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. 22047-25-2, name is Acetylpyrazine, A new synthetic method of this compound is introduced below., Formula: C6H6N2O

HL was prepared similarly to the published results [37], whereasempolying 2-acetylpyrazine instead of 2-acetylpyridine. In detail, amixture of 2-acetylpyrazine (1.22 g, 10 mmol) and isonicotinoylhydrazide (1.37 g, 10 mmol) in methanol (30 ml) were refluxing for4 h. The pale-yellow solid was precipitated, then filtered andwashed three times by methanol. Yield: 1.54 g (64%). Elementalanalysis for HL (C12H11N5O) (%): Calcd: C: 59.74; H: 4.60; N: 29.03;Found: C: 59.68; H: 4.47; N: 29.24. 1H NMR (400 MHz, CDCl3) d: 9.14(1H)/8.80 (2H)/8.52 (2H)/7.71e7.72 (2H) for AreH, 2.44 (3H, s,eCH3). FT-IR (cm1): n(NH) 3039, n(C]O) 1670 n(C]N) 1555. 13CNMR (100 MHz, CDCl3): d 165.1, 150.3, 149.8, 146.6, 143.2, 145.7,144.4, 140.9, 122.8, 25.9.

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; Xu, Jun; Zhou, Tao; Xu, Zhou-Qing; Gu, Xin-Nan; Wu, Wei-Na; Chen, Hong; Wang, Yuan; Jia, Lei; Zhu, Tao-Feng; Chen, Ru-Hua; Journal of Molecular Structure; vol. 1128; (2017); p. 448 – 454;,
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.

Reference Example 17-2 Preparation of N’-(3-chloropyrazin-2-yl)-1,2,3,4-tetrahydronaphthalene-1-carbohydrazide racemate To a 30 mL cylindrical flask were added 2-chloro-3-hydrazinylpyrazine (470 mg), tetrahydrofuran (5 mL), 1,2,3,4-tetrahydronaphthalene-1-carboxylic acid (573 mg), triethylamine (550 muL), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (700 mg) under argon atmosphere, and the resulting mixture was stirred at room temperature for 3 hours. To the reaction mixture were additionally added 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (350 mg) and triethylamine (280 muL), and the resulting mixture was stirred at room temperature for additional 2 hours. The reaction mixture was added to a saturated aqueous solution of sodium hydrogen carbonate, and the resulting mixture was extracted with ethyl acetate. The resulting organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resulting residues were subjected to silica gel column chromatography (Rf value=0.23 (solvent: hexane/ethyl acetate=1:1)) (Silica L (40 g), hexane/ethyl acetate=52/48 to 31/69) using YAMAZEN medium pressure preparative column, and the fractions comprising the target compound were concentrated under reduced pressure to give the title compound (308 mg) (yield 31%) as a white solid. MS(CI) m/z: 303/305 [M+H]+

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; MITSUBISHI TANABE PHARMA CORPORATION; UBE INDUSTRIES, LTD.; NAKAJIMA, Tatsuo; HAYASHI, Norimitsu; ISHIZAWA, Kouhei; TSUZAKI, Yasunori; IWAMURA, Ryo; TSUBOIKE, Kazunari; US2019/185479; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 36070-79-8, name is 6-Chloropyrazine-2-carboxamide, 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. Formula: C5H4ClN3O

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.

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

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: 622392-04-5, name is 2-Bromo-5-iodopyrazine, 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 622392-04-5, SDS of cas: 622392-04-5

To a solution of 2-bromo-5-iodopyrazine (500 mg, 1.76 mmol), phenylacetylene (224 mg, 241 mu, 2.19 mmol, 1.25 equiv.), triethylamine (533 mg, 734 mu, 5.27 mmol, 3 equiv.),bis(triphenylphosphine)palladium (II) chloride (73.9 mg, 0.105 mmol, 0.06 equiv.) and triphenyl-phosphine (13.8 mg, 0.053 mmol, 0.03 equiv.) in 10 ml of THF was added under an Argon atmosphere copper (I) iodide (10.0 mg, 0.053 mmol, 0.03 equiv.). The suspension was warmed to 60C overnight, taken up in 5 ml of ethyl acetate and adsorbed on 4 g of silica.Purification by flash chromatography on silicagel using a 2: 1 ethyl acetate/heptane mixture yielded the title compound as a light brown solid (107 mg, 23% yield). The material was directly used in the next step without further characterization.

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

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; GREEN, Luke; GUBA, Wolfgang; JAESCHKE, Georg; JOLIDON, Synese; LINDEMANN, Lothar; RICCI, Antonio; RUEHER, Daniel; STADLER, Heinz; VIEIRA, Eric; WO2011/128279; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 181284-14-0, name is 3-Chloro-5-methylpyrazine-2-carbonitrile, molecular formula is C6H4ClN3, 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. HPLC of Formula: C6H4ClN3

To a solution of 3-chloro-5-methylpyrazine-2-carbonitrile (19 g, 0.12 mol) and methyl 2-mercaptoacetate (14 g, 0.13 mol) in THF (200 mL) was added NaH (60% dispersion in mineral oil; 7.5 g, 0.19 mol) in small portions at 0 C. The reaction mixture was stirred overnight at RT and then water (200 mL) was carefully added to quench the reaction. The resulting mixture was extracted with ethyl acetate (2 x 300 mL). The combined organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified via silica gel column chromatography eluting with petroleum ether / EtOAc (90: 10 to 70:30) to afford methyl 7-amino-3-methylthieno[2,3-6]pyrazine-6-carboxylate (20 g, 72%> yield) as a light yellow solid. 1H NMR (400 MHz, DMSO-fifc): delta 8.68 (s, IH), 7.10 (br s, 2H), 3.83 (s, 3H), 2.65 (s, 3H)

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 181284-14-0, its application will become more common.

Reference:
Patent; FORMA THERAPEUTICS, INC.; GUERIN, David Joseph; BAIR, Kenneth W.; CARAVELLA, Justin A.; IOANNIDIS, Stephanos; LANCIA, JR., David R.; LI, Hongbin; MISCHKE, Steven; NG, Pui Yee; RICHARD, David; SCHILLER, Shawn E.R.; SHELEKHIN, Tatiana; WANG, Zhongguo; (113 pag.)WO2017/139779; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 951626-95-2,Some common heterocyclic compound, 951626-95-2, name is Ethyl 4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate, molecular formula is C9H11N3O3, 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 ethyl 4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate (30 mg, 0.143 mmol) in acetonitrile (1 mL) was added cesium carbonate (93.4 mg, 0.287 mmol) and benzyl bromide (25.6 muL, 0.215 mmol). The reaction mixture was stirred overnight at 70 C. Upon cooling to room temperature, the cesium carbonate was removed by filtration and the solvent evaporated under reduced pressure to afford crude Intermediate 32. LC-MS: (AA) ES+300.

The synthetic route of 951626-95-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Millennium Pharmaceuticals, Inc.; US2011/251184; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 24241-18-7, 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. 24241-18-7 name is 2-Amino-3,5-dibromopyrazine, 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.

[00195] Step 1 : (Trimethylsilyl)acetylene (1.9 g, 2.7 niL, 18.8 mmol) was added dropwise to a solution of 3,5-dibromopyrazin-2-amine (5.0 g, 19.8 mmol), triethylamine (10.0 g, 13.8 mL, 98.9 mmol), copper (I) iodide (452 mg, 2.37 mmol) and Pd(PPh3)4 (1.14 g, 0.99 mmol) in DMF (25 mL) and the resulting solution stirred at room temperature for 30 min. The reaction was diluted with ethyl acetate and water and the layers separated. The aqueous layer was extracted further with ethyl acetate and the combined organics washed with water, dried over MgS04, and concentrated in vacuo. The mixture was purified via silica gelchromatography (0-15% ethyl acetate/hexanes) to afford 5-bromo-3-((trimethylsilyl) ethynyl)pyrazin-2-amine as a yellow solid (3.99g, 75% yield). ¾ NMR (400 MHz, DMSO- d6) delta 0.30 (s, 9H), 8.06 (s, 1H); MS (ES+) 271.82

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

Reference:
Patent; VERTEX PHARMACEUTICALS INCORPORATED; CHARRIER, Jean-Damien; BINCH, Haley, Marie; HURLEY, Dennis, James; CLEVELAND, Thomas; JOSHI, Pramod; FANNING, Lev Tyler, Dewey; PINDER, Joanne; O’DONNELL, Michael; VIRANI, Anisa, Nizarali; KNEGTEL, Ronald, Marcellus Alphonsus; DURRANT, Steven, John; YOUNG, Stephen, Clinton; PIERRE-HENRI; KAY, David; REAPER, Philip, Michael; WO2011/143426; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 109-08-0,Some common heterocyclic compound, 109-08-0, name is 2-Methylpyrazine, molecular formula is C5H6N2, 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.

4-Bromobenzaldehyde (2.30 g, 12.5 mmol) and 2-methylpyrazine (1.17 g, 12.5 mmol)were dissolved in DMSO (7.5 mL). Powdered KOH (2.75 g, 50.0 mmol) was added and the reaction mixture was stirred atroom temperature for 8 h and then poured into 200 mL of water. The resulting precipitate was filtered and washed with water (2 x 150 mL). The crude product was crystallized from DCM/nheptaneto afford 10 (2.01 g, 62percent) as a brownish yellow solid. Mp:110-112 °C 1H NMR (300 MHz, CDCl3): delta (ppm): 7.14 (d, 1H,3J = 16.2 Hz), 7.45 (d, 2H, 3J = 8.7 Hz), 7.52 (d, 2H, 3J = 3.4 Hz), 7.68(d, 1H, 3J = 16.2 Hz), 8.42 (d, 1H, 3J = 2.4 Hz), 8.54 (dd, 1H,3J 2.4 Hz, 4J = 1.2 Hz), 8.62 (d, 1H, 4J = 1.2 Hz). 13C NMR (75 MHz, CDCl3): delta (ppm): 123.0 (C), 124.7 (CH), 128.7 (CH), 132.0 (CH), 133.9(CH), 135.0 (C), 143.0 (CH), 143.8 (CH), 144.4 (CH), 150.9 (C). IR (ATR) nu: 3048, 1487, 1403, 1009, 964 cm-1 HR-MS MALDI (matrix DHB):m/z calculated for C12H1079BrN2 [+M2H]+ 262.0095, found 262.0102.

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

Reference:
Article; Cvejn, Daniel; Achelle, Sylvain; Pytela, Old?ich; Malval, Jean-Pierre; Spangenberg, Arnaud; Cabon, Nolwenn; Bure?, Filip; Robin-Le Guen, Francoise; Dyes and Pigments; vol. 124; (2016); p. 101 – 109;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 14508-49-7, 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. 14508-49-7, name is 2-Chloropyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

A mixture of 2-hydrazinopyrazine (820 mg, 7.45 mmol), prepared from 2-chloropyrazine and hydrazine using a procedure analogous to that described in the literature (P. J. Nelson and K. T. Potts, J. Org. Chem. 1962, 27, 3243, except that the crude product was extracted into 10% methanol/dichloromethane and filtered, and the filtrate was concentrated and purified by flash chromatography on silica gel, eluting with 100% ethyl acetate followed by 10% methanol in dichloromethane), TFA (2.55 g, 22.4 mmol), and polyphosphoric acid (10 mL) was heated to 140 C. with stirring for 18 h. The solution was added to ice and neutralized by the addition of ammonium hydroxide. The aqueous solution was extracted with ethyl acetate (3×), washed with brine, and dried over anhydrous magnesium sulfate. Concentration followed by flash chromatography (silica gel, 1:1 hexane:ethyl acetate, then 100% ethyl acetate) afforded the title compound as a solid (861 mg). 1H NMR (500 MHz, CDCl3) delta 8.17-8.20 (m, 2H), 9.54 (s, 1H). LC/MS (M+1) 189.

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

Reference:
Patent; Merck Sharp & Dohme Corp.; Edmondson, Scott D.; Fisher, Michael H.; Kim, Dooseop; Maccoss, Malcolm; Parmee, Emma R.; Weber, Ann E.; Xu, Jinyou; US2015/359793; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 41110-34-3, 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. 41110-34-3, name is Ethyl 5-methylpyrazine-2-carboxylate, This compound has unique chemical properties. The synthetic route is as follows.

Preparative Example 1 5.40 g of ethyl 5-methylpyrazine-2-carboxylate was dissolved in 54.0 mL of carbon tetrachloride, and 5.78 g of 1-bromosuccinimide and 267 mg of 2,2′-azobis(isobutyronitrile) were added thereto, followed by heating with reflux for 3 hours. The reaction liquid was left to be cooled to room temperature and then concentrated under reduced pressure, and the obtained residue was suspended in 100 mL of ethyl acetate and the insoluble materials were separated by filtration. The filtrate was washed with a saturated aqueous sodium hydrogen carbonate solution, water, and saturated brine, and then dried over anhydrous magnesium sulfate. The solvent was evaporated and the obtained residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1 to 1:1) to obtain 2.62 g of ethyl 5-(bromomethyl)pyrazine-2-carboxylate.

The chemical industry reduces the impact on the environment during synthesis Ethyl 5-methylpyrazine-2-carboxylate. I believe this compound will play a more active role in future production and life.

Reference:
Patent; Astellas Pharma Inc.; EP2305641; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem