Category: Pyrazines

Electric Literature of 78342-42-4, A common heterocyclic compound, 78342-42-4, name is (S)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine, molecular formula is C9H16N2O2, 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 1 Production of (2R,5S)-2-(2-(diethoxy-phosphoryl)ethyl)-2,5-dihydro-3,6-dimethoxy-5-isopropyl pyrazine 0.52 mol of (S)-2,5-dihydro-3,6-dimethoxy-2-isopropyl pyrazine are solved in 400 ml of absolute THF under argon and are cooled to -78¡ã C. Under stirring, 200 ml of a 2.7 M solution of butyl lithium (in heptane) (0.54 mol) are added in drops and slowly. Subse-quently, a solution of 0.52 mol of diethyl-(2-bromoethyl) phosphonate in 300 ml of absolute THF is added in drops and slowly during stirring, and the mixture is stirred for further 3 h at -78¡ã C. Then, 11.7 ml (about 0.2 mol) anhydrous acetic acid are added slowly. The reaction mixture is allowed to warm up slowly to room temperature. The solvent is removed, and the residue is solved in 600 ml of diethyl ether and washed with 200 ml of water. The aqueous phase is still extracted three times with each 100 ml of diethyl ether. The combined ether phases are dried over MgSO4, filtered and the solvent is removed in vacuo. The residue is solved in a mixture of diethyl ether and hexane (1:10) and filtered over a bed of silica gel. Thereby, first it is eluted with diethyl ether and hexane (1:5). Yield: about 70percent of a yellow liquid. 1H-NMR (CDCl3): 0.71, 1.04 (d, 6H, CH(CH3)2), 1.33 (t, 6H, P(O)(OCH2CH3)2), 1.68-2.25 (m, 4H, CHCH2CH2P), 3.65, 3.67 (s, 6H, OCH3), 4.02 (m, 1H), 4.10-4.20 (m, 4H, P(O)(OCH2CH3)2).

The synthetic route of 78342-42-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Lindhorst, Thomas; Werner, Birgit; Bock, Holger; US2010/22478; (2010); 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., Formula: C4H6N4

In a 3-L, 3-necked, round-bottomed flask were charged 60.0 gr (Z)-3-(3-(3,5- bis(trifluoromethyl)phenyl)- 1 H- 1,2, 4-triazol- 1 -yl)acrylic acid (SLN- 105, prepared according to examples 27), Ethyl acetate (0.42 lit, 7V) and Acetonitrile (0.3 lit,5V) at 20-25C. Charged 2-hydrazino pyrazine (19.8 gr, 1.05 eq) then cooled to 0 to 5C. Charged EDC .HC1 (1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride) (49. lgr 1 .Seq) at 0 to 5C. The reaction mass was stirred for 3hrs and monitored by HPLC (till SLN-105 NMT 1.0%). Once the reaction completes, charge water (0.2lit, 2V) and stirred for 15-30 mm at 15-20C, settled and separated the organic layer. Collected the organic layer and washed with sodium bicarbonate solution (0.Slit, SV). Finally washed the organic layer with water (0.2lit, 2 V) and combined the collected organic layer containing the product. The solvent is distilled off under vacuum at 50 to 60C for 30 mm. To the obtained solid, added absolute Ethanol (0.6lit, 1OV) and stirred for 30mm at 20-25C then cooled to 0-5C and stirred for 1 hr at 0-5C. Filtered the compound under vacuum at 20-25C and washed with Ethanol (0.2lit, 2V). The wet cake was dried at 55-60C under vacuum (600 to 700 mm Hg) for 4 hrs. (Yield 83%).

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:
Patent; WATSON LABORATORIES INC.; MUTHUSAMY, Anantha Rajmohan; KANNIAH, Sundara Lakshmi; RAVI, Akash; DAS, Tonmoy Chitta; CHEMATE, Rajendra Popat; SINGH, Anil Kumar; WAGH, Yogesh Dhananjay; (60 pag.)WO2018/129227; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 5521-58-4, A common heterocyclic compound, 5521-58-4, name is 5-Methylpyrazin-2-amine, molecular formula is C5H7N3, 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.

3-{[5-(Azetidin-1-ylcarbonyl)pyrazin-2-yl]oxy}-5-[(1S)-2-methoxy-1-methylethoxy]-N-(5-methylpyrazin-2-yl)benzamide To a flask fitted with overhead stirrer, condenser, thermometer and nitrogen line was added 3-{[5-(azetidin-1-ylcarbonyl)pyrazin-2-yl]oxy}-5-[(1S)-2-methoxy-1-methylethoxy]benzoic acid (1.0 eq), and acetonitrile (10 vols) followed by pyridine (3 eq) under a nitrogen atmosphere. Thionyl chloride (1.2 eq) as a solution in acetonitrile (0.225 vols) was added slowly, drop-wise via syringe pump over at least 2 hours. 5-Methylpyrazin-2-amine (1.2 eq) was added to the mixture as a solid. After 2.5 hours the reaction was quenched by adding toluene (10 vols) and 1.0M sodium carbonate solution (2.5 eq). The layers were separated. The organic layer was retained in the flask, then 1.0M hydrochloric acid (1.94 eq) was added. The mixture was agitated for 15 minutes then separated. The organic layer was washed with two aliquots of water (5 vols) then the solvent was removed on the rotary evaporator. Toluene (5 vols) was added to the residue, and warmed to 45 C. Isohexane (1.7 vols) was added, the mixture was seeded, and allowed to cool to ambient temperature overnight. The mixture was cooled to 0 C. for 4 hours, and then cooled to -10 C. for 3 hours. The solid was isolated by filtration then washed with isohexane (2.5 vols). After drying in the vacuum oven at 40 C. overnight, the desired product was obtained as a solid (corrected yield 85%).

The synthetic route of 5521-58-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; AstraZeneca AB; US2010/210621; (2010); 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 313339-92-3 as follows. category: Pyrazines

3,5-Dichloropyrazine-2-carbonitrile (487.14 mg, 2.8 mmol) was added to a solution of tert-butyl N-[(2S,3S)-2-methylpiperidin-3-yl]carbamate (600.0 mg, 2.8 mmol) and DIPEA (1.0 mL, 5.6 mmol) in DMF (5mL) and stirred at room temperature for 2 hours. The mixture was poured into ice and extracted with ethyl acetate (3×50 mL), the organic phase dried on Na2SO4, filtered and concentrated under reduced pressure. The residue purified by flash chromatography (silica) eluting with ethyl acetate in cyclohexane from 0 to 60% to obtain tert-butyl N-[(2S,3S)- 1-(6-chloro-5-cyanopyrazin-2-yl)-2-methylpiperidin-3-yl]carbamate (274.3 mg, 28% yield).

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; PHARMACYCLICS LLC.; ATALLAH, Gordana, Babic; CHEN, Wei; JIA, Zhaozhong, J.; POZZAN, Alfonso; RAVEGLIA, Lucal, Francesco; ZANALETTI, Riccardo; (815 pag.)WO2016/196776; (2016); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 723286-80-4,Some common heterocyclic compound, 723286-80-4, name is tert-Butyl 3-bromo-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate, molecular formula is C10H15BrN4O2, 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 solution of 0.090 g (0.297 mmol) of 3-BROMO-7- (TERT-BUTOXYCARBONYL)- 5,6, 7,8-tetrahydro [1, 2,4] triazolo [4,3-a] pyrazine (Example 15, Step D) in 3 mL of dioxane was added 0.0630 g (0.899 mmol) of sodium thiomethoxide, and the reaction mixture was heated at 100 C for 1 d. The reaction was diluted with dichloromethane and washed sequentially with saturated aqueous sodium bicarbonate solution and brine, dried over magnesium sulfate, and concentrated in vacuo to afford the title compound. LC/MS 271.1 (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 tert-Butyl 3-bromo-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate, its application will become more common.

Reference:
Patent; MERCK & CO., INC.; WO2004/58266; (2004); 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. 4774-14-5, name is 2,6-Dichloropyrazine, A new synthetic method of this compound is introduced below., Application In Synthesis of 2,6-Dichloropyrazine

A mixture of 2,6-dichloropyrazine (2.5 g, 16.8 mmol, 1.0 equiv),/?- ? toluenesulfonic acid (6.4 g, 33.6 mmol, 2.0 equiv), sodium iodide (20.0 g, 133.3 mmol, 8.0 equiv), 15-crown-5 (2.0 mL) and sulfolane (40 mL) was heated at 150 0C and stirred in a sealed tube for 2 hr. After cooling, water (100 mL) was added to the reaction mixture. The mixture was then neutralized with a saturated solution of sodium hydrogencarbonate, and washed with a saturated solution of sodium thiosulfate. The mixture was extracted with diethyl ether (5 x 100 mL). The ether extracts were dried (Na2SO4) and concentrated in vacuo. 2,6-Diiodopyrazine was precipitated with 10 mL of water, filtered, washed with water and pentane to provide a pale yellow powder after lyophilization (2.1 g, 38%). 1H NMR (400 MHz, CDCl3) delta 8.74 (s, 2H); MS (M+H)+ = 332, R1= 1.29 min.

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; NOVARTIS AG; NOVARTIS PHARMA GmbH; XENON PHARMACEUTICALS INC; WO2008/24390; (2008); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 21279-64-1, 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 21279-64-1 as follows.

General procedure: Comp. 1a and 2a were prepared using microwave reactor. Special thick-walled tubes intended for use in microwave reactor were filled with a mixture of corresponding starting comp. 1 or 2 (150 mg, 0.952 mmol), 25% aqueous ammonia (2 mL, in excess) and MeOH (2 mL). Tubes fitted with stirrer and closed with a special cap were inserted into the reactor. Reaction conditions for microwave-assisted synthesis were: output 200 W, temperature 95 C, reaction time 30 min using PowerMAX mode.

According to the analysis of related databases, 21279-64-1, the application of this compound in the production field has become more and more popular.

Reference:
Article; Servusova, Barbora; Paterova, Pavla; Mandikova, Jana; Kubicek, Vladimir; Kucera, Radim; Kunes, Jiri; Dolezal, Martin; Zitko, Jan; Bioorganic and Medicinal Chemistry Letters; vol. 24; 2; (2014); p. 450 – 453;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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 24241-18-7, Recommanded Product: 2-Amino-3,5-dibromopyrazine

Example 137 Step A: Ethanol (10.0 mL) and chloroacetaldehyde (2.6953 g of 50 % by weight solution in water, 17.17 mmol) were added into a pressure tube containing 2-amino-3, 5- dibromopyrazine (2.015 gm, 7.97 mmol). The heterogeneous reaction mixture was stirred at 70C. The reaction mixture assumed a homogenous appearance after heating began, and precipitation started to appear 3 h later. After a total of 22 h of heating, the reaction mixture was cooled to rt. The precipitate was filtered, washed with EtOH (-10 mL), and exposed to high vacuum to afford impure imidazopyrazine 137A as an ash- colored solid (1.699 g). lH NMR: 9.03 (s, 1H), 8.24 (d, J = 0.9, 1H), 7.91 (d, J = 1.2, 1H). (ESI) m/z (M+H) + = 277.79.

In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 2-Amino-3,5-dibromopyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; BRISTOL-MYERS SQUIBB COMPANY; WO2003/84959; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 4774-14-5, name is 2,6-Dichloropyrazine, molecular formula is C4H2Cl2N2, 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: 2,6-Dichloropyrazine

General procedure: To the N,N-dimethylformamide (DMF) (4 mL) solution of N,N-dimethylethylenediamine (95 mL, 0.87 mmol) was added K2CO3 (0.19 g, 1.3 mmol). After the reaction mixture was stirred at room temperature (RT) for 30 min, 2,6-dichloropyrazine (0.10 g, 0.67 mmol) was added and the resulting reaction mixture was further stirred at RT for 12 h. After removal of solvent in vacuo, the residue was treated with dichoromethane. Insoluble impurities were removed by filtration. Removal of solvent in vacuo gave the product 0.095 g in 71 % yield;

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 4774-14-5, its application will become more common.

Reference:
Article; Lee, Jinho; Park, Jongseong; Hong, Victor Sukbong; Chemical and Pharmaceutical Bulletin; vol. 62; 9; (2014); p. 906 – 914;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 63286-28-2, 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. 63286-28-2 name is 2-Chloro-3-hydrazinylpyrazine, 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.

Intermediate b (5.0 g, 0.034 mol) was added to triethyl orthoformate (50 mL), and the reaction was carried out at 80 C. The reaction time was monitored with a plate. The reaction liquid was directly filtered with cold suction, and the filter cake was washed with petroleum ether. After the cake was dried, 4.8 g of a yellow powder was obtained with a yield of 90.1%.

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

Reference:
Patent; Jiangxi Science and Technology Normal University; Zhu Wufu; Zheng Pengwu; Liu Xiaobo; Xu Shan; Zhang Qian; Tang Qidong; Zhou Hualan; Wu Jinjin; Yuan Ping; Zhang Hongbo; (25 pag.)CN110407839; (2019); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem