Tag: M.W=0-100

5049-61-6,Some common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, molecular formula is C4H5N3, 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.

Referring to Scheme 3, pyrazin-2-ylamine (1 g, 10.5 mmol) was dissolved in a solution of DMSO (40 ml)/H2O (1 ml) at 0 C. N-bromosuccinimide (3.93 g, 22 mmol) was added over an hour keeping the temperature below 5 C. Once addition was complete, the mixture was stirred for 6 hours at RT. The mixture was poured over ice water (150 ml) whilst stirring, then extracted with EtOAc (4¡Á100 ml). The organic layers were combined, dried and evaporated to leave an orange oil, which solidified overnight under high vacuum. 3,5-dibromopyrazin-2-amine was produced as an orange/brown solid (2.24 g, 84%). The product was used for the next reaction without further purification. [M+H] calc’d for C4H3Br2N3, 254; found, 254.

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

Reference:
Patent; Dong, Qing; Hosfield, David J.; Paraselli, Bheema R.; Scorah, Nicholas; Stafford, Jeffrey A.; Wallace, Michael B.; Zhang, Zhiyuan; US2006/84650; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6270-63-9, A common compound: 6270-63-9, name is Pyrazin-2(1H)-one, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below.

General procedure: The appropriate nucleophile (1 equiv.), the epoxide (1-3 equiv.) and a base (1-5 equiv.) were suspended in a solvent and the reaction mixture was heated under the stated conditions. (0735) The reaction was allowed to cool to rt, saturated NH4CI(aq) or water was added and the resulting mixture was extracted using DCM or EtOAc (x 3). The combined organic extracts were dried (phase separator or MgS04), concentrated under reduced pressure and the remaining residue was purified by flash chromatography to give the product.

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, Pyrazin-2(1H)-one, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; ALMAC DISCOVERY LIMITED; ROUNTREE, James Samuel Shane; WHITEHEAD, Steven Kristopher; TREDER, Adam Piotr; PROCTOR, Lauren Emma; SHEPHERD, Steven David; BURKAMP, Frank; COSTA, Joana Rita Castro; O’DOWD, Colin; HARRISON, Timonthy; (333 pag.)WO2019/150119; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 5049-61-6, name is Pyrazin-2-amine, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below. 5049-61-6

A novel process for the reaction of a secondary amine by reaction of 2-aminopyrazine with triethylamine, comprising the steps of:Under nitrogen protection,Under nitrogen protection,2-aminopyrazine (95 mg, 1 mmol) was added to a 50 mL Schlenk tube,Triethylamine (304 mg, 3 mmol),[(Bt) 2 * Ir * P (nBu) 3] OTf (9.6 mg, 0.01 mmol, 1.0 mol%),Add 2.0mL xylene;The reaction solution was reacted at 155 C for 10 h,The resulting solution was separated on a silica gel column from 200 to 300 mesh (eluent 1:10 ethyl acetate / petroleum ether)After removal of the solvent,To get the product.Yield: 78%.

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, 5049-61-6, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Jingnan University; Zhang, Songlin; Fan, Huijun; Zhang, Donghui; Wang, Dawei; Ding, Yuqiang; (6 pag.)CN104710257; (2017); B;,
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. 5049-61-6, name is Pyrazin-2-amine, A new synthetic method of this compound is introduced below., 5049-61-6

Pyrazin-2-amine (11.3 g, 118.9 mmol) was dissolved in acetonitrile (100 mL) and Nchlorosuccinimide(NCS, 15.8 g, 118.9 mmol.) was added slowly inportions. Then, the reaction mixture was heated up to 40 and stirreduntil the amount of the main product did not increase anymore. Thesolution was filtered through Celite and the filter cake was washed byEA. The combined filtrate was washed by saturated aqueous NaHCO3solution (30 mL¡Á3) and brine, dried over anhydrous Na2SO4 anddecolorized by active charcoal. The mixture was filtered andconcentrated in vacuo. The precipitate was collected by filtration, andthe filtrate was purified on silica gel. A total of 8.4 g (yield 55%) wasobtained for compound 11b. 1H NMR (400 MHz, CDCl3): delta 8.01 (d, 1H,J=1.4 Hz), 7.76 (d, 1H, J=1.4 Hz), 4.57 (s, 2H).

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:
Article; Guo, Shuang; Xu, Mingshuo; Guo, Qi; Zhu, Fuqiang; Jiang, Xiangrui; Xie, Yuanchao; Shen, Jingshan; Bioorganic and Medicinal Chemistry; vol. 27; 5; (2019); p. 748 – 759;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding some certain compound to certain chemical reactions, such as: 5049-61-6, name is Pyrazin-2-amine, 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 5049-61-6. 5049-61-6

A 500ml three-neck flask, was added 2-amino pyrazine (19g, 0.2mol), dichloromethane (200ml) and pyridine (50ml) mixed solution at room temperature was slowly added dropwise bromine (67.2g, 0.42mol) in dichloro methane (100ml) solution, stirred at room temperature 4h, the reaction system was added to 100ml of water, stirred for 2h, the organic layer was washed with water (100ml ¡Á 3), the organic phase was moved to a flask with silica gel, and activated charcoal is heated at reflux for 1h, suction , the solvent was distilled off under reduced pressure, the resulting solid was added hexane (45 ml of) and refluxed for 2h and filtered while hot, and dried to give a yellow solid 39.4g, yield 77.8%.

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 Pyrazin-2-amine.

Reference:
Patent; Hubei University of Technology; Liu, Mingxing; Jiang, Weidong; Wang, Wanxia; (6 pag.)CN105622526; (2016); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, 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. 5049-61-6, name is Pyrazin-2-amine, A new synthetic method of this compound is introduced below.

Step 1: Imidazo[1,2-a]pyrazine A round bottom set up with reflux condenser was charged with pyrazin-2-amine (1000 mg, 10.52 mmol), 2-chloroacetaldehyde (-50% wt) (2.03 ml, 31.55 mmol), and EtOH (23 mL) and heated under reflux overnight. Next day LC/MS showed completion. The mixture was concentrated and passed through a plug of silica (solvent used: 1% MeOH/DCM) to afford imidazo[1,2-a]pyrazine as off-white solid. MS [M+H]=120.1; Calc’d for C6H5N3: 119.1

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; CEE, Victor J.; DEAK, Holly L.; DU, Bingfan; GEUNS-MEYER, Stephanie D.; HUA, Zihao; MARTIN, Matthew W.; MARX, Isaac; NGUYEN, Hanh Nho; OLIVIERI, Philip R.; PANTER FABER, Kathleen; ROMERO, Karina; SCHENKEL, Laurie; WHITE, Ryan; US2014/336182; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, Name is Pyrazin-2-amine, 5049-61-6, 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.

Step 1 Imidazo[1,2-a]pyrazine-2-carboxylic acid ethyl ester Ethyl bromopyruvate (62.9 g) was added to the DME (258 mL) solution of 2-aminopyrazine (24.8 g) at room temperature and stirred for 2.5 h. The reaction mixture was cooled to 0 C. and stirred for 30 min to afford a pale brown precipitate. The precipitate was filtered and washed with Et2O to give pale brown crystals. The suspension of the precipitate (66.1 g) in EtOH (1.29 L) was heated at reflux temperature to turn to clear solution. After refluxing for 2h, the reaction mixture was concentrated under reduced pressure, then mixed with CHCl3 and saturated NaHCO3aq. The mixture was filtered through a pad of Celite and the separated organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCl3-MeOH (99/1~97/3), and collected fractions were concentrated under reduced pressure followed by recrystallization from CHCl3-Et2O. The titled compound was obtained as pale pink crystals. Yield: 10.9 g, 22%). 1H NMR(CDCl3) d 1.46(t, 3H, J=7.2 Hz), 4.49(q, 2H, J=7.2 Hz), 7.96(d, 1H, J=4.7 Hz), 8.08(dd, 1H, J=1.2, 4.7 Hz), 8.26(s, 1H), 9.21(d, 1H, J=1.2 Hz).

Statistics shows that Pyrazin-2-amine is playing an increasingly important role. we look forward to future research findings about 5049-61-6.

Reference:
Patent; Wyeth; US2004/132708; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, 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. 5049-61-6, name is Pyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows.

Ethyl bromopyruvate (62.9 g) was added to the DME (258 mL) solution of 2-aminopyrazine (24.8 g) at room temperature and stirred for 2.5 h. The reaction mixture was cooled to 0 C. and stirred for 30 min to afford a pale brown precipitate. The precipitate was filtered and washed with Et2O to give pale brown crystals. The suspension of the precipitate (66.1 g) in EtOH (1.29 L) was heated at reflux temperature to turn to clear solution. After refluxing for 2 h, the reaction mixture was concentrated under reduced pressure, then mixed with CHCl3 and saturated NaHCO3aq. The mixture was filtered through a pad of Celite and the separated organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCl3-MeOH (99/1~97/3), and collected fractions were concentrated under reduced pressure followed by recrystallization from CHCl3-Et2O. The titled compound was obtained as pale pink crystals. Yield: 10.9 g, 22%). 1H NMR(CDCl3)delta d 1.46(t, 3H, J=7.2 Hz), 4.49(q, 2H, J=7.2 Hz), 7.96(d, 1H, J=4.7 Hz), 8.08(dd, 1H, J=1.2, 4.7 Hz), 8.26(s, 1H), 9.21 (d, 1H, J=1.2 Hz).

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; Wyeth; US2006/276445; (2006); A1;,
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. 109-08-0

Compound 16: (E)-2-[2-(Pyridin-2-yl)vinyl]pyrazine hydrochloride: s-Butyl lithium (2.5 M in hexanes, 4.8 mL, 12.0 mmol, 1.2 eq.) was added dropwise to a solution of diisopropylamine (1.83 mL, 1.32 g, 13.0 mmol, 1.3 eq.) in dry tetrahydrofuran (25 mL) at -78 ¡ãC. The mixture was stirred at -78 ¡ãC for 10 min and 2-methylpyrazine (0.91 mL, 0.94 g, 10.0 mmol, 1.0 eq.) was added dropwise. The resulting mixture was stirred at -78 ¡ãC for a further 30 min. 2-Pyridinecarboxaldehyde (0.96 mL, 1.07 g, 10.0 mmol, 1.0 eq.) was added dropwise and the mixture was allowed to slowly warm up to room temperature over 1 h while stirring. The reaction was quenched by addition of water (10 mL). The pH was adjusted to -10 by careful addition of cone. HCl and then the mixture was extracted with dichloromethane (2 x 25 mL). The combined organic extracts were washed with brine (25 mL), dried over sodium sulfate and evaporated in vacuo. The crude product was purified by column chromatography (Si02, 1:9 methanol-ethyl acetate) to provide 2-(pyrazin-2-yl)-1-(pyridin-2-yl)ethanol (1.08 g, 54percent yield) as a clear yellow oil. p-Toluenesulfonyl chloride (1.12 g, 5.9 mmol, 1.1 eq.) was added to a stirred solution of 2- (pyrazin-2-yl)-1-(pyridin-2-yl)ethanol (1.08 g, 5.4 mmol, 1.0 eq.) and triethylamine (2.24 mL, 1.63 g, 16.1 mmol, 3.0 eq.) in dichloromethane (25 mL). The mixture was stirred at room temperature for 23 h. The mixture was washed with aqueous NaOH (15percent, 25 mL), water (25 mL) and brine (25 mL). The organic layer was dried over sodium sulfate and evaporated in vacuo. The crude product was purified by column chromatography (Si02, 1:9 methanol-ethyl acetate) providing a mixture of 2-(pyrazin-2-yl)-1-(pyridin-2-yl)ethyl 4-methylbenzenesulfonate and (E)-2-(2-(pyridin-2-yl)vinyl)pyrazine (0.54 g). l,8-Diazabicyclo[5.4.0]undec-7-ene (0.45 mL, 0.46 g, 3.0 mmol, 2.0 eq.) was added dropwise to a stirred solution of 2-(pyrazin-2-yl)-1-(pyridin-2-yl)ethyl 4-methylbenzenesulfonate (0.54 g, 1.5 mmol, 1.0 eq.) in dichloromethane (10 mL). The mixture was stirred at room temperature for 4 h. The mixture was evaporated in vacuo and the crude product was purified by column chromatography (SiO2, ethyl acetate) providing (E)-2-(2-(pyridin-2-yl)vinyl)pyrazine (0.50 g, 100percent) as a white solid. A solution of hydrochloric acid (2.0 M in diethyl ether, 0.65 mL, 1.3 mmol, 1.2 eq.) was added dropwise to a stirred suspension of (E)-2-(2-(pyridin-2-yl)vinyl)pyrazine (0.20 g, 1.1 mmol, 1.0 eq.) in dry diethyl ether (7.5 mL). The mixture was stirred at room temperature for 1 h and then the solids removed by filtration. The product was washed with diethyl ether (3 x 10 mL) and then dried in vacuo to provide (E)-2-[2-(pyridin-2-yl)vinyl]pyrazine hydrochloride (0.21 g, 83percent yield) as a fine white solid; 1H NMR (400 MHz, DMSO-d6) delta 7.78 (t, J = 7.0 Hz, 1H, Ar), 7.99 (d, J = 16.0 Hz, 1H, C=CH), 8.11 (d, J = 16.0 Hz, 1H, C=CH), 8.25 (d, J = 8.0 Hz, 1H, Ar), 8.38 (t, J = 8.0 Hz, 1H, Ar), 8.65 (d, J = 2.5 Hz, 1H, Ar), 8.75 (t, J = 2.0 Hz, 1H, Ar), 8.79 (d, J = 5.0 Hz, 1H, Ar), 8.88 (d, J = 2.0 Hz, 1H, Ar).

Statistics shows that 109-08-0 is playing an increasingly important role. we look forward to future research findings about 2-Methylpyrazine.

Reference:
Patent; UNIVERSITY COLLEGE DUBLIN – NATIONAL UNIVERSITY OF IRELAND, DUBLIN; THE PROVOST, FELLOWS, FOUNDATION SCHOLARS, AND THE OTHER MEMBERS OF BOARD, OF THE COLLEGE OF THE HOLY AND UNDIVIDED TRINITY OF QUEEN ELIZABETH, NEAR DUBLIN; KENNEDY, Breandan; REYNOLDS, Alison; O’SULLIVAN, Jacintha; BAXTER, Andrew, Douglas; WO2015/107122; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

2423-65-6, These common heterocyclic compound, 2423-65-6, name is Pyrazine 1-oxide, 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.

General Procedure 2:; Palladium-Catalyzed Direct Arylation with Aryl Chlorides and Bromides.; To a dried flask was added the diazine N-oxide (1.0 to 3.0 equiv.), K2CO3 (2.0 equiv.), Pd(OAc)2 (5 mol %) and HP(t-Bu)3BF4 (15 mol %). If the arylhalide is a solid, it is added at this point (1.0 equiv.). The flask and its contents were then purged under nitrogen for 10 minutes. If the aryl halide is a liquid, it is added via syringe after purging, followed by the addition of degassed dioxane (to produce a reaction concentration of 0.3 M relative to the halide). The reaction mixture was then heated at 110 C. until the reaction was complete, after which the volatiles were removed under reduced pressure and the residue was purified via silica gel column chromatography.2-Styrylpyrazine N-oxide (Table 4, Entry 12) Synthesised according to general procedure 2. Purification via silica gel column chromatography using 100% DCM, then a mixture of 10% Acetone/DCM gave a brownish solid, 32% yield with 2 eq. of the N-oxide and 40% yield with 3 eq. of the N-oxide). 1H NMR (300 MHz, CDCl3, 293K, TMS): delta 8.82 (1H, s), 8.31-8.22 (1H, m), 8.14-8.11 (1H, m), 7.72 (1H, d, J=16.5 Hz), 7.62 (2H, dd, J=3.0 and 7.8 Hz), 7.53 (1H, d, J=16.5 Hz), 7.45-7.34 (3H, m) 13C NMR (75 MHz, CDCl3, 293K, TMS): 145.8, 143.9, 136.7, 135.7, 133.9, 129.5, 128.9, 128.4, 127.5, 115.6.

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 2423-65-6.

Reference:
Patent; University of Ottawa; US2008/132698; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem