Pyrazines

Electric Literature of 1458-01-1, The chemical industry reduces the impact on the environment during synthesis 1458-01-1, name is Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, I believe this compound will play a more active role in future production and life.

EXAMPLE 4 A mixture of 1-beta-aminoethylamino-3-alpha-naphthoxypropan-2-ol (3.9 g.) and methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (1.1 g.) was heated at 90° C. for 25 hours, cooled and chromatographed on a silica column (Merck `60`, 50 g., column 140 mm.long and 32 mm.diameter) using a 9:1 v/v mixture of chloroform and methanol as eluant. The fractions containing a product with an Rf of 0.2 when examined by thin layer chromatography using the above solvent system were collected, combined and evaporated to dryness under reduced pressure. The residue was converted into a hydrogen oxalate salt by a similar procedure to that described in Example 1, and the salt was crystallized from ethanol. There was thus obtained 3,5-diamino-6-chloro-N-beta-(2-hydroxy-3-alpha-naphthoxypropylamino)ethylpyrazine-2-carboxamide hydrogen oxalate, m.p. 224°-226° C. (with decomposition)

In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Imperial Chemical Industries plc; US4550111; (1985); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 77112-52-8, These common heterocyclic compound, 77112-52-8, name is Ethyl imidazo[1,2-a]pyrazine-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.

10% Pd/C (40 mg) was added to a solution of ethyl imidazo[1,2-a]pyrazine-2-carboxylate (410 mg, 2.15 mmol) and conc.HCl (0.5 mL) in EtOH (9.5 mL) and stirring was continued under a hydrogen atmosphere for 16 h. The reaction mixture was filtered over a celite bed and the filtrate was concentrated under reduced pressure to afford the crude product, which was purified by washing with diethyl ether and dried to afford 400 mg of the title compound as a yellow hygroscopic solid. MS (ESI): m/z 196 (M+H).

The synthetic route of 77112-52-8 has been constantly updated, and we look forward to future research findings.

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

Related Products 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

Related Products of 33332-29-5, 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. 33332-29-5 name is 2-Amino-5-chloropyrazine, 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.

General procedure: Method B is a modification of Method A and was performed under nitrogen atmosphere andwith extended work-up. Substituted benzoyl chloride (1.5 mmol, 1.2 equiv) was placed into the askunder nitrogen, diluted with dry DCM (5 mL) and dry pyridine (400 mg, 5 mmol, 4 equiv) was added.The mixture was mixed for 5 min under nitrogen. Then, 5-chloropyrazin-2-amine (162 mg, 1.25 mmol,1 equiv) dissolved in DCM (10 mL) was added dropwise over 10 min under nitrogen ow. The askwas closed by septum and stirred for additional 6 h. After reaction, the mixture was diluted with DCMto the final volume of 40 mL and washed with water (1 30 mL), 5% (m/m) aqueous NaHCO3 solution(1 30 mL), and brine (1 30 mL). The organic layer was dried over anhydrous Na2SO4 and adsorbedon silica (4 g) by evaporating the solvents under reduced pressure. Automated flash chromatographywas run using same conditions as described in Method A. If needed, the products were recrystallizedfrom hot EtOH (crystallization initiated by cooling and dropwise addition of cold water).

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

Reference:
Article; Zitko, Jan; Mindlova, Al?b?ta; Vala?ek, Ond?ej; Jand’ourek, Ond?ej; Paterova, Pavla; Janou?ek, Ji?i; Kone?na, Klara; Dole?al, Martin; Molecules; vol. 23; 9; (2018);,
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. 32974-92-8, name is 1-(3-Ethylpyrazin-2-yl)ethanone, A new synthetic method of this compound is introduced below., Product Details of 32974-92-8

(1) Dissolve 10 mmol of 2-acetyl-3-ethylpyrazine in 20 mL of methanol and stir at 60 C for 15 min.Then, 20 mL, 10 mmol of 4,4-dimethyl-3-aminourea methanol solution was added dropwise to the above solution, and refluxed at 60 C.After the reaction was stirred for 12 h, it was cooled to room temperature, poured into a beaker and evaporated. The obtained pale yellow crystals were filtered and washed with methanol.Times, get the ligand (L4);

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; Guangxi Normal University; Yang Feng; Yu Ping; Wang Jun; Liang Hong; (14 pag.)CN108912149; (2018); A;,
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. 54608-52-5, name is 2-Hydrazinopyrazine, A new synthetic method of this compound is introduced below., category: Pyrazines

A solution of 2-hydrazinopyrazine (1.10 g) in trifluoroacetic anhydride (10 mL) was stirred at room temperature for 4 h. To the mixture was added PPA (12 mL). The reaction mixture was heated at 80 C for another 15 h. The reaction mixture was cooled to room temperature and filtered to afford the title compound as a white solid (0.94 g, 50.00 %). The compound was characterized by the following spectroscopic data: MS (ESI, pos. ion) m/z: 189.0 (M+l); ? NMR (400 MHz, CDC13) ?: 8.64 (s, 3H).

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; SUNSHINE LAKE PHARMA CO., LTD.; ZHANG, Jiancun; ZHANG, Yingjun; ZHANG, Weihong; LIU, Bing; ZHANG, Jiquan; LIU, Jinlei; ZHANG, Lu; WO2013/71697; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 5521-58-4, 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 5521-58-4 as follows.

(a) A solution of bromine (0.11 ml) in chloroform (20 ml) was added dropwise over 20 minutes to a solution of 2-amino-5-methylpyrazine (0.218 g) in chloroform (30 ml) which was protected from light. The reaction mixture was stirred for 90 minutes after addition was complete and was then washed with water (50 ml). The organic phase was dried (MgSO4) and volatile material was removed by evaporation to give a yellow oil. The oil was purified by elution with dichloromethane through a silica gel Mega Bond Elut column to give 2-amino-3-bromo-5-methylpyrazine (0.286 g) as a white solid, m.p. 51-52 C.; mass spectrum (+ve CI): 188 (M+H)+.

According to the analysis of related databases, 5521-58-4, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Zeneca Limited; US5866568; (1999); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature 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. 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

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., category: Pyrazines

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