Tag: M.W=100-200

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 14508-49-7 as follows. name: 2-Chloropyrazine

Step 1 To a solution of chloropyrazine (11.5 g, 0.1 mmol) in absolute ethanol (50 ml) was added anhydrous hydrazine (16 ml, 0.5 mmol) and the reaction mixture was refluxed for 3 h. The organics were removed in vacuo and the residue was extracted with benzene to give hydrazinopyrazine (4.2 g).

According to the analysis of related databases, 14508-49-7, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Syntex (U.S.A.) LLC; US6316464; (2001); B1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 89464-87-9,Some common heterocyclic compound, 89464-87-9, name is 3-Methoxy-5-methylpyrazin-2-amine, molecular formula is C6H9N3O, 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.

c) Isobutylchloroformate (4.79 ml) was added to a stirred solution of 2-amino-3-methoxy-5-methylpyrazine (5 g) and pyridine (2.91 ml) in dichloromethane (10 ml) at ambient temperature. After 90 minutes the reaction mixture was diluted with dichloromethane (10 ml) and washed with 2M hydrochloric acid (3*20 ml), water (20 ml) and saturated sodium chloride solution (20 ml) and then dried (MgSO4). Volatile material was removed by evaporation to give a solid which was recrystallized from hexane to give isobutyl N-(3-methoxy-5-methylpyrazin-2-yl)carbamate (6.5 g); 1 H NMR (CDCl3): 1.0 (d, 6 H), 2.0 (m, 1 H), 2.4 (s, 3 H), 4.0 (d, 2 H), 4.02 (s, 3 H), 7.3 (s, 1 H), 7.8 (s, 1 H); mass spectrum (positive chemical ionisation (+ve CI)): 240 (M+H)+.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3-Methoxy-5-methylpyrazin-2-amine, its application will become more common.

Reference:
Patent; Zeneca Limited; US5866568; (1999); A;,
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. 873-42-7, name is 2-Amino-3,5-dichloropyrazine, This compound has unique chemical properties. The synthetic route is as follows., Product Details of 873-42-7

In a flask, under an inert atmosphere of argon, was added 3,5-dichloropyrazin-2-amine (7.0 g, 42.7 mmol), bis(triphenylphosphine)palladium(II) dichloride (3.0 g, 4.27 mmol) and THF (240 mL). The resulting mixture was allowed to stir for 1 h at RT. The intermediate from Step A (30 mL, 64 mmol) was added and the resulting solution was warmed at 35oC for 2 days. The reaction was then quenched by the addition of brine. The resulting solution was extracted with EtOAc (3X) and the organic layers combined, washed with brine, dried over anhydr. Na2SO4, and filtered. The residue was purified by silica gel chromatography with EtOAc:petroleum ether (5-20%) to afford the title compound.

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 873-42-7.

Reference:
Patent; MERCK SHARP & DOHME CORP.; BERGER, Raphaelle; DONG, Guizhen; RAGHAVAN, Subharekha; YANG, Zhiqiang; (179 pag.)WO2017/200857; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, 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 55557-52-3, Recommanded Product: 55557-52-3

EXAMPLE 8.1 (+-)-3-[(6R,8aS)-6-(hydroxymethyl)hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]pyrazin e-2-carbonitrile A mixture of (+-)-(6R,8aS)-octahydropyrrolo[1,2-a]pyrazin-6-ylmethanol (1.05 g, crude), 3-chloropyrazine-2-carbonitrile (860 mg, 6.2 mmol), Et3N (1.5 mL) and THF (10 mL) was stirred at 80 C. overnight. After concentration, the crude product was purified on a silica gel column to afford pure product (1.03 g, 77%). 1H NMR (300 MHz, CDCl3): delta (ppm) 1.45 (m, 1H), 1.85 (m, 3H), 2.41 (m, 3H), 2.63 (m, 1H), 2.92 (dd, 1H), 3.18 (m, 2H), 3.53 (t, 1H), 3.79 (dd, 1H), 4.61 (m, 2H), 8.03 (s, 1H), 8.27 (s, 1H).

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; AstraZeneca AB; NPS PHARMACEUTICALS; US2007/37817; (2007); 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. 59303-10-5, name is 2-Chloro-5-methylpyrazine, A new synthetic method of this compound is introduced below., Product Details of 59303-10-5

The 2-chloro-5-methylpyrazine (0.053 mL, 0.613 mmol), rac-l -((2S,3R,4R)-4-amino-2-cyclopropyl-6-(3,6-dihydro-2H-pyran-4-yl)-3-methyl-3,4-dihyd roquinolin- I (2H)-yl)ethanone (for a preparation seeIntermediate 78, 100 mg, 0.306 mmol), Pd2(dba)3 (42.1 mg, 0.046 mmol), sodium tert-butoxide (88mg, 0.919 mmol) and DavePhos (12.06 mg, 0.031 mmol) were suspended in 1,4-dioxane (10 mL)and allowed to stir at 100 C for 3 h. The reaction was allowed to cool and was partitioned between water and EtOAc, the organic layer was washed with brine, dried using a hydrophobic frit and concentrated to a gum. This gum was purified by column chromatography on silica gel eluting with 0- 50% EtOAc:cyclohexane and then 0-10% MeOH:DCM, to give a crude gum. This gum was furtherpurified using a MDAP (Formic) to give a white solid, this solid was eluted through a NH2 SPE (2 g) with MeOH the eluent was concentrated and dried to give the product (46 mg, 0.110 mmol, 35.9%) as an off-white solid. LCMS (2 mm Formic): Rt = 0.93 mi [MH] = 419.

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; GLAXOSMITHKLINE INTELLECTUAL PROPERTY (NO.2) LIMITED; AMANS, Dominique; ATKINSON, Stephen John; HARRISON, Lee Andrew; HIRST, David Jonathan; LAW, Robert Peter; LINDON, Matthew; PRESTON, Alexander; SEAL, Jonathan Thomas; WELLAWAY, Christopher Roland; WO2014/140076; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

16298-03-6, name is Methyl 2-aminopyrazine-3-carboxylate, 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: Methyl 2-aminopyrazine-3-carboxylate

Preparation of 3-aminopyrazine-2-carbaldehyde EPO Mpsithyl-3-aminopyrazine-2-carboxylate (11g) was dissolved in THF and cooled to – 780C. Diisobutylaluminum hydride (1 M in hexanes, 25OmL) was added, and the reaction stirred at -78¡ãC for 4 hours. The reaction was then warmed to 00C for one hour before being quenched slowly by addition of 1 M hydrochloric acid. Ethyl acetate was added and the layers separated. The organic layer was dried over magnesium sulfate, filtered and concentrated. The residue was triturated in hexanes to afford title compound (3.Og, 34percent).1H NMR (400 MHz, DMSO-D6) delta ppm 7.73 (br, 2H), 8.07 (d, J=2.25 Hz, 1 H), 8.36 (d, J=2.11 Hz, 1 H), 9.95 (s, 1 H).

The synthetic route of 16298-03-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SMITHKLINE BEECHAM CORPORATION; WO2006/63167; (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 4774-14-5 as follows. category: Pyrazines

To a solution of tert-butyl azetidin-3-ylcarbamate hydrochloride (LXIII) (2 g, 9.58 mmol) in dry DMF (19.2 mL) was added DIPEA (8.37 ml, 47.9 mmol). To this mixture was added 2,6-dichloropyrazine (LXIV) (1.428 g, 9.58 mmol) and the reaction was stirred at 95C for 3 h. The reaction was quenched with water (20 mL) and extracted with EtOAc. The organic layer was dried over anhydrous Na2SO4, filtered and concentrated. The residue was purified by silica gel column chromatography (40 g) (100% hexanes?hexanes:EtOAc 1 : 1) to yield tert-butyl (1-(6-chloropyrazin-2-yl)azetidin-3-yl)carbamate (LXV) (2.2882 g, 8.04 mmol, 84 % yield) as a white solid. ESIMS found for C12H17CIN4O2 m/z 285.1 (M+H).

According to the analysis of related databases, 4774-14-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; SAMUMED, LLC.; KC, Sunil, Kumar; WALLACE, David, Mark; CAO, Jianguo; CHIRUTA, Chandramouli; HOOD, John; (279 pag.)WO2017/23973; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

75907-74-3, name is (3,5,6-Trimethylpyrazin-2-yl)methanol, 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. Recommanded Product: 75907-74-3

Were added 2-hydroxymethyl-3,5,6-trimethyl pyrazine in 250mL three-necked flask (9.5g, 62.5mmol), MnO2(16.2g, 187.5mmol), ethanol 100mL, refluxed for 12h, TLC (petroleum ether – ethyl acetate 2: 1) detecting the reaction is substantially complete, cooled, filtered, recovering ethanol under reduced pressure to give a yellow solid by silica gel column chromatography (petroleum ether – ethyl acetate 4: 1) to give 8.8 g of a pale yellow solid, yield 93.9%.

The synthetic route of 75907-74-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Anhui University of Chinese Medicine; Hefei Medical Engineering Pharmaceutical Co., Ltd.; Hefei Enruite Pharmaceutical Co., Ltd.; Li Jiaming; He Guangwei; Zhang Yang; Huang Weijun; Zhang Yanchun; Liu Weizhong; Zuo Jian; Liu Huicai; Zhu Panhu; Wang Yujun; (14 pag.)CN106518791; (2017); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, 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 33332-25-1, SDS of cas: 33332-25-1

4-((7-azaspiro[3.4]nonan-2-oxy)methyl)-5-cyclopropyl-3-(2,6-dichlorophenyl)isoxazole (100 mg, 0.24 mmol) is dissolved in DMF (5 mL), followed by adding methyl 5-chloropyrazine -2-carboxylate (45 mg, 0.26 mmol) and potassium carbonate (81 mg, 0.59 mmol), and the mixture is heated to 80 C and continues to react for 2 hr. Then the reaction mixture is cooled down to room temperature, poured into water (20 mL), and extracted with ethyl acetate (15 mL * 2) and the organic layer is washed with saturated salt solution (20 mL * 2), then dried with anhydrous Na2SO4, filtered, rotated to dryness and purified by column chromatography (PE : EA = 1.5 : 1), so as to obtain a brown oily matter of 100 mg, that is methyl 5-(2-((5-cyclopropyl-3-(2,6-dichlorophenyl)isoxazol-4-yl)methoxy)-6-azaspiro[3.4]octan-6-yl)pyr azine-2-carboxylate with a yield of 81%. Spectrum is: 1H NMR (400 MHz, CDCl3) delta: 8.81(m, 1H), 7.86(m, 1H), 7.46-7.44(m, 2H), 7.39-7.34(m, 1H), 4.21(s, 2H), 3.97(m, 4H), 3.58-3.44(m, 4H), 2.16(m, 3H), 1.98(m, 2H), 1.83(m, 2H), 1.29(m, 2H), 1.15(m, 2H).

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; Guangzhou Henovcom Bioscience Co. Ltd.; ZHANG, Jiancun; ZOU, Qingan; CHEN, Yanwei; (64 pag.)EP3401315; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 109838-85-9,Some common heterocyclic compound, 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, molecular formula is C9H16N2O2, 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-6cA 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).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, its application will become more common.

Reference:
Patent; MERCK SHARP & DOHME CORP.; DWYER, Michael, P.; KEERTIKAR, Kartik, M.; ZENG, Qingbei; MAZZOLA, Robert, D., Jr.; YU, Wensheng; TANG, Haiqun; KIM, Seong Heon; TONG, Ling; ROSENBLUM, Stuart, B.; KOZLOWSKI, Joseph, A.; NAIR, Anilkumar Gopinadhan; WO2013/39876; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem