Pyrazines

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. 38557-72-1 name is 2-Chloro-3,5-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. 38557-72-1

Part 1, Step B: A mixture of 2-chloro-3,5-dimethylpyrazine (28.5 g, 0.2 mol), prepared above, CuO (0.8 g, 0.01 mol) and concentrated aqueous NH3 (28-30 %, 150 mL) was stirred in a sealed pressure vessel at 150 C for 3 days. After cooling, the mixture was concentrated to dryness and the residue was treated with ethyl acetate (500 mL), then stirred for 15 minutes and filtered. The precipitate was washed with additional ethyl acetate (about 1.5 L) until the starting material was no longer detected in the filtrate. The filtrates were combined and concentrated. The residue was chromatographed on a silica gel column (MeOH/CH2Cl2, 0-10%) to furnish a yellow/brownish solid (20.7 g, 84%). 1H NMR (500 MHz, CHLOROFORM-^) delta ppm 7.68 (1H, s), 2.46 (3H, s), 2.42 (3H, d, J=0.63 Hz).

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

Reference:
Patent; PTC THERAPEUTICS, INC.; CHEN, Guangming; DAKKA, Amal; KARP, Gary Mitchell; LI, Chunshi; NARASIMHAN, Jana; NARYSHKIN, Nikolai; WEETALL, Maria L.; WELCH, Ellen; ZHAO, Xin; WO2013/112788; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, molecular formula is C5H2ClN3, 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

Step 1. Preparation of N-(3-cyano-pyrazin-2-yl)-N-methyl-methane sulfonamide (B2-1): A solution of chloropyrazine-2-carbonitrile (4.2 g, 30.21 mmol) in acetonitrile (200 mL) at 25 C. was treated sequentially with Cs2CO3 (13.7831 g, 42.293 mmol) and N-methyl-methane sulfonamide (3.957 g, 36.25 mmol). The mixture was then heated to 80 C. After about 20 hours the mixture was cooled to 25 and filtered. The solids were washed with EtOAc (3*25 mL) and the combined filtrates were concentrated. The resultant residue was treated with water (50 mL) and extracted with EtOAc (3*75 mL). The combined organic layers were washed with water (50 mL), brine, dried over anhydrous sodium sulfate and concentrated. The resultant residue was purified by column chromatography (100-200 mesh silica gel; 40% EtOAc in petroleum ether as eluding solvent) to provide B2-1 as a pale brown liquid. Yield: 4.7 g, 73.43%). 1H NMR (CDCl3) delta: 8.92 (d, 2H), 3.4 (s, 3H) and 3.25 (s, 3H). Mass: (M+1) 213 calculated for C7H8N4O2S. (Note: The product contained unreacted N-methanesulfonamide as an impurity.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 55557-52-3, its application will become more common.

Reference:
Patent; Pfizer Inc.; US2009/54395; (2009); 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. 5049-61-6, name is Pyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows., 5049-61-6

To a stirred solution of pyrazin-2-amine (2.00 g, 21 .0 mmol) in CHCI3 (25 mL) was added NCS (3.65 g, 27.3 mmol) portionwise and the reaction mixture was stirred at room temperature for 6h. Progress of reaction was monitored by TLC. After completion, the reaction mixture was poured in to ice cold H20 (20 mL) and extracted with EtOAc (2 c 40 mL). The organic layer was separated, washed with brine (25 mL), dried over anhydrous Na2S04 and concentrated under vacuum. The crude obtained was purified by combi flash chromatography (20% EtOAc in hexane) to afford 3,5-dichloropyrazin-2-amine X-10a (1 .50 g) as an off-white solid. Yield: 37%. (0851) 1H NMR (400 MHz, DMSO-cfe) d 7.02 (brs, 2H), 8.06 (s, 1 H).

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; UCB PHARMA GMBH; PEGURIER, Cecile; PROVINS, Laurent; CARDENAS, Alvaro; LEDECQ, Marie; MUELLER, Christa E.; HOCKEMEYER, Joerg; EL-TAYEB, Ali; BOSHTA, Nader; RASHED, Mahmoud; (165 pag.)WO2019/243303; (2019); A1;,
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. 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. 36070-80-1

Preparation of Starting Material 5-chloro-N,N-dimethylpyrazine-2-carboxamide (SM-1) 5-chloropyrazine-2-carboxylic acid (1.00 gram, 6.31 mmol) in dichloromethane (30 ml) was treated with catalytic amount of dimethylformamide, followed by (COCl)2 (0.85 ml, 9.46 mmol). The resulting mixture was stirred over night. The reaction was concentrated in vacuo, and dried under vacuum to give desired 5-chloropyrazine-2-carbonyl chloride as solid (1.05 g, 100%).

The synthetic route of 36070-80-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Pfizer Inc; US2010/234285; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 1458-01-1, name is Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, 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 1458-01-1, 1458-01-1

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¡ãC. Yield: 99.6 g (107percent of theory) C5H5ClN4O2 ESI Mass spectrum: m/z = 189 [M+H]+; m/z = 187 [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, Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; BOEHRINGER INGELHEIM INTERNATIONAL GMBH; HECKEL, Armin; FRATTINI, Sara; HAMPRECHT, Dieter; KLEY, Joerg; WO2013/64450; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

24241-18-7, 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. 24241-18-7, name is 2-Amino-3,5-dibromopyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

To a stirred solution of amine 1 (1.0 mmol) in dry DMF (3 mL) was added sodium hydride (60% dispersion in mineral oil, 2.2 mmol) and alkyl iodide (4.0 mmol). The resulting mixture was stirred under nitrogen at room temperature for 25 minutes. The reaction mixture was then quenched with water (6 mL), extracted with diethyl ether (2¡Á12 mL) and the combined organics were washed with brine, dried over sodium sulfate and concentrated. Biorg. Med. Chem. 2001, 9, 1149-1154.; Prepared from 2-amino-3,5-dibromopyrazine and iodomethane (568 mg, 4.00 mmol) according to general procedure 1. Purification by column chromatography (12 g ISCO column eluding with hexanes and ethyl acetate; gradient 100% hexanes to 70% hexanes) provided the substituted aminopyrazine (171 mg, 61%) as a yellow oil; 1H NMR (300 MHz, CDCl3) delta 8.11 (s, 1H), 3.07 (s, 6H).

The synthetic route of 2-Amino-3,5-dibromopyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Alcon, Inc.; US2006/142307; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

4858-85-9, 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 4858-85-9 as follows.

A 12L 3-neck round bottom flask fitted with a magnetic stirrer under nitrogen was charged with zinc dust (745 g, pre-activated, 11.4 mol, 2 eq.) and DMA (2 L, anhydrous). 1, 2-dibromoethane (71 mL, 0.855 mol, 0.15 eq, Aldrich) was then added over 10 minutes, followed by TMSC1 (108 mL, 0.855 mol, 0.15 eq, Acros) over 20 minutes. The reaction mixture was stirred for 25 minutes at room temperature. A solution of N-Boc-3-iodoazetidine (2420 g, 8.55 mol, 1.5 eq, CNH Technologies) in DMA (5 L, anhydrous) was added via a 2L addition funnel over 2 h keeping the internal temperature below 65 C using a water bath. The suspension was stirred for 1 hour at RT at which point it was degassed with nitrogen. Stirring was stopped and the suspension was allowed to stand. A 22L 3-neck round bottom flask fitted with a mechanical stirrer was charged with 2, 3-dichloropyrazine (850 g, 5.70 mol, 1.0 eq, AK Scientific), PdCl2dppf-CH2Cl2 (140 g, 171 mmol, 0.03 eq, Aldrich), Cul (67.3 g, 353 mmol, 0.062 eq, Aldrich), and DMA (5 L, anhydrous). The solution was degassed with nitrogen. The clear zinc reagent solution above the residual solid zinc was poured into the 22L flask under nitrogen. The brown solution was degassed with nitrogen and heated to 80 C for 16 hours at which point LCMS indicated complete conversion of 2, 3-dichloropyrazine. The reaction mixture was transferred to brine (8 L) in 50L separatory funnel. Water (8 L) and EtOAc (15 L) were added and the layers were separated. The aqueous layer was extracted with EtOAc (2 x 10 L). The combined organics were washed with water (3 x 10 L) and brine (5 L), dried over sodium sulfate and evaporated. The resulting residue was purified by column chromatography (eluting with hexanes/ethyl acetate = 10: 1) to get 536 g of pure tert-butyl 3-(3-chloropyrazin-2- yl)azetidine- 1 -carboxylate and 121 g of mixed fractions. The impure material was distilled under high vacuum to remove the impurity (N-Boc-azetidine) to give 81 g of pure tert-butyl 3- (3-chloropyrazin-2-yl)azetidine- 1 -carboxylate.Total: 617g, Yield: 40%.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 4858-85-9, and friends who are interested can also refer to it.

Reference:
Patent; AMGEN INC.; ALLEN, Jennifer; FROHN, Michael; HARRINGTON, Paul; PICKRELL, Alexander; RZASA, Robert; SHAM, Kelvin; HU, Essa; WO2011/143366; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

98-97-5, A common compound: 98-97-5, name is Pyrazine-2-carboxylic acid, 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: Under Argon, a stirred solution of carboxylic acid (0.37 mmol,1.0 eq.) and Et3N (0.48 mmol, 1.3 eq.) in dry THF (7 mL) was cooledto 10 C. Ethyl chloroformate (0.55 mmol, 1.5 eq.) was drop wiseadded and the resulting mixture was stirred for 2 h. Afterwards, asolution of sodium azide (0.63 mmol, 1.7 eq.) in water (2 mL) wasadded in one portion. After 1 h at 10 C, the reactionwas found tobe complete (TLC) and was quenched into iced water (5 mL). Themixture was extracted with EtOAc (3 10 mL) and the combinedorganic layers were successively dried over MgSO4, filtered andevaporated. The crude acyl azide was placed in dry toluene (20 mL)and heated at reflux for 1 h to give the corresponding crude isocyanate.The latter was placed in dry dioxane (7 mL) prior to addingthe appropriate amine 8, 9 or 10 (0.37 mmol, 1.0 eq.). The solutionwas heated at 100 C for 24 h. The reaction mixture was cooled andthe volatiles were removed to dryness in vacuum at 40 C.

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, Pyrazine-2-carboxylic acid, other downstream synthetic routes, hurry up and to see.

Reference:
Article; Boulahjar, Rajaa; Ouach, Aziz; Bourg, Stephane; Bonnet, Pascal; Lozach, Olivier; Meijer, Laurent; Guguen-Guillouzo, Christiane; Le Guevel, Remy; Lazar, Said; Akssira, Mohamed; Troin, Yves; Guillaumet, Gerald; Routier, Sylvain; European Journal of Medicinal Chemistry; vol. 101; (2015); p. 274 – 287;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6863-74-7, 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. 6863-74-7, name is 6-Chloropyrazine-2-carbonitrile belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

General procedure: To an oven-dried microwave vial was added ethyl 2-amino-1,3-oxazole-5-carboxylate (546 mg, 3.50 mmol), Cs2CO3 (2279 mg, 6.99 mmol), Pd2(dba)3 (80 mg, 0.09 mmol) and (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphine) (152 mg, 0.26 mmol) and the vial was capped and purged with nitrogen. 2,4-Dichloropyridine (0.378 mL, 3.50 mmol) was added via syringe, followed by 1,4-dioxane (18 mL) (degassed) and the reaction mixture was heated to 160 C for 1 h under microwave irradiation. CH2Cl2 (40 mL) was added to the crude reaction mixture together with silica (5 g). The solvents were removed under reduced pressure and the crude product was purified by flash silica chromatography with CH2Cl2 (containing 1% methanolic ammonia) as eluent.The resulting brown solid was triturated with Et2O to give ethyl 2-(4-chloropyridin-2-ylamino)oxazole-5-carboxylate (626 mg, 67%) as a pale yellow solid, which was collected by filtration and dried under vacuum.

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

Reference:
Article; Noonan, Gary M.; Dishington, Allan P.; Pink, Jennifer; Campbell, Andrew D.; Tetrahedron Letters; vol. 53; 24; (2012); p. 3038 – 3043;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, 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.

Example 1 1-(5-{[3-(Cyclopropylmethyl)-2,3,4,5-tetrahydro-1 H-3-benzazepin- 7 -yl]oxy}-2- pyrazinyl)-2-pyrrolidinone (E1) Step 1: 5-Chloro-2-pyrazinamine; Aminopyrazine (10g, 10.5mmole) was dissolved in dry dimethylformamide (60ml) and was treated with N-chlorosuccinimide (15.36g, 11.5mmole) under argon at 0C. The mixture was stirred for 30 minutes and then allowed to warm to room temperature. The mixture was poured onto water and extracted with diethyl ether (x 5). The diethyl ether layers were combined and evaporated in vacuo. The resulting residue was purified by column chromatography (1: 9 ethyl acetate: pentane) to afford the title compound (1.40g). ?H NMR (CDCI3) 8.02 (1H, s), 7.76 (1H, s), 4.61 (2H, s).

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

Reference:
Patent; GLAXO GROUP LIMITED; WO2005/97778; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem