Category: Pyrazines

These common heterocyclic compound, 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, 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. 55557-52-3

General procedure: In a degassed solution of DME/water 2:1 (12mLmmol-1 of diazine), was introduced S-Phos (10mol%) and Pd(OAc)2 (5mol%). The solution was heated at 80C for 10min and sodium carbonate (4equiv), the arylboronic species (1.05 or 1.50equiv) and 3-chloropyrazine-2-carbonitrile (1equiv) were added. The solution was then refluxed (15min or overnight) under argon. The resulting solution was filtrated on celite and washed with ethyl acetate and water. The aqueous phase was then extracted 3 times with ethyl acetate. The combined organic phases were washed with water, dried over MgSO4 and evaporated to dryness. The residue was purified by silica gel chromatography to give the desired product.

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 55557-52-3.

Reference:
Article; Fresneau, Nathalie; Dumas, Noe; Tournier, Benjamin B.; Fossey, Christine; Ballandonne, Celine; Lesnard, Aurelien; Millet, Philippe; Charnay, Yves; Cailly, Thomas; Bouillon, Jean-Philippe; Fabis, Frederic; European Journal of Medicinal Chemistry; vol. 94; (2015); p. 386 – 396;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 123-32-0 name is 2,5-Dimethylpyrazine, 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. 123-32-0

Intermediate 55 2-(chloromethyl)-5-methylpyrazine To a solution of 2,5-dimethylpyrazine (500 mg, 4.62 mmol) in carbon tetrachloride (7 mL) was added NCS (679 mg, 5.09 mmol) followed by BPO (20 mg) and the mixture was heated to 80 C for 6 hours. The mixture was diluted with DCM and extracted with saturated aqueous sodium sulfite solution and brine. The organic layer was dried and concentrated to give a crude product which was purified via silica gel chromatography eluting with petroleum ether/ ethyl acetate (1 :0 to 15: 1) to give 2-(chloromethyl)-5-methylpyrazine (133 mg, 20.19% yield) as yellow oil. LCMS retention time 0.557 min; LCMS MH+ 143.

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

Reference:
Patent; HYDRA BIOSCIENCES, INC.; CHENARD, Bertrand; GALLASCHUN, Randall; WO2014/143799; (2014); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 123-32-0, name is 2,5-Dimethylpyrazine, 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. 123-32-0

The method of preparing 3,6-dimethyl-2- (4-fluoro) benzoyl pyrazine, comprising the steps of:(1) 2,5-dimethyl pyrazine take 0.2mmol, 4- fluoro-benzoyl acid 0.4mmol, silver phosphate 0.02mmol, potassium persulfate 0.4mmol, 1.4mL was added dichloromethane, 0.6mL distilled water was added, and the mixture was placed in a reaction tube in 5mL, 40 oil bath was heated, reaction 24h, cooled to room temperature to obtain a reaction solution;(2) The step (1) the resulting reaction mixture was directly concentrated to give a concentrate, the concentrate with ethyl acetate / petroleum ether = 1/2 (v / v) as the developing solvent, separation by thin layer chromatography to give 34 mg desired product in 74% yield.

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 123-32-0.

Reference:
Patent; Henan Agricultural University; Wu Zhiyong; Zhao Mingqin; Li Yuan; (10 pag.)CN108101856; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

38557-72-1, Adding a certain compound to certain chemical reactions, such as: 38557-72-1, name is 2-Chloro-3,5-dimethylpyrazine, 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 38557-72-1.

0.39 g of 2-chloro-3,5-dimethylpyrazine, 0.87 g of 2-(3-diphenylaminophenyl)-1,3,2-dioxaborolane which was obtained in Step 1, 0.30 g of sodium carbonate, 0.013 g of bis(triphenylphosphine)palladium(II) dichloride (abbreviation: Pd(PPh3)2Cl2), 10 mL of water, and 10 mL of acetonitrile in a recovery flask equipped with a reflux pipe. The air in the flask was then replaced by argon. This reaction container was heated by microwave irradiation (2.45 GHz, 100 W) for 20 minutes. After that, the reaction container was cooled to 50 C. or lower. Then, water was added to the reaction solution, and the organic layer was subjected to extraction with dichloromethane. The obtained organic layer was washed with water and dried with magnesium sulfate. After the drying, the solution was filtered. The solvent of this solution was distilled, and the obtained residue was purified by silica gel column chromatography using a mixed solvent of dichloromethane and ethyl acetate as a developing solvent, thereby obtaining the objective pyrazine derivative Hdm5dpappr (white powder, 11% yield). Note that the microwave irradiation was performed using a microwave synthesis system (Discover, produced by CEM Corporation). The synthesis scheme of Step 2 is shown by (b-1).

According to the analysis of related databases, 38557-72-1, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Semiconductor Energy Laboratory Co., Ltd.; US2012/165523; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 5521-58-4, name is 5-Methylpyrazin-2-amine, 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 5521-58-4, 5521-58-4

DMF (2 drops) was added to a solution of3-{[(LS}1-methyl-2-(methyloxy)ethyl]oxy}-5- [(phenylmethyl)oxy]benzoic acid (6.0 g, 19.0 mmol) and oxalyl chloride (1.99 mL, 22.8 mmol) in DCM (40 mL) The mixture was stirred at ambient temperature for 2 hours and the DCM and excess oxalyl chloride evaporated in vacuo. The residual acid chloride was dissolved in DCM and added dropwise to 2-amino-5 methylpyrazine [Tett lett. 2002, 9287-90] (2.28 g, 19.8 mmol) and pyridine (2.56 mL, 38 mmol) in DCM (40 mL), at 0C. Stirred at ambient temperature for 24 hours. The DCM was evaporated in vacuo, and the residue partitioned between ethyl acetate (100 mL) and IN hydrochloric acid (50 mL). The ethyl acetate layer was washed sequentially with saturated aqueous sodium hydrogen carbonate (50 mL) and brine (50 mL), dried (MgS04), and evaporated in vacuo. The residue was chromatographed on silica, eluting with a gradient of 30-100% ethyl acetate in isohexane, to give the desired compound (7.6 g) ‘H NMR No. (CDC13): 1.32 (d, 3H), 2.55 (s, 3H), 3.40 (s, 3H), 3.50-3.62 (m, 2H), 4.60 (m, 1H), 5.10 (s, 2H), 6.75 (s, 1H), 7.09 (m, 1H), 7.13 (m, 1H), 7.32-7.46 (m, 5H), 8.13 (s, 1 H), 8.38 (s, 1H), 9.55 (s, 1H). m/z 408 (M+H)+

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, 5-Methylpyrazin-2-amine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2005/121110; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 1458-18-0

A. 2-Amino-5,6-dichloro-3-(hydroxymethyl)pyrazine To 70 ml of dry tetrahydrofuran there was added 2-amino-5,6-dichloro-3-(methoxycarbonyl)pyrazine (8.8 g; 0.04M), potassium borohydride (2.7 g; 0.05M), and lithium chloride (2.1 g; 0.05M), and the mixture was stirred at room temperature overnight (17 hours). The reaction mixture was then diluted with about 200 ml of water and chilled, after which the product crystallized, was filtered and dried (5.3 g).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1458-18-0, its application will become more common.

Reference:
Patent; Merck & Co., Inc.; US4507299; (1985); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

36070-80-1, The chemical industry reduces the impact on the environment during synthesis 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, I believe this compound will play a more active role in future production and life.

The starting 5-chloropyrazine-2-carboxylic acid (317 mg, 2 mmol) was converted to5-aminopyrazine-2-carboxylic acid (1) by substitution reaction with 25% (m/m) aqueous solutionof ammonia (3 mL). The reaction was carried out 10 mL microwave pressurized vials with stirring(reaction temperature: 100 C, reaction time: 30 min, power output: 80 W). The reaction was repeated20 times to yield reasonable quantity of the starting acid. Once the reaction was completed, the vials content was put onto Petri dish and heated above a water bath with intermittent stirring until a drysolid was obtained (ammonium salt of the product). To get the free acid form, the ammonium salt wasdissolved in water and drop-wise acidified with 10% hydrochloric acid to reach pH of 4. The mixturewas then left to cool down in room temperature for 5 min then kept in the fridge for 15 min. The formedfree acid crystals were filtered off by filtration paper with suction and left to dry overnight. After itwas dried, the resulting 5-aminopyrazine-2-carboxylic acid (1) was esterified in several microwavepressurized vials; 3 mL of anhydrous propanol and 2 drops of concentrated sulfuric acid were added to278 mg (2 mmol) of compound 1 in each vial. The esterification was carried out in microwave reactor(reaction temperature: 100 C, reaction time: 1 h, power output: 80 W). The completion of reaction wasmonitored by TLC in system hexane/ethyl acetate (EtOAc) (1:3). The ester was then purified by flashchromatography using gradient elution 40 to 100% EtOAc in hexane.

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

Reference:
Article; Bouz, Ghada; Juhas, Martin; Niklova, Pavlina; Jand?ourek, Ond?ej; Paterova, Pavla; Ek, Ji?i Janou; T?mova, Lenka; Kovalikova, Zuzana; Kastner, Petr; Dole al, Martin; Zitko, Jan; Molecules; vol. 22; 10; (2017);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

122-05-4, Name is Pyrazine-2,5-dicarboxylic acid, 122-05-4, 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.

Pyrazine-2,5-dicarboxylic acid (0.58 g; 3.42 mmol), anhydrous HOBt (0.69 g; 5.13 mmol) and l-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.98 g: 5.13 mmol) were added to 5 ml of DCM. 2-(5-(3,4-dichlorophenyl)furan-2-yl)- ethanamine hydrochloride (1.0 g; 3.42 mmol) and DIPEA (0.89 ml; 5.13 mmol) were dissolved in 5 ml of DCM and added dropwise to the previous mixture. The reaction mixture was stirred overnight after which pyrazine-2,5-dicarboxylic acid (0.58 g; 1.59 mmol) and DIPEA (0.60 ml; 3.42 mmol) were added and the mixture was again stirred for 5 h. Anhydrous HOBt (0.69 g; 5.13 mmol), l-(3-dimethylaminopropyl)-3- ethylcarbodiimide hydrochloride (0.98 g: 5.13 mmol) and DIPEA (0.89 ml; 5.13 mmol) were again added to drive the reaction to completion. After overnight stirring the mixture was diluted with 20 ml of DCM and washed with 3×10 ml water. The organic phase was dried over Na2S04, filtered and used as such without further purification.

Statistics shows that Pyrazine-2,5-dicarboxylic acid is playing an increasingly important role. we look forward to future research findings about 122-05-4.

Reference:
Patent; ORION CORPORATION; WOHLFAHRT, Gerd; TOeRMAeKANGAS, Olli; SALO, Harri; HOeGLUNG, Lisa; KARJALAINEN, Arja; KNUUTTILA, Pia; HOLM, Patrick; RASKU, Sirpa; VESALAINEN, Anniina; WO2011/51540; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 23611-75-8, name is Methyl 6-chloropyrazine-2-carboxylate, 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. 23611-75-8

Step 1 :Preparation of6-(6-chloropyrazin-2-yl)-N2,N?-bis (4,4-dfluorocyclohexyl)-1,3,5-triazine-2,4-diamine. To a mixture of methyl 6-chloropyrazine-2-carboxylate (300mg, 1. 74mmol) and N?,N5-di-(4,4-difluorocyclohexanamine)- biguanide (700 mg, 2.10 mmol)in MeOH (8 mL) was added MeONa (340 mg, 6.28 mmol).The reaction mixture was stirred at r.t. overnight, and then partitioned between EtOAc (30 mL) and 1120(3OmL). The organic layerwas separated, washed with brine (30 mL), dried over anhydrous Na2SO4, and concentrated and purified by standard methods to afford the desired product. ?H NIVIR (400MHz, DMSO-d6) 9.48 – 9.32 (m, 111), 8.93 (d,J811z, 111), 7.92 – 7.59 (m, 211), 4.15 -3.95(m, 211), 2.08 – 1.60(m, 1611).LCMS:m/z 460(M+H).

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, 23611-75-8, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; AGIOS PHARMACEUTICALS, INC.; KONTEATIS, Zenon D.; POPOVICI-MULLER, Janeta; TRAVINS, Jeremy M.; ZAHLER, Robert; CAI, Zhenwei; ZHOU, Ding; WO2015/3640; (2015); 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. 19838-08-5, name is 3-Methylpyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows., 19838-08-5

3-Methyl-pyrazin-2-ylamine (2) (109 mg, 1.0 mmol) , benzaldehyde (106 mg, 1.0 mmol) and 3-chloro- phenylisonitrile (138 mg, 1.0 mmol) were dissolved in a mixture of dry methanol (2.0 mL) and trimethyl orthofor- mate (2.0 mL) under argon. The mixture was stirred at 6O0C for 3 hours, then cooled to rt . An analytically pure sample of 3 was obtained from the crude product using preparative HPLC.

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; ESBATECH AG; WO2006/131003; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem