Month: March 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. 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, A new synthetic method of this compound is introduced below., Product Details of 875781-43-4

To a solution of 2-bromo-5H-pyrrolo [2,3-b] pyrazine (3.1 g, 16 mmol)Of 1,4-dioxane (20 mL)Phosphorus oxychloride (2.27 mL, 24.1 mmol) was added to the solution andTriethylamine (220 [mu] L, 1.58 mmol)110 C for 6 hours,(50 mL x 3), dried over anhydrous sodium sulfate, and the mixture was concentrated and beaten (petroleum ether / ethyl acetate (v / v), and the mixture was stirred at room temperature (7 mL) ) = 2/1), filtration,Dried to give 1.3 g of a gray solid in 54% yield.

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; Guangdong Dongyangguang Pharmaceutical Co., Ltd.; Liu Bing; Huang Jiuzhong; Zheng Changchun; Zhang Yingjun; Ouyang Luo; Mao Hongfen; Nie Biao; Xu Juan; Chen Hongfen; (137 pag.)CN106336413; (2017); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 5780-66-5, name is Pyrazine-2-carbaldehyde, 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 5780-66-5, Recommanded Product: Pyrazine-2-carbaldehyde

EXAMPLE 28 To a suspension of 4 g of 5H,10H-imidazo-[1,2-a]indeno[1,2-e]pyrazin-4-one in 70 ml of dimethyl sulphoxide are added, with stirring and under cover of nitrogen, 3.9 g of 2-pyrazinecarboxaldehyde and, after cooling to 19¡ã C., 1.6 g of 60percent sodium hydride are added portionwise while maintaining the reaction medium at a temperature between 15¡ã and 21¡ã C. The stirring is continued for 4 hours and then 70 ml of water, 5 ml of acetic acid and 50 ml of methanol are successively added dropwise at a temperature in the region of 20¡ã C. The suspension obtained is filtered and the solid thus isolated is washed with methanol, air-dried and triturated in a mixture of 80 ml of dimethylformamide and 25 ml of methanol. After drying at 60¡ã C. under vacuum (1 mmHg; 0.13 kPa) 3.3 g of 10-(2-pyrazinylmethylene)-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one are obtained, in the form of a red-orange solid melting above 260¡ã C. (Analysis percent calculated C: 69.00, H: 3.54, N: 22.35, O: 5.11, percent found C: 69.6, H: 3.6, N: 22.0, O: 4.9).

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; Rhone-Poulenc Rorer S.A.; US5753657; (1998); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 4949-13-7, A common heterocyclic compound, 4949-13-7, name is 2-Fluoropyrazine, molecular formula is C4H3FN2, 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.

Example 8. Preparation of 4,5,6, 7-tetrahydro-5-(5-methoxypyridin-3-yl)-Lambda/-(pyrazin-2- yl)thiazolo[5,4-c]pyridin-2-amine (Compound 18)[00121] As shown in step 8-i of Scheme 8, to a solution of 5-(5-methoxypyridin-3-yl)- 4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-amine (Compound 1026, 20 mg, 0.076 mmol) in NMP (1 mL) was added 2-fluoropyrazine (22.4 mg, 0.229 mmol) and Cs2CO3 (149 mg, 0.46 mmol). The reaction mixture was heated 110 0C for 18 h. The crude mixture was purified by medium pressure silica gel chromatography (0 to 10% MeOH in DCM) followed by a second purification using reversed-phase chromatography (5 to 90 % CHsCN/water). Fractions containing pure produce were brought to a neutral pH and the product isolated as the bis-HCl salt to give 4,5,6,7-tetrahydro-5-(5-methoxypyridin-3-yl)-Lambda/-(pyrazin-2-yl)thiazolo[5,4- c]pyridin-2-amine (Compound 18, 4 mg): ESMS (M+H) 341.13; 1H NMR (CD3OD, 300MHz) delta 8.65 (d, J=I.5 Hz, IH), 8.51 (t, J= 1.5Hz, IH), 8.41 (d, J=2.7Hz, IH), 8.22 (d, J=2.4 Hz, 1H),7.96 (d, J=2.4 Hz, 1H),7.69 (t, J=2.4 Hz, IH), 4.67 (s, 2H), 4.04 (s, 3H), 3.98 (t, J=5.7 Hz, 2H), 3.01 (t, J=5.7 Hz, 2H) ppm.

The synthetic route of 4949-13-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; VERTEX PHARMACEUTICALS INCORPORATED; ARONOV, Alex; BANDARAGE, Upul, Keerthi; COTTRELL, Kevin; DAVIES, Robert; KRUEGER, Elaine; LEDEBOER, Mark; LEDFORD, Brian; LE TIRAN, Arnaud; LIAO, Yusheng; MESSERSMITH, David; WANG, Tiansheng; XU, Jinwang; WO2010/96389; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 123-32-0, 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. 123-32-0, name is 2,5-Dimethylpyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

A solution of m-CPBA (70% purity, 100.0 g, 405.63 mmol) in ethyl acetate (150 mL) was washed with brine (150 mL). The organic layer was separated, dried over MgSO4 and filtered. The filtrate was added to a solution of 2,5-dimethylpyrazine 2 (20.20 mL, 184.94 mmol) in ethyl acetate (50 mL) and the resulting solution was stirred for 24 h at rt. The white solid precipitated was filtered, washed by ethyl acetate (3×100 mL) and dried to give the title compound 6 (23.5 g, 90%) as a white crystalline solid. M.p.: 286 C (dec.).1 1H MNR (200 MHz, D2O): d 8.48 (s, 2H), 2.42 (s, 6H). 13C MNR (50 MHz, D2O): d 145.8, 136.0, 13.7. HRMS (DCI+CH4) Calcd. for C6H9N2O2 [M+H]+: 141.0664. Found: 141.0674.

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

Reference:
Article; Das, Sajal Kumar; Frey, Joseph; Tetrahedron Letters; vol. 53; 30; (2012); p. 3869 – 3872;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, 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. category: Pyrazines

Example 10: Pyratzetajne-2,3-dicarboxylic arid mono-((3S,4aR,6aR,6bS,8aS, 11S, 12aR, 14aR, 14bS)-11-methoxycarbonyl-4,4,6a,6b,8a, 11, 14b-heptamethyl-14-oxo-1 ,2,3,4,4a, 5, 6,6a,6b,7, 8, 8a,9, 10, 1 1, 12, 12a, 14, 14a, 14b-icosahydro-picen-3-yl) ester (YP034JGlycyrrhetinic acid methyl ester (1.0 g, 2.0 mmol) was stirred in toluene (25 ml) and 2,3-pyrazine-dicarboxylic anhydride (1.7 g, 11.5 mmol) added. The mixture was heated at 110C for 16-20 hours. After cooling, the mixture was added to water (200 ml) and extracted into /-propyl acetate (3 x 70 ml), which was dried (MgSO4) and concentrated to give the crude adduct. Purification was effected using silica chromatography (eluent: 0-10% methanol in DCM) to give the title compound as a yellow solid (500 mg). LCMS purity 90.5% (633 = [M-H] ).1H NMR (400MHz, CDCl3) delta 8.78 (IH, br), 8.70 (IH, br), 5.68 (IH, s) 4.88 (IH, dd, J = 11.6Hz, 4.8Hz), 3.62 (3H, s), 2.80 (IH, br d), 2.35 (IH, s), 2.1-0.6 (4OH, m).

The synthetic route of 4744-50-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; YORK PHARMA PLC; WO2007/105015; (2007); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

109-08-0, name is 2-Methylpyrazine, 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. name: 2-Methylpyrazine

2-methylpyrazine (0.18 mL, 2.0 mmol), 4-methoxybenzaldehyde (0.24 mL, 2.0 mmol) and 50percent solution of tetrabutylammoniumsulfate in water (0.23 mL, 0.2 mmol) were added to 2 mL 5N NaOH stirring under nitrogen. The reaction was carried on at 105¡ã C. for 48 h. After cooling to r.t., the mixture was extracted with DCM (3¡Á20 mL), and then the oil phase was washed with water and brine, dried over Na2SO4, concentrated via vacuum. The desired compound was obtained via silica gel chromatograph (EA:hexane=1:2). Faint yellow solid in 43percent yield. M.p.:101.4-102.3¡ã C. 1H NMR (400 MHz, CDCl3) delta 8.61 (d, J=1.0 Hz, 1H), 8.51 (s, 1H), 8.37 (d, J=2.3 Hz, 1H), 7.70 (d, J=16.1 Hz, 1H), 7.54 (d, J=8.7 Hz, 2H), 7.02 (d, J=16.1 Hz, 1H), 6.93 (d, J=8.7 Hz, 2H), 3.85 (s, 3H). 13C NMR (101 MHz, CDCl3) delta 160.32, 151.60, 144.21, 143.54, 142.26, 134.70, 128.78, 128.72, 121.74, 114.25, 55.33. Anal. Calcd for C13H12N2O: C, 73.56; H, 5.70; N, 13.20. Found: C, 73.12; H, 5.79; N, 12.30.

The synthetic route of 109-08-0 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Washington University; Tu, Zhude; Li, Junfeng; Yue, Xuyi; Kotzbauer, Paul; (100 pag.)US2017/189566; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 109838-85-9, 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 109838-85-9 as follows.

Step A – Synthesis of Intermediate Compound Int-23c (0372) A 5 L- 3 necked round bottomed flask, equipped with a mechanical stirrer, temperature probe, addition funnel and N2 inlet, was charged with the Schollkopf chiral auxiliary-(Int-23a, 200 g, 1.09 mol, 1.0 eq), bis(chloromethyl) dimethylsilane (Int-23b, 256 g, 1.63 mol, 1.5 eq), and THF (2 L, Aldrich anhydrous). The flask was cooled in a dry ice/ 2-propanol bath until the internal temperature reached -75 ¡ãC. n-Butyl lithium (Aldrich 2.5 M in hexanes , 478 mL, 1.19 mol, 1.09 eq) was added via a dropping funnel over 1 hour while maintaining the internal reaction temperature between -67 ¡ãC and -76 ¡ãC. The resulting orange-red solution was allowed to gradually warm to room temperature for about 15 hours. The reaction mixture was then recooled to 0 ¡ãC and quenched with 500 mL of water. Diethyl ether (2L) was added and the layers were separated. The aqueous layer was extracted with 1 L of diethyl ether. The combined organic layers was washed with water and brine, dried with MgSO4, filtered, and concentrated in vacuo to provide 480 g of an orange oil. This material was left under vacuum for about 15 hours to provide 420 g of oil (mixture of Int-23c and Int-23c’). The crude product was split into two batches and purified via silica gel chromatography on a 1.6 Kg flash column. The column was eluted with gradient of 0-4percent Et2O in hexanes. The product fractions were concentrated in vacuo at a bath temperature at or below 40 ¡ãC to provide 190 grams of Compound Int-25c-(60percent yield).

According to the analysis of related databases, 109838-85-9, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Merck Sharp & Dohme Corp.; Nair, Anilkumar Gopinadhan; Keertikar, Kerry M.; Kim, Seong Heon; Kozlowski, Joseph A.; Rosenblum, Stuart; Selyutin, Oleg B.; Wong, Michael; Yu, Wensheng; Zeng, Qingbei; EP2545060; (2015); B1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 6705-33-5, name is Pyrazin-2-ylmethanol, molecular formula is C5H6N2O, 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. Formula: C5H6N2O

General procedure: 1.0 eq. ethyl (2R)-2-acetoxy-3-(2-hydroxyphenyl)propanoatc (Preparation 3aa-(R)), 2.0eq. of the appropriate alcohol and 2.0 eq. triphenylphosphine were dissolved in dry toluene(0.2 M for the phenol), then 2.0 eq. di-tert-butyl azodicarboxylate was added. The mixturewas stirred at 50C under nitrogen. After reaching an appropriate conversion the volatileswere removed under reduced pressure, the crude intermediate was purified via flash chromatography using heptane / EtOAc as cluents.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 6705-33-5, its application will become more common.

Reference:
Patent; LES LABORATOIRES SERVIER; VERNALIS (R&D) LIMITED; KOTSCHY, Andras; SZLAVIK, Zoltan; CSEKEI, Marton; PACZAL, Attila; SZABO, Zoltan; SIPOS, Szabolcs; RADICS, Gabor; PROSZENYAK, Agnes; BALINT, Balazs; BRUNO, Alain; GENESTE, Olivier; DAVIDSON, James Edward Paul; MURRAY, James Brooke; CHEN, I-Jen; PERRON-SIERRA, Francoise; WO2015/97123; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 98-97-5, name is Pyrazine-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 98-97-5, category: Pyrazines

To a solution of pyrazine-2-carboxylic acid (1 g, 8.06 mmol) in DMF (5 mL), 4-methyl-3-thiosemicarbazide (933 mg, 8.87 mmol) was added. DIPEA (2.5 mL, 14.5 mmol) was added drop-wise at RT, then the mixture was cooled in an ice-bath before adding T3P (50% w/wEtOAc) (7.1 mL, 12.09 mmol). The reaction was stirred at RT on. NaOH 4 M solution (7.5mL) was added (resulting pH=8). The reaction was diluted with EtOAc and the two resulting phases were separated (the upper organic layer eliminated). The pH was increased to 11 NaOH 4and the mixture heated to 70 C for 2h. The yellow solution was then cooled in an ice bath and 37% HC1 was slowly added till pH 5. A precipitate formed. It was filtered under vacuum, washed with water and Cy and dried to obtain 1.44 g of title compound (p20, y%92). MS(m/z): 194.1 [MH]t

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; INDIVIOR UK LIMITED; CREMONESI, Susanna; MICHELI, Fabrizio; SEMERARO, Teresa; TARSI, Luca; (318 pag.)WO2017/21920; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 109838-85-9, These common heterocyclic compound, 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, 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.

Step A – Synthesis of Intermediate Compound Int-6c A 5 L- 3 necked round bottomed flask, equipped with a mechanical stirrer, temperature probe, addition funnel and N2 inlet, was charged with the Schollkopf chiral auxiliary-(Int-6a, 200 g, 1.09 mol, 1.0 eq), bis(chloromethyl) dimethylsilane (Int-6b, 256 g, 1.63 mol, 1.5 eq), and THF (2 L, Aldrich anhydrous). The flask was cooled in a dry ice/ 2- propanol bath until the internal temperature reached -75 ¡ãC. n-Butyl lithium (Aldrich 2.5 M in hexanes , 478 mL, 1.19 mol, 1.09 eq) was added via a dropping funnel over 1 hour while maintaining the internal reaction temperature between -67 ¡ãC and -76 ¡ãC. The resulting orange-red solution was allowed to gradually warm to room temperature for about 15 hours. The reaction mixture was then re-cooled to 0 ¡ãC and quenched with 500 mL of water.Diethyl ether (2L) was added and the layers were separated. The aqueous layer was extracted with 1 L of diethyl ether. The combined organic layers was washed with water and brine, dried with MgS04, filtered, and concentrated in vacuo to provide 480 g of an orange oil. This material was left in vacuo for about 15 hours to provide 420 g of oil(mixture of Int-6c and Int-6c’). The crude product was split into two batches and purified via silica gel chromatography on a 1.6 Kg flash column. The column was eluted with gradient of 0-4percent Et20 in hexanes. The product fractions were concentrated in vacuo at a bath temperature at or below 40 ¡ãC to provide 190 grams of Compound Int-6c (60percent yield).

Statistics shows that (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine is playing an increasingly important role. we look forward to future research findings about 109838-85-9.

Reference:
Patent; MERCK SHARP & DOHME CORP.; DWYER, Michael, P.; KEERTIKAR, Kartik, M.; ZENG, Qingbei; MAZZOLA, Robert, D., Jr.; CALDWELL, John, P.; TANG, Haiqun; NAIR, Anilkumar Gopinadhan; SHANKAR, Bandarpalle, B.; ROSENBLUM, Stuart, B.; KOZLOWSKI, Joseph, A.; WO2013/39878; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem