Tag: M.W=100-200

Adding a certain compound to certain chemical reactions, such as: 78342-42-4, name is (S)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine, 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 78342-42-4, Safety of (S)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine

Into a 500-mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed (2 S)-3 , 6-dimethoxy-2-(propan-2-yl)-2, 5 -dihydropyrazine (3 g, 15.47 mmol) and THF (200 mL). A solution of n-BuLi in n-hexane (2.5 M) (9.8 mL, 24.5 mmol) was added at -80 °C in a liquid nitrogen bath. The resulting solution was stirred for 30 mm at -80°C in a liquid nitrogen bath. Then a solution of 5-(bromomethyl)-2,4-dichloropyridine (4.7 g, 18.53 mmol) in THF (lOmL) was added. The resulting solution was allowed to react, with stirring, for an additional 1 h while the temperature was maintained at -80°C in a liquid nitrogen bath. The reaction was then quenched by the addition of 120 mL of ammonium chloride (sat. aq.). The resulting mixture was extracted with DCM (2 x 150 mL) and the organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated under vacuum. The residue was purified by silica gel chromatography (eluting with 1:10 ethyl acetate/pet. ether) to afford (2R,5S)- 2- [(4,6-dichloropyridin-3 -yl)methyl]-3 , 6-dimethoxy-5 -(propan-2-yl)-2, 5 -dihydropyrazine as a white solid. MS: (ESI, m/z): 344, 346 [M+H]t

At the same time, in my other blogs, there are other synthetic methods of this type of compound, (S)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine, and friends who are interested can also refer to it.

Reference:
Patent; FORMA THERAPEUTICS, INC.; ZABLOCKI, Mary-Margaret; GUERIN, David J.; NG, Pui Yee; WANG, Zhongguo; SHELEKHIN, Tatiana; CARAVELLA, Justin; LI, Hongbin; IOANNIDIS, Stephanos; (518 pag.)WO2019/32863; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 5521-55-1, 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. 5521-55-1 name is 5-Methylpyrazine-2-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 1: To a solution of 2-methylpyrazine-5-carboxylic acid (10 g, 72.4 mmol) and TEA (20 mL, 108 mmol) in t-butanol (156 mL) and dioxanes (100 mL) was added diphenyl phosphorylazide (23.4 mL, 108 mmol) and the resulting solution was warmed at 100 C. for 3 hours and then cooled to room temperature overnight. The crude reaction mixture was concentrated in vacuo. Purification by chromatography (silica 0-15% ethyl acetate/hexanes) following trituration of impure fractions with ether afforded (5-methyl-pyrazin-2-yl)-carbamic acid tert-butyl ester (10.6 g, 70%): 1H NMR (300 MHz, CHLOROFORM-d) delta ppm 1.56 (s, 9H) 2.51 (s, 3H) 8.02 (br. s., 1H) 8.07-8.14 (m, 1H) 9.18 (d, J=1.13 Hz, 1H).

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:
Patent; Brotherton-Pleiss, Christine E.; Walker, Keith A. M.; US2012/149718; (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. 54608-52-5, name is 2-Hydrazinopyrazine, This compound has unique chemical properties. The synthetic route is as follows., Recommanded Product: 54608-52-5

General procedure: The desired compounds 1a-g and 2a-f were prepared by reaction between pyridoxal hydrochloride (0.15 g, 0.74mmol) and the appropriate aromatic or heteroaromatic hydrazine or N-acylhydrazine (1.1 eq., 0.81mmol) in ethanol (10.0 mL). The reaction mixture was stirred for 1-48 hours at room temperature. After that, product was purified by wash-ing with cold ethanol (3.0 mL) and cold diethyl ether (3.0 mL), leading to the pure derivatives 1a-g and 2a-f as solid in 42-86% yields.

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 54608-52-5.

Reference:
Article; Nogueira, Thais Cristina Mendonca; Cruz, Lucas Dos Santos; Lourenco, Maria Cristina; de Souza, Marcus Vinicius Nora; Letters in drug design and discovery; vol. 16; 7; (2019); p. 792 – 798;,
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. 313339-92-3, name is 3,5-Dichloropyrazine-2-carbonitrile, A new synthetic method of this compound is introduced below., Recommanded Product: 313339-92-3

Step 1: To a mixture of 3,5-dichloropyrazine-2-carbonitrile (369 mg, 2.09 mmol) and tert-butyl (3R,4R)-4-aminotetrahydro-2H-pyran-3-ylcarbamate (500 mg, 2.3 mmol) in AcCN (7.5 mL) was added DIPEA (0.41 mL, 2.3 mmol). After stirring at room temperature for 5 h, it was diluted with EtOAc, washed with sat. NaHCO3, organic layer was separated and washed with brine, dried and concentrated to give tert-butyl (3R,4R)-4-(6-chloro-5-cyanopyrazin-2-ylamino)tetrahydro-2H-pyran-3-ylcarbamate (880 mg).

The synthetic route of 313339-92-3 has been constantly updated, and we look forward to future research findings.

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

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. 41270-62-6, name is 2-Chloro-6-phenylpyrazine, A new synthetic method of this compound is introduced below., Quality Control of 2-Chloro-6-phenylpyrazine

2-Chloro-6-phenylpyrazine (108 mg, 0.56 mmol), tert-butyl 3-amino-5- methyl-lH-pyrazole-1-carboxylate (142 mg, 0.72 mmol), palladium(II) acetate (15 mg, 0.07 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (65 mg, 0.1 mmol), potassium carbonate (820 mg, 5.9 mmol), and dioxane (4 mL) were combined and the mixture degassed with nitrogen for 2 minutes before heating to 90C for one hour. The reaction was partitioned between ethyl acetate and water. The aqueous layer was washed with ethyl acetate (3x), organics were combined, dried over magnesium sulfate, filtered, and concentrated. The crude material was purified by silica gel chromatography (10-65% ethyl acetate in hexanes) to give the title compound as a white solid (92 mg, 0.26 mmol, 46% yield); MS (ESI) MS (ESI) m/z 352.4 [M+l]+.

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; SIGNAL PHARMACEUTICALS, LLC; WO2009/89042; (2009); 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. 19745-07-4, name is 2,5-Dichloropyrazine, This compound has unique chemical properties. The synthetic route is as follows., category: Pyrazines

Add [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (0.445 g, 0.596 5 mmol) to the suspensions ofmethyl1-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2yl)phenyl]cyclo propanecarboxylate (2.00 g, 5.4 mmol,), sodium carbonate (1.26 g, 11.9 mmol) and 2,5-dichloropyrazine (8.93 mmol) in 1,4-dioxane (20 mL) and water (4 mL) under N2. Then the reaction mixture is stirred at 100 oc for 3 h under N2. The reaction mixture is concentrated to give a black solid. The mixture is diluted with water (20 mL) and 10 extracted with EtOAc (30 mL x 3). The combined organic layers are washed with brine (20 mL), dried over anhydrous Na2S04, filtered and evaporated to afford the crude product. The crude product is purified by flash chromatography eluting with petroleum ether: EtOAc (1 :2) to afford title compound (1.0 g 57.6percent) as a yellow solid, LCMS (m/z): 288.9 [M+Ht. 1H NMR (400 MHz, CD3Cl) 8 = 8.80 (d, J = 1.2 Hz, 1H), 8.65 (d, J = 1.2 Hz, 1H), 7.96 (d, J 15 = 8.4 Hz, 2H), 7.51 (d, J= 8.4 Hz, 2H), 3.67 (s, 3H), 1.72- 1.66 (m, 2H), 1.28- 1.23 (m, 2H)

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 19745-07-4.

Reference:
Patent; ELI LILLY AND COMPANY; LILLY CHINA RESEARCH AND DEVELOPMENT CO., LTD.; MA, Tianwei; WU, Liang; ZHANG, Xuejun; (109 pag.)WO2019/41340; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 33332-28-4, name is 2-Amino-6-chloropyrazine, 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. Recommanded Product: 2-Amino-6-chloropyrazine

A solution of 6-chloropyrazin-2-amine (2 g, 15.44 mmol) and N BS (13.7 g, 77 mmol) in CHCI3 (100 ml) was heated at reflux for 20 hours. The resulting mixture was purified bychromatography on silica eluting with DCM. The relevant fractions were concentrated in vacuo and the crude product was dissolved in EtOAc (~100 ml), washed with 10 percent sodium thiosulfate (2 x 100 ml), brine, dried (MgS04) and were concentrated in vacuo to afford the title compound; 1 H NMR (400 MHz, CDCI3) delta 5.4-5.0 (2H, br s).

The synthetic route of 2-Amino-6-chloropyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; NOVARTIS AG; CHARLTON, Steven, John; LEBLANC, Catherine; MCKEOWN, Stephen, Carl; WO2012/7539; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 297172-19-1, name is 5,6,7,8-Tetrahydroimidazo[1,5-a]pyrazine, 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 297172-19-1, Computed Properties of C6H9N3

EXAMPLE 3 5-[5,6-Dihydroimidazo[1,5-a]pyrazin-7(8H)-yl]-3-(2-fluorophenyl)-[1,2,3]triazolo[1,5-a]quinazoline Prepared from 5,6,7,8-tetrahydroimidazo[1,5-a]pyrazine as described for Example 1, step c (0.033 g, 37%). deltaH (360 MHz; CDCl3) 4.07 (2H, dd, J=6 and 6), 4.44 (2H, dd, J=6 and 6), 4.92 (2H, s), 6.93 (1H, s), 7.22-7.32 (2H, m), 7.37-7.41 (1H, m), 7.60 (1H, s), 7.69 (1H, dd, J=8 and 8), 7.96 (1H, dd, J=8 and 8), 8.05-8.09 (2H, m), 8.73 (1H, d, J=8); m/z (ES+) 386 (M+H+).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5,6,7,8-Tetrahydroimidazo[1,5-a]pyrazine, and friends who are interested can also refer to it.

Reference:
Patent; Chambers, Mark Stuart; Collins, Ian James; Goodacre, Simon Charles; Hallett, David James; Jones, Philip; Keown, Linda Elizabeth; Maxey, Robert James; Street, Leslie Joseph; US2003/45532; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 23688-89-3, 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 23688-89-3 as follows.

4-Phenoxyaniline (0.185 g, 1.0 mmol), 6-chloropyrazine-2-carboxylic acid (0.158 g, 1.0 mmol) and 30 mL of dichloromethane were added to the reaction flask, and Et3N (0.202 g, 2.0 mmol) was added. Then, EDCI (0.287 mg, 1.5 mmol), HOBt (0.20 g, 1.5 mmol) was added, and the reaction was carried out at 25 C for 2.0 hours. The reaction was completed by TLC, and the reaction was completed. The reaction mixture was washed twice with water and once with saturated brine.The organic phase is dried over anhydrous sodium sulfate and de-solued to give a crude product.The ethanol was recrystallized to give a white solid, m.p. 160-162 C, yield: 83.0%

According to the analysis of related databases, 23688-89-3, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Chen Lei; (6 pag.)CN108997228; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

22047-25-2, name is Acetylpyrazine, 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. Application In Synthesis of Acetylpyrazine

Step 1 Preparation of 4,4-difluoro-1-(2-pyrazinyl)butane-1,3-dione Ethyl difluoroacetate (2.23 g, 18 mmol) was placed in a 100 mL round bottom flask and dissolved in ether (10 mL). To the stirred solution was added 25% sodium methoxide (4.68 g, 22 mmol) followed by acetylpyrazine (2.00 g,16 mmol). After two hours stirring at room temperature, a precipitate formed and THF (10 mL) was added to the reaction. The reaction was stirred an additional 25.9 hours, then treated with 3N HCl (10 mL). The organic layer was collected, washed with brine (20 mL), dried over MgSO4, and concentrated in vacuo and recrystallized from methylene chloride/iso-octane to give the diketone as a brown solid (2.23 g, 68%); mp 103-110 C.; 1 H NMR (CDCl3) 300 MHZ 14.00 (br s, 1H), 9.31 (d, J=1.4 Hz, 1H), 8.76 (d, J=2.4 Hz, 1H), 8.68 (dd, J=1.4 Hz 2.4 Hz, 1H), 7.20 (s, 1H), 6.03 (t, J=54.0 Hz, 1H); 19 F NMR (CDCl3) 300 MHz: -127.16 (d); M+200.

The synthetic route of 22047-25-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; G.D. Searle & Co.; US5756529; (1998); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem