Pyrazines

Electric Literature of 345311-03-7, A common heterocyclic compound, 345311-03-7, name is tert-Butyl 5,6-dihydroimidazo[1,2-a]pyrazine-7(8H)-carboxylate, molecular formula is C11H17N3O2, 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.

1,1-Dimethylethyl 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazin-7-carboxylate (Description 163, 505 mg, 2.26 mmol) in dichloromethane (2.5 mL) was added to stirred, cooled (0 C.) trifluoroacetic acid (5 mL) and the mixture was stirred at 0 C. for 15 minutes, then at room temperature for 45 minutes. The solvent was evaporated under reduced pressure to give the title compound. m/z (ES+) 124 (M+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; Castro Pineiro, Jose Luis; Dinnell, Kevin; Elliott, Jason Matthew; Hollingworth, Gregory John; Shaw, Duncan Edward; Swain, Christopher John; US2003/236250; (2003); 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. 43029-19-2, name is 3-Aminopyrazin-2(1H)-one, A new synthetic method of this compound is introduced below., Computed Properties of C4H5N3O

General procedure: The pyrazin-2(1H)-one base (11a, 14, 19, 20, 21 or 23) (2 mmol)was added in 1,1,1,3,3,3-hexamethyl-disilazane (HMDS, 10 mL) andheated at 120 for 3 h. Then, the solvent was removed in vacuo asmuch as possible and the obtained residue was dissolved or suspendedin DCM (15 mL), followed by the addition of sugar donor (B or C,2.4 mmol, 1.2 eq.). SnCl4 (2.0 mmol, 1.0 eq.) was added dropwise to thesolution in an ice bath and the reaction mixture was stirred overnight atrt. The solution was diluted with DCM (50 mL), washed with water(20 mL×2), dried over Na2SO4 and concentrated in vacuum. Thecrude residue was purified by silica gel column chromatography to giveintermediates 24a-24e and 27a-27c, which were subsequently treatedwith K2CO3 (2 mmol, 2 eq.) in MeOH (15 mL) to give nucleosides 25 a-25e and 28a-28c.

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

Electric Literature of 186534-02-1,Some common heterocyclic compound, 186534-02-1, name is 3,5,6-Trimethylpyrazine-2-carbaldehyde, molecular formula is C8H10N2O, 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: Take 3,5,6-trimethylpyrazine-2-carbaldehyde (0.15 g, 1 mmol),Dissolved in 10mL of absolute ethanol,10 mL of a solution of substituted acetophenone (1 mmol) in ethanol was added dropwise.Stir for 5 min under ice bath conditions.Add 2.4 mL of 20% NaOH solution dropwise.Ice bath reaction for 0.3h,TLC detects the reaction completely,Add 10% dilute hydrochloric acid to adjust the pH to 5,Add 100mL of water,Filter under reduced pressure,The target compound is obtained by rapid column chromatography.Further, it was subjected to double solvent recrystallization in methanol-water to obtain the target compound Z1-Z16.

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

Reference:
Patent; Shandong University; Liu Xinyong; Zou Jinmi; Zhan Peng; (14 pag.)CN108484511; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 4430-75-5, name is Octahydro-2H-pyrido[1,2-a]pyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. SDS of cas: 4430-75-5

1-fluoro-2-nitrobenzene (1.2 g, 8.56 mmol),Octahydro-1H-pyrido[1,2-a]pyrazine (1.0 g, 7.13 mmol), N,N-diisopropylethylamine (1.9 mL, 10.7 mmol) was added to N,N-dimethyl In formamide (20 mL),The reaction was heated to 90 C under nitrogen for 4 hours.After completion of the reaction, the mixture was cooled to room temperature, and the reaction mixture was diluted with water (80 mL)The organic phases were combined and washed successively with water (50 mL) and brine (50 mL).Dry over anhydrous sodium sulfate, and distill off the solvent under reduced pressure.The resulting crude product was purified by silica gel column chromatography (petroleum ether: ethyl acetate (V: V) = 5: 1) to give further title compound (yellow oil, 1.74g, 93.4%).

The synthetic route of 4430-75-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Guangdong Dongyangguang Pharmaceutical Co., Ltd.; Jin Chuanfei; Du Changfeng; Zhang Yingjun; (29 pag.)CN108409729; (2018); A;,
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. 1458-01-1, name is Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., Formula: C6H7ClN4O2

A mixture of methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (100 g; 494 mmol), methanol (1 l) and NaOH (6 mol/l in water; 240 mL; 1.44 mol) is refluxed for 3 h. The mixture is allowed to cool to r.t. and then neutralized by addition of hydrochloric acid (6 mol/l in water; approx. 240 mL). Water (200 mL) is added. The precipitate formed is filtered off with suction, washed with water and dried at 60° C. C5H5ClN4O2 ESI Mass spectrum: m/z=189 [M+H]+; m/z=187 [M-H]-

The synthetic route of 1458-01-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; BOEHRINGER INGELHEIM INTERNATIONAL GMBH; KLEY, Joerg; HECKEL, Armin; US2014/323447; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 32111-21-0,Some common heterocyclic compound, 32111-21-0, name is 2-Iodopyrazine, molecular formula is C4H3IN2, 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 9 A flask was charged with pinacol borobate (383.0 mg, 1.0 mmol), iodopyrazole (226.6 mg, 1.1 mmol), Pd(OAc)2 (11.2 mg, 0.05 mmol), TFP (46.4 mg, 0.2 mmol), K2CO3 (690.0 mg, 5 mmol), water (3 mL) and DME (2 mL). After 3 vacuum/argon cycles, the resulting mixture was heated to 80 C. 45 min later, HPLC revealed that all boronate disappeared. The area ratio of C-H, coupling product and dimer was about 3.3:85.3:11.4 on HPLC. After the reaction mixture was cooled down to room temperature, EtOAc (5 mL) was added. The aqueous layer was separated and extracted with EtOAc (2*10 mL). The combined organic extracts were washed with brine (10 mL), dried over Na2SO4, and concentrated in vacuo. The crude product was purified via silica gel chromatography to afford the indole (0.27 g, 81%). 1H NMR (300 HMz, CDCl3) delta 8.77 (2H, bs), 8.60 (1H, s), 8.16 (1H, s), 7.82-7.76 (2H, m), 3.96 (3H, s), 3.78 (3H, s), 3.20 (1H, m), 2.08-1.92 (6H, m), 1.72-1.69 (2H, m); 13C NMR (100 HMz, CDCl3) delta 168.0, 147.4, 146.6, 144.4, 143.2, 138.0, 135.3, 129.0, 124.2, 120.5, 120.3, 120.0, 112.4, 52.0, 37.3, 33.6, 31.3, 26.5.

The synthetic route of 32111-21-0 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Boehringer Ingelheim International GmbH; US2006/183752; (2006); 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. 2423-65-6, name is Pyrazine 1-oxide, A new synthetic method of this compound is introduced below., Computed Properties of C4H4N2O

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-p-Tolylpyrazine N-oxide (81) Synthesised according to general procedure 2 employing the corresponding aryl bromide and chloride or 60 with the corresponding aryl iodide. Purification via silica gel column chromatography using 100% DCM then a mixture of 20% Acetone/DCM gave a white solid, 72% (from the bromide), 75% (from the chloride) and 77% (from the iodide). 1H NMR (300 MHz, CDCl3, 293K, TMS): delta 8.63 (1H, s), 8.37 (1H, s), 8.20 (1H, s), 7.72 (2H, d, J=8.1 Hz), 7.33 (2H, d, J=7.8 Hz), 2.43 (3H, s). 13C NMR (75 MHz, CDCl3, 293K, TMS): 148.2, 145.2, 144.6, 140.8, 134.2, 129.8, 129.0, 125.9, 21.5.

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; University of Ottawa; US2008/132698; (2008); 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. 330786-09-9, name is Methyl 3,5-dichloropyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., HPLC of Formula: C6H4Cl2N2O2

b) Synthesis of 3-chloro-5-morpholin-4-yl-pyrazine-2-carboxylic acid methyl ester To a solution of 3,5-dichloro-pyrazine-2-carboxylic acid methyl ester (1.20 g, 5.82 mmol) in dimethylformamide (12 ml) is added potassium carbonate (0.96 g, 6.98 mmol) at RT followed by the addition of morpholine (0.5 ml, 5.82 mmol). The resulting mixture is stirred at RT for 3 h. After completion of the reaction, the mixture is diluted with water (20 ml) and extracted with EtOAc (3*30 ml). The combined organic layers are washed with water (30 ml), brine (30 ml), dried over anhydrous sodium sulfate and evaporated in vacuo to get the crude product, which is purified by column chromatography (silica gel, 10% acetone/hexane) to yield 3-chloro-5-morpholin-4-yl-pyrazine-2-carboxylic acid methyl ester (1.10 g, 4.28 mmol, 73%).

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; GRUeNENTHAL GMBH; LUCAS, Simon; Kuehnert, Sven; Bahrenberg, Gregor; Schroeder, Wolfgang; US2014/148454; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

38557-72-1, 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. 38557-72-1, name is 2-Chloro-3,5-dimethylpyrazine, A new synthetic method of this compound is introduced below.

Step 1: Synthesis of 3,5-Dimethyl-2-(dibenzofuran-4-yl)pyrazine (abbreviation: Hdm4 dbfpr) First, into a recovery flask equipped with a reflux pipe were placed 1.51 g of 2-chloro-3,5-dimethylpyrazine, 2.25 g of 4-dibenzofuranylboronic acid, 1.12 g of sodium carbonate, 0.048 g of bis(triphenylphosphine)palladium(II) dichloride (abbreviation: Pd(PPh3)2Cl2), 15 mL of water, and 15 mL of acetonitrile, and the air inside the flask was replaced with argon. Heating was performed by microwave irradiation (2.45 GHz, 100 W) of this reaction container for 10 minutes, so that reaction occurred. After that, water was added to this reaction solution, and extraction with dichloromethane was carried out. A solution of the obtained extract was washed with water and dried over magnesium sulfate. After the drying, the solution was filtered. After the solvent of this solution was distilled, the obtained residue was washed with methanol, so that the pyrazine derivative which was the object of the synthesis, Hdm4 dbfpr, was obtained (a pale orange powder in a yield of 65%). Note that a microwave synthesis system (Discover, produced by CEM Corporation) was used for the microwave irradiation. The synthesis scheme of Step 1 is illustrated in the following scheme (x-1).

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; Semiconductor Energy Laboratory Co., Ltd.; US2012/104373; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 1458-18-0,Some common heterocyclic compound, 1458-18-0, name is Methyl 3-amino-5,6-dichloropyrazine-2-carboxylate, molecular formula is C6H5Cl2N3O2, 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.

Methyl 3-amino 5,6-dichloro-2-pyrazinecarboxylate (10 g, 45 mmol) was placed in a three-necked round bottom flask flushed with nitrogen, equipped with a bubbler and a gas condensor. The round bottomedflask and condensor were cooled to -80 C using a dry ice in acetone bath. Gaseous ammonia (500 mL) was condensed into the flask over a period of 1.5 h. Thereaction mixture was allowed to warm to reflux and maintained at reflux for a period of10 h. The ammonia then was allowed to evaporate from the flask (fume hood!) and the solid obtained was dried under high vacuum overnight to provide 3-amino-5,6-dichloro-2-pyrazinecarboxamide 4 (9.5 g, 100%) as solid,

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 3-amino-5,6-dichloropyrazine-2-carboxylate, its application will become more common.

Reference:
Article; Massey, Archna P.; Harley, William R.; Pasupuleti, Nagarekha; Gorin, Fredric A.; Nantz, Michael H.; Bioorganic and Medicinal Chemistry Letters; vol. 22; 7; (2012); p. 2635 – 2639;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem