Category: Pyrazines

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. 51171-02-9, name is Methyl 3-Bromo-2-pyrazinecarboxylate, A new synthetic method of this compound is introduced below., Safety of Methyl 3-Bromo-2-pyrazinecarboxylate

To a solution of 6.5 g 3-(2-amino-4-chloro-N-methyl-phenylamino)-pyrazine-2-carboxylic acid methyl ester in 100 ml N,N-dimethyl-formamide are added 5.0 g potassium tert. butylate at 0 C. The mixture is stirred at room temperature for 2 hours, poured into ice water and acidified to pH 4 with glacial acetic acid, whereupon the heading compound is precipitated, m.p. 305-307 (recrystallized from methanol). In analogous manner to that described in Example 1, the following compounds of formula I are obtained: The starting materials of formula III for Examples 10-16, 20-23 and 25 are prepared in analogous manner to that described in Example 1, steps (a) to (e). The starting material of formula III for Examples 2 to 5 and 17 may be obtained as follows: 2.2 g of 3-bromo-pyrazine-2-carboxylic acid methyl ester and 2.2 g 1,2-phenylene diamine suspended in 50 ml triethylamine are boiled for 17 hours under reflux. After the mixture has been cooled, water and ethyl acetate are added to precipitate out pyrazino [2,3-b][1,5]benzodiazepin-11(10H)-one, m.p. 298-300.

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; Sandoz Ltd.; US4337198; (1982); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 113305-94-5,Some common heterocyclic compound, 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, molecular formula is C5H4N4, 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.

1 E. Benzyl-{4-[(Z)-3-(5-cyano-yrazin-2-ylamino)-3-methylsulfanyl-acryloyl]-35- dimethoxy-henyl}-carbamic acid tert-butyl esterA solution of 2-amino-5-cyanopyrazine (1.25 g, 5.2 mmol) in THE (10 mL) was added slowly to a stirred slurry of NaH (60% in mineral oil) (0.21 g, 5.2 mmol) in THE (17 mL)at 0C. The mixture was stirred for 30 minutes at 0C then a solution of benzyl-[4-(3,3- bis-methylsulfanyl-acryloyl)-3,5-dimethoxy-phenyl]-carbamic acid tert-butyl ester (1 .7 g, 3.48 mmol) in THE (7 mL) was added dropwise and the reaction mixture was heated to 80C for 12 hours. The solution was allowed to cool to room temperature then water (40 mL) was carefully added and the mixture extracted with EtOAc (3 x 25 mL). The combined organic extracts were dried (Na2SO4) and evaporated under reduced pressure to leave a residue that was purified by column chromatography on neutral silica gel (60-120 mesh size) using 0-70% EtOAc/hexanes as the eluentto give thetitle compound (0.9 g, 46%).

The synthetic route of 113305-94-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ONCOTHYREON INC.; BOYLE, Robert, George; WALKER, David, Winter; BOYCE, Richard, Justin; PETERSON, Scott; FAROUZ, Francine; VO, Cong, Hung; WO2015/120390; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 54608-52-5,Some common heterocyclic compound, 54608-52-5, name is 2-Hydrazinopyrazine, molecular formula is C4H6N4, 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.

A solution of 15.0 g (136 mmol) of 2-hydrazinopyrazine in 100 ML of trimethyl orthoformate was heated to reflux at 100 C for 1.5 h. The solvent was removed in vacuo and the crude product was applied to a pad of silica gel and eluted with 15: 85 methanol : ethyl acetate. The resulting solution was concentrated in vacuo to yield the title compound. LC/MS 121.0 (M+1).

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

Reference:
Patent; MERCK & CO., INC.; WO2004/58266; (2004); 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. 173253-42-4, name is 2-Amino-5-bromo-6-chloropyrazine, This compound has unique chemical properties. The synthetic route is as follows., COA of Formula: C4H3BrClN3

EXAMPLE 27 2-Amino-5-bromo-6-chloropyrazine (0.417 g) was added to a stirred suspension of sodium hydride (oil-free; 0.24 g) in dry dimethoxyethane (20 ml). When evolution of hydrogen ceased, 5-dimethylamino-1-naphthalenesulphonyl chloride (0.594 g) was added. The mixture was stirred for 24 hours and then water (25 ml) and 2M hydrochloric acid (2 ml) were added. The mixture was extracted with ethyl acetate (2*25 ml) and the extracts were dried (MgSO4). Volatile material was removed by evaporation and the residue was purified by elution with ethyl acetate/hexane (1:3 v/v) through a silica gel Mega Bond Elut column to give 5-dimethylamino-N-(5-bromo-6-chloro-2-pyrazinyl)-1-naphthalenesulphonamide (0.46 g), m.p. 180-182 C. (after trituration with ether); mass spectrum (+ve FAB, methanol/NBA): 442 (M+).

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 173253-42-4.

Reference:
Patent; Zeneca Limited; US5861401; (1999); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 54608-52-5, 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 54608-52-5 as follows.

General procedure: To a well-stirred solution of I 2 (0.2 mmol)TBHP (2 mmol,70% in water) K2CO3 (1 mmol) in 1,4-dioxane (10 mL) were added benzaldehyde 1a (1 mmol) and 2-hydrazinopyridine 2a (1 mmol), and then the reaction mixture was stirred at 60 C. After completion of the raction as indicated by TLC (1 h), the reaction mixture was cooled to room temperature. Then the reaction mixture was treated with 10 % Na2S2O3 (20 mL) and extracted with ethyl acetate (10 mL×3). The combined organic layer was dried over anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified through silica gel column chromatography using a mixture of EtOAc and petroleum ether as eluent to afford the targeted product in 72-97 % yield.

According to the analysis of related databases, 54608-52-5, the application of this compound in the production field has become more and more popular.

Reference:
Article; Wu, Yachuang; Yang, Yifeng; Qi, Yinliang; Du, Shimei; Zhang, Yongsheng; Ding, Liang; Zhao, Yanfang; Tetrahedron Letters; vol. 59; 48; (2018); p. 4216 – 4220;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 63286-28-2, name is 2-Chloro-3-hydrazinylpyrazine, 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. name: 2-Chloro-3-hydrazinylpyrazine

A mixture of l-(3-chloropyrazin-2-yl)hydrazine (0.90 g, 62 mmol), triethyl orthoformate (2.3 mL), 14 mmol), and dry xylene (15 mL) was refluxed with stirring for 2 h. The mixture was brought to RT, diethyl ether was added and the suspension was filtered. The solid collected was washed with diethyl ether to afford 8-chloro-[l,2,4]triazolo[4,3- ajpyrazine (0.60 g, 62% yield). MS m/z: 155.0 (M+l).

The synthetic route of 2-Chloro-3-hydrazinylpyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; AMGEN INC.; WO2009/64418; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 74290-67-8, 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. 74290-67-8 name is 2-Amino-5-bromo-3-methylpyrazine, 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.

a) 3-(N-(3-((5-amino-6-methylpyrazin-2-yl)ethynyl)-2,4-difluorophenyl)sulfamoyl)-5-chloro-2-methoxybenzyl Acetate A mixture of 5-chloro-3-(N-(3-ethynyl-2,4-difluorophenyl)sulfamoyl)-2-methoxybenzyl acetate (200 mg), dichlorobis(tricyclohexylphosphine)palladium(II) (34.3 mg), DIPEA (2 mL), copper(I) iodide (17.7 mg), 5-bromo-3-methylpyrazin-2-amine (114 mg) and DMSO (2 mL) was stirred under microwave irradiation at 100 C. for 1 hr. After cooling to room temperature, the reaction mixture was diluted with water and extracted with ethyl acetate. The obtained organic layer was washed with saturated brine, dried over magnesium sulfate and concentrated to give a residue. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give the title compound (216 mg). MS: [M+H]+ 537.0.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2-Amino-5-bromo-3-methylpyrazine, and friends who are interested can also refer to it.

Reference:
Patent; Takeda Pharmaceutical Company Limited; FUJIMOTO, Jun; LIU, Xin; KURASAWA, Osamu; TAKAGI, Terufumi; CARY, Douglas Robert; BANNO, Hiroshi; ASANO, Yasutomi; KOJIMA, Takuto; (159 pag.)US2019/169166; (2019); 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 24241-18-7 as follows. Recommanded Product: 24241-18-7

Reference ASynthesis of 2-bromo-5H-pyrrolo[2,3-b]pyrazineStep 1To a 500 ml three necked round bottom flask, 3,5-dibromopyrazine-2-amine (25.0 g,0.0988 mole) was taken in acetonitrile (250 ml). The reaction mixture was cooled to 0 C and triethylamine (50.0 g, 0.4941 mole), copper (1) iodide (2.26 g, 0.0119 mole), and Pd (PPh3)4 (5.7 g, 0.0049 mole) were added under nitrogen atmosphere. The reaction mixture was stirred for 10 min at 0 C followed by slow addition of trimethylsilylacetylene (10.7g, 0.1089 mole) over 15 min at the same temperature. After completion of the addition, the reaction mixture was warmed up to RT and stirred for 90 min.The completion of the reaction was monitored on TLC using hexanes: ethyl acetate (5:5) as a mobile phase. After completion of the reaction, the reaction mixture was diluted by ethyl acetate and filtered through high flow. Filtrate was collected and washed with water. Layers were separated and aq. layer was re-extracted by ethyl acetate. Attorney Docket No. 11913-1008Combined organic layer was dried over Na2S04, filtered and concentrated to afford crude product which was subjected for the column purification. The crude compound was purified using column purification by eluting the compound with 7-10 % ethyl acetate in hexanes to yield 20.0 g of 5-bromo-3-((trimethylsilyl)ethynyl)pyrazine-2-amine.

According to the analysis of related databases, 24241-18-7, the application of this compound in the production field has become more and more popular.

Reference:
Patent; PRINCIPIA BIOPHARMA INC.; GOLDSTEIN, David Michael; BRAMELD, Kenneth Albert; VERNER, Erik; WO2012/158785; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 4858-85-9, name is 2,3-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 4858-85-9, Recommanded Product: 4858-85-9

A mixture 2,3-dichloro-pyrazine (5.0 g, 34 mmol), 1-isopropylpiperazine (6.5 g, 51 mmol) and potassium carbonate (7.0 g, 51 mmol) in acetonitrile (100 mL) was stirred at ambient temperature for 2 h. Addition of hexane, followed by filtration and concentration of the filtrate gave 9.5 g of crude material as an orange liquid. Purification by filtration through silica using heptane/EtOAc (3: 1), followed by EtOAc/acetone (1: 1), provided 6.5 g (79%) of the title compound as a yellow oil which solidified upon cooling. HPLC purity: 98%. MS m/z 241 (M+H) +. HRMS m/z calcd for C11H17ClN4 (M) + 240.1142, found 240.1138.

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

Reference:
Patent; BIOVITRUM AB; WO2004/9586; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 109838-85-9, 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. 109838-85-9 name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, 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.

[0562] A solution of compound 4-01-5 (8.9 g, 48 mmol) in tetrahydrofuran (100 mL) was cooled to -70C and n-butyl lithium (2.5 M, 19.5 mL, 49 mmol) was added under nitrogen while the temperature was kept below -70C. A solution of compound 7- bromohept-l-ene (8.0 g, 45 mmol) in tetrahydrofuran (15 mL) was added at -70C. The reaction mixture was stirred at -70C for 2 hours, then slowly heated to 20C and stirred for 1 hour. The reaction mixture was poured into saturated ammonium chloride solution (50 mL) and extracted with ethyl acetate (200 mL *2). The combined organic phase was washed with brine (100 mL*2), dried over anhydrous sodium sulfate, and concentrated in reduced pressure. The residue was purified by column chromatography (petroleum ether to petroleum ether: ethyl acetate = 50: 1) to afford compound 4-01-6 (7 g, 55% yield) as a colorless oil.

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

Reference:
Patent; CORNELL UNIVERSITY; TRI-INSTITUTIONAL THERAPEUTICS DISCOVERY INSTITUTE; LIN, Gang; NATHAN, Carl; KIRKMAN, Laura; ZHAN, Wenhu; MORGAN, Trevor; SATO, Kenjiro; HARA, Ryoma; KAWASAKI, Masanori; IMAEDA, Toshihiro; TOITA, Akinori; OKAMOTO, Rei; YUKAWA, Takafumi; ASO, Kazuyoshi; WONG, Tzu-Tshin; GINN, John, D.; FOLEY, Michael, A.; (296 pag.)WO2019/75259; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem