Month: January 2021

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. 2423-65-6, name is Pyrazine 1-oxide, A new synthetic method of this compound is introduced below., Recommanded Product: 2423-65-6

Conditions: The N-oxide (2 equiv.), aryl halide, Pd(OAc)2 (5 mol %), Pt-Bu3-HBF4 (15 mol %), K2CO3 (2 equiv.) and the additive (if indicated, 2 equiv.) were added to a round bottom flask followed by the addition of dioxane and heating to 110 C.; Initial reaction screens with N-oxides 60, 70 and 80 under previously described conditions lead to disappointing results, probably due to the fact that the N-oxides were only sparingly soluble in toluene. The reaction conditions were reinvestigated. These efforts lead to the discovery that dioxane provides superior conversions with N-oxides 60 and 80 giving the cross coupled products 81 and 82 in 75% and 72% yields respectively (Table 3, entries 1 and 2). These two substrates actually exhibit superior reactivity compared to pyridine N-oxide as demonstrated by a competition experiment between 80 and pyridine N-oxide which results in exclusive arylation of 60 (Table 3, entry 4). In contrast to the excellent results obtained with 60 and 80, pyrimidine N-oxide 70 reacts in low yield (Table 3, entry 3).

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; University of Ottawa; US2008/132698; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 63744-22-9, 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.

To a stirred suspension of intermediate example 1 -1 6,8-dibromo-imidazo[1 ,2-a]pyrazine (489 g, 1766 mmol) in MeOH (2900 mL) at -20C was dropwise added a solution of sodium methan thiolate (225 g, 3214 mmol, 1.8 eq) in 800 mL water. After stirring overnight, the clear solution was poured on 30 L water and the yellowish precipitate was filtered, washed with 3 L water and dried in vaccuo to yield 301 g 6-bromo-8-methylsulfanyl-imidazo[1 ,2-a]pyrazine (69.8 %). 1H-NMR (300 MHz, de-DMSO): delta = 8.64 (1 H, s), 8.00 (1 H, d), 7.66 (1 H, d2.54 (3H, s) ppm.

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; BAYER PHARMA AKTIENGESELLSCHAFT; SIEMEISTER, Gerhard; BADER, Benjamin; WENGNER, Antje, Margret; MUMBERG, Dominik; KOPPITZ, Marcus; KLAR, Ulrich; KROEMER, Guido; VITALE, Ilio; JEMAA, Mohamed; WO2014/20041; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 313339-92-3, 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 313339-92-3 as follows.

A solution of 3,5-dichloropyrazine-2-carbonitrile (150 mg, 0.862 mmol), (R)-2-amino-2-phenylacetamide hydrochloride (160 mg, 0.858 mmol) and DIEA (0.400 mL, 2.30 mmol) in DMF (5 mL) was stirred at room temperature for 6 h. Water and EtOAc were added. Organic phase was separated, washed with 1N HCl, then with 5% NaHCO3, dried over Na2SO4, concentrated in vacuo to give (R)-2-(6-chloro-5-cyanopyrazin-2-ylamino)-2-phenylacetamide (245 mg).

According to the analysis of related databases, 313339-92-3, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Portola Pharmaceuticals, Inc.; Song, Yonghong; Xu, Qing; Jia, Zhaozhong J.; Kane, Brian; Bauer, Shawn M.; Pandey, Anjali; US2013/131040; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 1111638-10-8, 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 1111638-10-8 as follows.

To a stirring solution of product of step 2 (20 mg, 0.130 mmol) in acetic acid (1 ml) and water (2.0 ml) was added Hexamethylenetetramine (20.08 mg, 0.143 mmol) and the reaction mixture was heated for 5 h at l20C. After completion of reaction it was diluted with ethyl acetate (10 ml) and 10 ml of water. Organic layer was separated, dried over Na2S04 and evaporated to get desired product. ESI-MS (m/z): 180.00 (M-H).

According to the analysis of related databases, 1111638-10-8, the application of this compound in the production field has become more and more popular.

Reference:
Patent; CADILA HEALTHCARE LIMITED; DESAI, Ranjit; PANDYA, Vrajesh; PUJARA, Mehul; ARGADE, Anil; JOSHI, Jignesh; SATYANAND, Anshul; (66 pag.)WO2019/239382; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-29-5, name is 2-Amino-5-chloropyrazine, 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. Quality Control of 2-Amino-5-chloropyrazine

17 (1.1 g, 8.5 mmol) was dissolved in dichloromethane (25 mL) followed by the addition of NBS (1.52 g, 8.5 mmol) in batches over a period of 15 min at room temperature. When the reaction was completed, saturated aqueous Na2CO3 solution (10 mL) was added. After stirring for 10 min, the mixture was partitioned between dichloromethane (100 mL) and water (100 mL). The organic layer was dried over anhydrous Na2SO4, decolorized with activated charcoal (0.5 g), and concentrated to give a yellow solid (1.53 g, yield 87%). 2-Amino-3-bromo-5-chloropyrazine (18a) Yield: 87%, yellow solid, M.p.: 108-110 C. 1H NMR(400 MHz, CDCl3): delta 7.97 (s, 1H), 5.08 (s, 2H). 1H NMR(400 MHz, DMSO-d6): delta 8.10 (s, 1H), 6.99 (s, 2H). 13CNMR (125 MHz, CDCl3):delta 151.66, 140.26, 134.75, 123.27. EI-MS m/z: 207 (M+, Cl35, Br79,76), 209 (M+, Cl37,Br79 and Cl35,Br81,100), 211 (M+, Cl37, Br 81,26), 128 (M+,Cl35,-Br, 75), 130 (M+, Cl37,-Br, 25), 101 (M+, Cl35,-Br,-HCN, 30), 103 (M+, Cl37,-Br, -HCN, 10).

The synthetic route of 33332-29-5 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Guo, Qi; Xu, Mingshuo; Guo, Shuang; Zhu, Fuqiang; Xie, Yuanchao; Shen, Jingshan; Chemical Papers; vol. 73; 5; (2019); p. 1043 – 1051;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 126069-70-3, name is 2-(Trifluoromethyl)-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine, 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. Quality Control of 2-(Trifluoromethyl)-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine

The title compound was prepared from 2-(trifluoromethyl)-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine (277 mg, 1.45 mmol, from Example 1, Step B), (3R)-3-[(1,1-dimethylethoxycarbonyl)amino]-4-(2,5-difluorophenyl)butanoic acid (Intermediate 1, 416 mg, 1.32 mmol), DIPEA (226 mg, 1.58 mol), HOBT (216 mg, 1.98 mol) and HATU (753 mg, 1.98 mol) in DMF (6 mL), using a procedure analogous to that described in Example 1 Step C, except for the purification method. The compound was purified by preparative TLC (silica gel, 20% hexane in ethyl acetate, then 10% methanol in dichloromethane) to give 360 mg of the title compound as a foamy solid. 1H NMR (500 MHz, CDCl3) delta 1.35 (s, 9H), 2.62 (m, 2H), 2.88 (m, 2H) 3.88-4.16 (m, 5H), 4.73 (s, 1H), 4.85 (m, 1H) 5.26-5.39 (m, 1H) 6.90 (bs, 1H), 7.06 (m, 2H), 7.24 (m, 1H). ESI-MS 489 (M+1)

The synthetic route of 2-(Trifluoromethyl)-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine has been constantly updated, and we look forward to future research findings.

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;,
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. 957230-70-5, name is 3,6-Dibromopyrazin-2-amine, A new synthetic method of this compound is introduced below., Recommanded Product: 957230-70-5

3,6-dibromopyrazin-2-ylamine (4.0 g, 15.80 mmol) and bromoacetaldehyde diethyl acetal (3.7 mL, 24.00mmol) and tetrahydrofuran (5.3 mL) eere dissolved in distilled water (53 mL), the mixture was stirred for 4 hours at 120C .Saturated aqueous sodium hydrogen carbonate solution to the reaction solution was neutralized by addition. The resulting solid was filtered and washed with distilled water and dried to give the title compound (2.75 g).

The synthetic route of 957230-70-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; HANMI PHARM. CO., LTD.; HAM, YOUNG JIN; SON, JUNG BEOM; PARK, CHANG HEE; KANG, SEOK JONG; CHOI, JAE YUL; KIM, SEO HEE; (36 pag.)KR2015/113801; (2015); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 1422772-78-8, 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. 1422772-78-8 name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid, 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.

Step 22-Bromo-5H-pyrrolo[2,3-b razine-7-carboxylic acid methyl esterTo a stirred solution of 2-bromo-5H-pyrrolo [2,3-b]pyrazine-7-carboxylic acid (0.527 g, 2.18 mmol) in 50 mL of methanol was added H2SO4 (1.5 mL) slowly at room temperature. The reaction mixture was stirred at reflux for 16 h. The solvent was evaporated at 40C under reduced pressure then the residue was suspended in 5 mL of water and treated with solidNaHC03 until pH = 7. The solution was extracted with ethyl acetate (90 mL), then the organics were washed with water (20 mL), brine (20 mL) and dried over anhydrous sodium sulfate. The drying agent was removed by filtration and the solvent was evaporated at 40C under reduced pressure to give a crude product, which was purified by column chromatography (silica gel, 200 – 300 mesh, eluting with a mixture of petroleum ether and ethyl acetate (1 :1 , v/v) to give 2- bromo-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid methyl ester (0.24 g, 43 %) as a white solid. LCMS: (M+H)+ = 278; 1H NMR (300 MHz, DMSO-d6): ? 8.62 (s, 1H), 8.48 (s, 1H), 3.91 (s,3H).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2-Bromo-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid, and friends who are interested can also refer to it.

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; CHEN, Shaoqing; DE VICENTE FIDALGO, Javier; HAMILTON, Matthew Michael; HERMANN, Johannes Cornelius; KENNEDY-SMITH, Joshua; LI, Hongju; LOVEY, Allen John; LUCAS, Matthew C.; LUK, Kin-Chun Thomas; LYNCH, Stephen M.; O’YANG, Counde; PADILLA, Fernando; SCHOENFELD, Ryan Craig; SIDDURI, Achyutharao; SOTH, Michael; WANG, Ce; WOVKULICH, Peter Michael; ZHANG, Xiaohu; WO2013/30138; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 19745-07-4, name is 2,5-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 19745-07-4, Computed Properties of C4H2Cl2N2

General procedure: m-DCzP, o-DCzP were synthesized by nucleophilic reaction without heavy metal catalysts. Carbazole (0.34 g,2 mmol), dichloropyrazine (0.148 g, 1 mmol), and K2CO3 (1.136 g, 8 mmol) were mixed in dimethyl sulfoxide (DMSO, 5ml), then the mixture was stirred at 150C for 4 h under a nitrogen atmosphere. After cooling to room temperature, the mixture was poured into water, stirred, and filtered. The residue was dried in vacuum drying over at 60C for 4 h, and thenpurified by column chromatography over silica gel with CH2Cl2/petroleum ether as the eluent to afford a yellow/white solid. To further purify the products, CH2Cl2/ethyl acetate was used as solvents for recrystallization resulting in pure single crystals of p-DCzP, m-DCzP and o-DCzP. They were obtained with high yields (75%) except for o-DCzP which was obtained with only 50% yield.

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; Zhang, Yanni; Zhao, Jianfeng; Zhu, Caixia; Bian, Lifang; Shi, Huifang; Zhang, Shiming; Ma, Huili; Huang, Wei; Chinese Chemical Letters; vol. 30; 11; (2019); p. 1974 – 1978;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, 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 5521-55-1, SDS of cas: 5521-55-1

To the solution of 5-methyl-2-pyrazine carboxylic acid (1) (0.01 mol) in absolute ethyl alcohol (10 mL), conc. H2SO4 (2 mL) was added. The mixture was refluxed for 4 hwith constant stirring. After completion of the reaction (monitored by the TLC), the mixture was poured into ice-cold water. Crude product was collected by filtration, washed with 10 % NaHCO3 solution, dried and recrystallized from ethyl alcohol to get pure 5-methyl-2-pyrazine carboxylic acid ethyl ester (2).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5-Methylpyrazine-2-carboxylic acid, and friends who are interested can also refer to it.

Reference:
Article; Maddireddi, Chandra Sekhara Reddi; Parimi, Uma Devi; Reddy, Sreenivasa Reddy Bhimi; Mandapati, Satyanarayana Reddy; Asian Journal of Chemistry; vol. 28; 11; (2016); p. 2453 – 2456;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem