Category: Pyrazines

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. 951626-95-2, name is Ethyl 4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. Recommanded Product: 951626-95-2

To a solution of cyclopropylmethyl bromide (0.101 g, 0.75 mmol) and ethyl 4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate (31.4 mg, 0.150 mmol) in acetonitrile (2 mL) was added cesium carbonate (147 mg, 0.45 mmol). The reaction mixture was heated overnight at 70 C. Upon cooling to room temperature, the insolubles were removed by filtration and the solvent evaporated to dryness to afford crude Intermediate 33.

The synthetic route of 951626-95-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Millennium Pharmaceuticals, Inc.; US2011/251184; (2011); A1;,
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. 88625-24-5, name is 5-Chloropyrazine-2-carbaldehyde, A new synthetic method of this compound is introduced below., Safety of 5-Chloropyrazine-2-carbaldehyde

To a solution of 5-chloropyrazine-2-carbaldehyde (500 mg, 3.51 mmol) in CH2CI2 (10 mL) was added (diethylamino)difluorosulfonium tetrafluoroborate (2.0 g, 8.77 mmol) and triethylamine trihydrofluoride (0.57 mL, 3.51 mmol). The reaction mixture was stirred for 18 hours at ambient temperature. The reaction mixture was diluted with water and was extracted with CH2CI2. The organic layer was dried over anhydrous MgSO/t, filtered and concentrated under reduced pressure. Purification of the residue via column chromatography (Si(, heptane:ethyl acetate 0-65%) gave the title (200 mg, 1.22 mmol, 35% yield). JH NMR (500 MHz, DMSO- ) delta ppm 9.00 – 8.93 (m, 1H), 8.86 (q, J = 1.1 Hz, 1H), 7.17 (t, J = 54.0 Hz, 1H); MS (ESI+) m/z 186 (M+Na)+.

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; CALICO LIFE SCIENCES LLC; ABBVIE INC.; MARTIN, Kathleen, Ann; SIDRAUSKI, Carmela; FROST, Jennifer, M.; PLIUSHCHEV, Marina, A.; TONG, Yunsong; BLACK, Lawrence, A.; XU, Xiangdong; SHI, Lei; ZHANG, Qingwei, I.; CHUNG, Seungwon; SWEIS, Ramzi, Farah; DART, Michael, J.; RANDOLPH, John, T.; MURAUSKI, Kathleen; (674 pag.)WO2019/90076; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 486424-37-7, A common heterocyclic compound, 486424-37-7, name is 3-Amino-6-bromopyrazine-2-carboxylic acid, molecular formula is C5H4BrN3O2, 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.

Triethyl amine (0.57 ML, 4.13 mmol) was added to a mixture of 3-AMINO-6-BROMO-2- pyrazinecarboxylic acid (0.30 g, 1.38 mmol; described in: Ellingson, R. C.; Henry, R. L. J. Am. Chem. Soc. 1949,2798-2800), 0- (BENZOTRIAZOL-1-YL)-NNN’, N’- tetramethyluroniumtetrafluoroborate (0.486 g, 1.51 mmol) and 1-hydroxybenzotriazole (0.204 g, 1.51 mmol) in N, N-DIMETHYLFORMAMIDE/ACETONITRILE, (1: 1,5 ML). After stirring for 0.5 h at room temperature, 2-(LH-PYRROL-L-YL)-L-ETANAMINE (0.182 g, 1.65 mmol) was added and the resulting mixture was stirred overnight at room temperature. Approximately, 10 ML water was added and a precipitation was formed. The precipitation was filtered and washed with water which gave 0.21 g (50% yield) of a light brown solid: MS (ESP) M/Z 310,312 (M++1). The solid (0.16 g, 0.516 mmol) from previous step was dissolved in tetrahydrofuran/water (5: 1,5 mL) together with [4- [ (4-methyl-l-piperazinyl) sulfonyl] phenyl] boronic acid (0.220 g, 0.77 mmol), sodium carbonate (0.164 g, 1.55 mmol) and Pd (dppf) CL2 (0.013 g, 1.5 nmmol). The resulting mixture was stirred at 70 C overnight (N2-atmosphere). The mixture was evaporated onto silica and purified on silica using toluene/acetonitrile, (1: 2 to 1: 4), as the eluent which afforded a yellow solid which was dried in vacuo at 40 C. The product was dissolved in a methylene chloride/methanol mixture, (9: 1), and hydrochloride acid in diethyl ether (0.28 mL, 1 M) was added. The precipitate was washed with diethyl ether and dried in vacuo to give 69 mg (23% yield) of the title compound : 1H NMR (DMSO-d6) 5 8.94 (s, 1 H), 8.90 (t, J = 6 Hz, 1 H), 8.43 (d, J = 8 Hz, 2 H), 7.82 (d, J = 8 Hz, 2 H), 6.79 (t, J = 2 HZ, 2 H), 6.01 (t, J = 2 HZ, 2 H), 4.12 (t, J = 7 Hz, 2 H), 3.83 (d, J = 12 Hz, 2 H), 3.63 (quart, J = 6 Hz, 2 H), 3.44 (d, J = 12 Hz, 2 H), 3.15 (m, 2 H), 2.73 (m, 5 H) ; 13C NMR (DMSO-d6) 8 165.8, 154.5, 144.8, 140.8, 135.9, 133.3, 127.9, 126.1, 124.6, 120.7, 107.8, 51.5, 47.6, 43.0, 41.8 ; MS (ESP) M/Z 470 (M++1).

The synthetic route of 486424-37-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ASTRAZENECA AB; WO2004/55009; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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

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. 14508-49-7, name is 2-Chloropyrazine, This compound has unique chemical properties. The synthetic route is as follows., 14508-49-7

General procedure: A 10 mL round-bottom flask was charged with the prescribedamount of catalyst Pd/Cu, aryl chlorides (0.5 mmol), phenylboronicacids containing hydroxymethyl (0.75 mmol), Cs2CO3 (1.0 mmol)and dioxane (5 mL) in air. The reaction mixture was then placedin an oil bath and heated at 110 C for 24 h. After removal of thesolvent, the resulting residue was purified by flash chromatographyon silica gel using CH2Cl2 as eluent. The products 4a-k, and4m are known compounds [6,9] except for 4l and 4n.

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; Xu, Chen; Li, Hong-Mei; Wang, Zhi-Qiang; Fu, Wei-Jun; Inorganica Chimica Acta; vol. 423; 1; (2014); p. 11 – 15;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

57948-41-1, 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 57948-41-1 as follows.

A solution of bromo compound (70 mg, 0.353 mmol, 1 equiv), Pd(PPh3)2Cl2 (10 mol%), Cul (5 mol%) and Triphenylphosphine (10.5 mg, 0.04 mmol, 10 mol%) in triethylamine (1.5 mL, 10.78 mmol, 30.5 equiv) was deoxygenated using argon gas. A deoxygenated solution of alkyne (170 mg, 0.424 mmol, 1.2 equiv) in DMF (4 mL) was slowly added over 10 minutes. The reaction was then moved to 50 C and allowed to run for 15 hrs. The reaction was the cooled to room temperature, diluted with ethyl acetate (150 mL) and washed with water (5 x 50 mL) and brine (1 x 50 mL). Combined organic layers were dried over anhydrous sodium sulphate, concentrated in vacuo and purified via column chromatography. Yield: 71.9 mg, 39.2 % [0191] 1H NMR (500 MHz, DMSO-7,) d 10.85 (s, 1H), 9.21 (d, 7 = 1.5 Hz, 1H), 9.11 (dd, J = 18.4, 2.1 Hz, 2H), 8.88 (dd, J = 4.5, 1.5 Hz, 1H), 8.69 (d, J = 2.2 Hz, 1H), 8.28 (s, 1H), 8.21 (d, J = 2.2 Hz, 1H), 8.14 (d, J = 4.5 Hz, 1H), 8.05 (dd, 7 = 8.4, 2.2 Hz, 1H), 7.72 (d, J = 8.5 Hz, 1H), 3.57 (s, 3H), 2.48 – 2.28 (m, 8H), 2.23 (s, 3H). 13C NMR (126 MHz, DMSO-7,) d 163.9, 154.1, 148.9, 143.7, 140.9, 140.4, (0226) 138.3, 137.9, 132.9, 131.8, 131.3, 130.3, 128.0, 127.8, 125.8, 124.0, 123.6, 119.9, 118.8, 117.8, 108.9, 96.7, 79.8, 57.8, 54.9, 52.7, 45.7, 40.5, 40.3, 40.1, 40.0, 39.8, 39.6, 39.5.

According to the analysis of related databases, 3-Bromoimidazo[1,2-a]pyrazine, the application of this compound in the production field has become more and more popular.

Reference:
Patent; PURDUE RESEARCH FOUNDATION; SINTIM, Herman O.; LAROCQUE, Elizabeth; NAGANNA, N; (98 pag.)WO2020/53812; (2020); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

54013-07-9, The chemical industry reduces the impact on the environment during synthesis 54013-07-9, name is 5-Methoxypyrazin-2-amine, I believe this compound will play a more active role in future production and life.

Example 1AX; Preparation of 2-ethyl-N-(5-methoxypyrazin-2-yl)-4-f4- (methylsulfonyl)phenoxyl-2H-indazole-6-carboxamide (1AX): To a solution of 5-methoxypyrazin-2-annine (167 mg, 1.34 mmol) in dry dichloroethane (2.0 ml_) was added dimethylaluminum chloride (2.67 ml_, 2.67 mmol) slowly at O0C under nitrogen. After addition, the mixture was stirred for 1 hour at room temperature and then added methyl 2-ethyl-4-(4- (methylsulfonyl)phenoxy)-2H-indazole-6-carboxylate (1-1 f-7,100.0 mg, 0.267 mmol). Then the mixture was heated to 60-700C overnight. The reaction mixture was cooled to room temperature, poured into potassium sodium tartrate (aq., 10 ml_), and extracted with ethyl acetate (10 ml_ 3 times). The combined organic layers were dried and concentrated under reduced pressure and purified by preparative HPLC to afford the title compound (1AX, 20.0 mg, yield: 16%) as a white solid.1H NMR (400 MHz, DMSO-d6): delta 1.46-1.49 (t, 3H), 3.15 (s, 3H), 3.88 (s, 3H), 4.43-4.49 (q, 2H), 7.20 (s, 1 H), 7.17-7.31 (d, 2H), 7.91 -7.93(d, 2H), 8.15(s, 1 H), 8.32(s, 1 H), 8.44 (s, 1 H), 8.88 (s, 1 H), 10.97 (s, 1 H). MS (M+1 ): 468.2.

The chemical industry reduces the impact on the environment during synthesis 5-Methoxypyrazin-2-amine. I believe this compound will play a more active role in future production and life.

Reference:
Patent; PFIZER INC.; CORBETT, Jeffrey Wayne; GUZMAN-PEREZ, Angel; PFEFFERKORN, Jeffrey Allen; TU, Meihua Mike; WO2010/103438; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

312736-49-5, A common compound: 312736-49-5, name is 3,5-Dichloropyrazine-2-carboxylic acid, 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.

Step 2: methyl 3,5-dichloropyrazine-2-carboxylate To a solution of 3,5-dichloropyrazine-2-carboxylic acid (0.304 g, 1.58 mmol) in MeOH (5 mL) and diethyl ether (5 mL) at RT was added (trimethylsilyl)diazomethane (2.0 M solution in hexanes, 4.00 mL, 8.00 mmol). The reaction mixture was stirred at RT for 30 min and then concentrated. Purification by flash column chromatography on silica gel (5% to 20% EtOAc in hexanes) gave methyl 3,5-dichloropyrazine-2-carboxylate (0.312 g, 1.51 mmol, 96% yield) as a white solid.

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-Dichloropyrazine-2-carboxylic acid, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; LEWIS, Richard T.; ALLEN, Jennifer R.; CHENG, Yuan; CHOQUETTE, Deborah; EPSTEIN, Oleg; GUZMAN-PEREZ, Angel; HARRINGTON, Paul E.; HUA, Zihao; HUNGATE, Randall W.; HUMAN, Jason Brooks; JUDD, Ted; LIU, Qingyian; LOPEZ, Patricia; MINATTI, Ana Elena; OLIVIERI, Philip; ROMERO, Karina; RUMFELT, Shannon; RZASA, Robert M.; SCHENKEL, Laurie; STELLWAGEN, John; WHITE, Ryan; XUE, Qiufen; ZHENG, Xiao; ZHONG, Wenge; US2014/107109; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

122-05-4, 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. 122-05-4, name is Pyrazine-2,5-dicarboxylic acid, This compound has unique chemical properties. The synthetic route is as follows.

5 mmol of (2FPpy)2Ir(Cl)2Ir(2FPpy)2, 25 mmol of pyrazine-2,5-dicarboxylic acid (Py2CA), and 50 mmol of potassium carbonate were mixed in 100 mL of 1,2-dichloroethane, and refluxed for 24 hours under a nitrogen atmosphere. After the reaction was complete, the solution was cooled down to about 50 C., and filtrated. The filtrated solution was purified by using column chromatography to thereby produce (2FPpy)2Ir(Py2CA)Ir(2FPpy)2 at a yield of 86%.

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; SAMSUNG ELECTRONICS CO., LTD.,; US2008/269484; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 21279-62-9

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).

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 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