ion) m/z: 206.1 [M+Ht.

The synthetic route of 74290-65-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SUNSHINE LAKE PHARMA CO., LTD.; TANG, Changhua; REN, Qingyun; YIN, Junjun; YI, Kai; LEI, Yibo; WANG, Yejun; ZHANG, Yingjun; (303 pag.)WO2018/108125; (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. 912773-24-1, name is 6-Bromoimidazo[1,2-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., Product Details of 912773-24-1

A 20 mL Biotage microwave vial loaded with 6-bromoimidazo[1,2-a]pyrazine (1.188 g, 6 mmol) was dissolved in DCM (15 mL), and N-chlorosuccinimide (881 mg, 6.60 mmol) was added in portions, and the mixture was sealed and stirred at 50 C. for 18 h. The vial was diluted with DCM and 10% NaOH, then extracted multiple times with DCM, washed with 10% NaOH, H2O, brine, and the organic layer was dried over Na2SO4, concentrated, dryloaded onto silica gel and purified on a 12 g silica gel column (hexanes/EtOAc, 0-25%), affording 6-bromo-3-chloroimidazo[1,2-a]pyrazine 67-A as a white solid (916 mg, 3.94 mmol, 66% yield, 25% EtOAc in hexanes). 1H NMR (DMSO) delta: 8.98 (d, J=1.3 Hz, 1H), 8.77 (d, J=1.3 Hz, 1H), 8.01 (s, 1H). 13C NMR (DMSO) delta: 143.03, 139.15, 134.20, 123.70, 117.92, 112.33.

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 912773-24-1.

Reference:
Patent; Arizona Board of Regents on Behalf of the University of Arizona; Hulme, Christopher; Foley, Christopher; (166 pag.)US2020/39989; (2020); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 4745-93-1, 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 4745-93-1 as follows.

1.1 A solution of 2.57 g (11.0 mmol) of iodine in 15 ml of DMF is added dropwise to a mixture of 1.25 g (10.0 mmol) of 5H-pyrrolo[2,3-b]pyrazine and 1.65 g (25.0 mmol) of solid potassium hydroxide in 15 ml of DMF, and the mixture is subsequently stirred at room temperature for 45 minutes. The reaction mixture is poured into 200 ml of ice-water (containing 0.5% by weight of ammonia and 0.1% by weight of sodium disulfite) and left at 5 C. for 12 hours. The resultant precipitate is filtered off with suction, washed with 100 ml of ice-water and dried in vacuo: 7-iodo-5H-pyrrolo[2,3-b]pyrazine as yellow solid.

According to the analysis of related databases, 4745-93-1, the application of this compound in the production field has become more and more popular.

Reference:
Patent; MERCK PATENT GMBH; Dorsch, Dieter; Wucherer-Plietker, Margarita; Mueller, Thomas J.J.; Merkul, Eugen; US2013/217951; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem