Category: Pyrazines

4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, 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. Formula: C6H2N2O3

A solution of (S)-[1-(trans-4-amino-cyclohexyl)-2-oxo-2-pyrrolidin-1-yl-ethyl]-carbamic acid tert-butyl ester (176 mg, 0.5 mmol) and 2,3-pyrazinecarboxylic anhydride (75 mg, 0.5 mmol) in THF (5 mL) was stirred at reflux for 2 hours. The mixture was concentrated to dryness, treated with acetic anhydride (4 mL) and heated to reflux for 3 hours. The excess acetic anhydride was removed under high vacuum and the residue was partitioned between ethyl acetate and water. The aqueous layer was extracted with ethyl acetate and the combined organic phases were washed with water (3×) and brine, dried over magnesium sulfate and concentrated to dryness. The residue was triturated with ether and the light brown solid was isolated. This solid was dissolved in 4 N hydrogen chloride/dioxane (1 mL) and the solution was stirred at room temperature for 1 hour. Ether (2 mL) was added and the precipitate was collected and dried (17 mg, 8.6%). MS m/z 358 (MH+).

The synthetic route of 4744-50-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Pfizer Inc; US2005/234065; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 123-32-0, A common heterocyclic compound, 123-32-0, name is 2,5-Dimethylpyrazine, molecular formula is C6H8N2, 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.

Preparation of 3,6-dimethyl-2- (2-thenoyl) pyrazine, comprising the steps of:(1) 2,5-dimethyl pyrazine take 0.2mmol, 2- benzoyl-carboxylic acid thiophene 0.4mmol, 0.02 mmol silver phosphate, potassium persulfate 5mL reaction tube was placed 0.4mmol, 1.4mL was added dichloro methane, 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 ethyl acetate / petroleum ether = 1/2 (v / v) as the developing solvent, separation by thin layer chromatography to give 30mg target The product, in 69% yield.

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; 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. 91476-80-1, name is 5,6,7,8-Tetrahydroimidazo[1,2-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., Recommanded Product: 91476-80-1

The title compound was prepared from 5,6,7,8-tetrahydroimidazo[1,2-c]pyrazine (31.3 mg, 0.254 mmol, from Step B), (3R)-3-[(1,1-dimethylethoxycarbonyl)amino]-4-(3,4-difluorophenyl)butanoic acid (80 mg, mmol), DIPEA (32.8 mg, 0.254 mmol), HOBT (41.2 mg, 0.305 mmol) and EDC (73 mg, 0.381 mmol) in 5 mL of dichloromethane, using a procedure analogous to that described in Example 1, Step C. Purification by HPLC (Gilson; YMC-Pack Pro C18 column, 100×20 mm I.D.; solvent gradient system from 10% acetonitrile, 90% water, and 0.1% trifluoroacetic acid to 90% acetonitrile, 10% water, and 0.1% trifluoroacetic acid) gave 75 mg of the title compound as a viscous oil. 1H NMR (500 MHz, CDCl3) delta 1.38 (s, 9H), 2.05 (bs, 1H), 2.62 (m, 2H), 2.89 (m, 2H) 3.81-4.04 (m, 5H), 4.64-4.88 (m, 2H). 5.38 (m, 1H) 6.88 (m, 2H), 7.05 (m, 3H). ESI-MS 421 (M+1)

According to the analysis of related databases, 91476-80-1, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Merck Sharp & Dohme Corp.; Edmondson, Scott D.; Fisher, Michael H.; Kim, Dooseop; Maccoss, Malcolm; Parmee, Emma R.; Weber, Ann E.; Xu, Jinyou; US2015/359793; (2015); A1;,
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Synthetic Route of 5049-61-6,Some common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, molecular formula is C4H5N3, 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.

Synthesis of 206-A. A mixture of ethyl 3-bromo-2-oxopropanoate (10.8 g, 55.3 mmol) and pyrazin-2-amine (5.0 g, 52.6 mmol) in DME (150 mL) was stirred at room temperature for 5 h. The precipitate was collected by filtered. Then the cake was dissolved in EtOH (100 mL) and stirred at 80 oC for 2 h. The solvent was removed in vacuo. The residue was purified by column chromatography on silica gel (PE : EtOAc = 2 : 1~ 1 : 2) to give 206-A (2.0 g, 20%) as a yellow solid.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Pyrazin-2-amine, its application will become more common.

Reference:
Patent; RODIN THERAPEUTICS, INC; JEFSON, Martin, R.; LOWE, John, A., III; DEY, Fabian; BERGMANN, Andreas; SCHOOP, Andreas; FULLER, Nathan, Oliver; (165 pag.)WO2017/7756; (2017); A1;,
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Electric Literature of 36070-80-1,Some common heterocyclic compound, 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, molecular formula is C5H3ClN2O2, 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.

The title compound is prepared by essentially following the procedure of Method C, using 5-chloro-pyrazine-2-carboxylic acid (Kiener, A.; Roduit, J.-P.; Tschech, A.; Tinschert, A.; Heinzmann, K. Synlett 1994, 814-16), (0.096 g, 1.20 mmol), oxalyl chloride (0.35 mL, 3.99 mmol) and N*2*-(2-dimethylamino-ethyl)-N*2*-methyl-benzothiazole-2,6-diamine (0.20 g, 0.80 mmol) to afford 0.21 g, (67%). MS (m/z): calcd for Ci7Hi9ClN6OS (M+H)+: 391.9; found: 391.2.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 5-Chloropyrazine-2-carboxylic acid, its application will become more common.

Reference:
Patent; ELI LILLY AND COMPANY; WO2006/66173; (2006); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 1174321-06-2, name is 5-(Difluoromethyl)pyrazine-2-carboxylic 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: 5-(Difluoromethyl)pyrazine-2-carboxylic acid

Example 193 N-(3-((4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-oxazin-4-yl)-4,5-difluorophenyl)-5-(difluoromethyl)pyrazine-2-carboxamide The title compound was synthesized by procedures and steps analogous to those described in Method Z, Example 186 above, but using 5-(difluoromethyl)pyrazine-2-carboxylic acid (Aurigene Discovery Technologies). MS m/z=466.1 [M+H]+. Calculated for C18H14F7N5O2: 465.32 1H NMR (300 MHz, CHLOROFORM-d) delta=9.65 (br. s., 1H), 9.52 (s, 1H), 8.93 (s, 1H), 8.14-8.02 (m, 1H), 7.15 (br. s., 1H), 6.99-6.60 (m, 1H), 4.13-3.98 (m, 1H), 2.81 (d, J=13.6 Hz, 1H), 1.94 (t, J=13.1 Hz, 1H), 1.67 (s, 3H)

The synthetic route of 5-(Difluoromethyl)pyrazine-2-carboxylic acid has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MINATTI, Ana Elena; LOW, Jonathan D.; ALLEN, Jennifer R.; CHEN, Jian; CHEN, Ning; CHENG, Yuan; JUDD, Ted; LIU, Qingyian; LOPEZ, Patricia; QIAN, Wenyuan; RUMFELT, Shannon; RZASA, Robert M.; TAMAYO, Nuria A.; XUE, Qiufen; YANG, Bryant; ZHONG, Wenge; US2014/249104; (2014); A1;,
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These common heterocyclic compound, 870787-06-7, name is 3-(Trifluoromethyl)pyrazine-2-carboxylic 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. Product Details of 870787-06-7

N- [2- (3,5- dichloro-pyridin-2-yl) -2- (tert- Butokishiimino) ethyl] -3-(trifluoromethyl) pyrazine-2-carboxamide 3- (tri N in dichloromethane 3ml solution of fluoromethyl) pyrazine-2-carboxylic acid 74mg, added N- dimethylformamide 10mg and oxalyl chloride 57mg, I was stirred at room temperature for 1 hour.After completion of the reaction, distilling off the solvent under reduced pressure, the residue was dissolved in dichloromethane 10ml, stirring under ice cooling, 2-amino-1- (3,5-dichloro-2-yl) ethanone -O- ( was added tert- butyl) oxime and triethylamine 89mg 39mg, it was continued for a further 1 hour stirring at room temperature.After completion of the reaction, extracted with added water 10ml reaction mixture chloroform (10mlx1), and the organic layer brine then dehydrated and dried in this order over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure.The residue was ethyl acetate – hexane (1: 9 to 3: 7 gradient) was purified by silica gel column chromatography eluting with a respective geometric isomers 22mg (isomer A) of the object and 111mg (isomers The B) it was obtained as a colorless resin-like substance

The synthetic route of 3-(Trifluoromethyl)pyrazine-2-carboxylic acid has been constantly updated, and we look forward to future research findings.

Reference:
Patent; NISSAN CHEMICAL INDUSTRIES LIMITED; Iwasa, Motoyoshi; Tomizawa, Mitsutaka; Tsuji, Keisuke; Nakamura, Toshiyuki; Mita, Takeshi; Kuwahara, Hidehito; asahi, Miho; Imanaka, Hotaka; (342 pag.)JP2016/11286; (2016); 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. 330786-09-9, name is Methyl 3,5-dichloropyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., Product Details of 330786-09-9

At 0 C. a solution of 12 (2.59 g) and NEt3 (1.744 ml) in DMF (20 ml), was added to a solution of 6 (2.95 g) in DMF (5 ml) and stirred for 16 h at 25 C. The mixture was diluted with ethyl acetate (70 ml) and washed with water (50 ml). The aqueous phase was extracted with ethyl acetate (30 ml), the combined organic phases washed with brine, dried over Na2SO4 and the solvent evaporated. Chromatography on silica (gradient cyclohexane/ethyl acetate) gave 13 (950 mg) as a yellow solid. UPLC/MS found for C17H25ClN4O4 as (M+1)+ 385.0, UPLC retention time 1.03 min.

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; NOVARTIS AG; Thoma, Gebhard; Smith, Alexander Baxter; van Eis, Maurice; US2013/310387; (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 912773-21-8 as follows. Safety of 2-Bromo-5-chloropyrazine

A mixture of 2-bromo-5-chloro-pyrazine (4 g, 20.68 mmol), 2-benzyloxy-3-fluoro-5-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)pyridine (6.81 g, 20.68 mmol), CS2CO3 (13.47 g, 41.36 mmol) and Pd(dppf)Cl2 (2.27 g, 3.1 mmol) in 1,4- dioxane (30 mL) and water (3 mL) was stirred at 50 C under N2 for 16 hours. After cooling to room temperature, the mixture was filtered, and the filtrate was concentrated. Water (50 mL) was added and the aqueous layer was extracted with EtOAc (50 mL x 2). The combined organic layer was washed with brine (50 mL), dried over anhydrous Na2S04, filtered and concentrated. The crude product was purified by flash chromatography on silica gel (EtOAc in PE = 0% to 15% to 30%) to give the product (5.5 g, 17.42 mmol, 84% yield) as a solid. ‘H NMR (400MHz, DMSO-r) dH= 9.15 (s, 1H), 8.85 (s, 1H), 8.77 (s, 1H), 8.37 (d, 1H), 7.52 – 7.46 (m, 2H), 7.44 – 7.32 (m, 3H), 5.51 (s, 2H).

According to the analysis of related databases, 912773-21-8, the application of this compound in the production field has become more and more popular.

Reference:
Patent; PRAXIS PRECISION MEDICINES, INC.; GRIFFIN, Andrew, Mark; MARRON, Brian, Edward; MARTINEZ BOTELLA, Gabriel; REDDY, Kiran; WITTMANN, Marion; (0 pag.)WO2019/232209; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 768-05-8, name is Pyrazinoic acid hydrazide, molecular formula is C5H6N4O, 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. COA of Formula: C5H6N4O

General procedure: To the solution of pyrazine carboxylic acid hydrazide (0.55 g, 4 mmol) in methanol (30 mL) was added dropwise with continuous stirring, a solution of 2-benzoyl pyridine (0.73 g, 4 mmol) in the same solvent. The reaction mixture was then refluxed for 5 h. The solid product so obtained was filtered and recrystallised in hot methanol.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 768-05-8, its application will become more common.

Reference:
Article; Devi, Jai; Batra, Nisha; Malhotra, Rajesh; Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy; vol. 97; (2012); p. 397 – 405,9;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem