Month: December 2020

63744-22-9, name is 6,8-Dibromoimidazo[1,2-a]pyrazine, 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. 63744-22-9

Example 8-1 :Preparation of 6,8-dibromo-3-iodo-imidazo[1 , 2-a]pyrazineTo a stirred solution of intermediate example 1 -1 (8.7 g g, 31 .4 mmol) in DMF (210 mL) was added NiS (7.42 g, 33 mmoi, 1 .05 eq) in one portion at rt. After 18 h stirring at 60 C, the solvent was removed in vaccuo and the residue was taken up in DCM and washed with water and saturated sodium thiosulfate solution. The organic phase was dried over sodium sulphate, filtered and the solvent was evaporated to yield 9.46 g (74.8 %) 6,8-Dibromo-3-iodo-imidazo[1 ,2-a]pyrazine: 1H-NMR (300 MHz, CDCl3): delta = 8.22 (1 H, s), 7.91 (1 H, s) ppm.

Statistics shows that 63744-22-9 is playing an increasingly important role. we look forward to future research findings about 6,8-Dibromoimidazo[1,2-a]pyrazine.

Reference:
Patent; BAYER PHARMA AKTIENGESELLSCHAFT; KOPPITZ, Marcus; KLAR, Ulrich; JAUTELAT, Rolf; KOSEMUND, Dirk; BOHLMANN, Rolf; BADER, Benjamin; LIENAU, Philip; SIEMEISTER, Gerhard; WO2012/80228; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

36070-75-4, Adding some certain compound to certain chemical reactions, such as: 36070-75-4, name is 5-Chloropyrazine-2-carbonitrile, 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 36070-75-4.

Preparation of tert-Butyl 2-((R)-5-(5-cyanopyrazin-2-yl)-2,3-dihydro-1H-inden-1-yl)-2,7-diazaspiro[3.5]nonane-7-carboxylate (10-1a) To a solution of tert-butyl 2-[(1R)-5-bromo-2,3-dihydro-1H-inden-1-yl]-2,7-diazaspiro[3.5]nonane-7-carboxylate (3-1a, 700 mg, 1.66 mmol) in anhydrous dioxane (10 mL) was added bis(pinacolato)diboron (473 mg, 1.86 mmol) and potassium acetate (659 mg, 6.71 mmol). The mixture was purged with nitrogen for 15 minutes. Pd(dppf)Cl2 (62 mg, 0.07 mmol) was added and the reaction mixture was purged with nitrogen for an additional 15 minutes. The reaction was heated to 110 C. under nitrogen for 5 hours. TLC indicated the complete consumption of the starting material (3-1a). The reaction was cooled to room temperature and 5-chloropyrazine-2-carbonitrile (278 mg, 1.99 mmol), Pd(dppf)Cl2 (62 mg, 0.07 mmol) and 5.81 mL of 2M aqueous K2CO3 solution (de-oxygenated with a stream of nitrogen for 15 minutes prior to addition) were added. The reaction was purged with nitrogen (3¡Á) and was heated for 20 hours at 110 C. The reaction was cooled and concentrated in vacuo. The residue was partitioned between 50 mL of ethyl acetate and 50 mL of 1N NaOH solution. The organics layer was washed with 50 mL of brine, dried (Na2SO4) and concentrated to give crude product as black semi-solid. The crude product was purified via silca gel chromatography using a Combiflash ISCO purification system (Teledyne Corp., Lincoln, Nebr.) system, eluting with 0-100% EtOAc:heptanes to give the title compound as a brown solid (440 mg, 59%). MS (ES+) 446.3 (M+H)+. 1H NMR (DMSO-d6) delta 1.39 (s, 9H), 1.56-1.64 (m, 4H), 1.81-1.92 (m, 1H), 2.06 (dd, 1H), 2.77-2.87 (m, 1H), 2.92-3.04 (m, 3H), 3.12 (d, 2H), 3.24-3.28 (m, 4H), 3.86 (dd, 1H), 7.41 (d, 1H), 7.55 (d, 1H), 7.62-7.68 (m, 1H), 8.09 (s, 1H), 8.90 (s, 1H).

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 36070-75-4.

Reference:
Patent; Bhattacharya, Samit K.; Cameron, Kimberly O.; Fernando, Dilinie P.; McClure, Kim F.; Kung, Daniel W.; Londregan, Allyn T.; Simila, Suvi T. M.; US2011/230461; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 912773-21-8, name is 2-Bromo-5-chloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. 912773-21-8

To a suspension of copper (0) powder (244 g, 3880 mmol) in DMSO (5 L) was added ethyl 2-bromo-2,2-difluoroacetate (394 g, 1940 mmol) at room temperature. The reaction mixture was stirred at room temperature for 1 hour and 2-bromo-5-chloropyrazine (Shanghai Fchemicals Technology Co., Ltd., Shanghai, China) (250 g, 1290 mmol) was added in portion-wise manner. The reaction mixture was stirred at room temperature for 3 hours, then quenched with sat’d solution of ammonium chloride (2.0 L). The mixture was filtered through a celite pad and the filtrate was extracted with ethyl acetate (2 x 2 L). The combined organic layers were dried over Na2S04 and concentrated under reduced pressure. The residue was purified via silica gel chromatography (0 to 2% ethyl acetate in hexanes) to afford 4a (215 g, 70% yield) as a viscous colorless liquid. NMR (400 MHz, DMSO-t/6) delta 9.05 (d, J = 1.4 Hz, 1H), 8.98 (dd, J= 1.4, 0.7 Hz, 1H), 4.39 – 4.34 (m, 2H), 1.24 (t, J= 7.1 Hz, 3H).

The synthetic route of 912773-21-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; AMGEN INC.; ALLEN, Jennifer R.; BOURBEAU, Matthew P.; CHEN, Ning; FROHN, Michael J.; HARRINGTON, Paul E.; LIU, Qingyian; REEVES, Corey; (108 pag.)WO2018/112081; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

32111-28-7, The chemical industry reduces the impact on the environment during synthesis 32111-28-7, name is N-Methylpyrazin-2-amine, I believe this compound will play a more active role in future production and life.

To a stirred solution of aminopyrazine 4 (5.0 mmol) in dimethyl sulfoxide (10 mL)/water (0.20 mL) at 10 C. was added N-bromosuccinimide (10 mmol) in portions. The reaction mixture was then allowed to warm to room temperature slowly and stirred at that temperature overnight. An additional aliquot of N-bromosuccinimide (10 mmol) was then added at room temperature. After stirring for 6.5 h, the reaction mixture was poured onto ice (30 g). The precipitate was collected, washed with cold water (2¡Á10 mL), and dried to provide the product 2, which could be purified by column chromatography, but was usually used in the next step without purification. ; Step B: 3,5-Dibromo-N-methylpyrazin-2-amine Prepared from the product of Step A according to general procedure 3 providing the dibromopyrazine (700 mg, 44%) as a yellow solid; 1H NMR (300 MHz, CDCl3) delta 8.07 (s, 1H), 5.26 (br s, 1H), 3.03-3.01 (d, J=5.0 Hz, 3H).

The chemical industry reduces the impact on the environment during synthesis N-Methylpyrazin-2-amine. I believe this compound will play a more active role in future production and life.

Reference:
Patent; Alcon, Inc.; US2006/142307; (2006); 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 951626-95-2 as follows. 951626-95-2

To the solution of piperidine (25 mg, 0.29 mmol) in dry THF (5 mL) was added trimethylaluminium (0.14mL, 0.29 mmol) drop wise at -10C under nitrogen over a period of 10 min. This solution was allowed to stir at room temperature for 45 minutes. Further the reaction mixture was re-cooled to -10C and thereto was added a solution of compound 5a (50 mg, 0.22 mmol) in THF (2.5 mL) drop wise. The resulting reaction mixture was stirred at room temperature initially then refluxed for 18 h. Reaction mixture was cooled to room temperature and quenched with iso-propanol (IPA) followed by methanol and then with saturated Na2SO4 solution. The reaction mixture was filtered and the filtrate was evaporated to dryness. The crude material was purified by column chromatography on silica gel (100-200 mesh) using MeOH in DCM to give desired compound 6a (50 mg, 85%). MS (ES+) m/z: 249. 1H NMR (400 MHz, CDCl3) delta 7.13 (s, 1H), 6.14-6.28 (m, 1H), 4.43 (m, 2H), 3.77-3.85 (m, 2H), 3.68-3.74 (m, 4H), 1.51-1.76 (m, 6H)

According to the analysis of related databases, 951626-95-2, the application of this compound in the production field has become more and more popular.

Reference:
Article; Surase, Yogesh B.; Samby, Kirandeep; Amale, Sagar R.; Sood, Ruchi; Purnapatre, Kedar P.; Pareek, Pawan K.; Das, Biswajit; Nanda, Kamna; Kumar, Subodh; Verma, Ashwani K.; Bioorganic and Medicinal Chemistry Letters; vol. 27; 15; (2017); p. 3454 – 3459;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

16298-03-6, The chemical industry reduces the impact on the environment during synthesis 16298-03-6, name is Methyl 2-aminopyrazine-3-carboxylate, I believe this compound will play a more active role in future production and life.

A solution of methyl 3-aminopyrazine-2-carboxylate (3.0 g, 19.6 mmol) and NBS(3.5 g, 23.5 mol) in MeCN (70 mL) was stirred at 70¡ãC for 5 h. Then the mixture was concentrated and extracted with EtOAc. The organic layer was washed with Na2503 (a.q.) and brine, dried over Na2504 and concentrated in vacuo. The crude product of methyl 3-amino-6-bromopyrazine-2-carboxylate (3.0 g, yield: 92percent) was used for next step without further purification. ?H-NMR(CDC13, 400 MHz) 8.18 (s, 1H), 6.546.93 (m, 2H), 3.86 (s, 3H). MS (M+H): 232 / 234.

The chemical industry reduces the impact on the environment during synthesis Methyl 2-aminopyrazine-3-carboxylate. I believe this compound will play a more active role in future production and life.

Reference:
Patent; MERCK SHARP & DOHME CORP.; DAI, Xing; LIU, Hong; PALANI, Anandan; HE, Shuwen; NARGUND, Ravi; XIAO, Dong; ZORN, Nicolas; DANG, Qun; MCCOMAS, Casey C.; PENG, Xuanjia; LI, Peng; SOLL, Richard; WO2014/205593; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

91476-80-1, A common compound: 91476-80-1, name is 5,6,7,8-Tetrahydroimidazo[1,2-a]pyrazine, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below.

(5) A mixture of 4-benzylthio-5-methoxycarbonyl-6-(4-hydroxypiperidine-1-yl)-2-chloropyrimidine (prepared in the above (4)) 120 mg, 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine 70 mg, triethylamine 57 mg and N,N-dimethylacetamide 3 ml is stirred at 10 C. for 3 hours. The reaction mixture is diluted with an aqueous citric acid solution and extracted with ethyl acetate. The water layer is made basic with an aqueous sodium hydrogen carbonate solution and extracted with ethyl acetate. The organic layer is washed, dried and concentrated in vacuo to give 4-benzylthio-5-methoxycarbonyl-6-(4-hydroxypiperidin-1-yl)-2-(5,6,7,8-tetrahydroimidazo[1,2-a]pyrazin-7-yl)pyrimidine as a colorless foam, 105 mg. IR (Neat+CHCl3)cm-1: 3050-3600,1695,1533,1503, 1433 APCI-MS(m/z): 481 (M+H)+

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, 5,6,7,8-Tetrahydroimidazo[1,2-a]pyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Yamada, Koichiro; Matsuki, Kenji; Omori, Kenji; Kikkawa, Kohei; US2004/142930; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

4744-50-7, 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. 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, This compound has unique chemical properties. The synthetic route is as follows.

General procedure: Pyrazine-2,3-dicarboxylic anhydride (1.0 g, 6.7 mmol) was dissolved in tetrahydrofuran (40 mL)in an Erlenmeyer flask and the corresponding substituted aniline (6.7 mmol, 1 equiv.) was added in one dose. The reaction mixture was stirred for 1 hour at laboratory temperature. Water (30 mL) was added into the mixture followed by the saturated aqueous solution of NaHCO3 until pH 6 to form thecorresponding 3-(phenylcarbamoyl)pyrazine-2-carboxylic acid 1-18. Obtained crystals were filtered off and washed with water. The progress of the procedure was monitored by TLC eluted with thesystem water/butanol/acetic acid 5:4:1.

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:
Article; Semelkova, Lucia; Jano?cova, Petra; Fernandes, Carlos; Bouz, Ghada; Jand?Ourek, Ond?ej; Kone?na, Klara; Paterova, Pavla; Navratilova, Lucie; Kune?, Ji?i; Dole?al, Martin; Zitko, Jan; Molecules; vol. 22; 9; (2017);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

The chemical industry reduces the impact on the environment during synthesis 87486-34-8, name is 3,5-Dibromo-1-methylpyrazin-2(1H)-one, I believe this compound will play a more active role in future production and life. 87486-34-8

A flask equipped with a magnetic stirrer was charged with l-(2-(tert- butyldimethylsilyloxy)ethyl)-lH-pyrazol-4-amine 116b (1. 7 g, 7.1 mmol), 3,5-dibromo-l- methylpyrazin-2(lH)-one (1.25 g, 4.7 mmol), and IPA (25 rriL). The system was evacuated and then refilled with N2. The reaction mixture was heated at 90¡ãC for 6 h. Then, the mixture was cooled to room temperature and concentrated under reduced pressure. The residue was purified by flash column chromatography eluting with petroleum ether/ethyl acetate to afford 140a (1.7 g, 78percent). LCMS: [M+H]+ 314.

The chemical industry reduces the impact on the environment during synthesis 87486-34-8. I believe this compound will play a more active role in future production and life.

Reference:
Patent; GILEAD CONNECTICUT, INC.; GENENTECH, INC.; BARBOSA, Antonio, J., M.; BLOMGREN, Peter, A.; CURRIE, Kevin, S.; KRISHNAMOORTHY, Ravi; KROPF, Jeffrey, E.; LEE, Seung H.; MITCHELL, Scott A.; ORTWINE, Daniel; SCHMITT, Aaron, C.; WANG, Xiaojing; XU, Jianjun; YOUNG, Wendy; ZHANG, Honglu; ZHAO, Zhongdong; ZHICHKIN, Pavel E.; WO2011/140488; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

87486-34-8, A common compound: 87486-34-8, name is 3,5-Dibromo-1-methylpyrazin-2(1H)-one, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below.

General procedure: To a solution of 2a-j (10 mmol, 1.0 eq) , 3,5-dibromo-1-methylpyrazin-2(1H)-one (2.95 g, 11 mmol, 1.1 eq) and DIEA (3.3 mL,20 mmol, 2.0 eq) in MeCN (20mL) was stirred at 80 ¡ãC for 5 hours. After cooling to room temperature, thesolvent was removed in vacuo, and the residue was purified using silica gelchromatography to give the title compounds, yield 72-85percent.

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, 3,5-Dibromo-1-methylpyrazin-2(1H)-one, other downstream synthetic routes, hurry up and to see.

Reference:
Article; Yang, Jianhong; Du, Jiatian; Huang, Chong; Wang, Tianqi; Huang, Luyi; Yang, Shengyong; Li, Linli; Bioorganic and Medicinal Chemistry Letters; vol. 29; 13; (2019); p. 1609 – 1613;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem