Month: March 2021

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. 98-97-5, name is Pyrazine-2-carboxylic acid belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. category: Pyrazines

Synthesis of methyl pyrazine-2-carboxylate: To a stirred solution of pyrazine-2-carboxylic acid (5 g, 40.29 mmol) in MeOH (20 mL) was added concentrated H2S04 (1 mL) drop wise and stirred under reflux for 5 h. The reaction mixture was cooled to RT; volatiles were evaporated under reduced pressure. The residue was diluted with water and basified to pH~ 8.5 using NaHC03 and extracted with EtOAc. Combined organic layer was dried over sodium sulphate, filtered and concentrated in vacuo to afford methyl pyrazine-2-carboxylate (3.5 g, 63.63%) as an off- white solid. 1H-NMR (DMSO d6, 400 MHz): delta 9.21 (s, 1H), 8.91 (d, 1H), 8.82 (d, 1H), 3.92 (s, 3H); TLC: 50% EtOAc/Hexane (Rf: 0.4).

The synthetic route of 98-97-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ENVIVO PHARMACEUTICALS, INC.; RIPKA, Amy; SHAPIRO, Gideon; MCRINER, Andrew; WO2012/40230; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 1379338-74-5,Some common heterocyclic compound, 1379338-74-5, name is 5,7-Dichloropyrido[3,4-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 solution of 6-(aminomethyl)morpholin-3-one (130 mg, 1 mmol), 5,7-dichloropyrido[4,3-b]pyrazine (200 mg, 1 mmol) and DIEA (260 mg, 2 mmol) in THF (20 mL) was stirred at reflux overnight. After concentration, the residue was purified by column chromatography to give product as yellow solid (100 mg).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 5,7-Dichloropyrido[3,4-b]pyrazine, its application will become more common.

Reference:
Patent; HUTCHISON MEDIPHARMA LIMITED; Su, Wei-Guo; Deng, Wei; Ji, Jianguo; US2014/121200; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 77112-52-8, 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 77112-52-8 as follows.

To the suspension of imidazo[1,2-a]pyrazine-2-carboxylic acid ethyl ester (0.3 g, 0.0016 mol) in anhydrous ethanol (7 mL), the chilled solution of bromine (0.16 mL, 0.0032 mol) in anhydrous ethanol (7 mL) was added dropwise and the resulting mixture was heated at reflux under continuous nitrogen flow for 1.5 hours. The reaction mixture was concentrated under reduced pressure and treated with the saturated solution of sodium bicarbonate in water (50 mL). The aqueous layer was extracted with ethyl acetate (3×25 mL), the combined organic extracts were dried with magnesium sulfate and concentrated. The residue was suspended in heptane (30 mL) and the precipitate was collected by filtration and dried to yield 5-bromo- imidazo [1,2-a]pyrazine-2-carboxylic acid ethyl ester (0.075 g, 0.00028 mol) as a yellow solid. m/z: (M + H) + 270,272.

According to the analysis of related databases, 77112-52-8, the application of this compound in the production field has become more and more popular.

Reference:
Patent; ABBOTT LABORATORIES; WO2005/110410; (2005); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 1196151-53-7, name is 6-Bromopyrazine-2-carboxylic acid, molecular formula is C5H3BrN2O2, 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. HPLC of Formula: C5H3BrN2O2

Example 21 Preparation of Compound 297 Step A-Synthesis of Intermediate Compound Int-21a A mixture of 6-bromopyrazine-2-carboxylic acid (404 mg, 1.99 mmol), 2-(4-fluorophenyl)-N-methyl-6-(N-methylmethylsulfonamido)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzofuran-3-carboxamide (1 g, 1.99 mmol), 2M sodium carbonate (4 ml, 8 mmol), Bis(triphenylphosphine)palladium(II) dichloride (70 mg, 0.1 mmol) was suspended in DME (7 ml), DMf (2 ml), water (3 ml) and EtOH (2 ml) in a sealed tube and heated in a microwave oven at 120 C. for 20 min. Then concentrated under vacuum, applied onto Prep HPLC and eluted with H2O (0.1% TFA) and Acetonitrile (0.1% TFA). This resulted in 0.96 g (95%) of 6-(2-(4-fluorophenyl)-3-(methylcarbamoyl)-6-(N-methylmethylsulfonamido)benzofuran-5-yl)pyrazine-2-carboxylic acid as a white solid. LC-MS (ES, m/z) C23H19FN4O6S: 498. Found: 499 [M+H]+.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1196151-53-7, its application will become more common.

Reference:
Patent; McComas, Casey Cameron; Liverton, Nigel J.; Habermann, Joerg; Koch, Uwe; Narjes, Frank; Li, Peng; Peng, Xuanjia; Soll, Richard; Wu, Hao; Palani, Anandan; Dai, Xing; Liu, Hong; He, Shuwen; Lai, Zhong; Dang, Qun; Zorn, Nicolas; US2014/199263; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 22047-25-2, A common heterocyclic compound, 22047-25-2, name is Acetylpyrazine, molecular formula is C6H6N2O, 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: A 2-neck round bottom flask attached with calcium chloride guard tube was charged with MeOH (30mL). Then, 2-acetylpyrazine (1.47g, 2mmol) followed by KOH pellets (0.675g, 2mmol) were added and initiated magnetic stirring. To this mixture, distilled water (2mL) was added and continued stirring for 10min. Now, the resulting solution was added the respective n,n?,n?-trimethoxyphenyl benzaldehydes (1.0g, 1mmol) under stirring at room temperature slowly and then 6mL of ammonia solution was added. The reaction mixture was stirred further for 4h. The reaction was monitored by TLC. On completion of reaction by TLC, the reaction mass was filtered and washed with methanol (3¡Á10 mL) and then diethyl ether (3¡Á10 mL) to obtain a white precipitate of respective compounds. Each of the above precipitates was recrystallised in a mixture of CHCl3 and MeOH (1:1) at room temperature for 48h. The resulting colourless single crystals of 1-3 were collected by filtration.

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

Reference:
Article; Ramesh; Sharath Kumar; Raghavendra Kumar; Suchetan; Devaraja; Sabine, Foro; Nagaraju; Journal of Molecular Structure; vol. 1200; (2020);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

76537-18-3, name is 3-Bromo-5-chloropyrazin-2-amine, 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. COA of Formula: C4H3BrClN3

3-Bromo-5-chloropyrazin-2-amine (200 mg, 0.96 mmol), triethylamine (290 mg, 2.88 mmol), cuprous iodide (5 mg, 0.33 mmol) and bis(triphenyl) Palladium dichloride (13 mg, 0.02 mmol) was dissolved in tetrahydrofuran (5 mL).The reaction solution was stirred at room temperature.Then, trimethylethynyl silicon (0.15 mL, 1.06 mmol) was slowly added dropwise to the above reaction solution.After the completion of the dropwise addition, the obtained reaction liquid was transferred to a condition of 55 C to continue the reaction for 1 hour. After the reaction system is cooled to room temperature,The reaction solution was diluted with ethyl acetate (50 mL) and filtered.The filtrate was concentrated under reduced pressure.The residue obtained was subjected to silica gel column chromatography(PE/EA(nu/nu) = 30/1) purified,The title compound was obtained as a pale yellow solid (208 mg,96%).

The synthetic route of 76537-18-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Guangdong Dongyangguang Pharmaceutical Co., Ltd.; Ren Qingyun; Tang Changhua; Yin Junjun; Wang Yejun; Yi Kai; Lei Yibo; Zhang Yingjun; S ¡¤geerdeman; Yan Huan; Nie Biao; Xu Juan; Chen Jianping; Chen Yunfu; Zhang Weihong; Cheng Lijun; Ye Weiliang; (197 pag.)CN110117285; (2019); A;,
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 710322-57-9 as follows. Quality Control of Methyl 5-formylpyrazine-2-carboxylate

[000243] A mixture of 5-formyl-pyrazine-2-carboxylic acid methyl ester (325 mg, 1.56 mmol), ethylene glycol (100 pL, 1.79 MMOL), and p-toluenesulfonic acid monohydrate (30 mg, 0.157 mmol) in benzene (10 mL) was heated under reflux with a Dean-Stark condenser for 17 h. The mixture was cooled and diluted with benzene (25 mL). The organic layer was washed with a saturated aqueous sodium bicarbonate solution (25 ML) and a saturated aqueous sodium chloride solution (25 mL). Each aqueous wash was back-extracted with a small portion of benzene. The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo to afford 5- [L, 3dioxolan-2-yl-pyrazine-2-carboxylic acid methyl ester as an orange-red oil (250 mg).

According to the analysis of related databases, 710322-57-9, the application of this compound in the production field has become more and more popular.

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; WO2004/52869; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 21279-62-9, These common heterocyclic compound, 21279-62-9, name is 3-Chloropyrazine-2-carboxamide, 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: 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).

Statistics shows that 3-Chloropyrazine-2-carboxamide is playing an increasingly important role. we look forward to future research findings about 21279-62-9.

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);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 22047-25-2, name is Acetylpyrazine, molecular formula is C6H6N2O, 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. HPLC of Formula: C6H6N2O

General procedure: Catalyst (0.1mol %) and KOH (1mmol) were dissolved in 2-propanol (4mL). To this solution, substrate (1mmol) was added and the mixture was refluxed (82C). The progress of the reaction was monitored by GC at regular intervals. After the completion of the reaction, the reaction mixture was cooled to room temperature and filtered through silica gel or alumina bed, and eluted using 50% ethyl acetate-hexane mixture. The eluted solution was reduced and analyzed by GC and/or GCMS.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 22047-25-2, its application will become more common.

Reference:
Article; Sathishkumar, Pushpanathan N.; Raveendran, Neethi; Bhuvanesh, Nattamai S.P.; Karvembu, Ramasamy; Journal of Organometallic Chemistry; vol. 876; (2018); p. 57 – 65;,
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, name: 2,3-Dichloropyrazine

To 2,3-Dichloro-pyrazine (18 g, 120.82 mmol), ammonium hydroxide (50 ml, 1280 mmol) is added and the reaction mixture is microwaved at 140 C. for 25 minutes. The reaction mixture is filtered and washed with water to yield 3-Chloro-pyrazin-2-ylamine.

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; BRUCE, Ian; BUDD, Emma; EDWARDS, Lee; HOWSHAM, Catherine; US2009/239847; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem