Month: November 2020

33332-25-1, Adding some certain compound to certain chemical reactions, such as: 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, 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 33332-25-1.

a) 5-r3-(4-Fluoro-phenyl)-5-methyl-3H-ri,2,31triazol-4-ylmethoxyl-pyrazine-2-carboxylic acid methyl esterTo a suspension of NaH (55% in oil, 116 mg, 2.7 mmol) in THF (4 mL) was added a solution of [3-(4-fluoro-phenyl)-5-methyl-3H-[l,2,3]triazol-4-yl]-methanol (500 mg, 2.4 mmol) in THF (6 mL) dropwise at 0 C and the reaction mixture was stirred at room temperature for 30 min. Then a solution of methyl 5-chloropyrazine-2-carboxylate (460 mg, 2.65 mmol) in THF (6 mL) was added dropwise at 0 C and the reaction mixture was stirred at room temperature for 16 h. The mixture was then poured into ice water and extracted with ethyl acetate and the combined organic extracts washed with brine, dried over sodium sulphate, filtered and evaporated.Purification by chromatography (silica, 0 to 50% ethyl acetate in heptane, then 0 to 5% methanol in dichloromethane) afforded the title compound (787 mg, 95%) as a white solid. MS: m/e = 344.3 [M+H]+.

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 33332-25-1.

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; HERNANDEZ, Maria-Clemencia; LUCAS, Matthew C.; THOMAS, Andrew; WO2012/62687; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

19745-07-4, 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. 19745-07-4, name is 2,5-Dichloropyrazine, A new synthetic method of this compound is introduced below.

2-(4-Benzyloxyphenyl)-5-(6-octyloxypyridin-3-yl)pyrazine STR50 Step 1 In accordance with scheme C-I, 30 g (201 mmol) of 2,5-dichloropyrazine and 45.92 g (201 mmol) of 4-benzyloxyphenylboronic acid are coupled analogously to Example 4a to give 2-chloro-5-(4-benzyloxyphenyl)pyrazine.

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; Hoechst Aktiengesellschaft; US5512207; (1996); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, molecular formula is C6H5ClN2O2, 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. 33332-25-1.

A round bottomed flask was charged with methyl2-chloropyrazine-5-carboxylate (Lonza, 4.83 g, 28 mmol), 1 -Boc-2(S)-ethyl- 5(R)-methylpiperazine free base (6.4 g, 28 mmol), cesium carbonate (Aldrich, 14 g, 42 mmol) and 1 ,4 dioxane (100 ml). The resulting suspension was stirred at 100 0C for 2 d and then filtered. The solid was washed with ethyl acetate (3X400 ml). The combined organic solutions were concentrated on a rotary evaporator to remove the solvent. The residue was purified by flash chromatography on silica gel using 1 % methanol (containing 10% ammonium hydroxide) in dichloromethane as an eluent to provide A21 (9.0 g, 90%), as a beige solid

The synthetic route of Methyl 5-chloropyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SCHERING CORPORATION; PHARMACOPEIA DRUG DISCOVERY, INC.; WO2006/91428; (2006); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

356783-16-9, 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. 356783-16-9, name is 3,6-Dichloropyrazine-2-carbonitrile belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

REFERENTIAL EXAMPLE II-11 In 15 ml of dimethylformamide was dissolved 1.5 g of 3,6-dichloro-2-pyrazinecarbonitrile. After adding 1.2 g of 4-methoxyphenol and 1.8 g of potassium carbonate, the mixture thus obtained was stirred at room temperature for 30 minutes. A mixture of 20 mL of ethyl acetate and 60 mL of water was added to the reaction mixture, and the organic layer was separated. The organic layer was washed successively with water and saturated aqueous solution of sodium chloride and dried on anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. The residue thus obtained was purified by silica gel column chromatography [eluent: n-hexane:ethyl acetate=5:1] to obtain 2.1 g of 6-chloro-3-(4-methoxyphenoxy)-2-pyrazinecarbonitrile as a yellow-colored solid product. R (KBr) cm-1: 2236 H-NMR (CDCl3) delta: 3.83(3H,s), 6.95(2H,d,J=9.2 Hz), 7.11(2H,d,J=9.2 Hz), 8.26(1H,s)

The synthetic route of 356783-16-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Toyama Chemical Co., Ltd.; US2003/130213; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

24241-18-7, A common compound: 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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.

To the reaction flask was added tetrahydrofuran (50 ml). trimethylsilylacetylene (580 mg, 5.9 mmol), triethylamine (1.2 g, 11.8 mmol), CuI (0.1 g), Pd(PPh3)4 (0.1 g) and the compound 3,5-dibromo-2-aminopyrazine 1a (1.0 g, 3.95 mmol) were reacted under nitrogen for 3 hours at room temperature.TLC showed the reaction was completed, 50ml of water was added and extracted with ethyl acetate (30mL) twice the aqueous phase, the organic phases are combined,Once, dried over anhydrous sodium sulfate washed with brine, and dried to give the crude product under reduced pressure using a rotary evaporator,Through the column to give the crude title compound 5a (0.5g, 18.5mmol), a yield of 47.1%

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, 2-Amino-3,5-dibromopyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Shanghai Huahuituo Pharmaceutical Technology Co., Ltd.; Zhejiang Huahai Pharmaceutical Co., Ltd.; Xu Xin; Zhang Tian; Li Yunfei; Wang Guan; Zhu Weibo; Li Qiang; Qu Minkai; Zhang Linli; Song Jinqian; Liu Lei; Chen Haiji; Liu Qiang; Wang Yijin; Ge Jian; (67 pag.)CN109535164; (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 33332-29-5 as follows. 33332-29-5

compound 5-a (2.6g, 20mmol), 2- bromo-1,1-diethoxyethane (12.0g, 60.89mmol) was dissolved in 30ml isopropanol was then added a solution of hydrogen bromide (10.5g, 62.22mmol), 80 deg. C stirred overnight. Completion of the reaction, cooled to room temperature, adjusted to pH 8 sodium hydrogen carbonate, extracted with dichloromethane, the combined organic phases separated, concentrated under reduced pressure to give a crude product which, by Combi-flash chromatography [DCM: MeOH = 90: 10 ~ 70: 30 ] to give a brown solid compound 16-b (2.3g), was used directly in the next reaction. Yield: 49.75%, purity 96.63%.

According to the analysis of related databases, 33332-29-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Shanghai Haiyan Pharmaceutical Technology Co. Ltd; Yangtze River Pharmaceutical Group Co., Ltd; Jin, Yunzhou; Bo, Ping; He, Qi; Lan, Jiong; Zhou, Fusheng; Zhang, Liang; He, Xiangyu; (59 pag.)CN105524068; (2016); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

55557-52-3, 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. 55557-52-3 name is 3-Chloropyrazine-2-carbonitrile, 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.

(3-hydroxy-cyclobutyl) methyl benzoate (1.48g, 7.18mmol, 1.05eq.) In anhydrous THF (2mL) was added to sodium hydride(60%, 274mg, 6.84mmol, 1eq.) In anhydrous THF (30mL) suspension, and the mixture was stirred for 1h at room temperature, and then added 3-Chloro-pyrazine-2-carbonitrile (909mg, 6.84mmol, 1eq.), The reaction mixture was stirred at room temperature for 15h. The mixture was diluted with 50mL of water was added,Then EtOAc (30mL x 2) and extracted. The organic solution was washed with saturated sodium chloride combined (30mL x 2), dried over anhydrous sodium sulfate,Then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: PE / EtOAc (V / V) = 2.7 / 1) to give the title compound as a white solid (1g, 28%).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-Chloropyrazine-2-carbonitrile, and friends who are interested can also refer to it.

Reference:
Patent; East Sunshine Pharmaceutical Co., Ltd. of Guangdong; Ren, Qingyun; Luo, Huichao; Tang, Changhua; Zhang, Jiancun; Zhang, Yingjun; (30 pag.)CN104447583; (2016); B;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

13301-04-7, The chemical industry reduces the impact on the environment during synthesis 13301-04-7, name is Methyl 3,6-dibromopyrazine-2-carboxylate, I believe this compound will play a more active role in future production and life.

To a solution of methyl 3,6-dibromopyrazine-2-carboxylate (583 mg, 1.97 mmol), and (2,3-dichlorophenyl)boronic acid (375 mg, 1.97 mmol) in dioxane (40 ml) was added CS2CO3 (1.93 g, 5.91 mmol) in H2O (10 mL) and PdCkdppf (144 mg, 0.2 mmol). The reaction was refluxed for 20 min, allowed to cool to rt, and extracted with EtOAc. The combined organic layers were washed with brine and dried over MgS04. The mixture was concentrated under reduced pressure. Purification by flash chromatography resulted in 370 mg (52%) of the desired product. NMR (500 MHz, CDCh) delta 8.58 – 8.53 (m, 1H), 7.38 – 7.32 (m, 1H), 7.29 – 7.22 (m, 1H), 7.14 – 7.08 (m, 1H), 3.82 – 3.76 (m, 3H).

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

Reference:
Patent; REVOLUTION MEDICINES, INC.; LI, Jie Jack; KOLTUN, Elena S.; GILL, Adrian Liam; BUCKL, Andreas; WON, Walter; AAY, Naing; MELLEM, Kevin; TZITZILONIS, Christos; JOGALEKAR, Ashutosh; CREGG, James Joseph; (177 pag.)WO2019/75265; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 63744-22-9, name is 6,8-Dibromoimidazo[1,2-a]pyrazine, molecular formula is C6H3Br2N3, 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. 63744-22-9.

General procedure: Method F: compound 6 (2 mmol) was dissolved in MeOH, and stirred at 0 C., to which was added NaSMe (20% aq, 1.8 eq.), followed by naturally warming to room temperature, and reacting overnight, monitored by TCL until complete conversion, to which was added DCM. The system was washed with water, and the organic phase was concentrated to obtain a while solid, which was directly used for the next step reaction.

The synthetic route of 6,8-Dibromoimidazo[1,2-a]pyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Xiamen University; Deng, Xianming; Huang, Wei; Sun, Xihuan; Zhang, Ting; He, Zhixiang; Liu, Yan; Wu, Xinrui; Zhang, Baoding; Li, Xiaoyang; Zhang, Jingfang; Chen, Yun; Li, Li; Xu, Qingyan; Hu, Zhiyu; (206 pag.)US2020/165246; (2020); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

24241-18-7, 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. 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, A new synthetic method of this compound is introduced below.

Step 1: Synthesis of 5-Bromo-3-trimethylsilanylethynyl-pyrazm-2-yIamine.[0282] To a solution of 3,5-Dibromo-pyrazin-2-ylamine (3.00 g, 11.86 mmol) in DMF(35 ml) was added triethylamine (16 ml), then tetraldstriphenylphine palladium (0) (685 mg,0.59 mmol) and copper(i) iodide (271 mg, 1.42 mmol) were added sequentially. Finallytrimethylsilylacetylene (2.0 ml, 14.3 mmol) was added dropwise. The reaction mixture wasstirred at 120 C for 30 minutes and then directly adsorbed onto silica gel. Purification byflash chromatography on silica gel with a gradient of ethyl acetate/hexane afforded the titlecompound (2.30g, 71% yield) as yellow oil. MS: m/z 270.0/272.0 [MH+].

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; SGX PHARMACEUTICALS, INC.; WO2006/15124; (2006); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem