Category: Pyrazines

Reference of 89123-58-0, 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. 89123-58-0 name is 5-Bromopyrazine-2,3-diamine, 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.

Example 52A 5-[1-(2-Fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrazine-2,3-diamine Under argon, 425 mg (1.20 mmol) of the compound from Example 33A were initially charged in 1,4-dioxane (11 ml), and the reaction mixture was purged with argon for 10 min. Thereafter, 0.91 ml (1.80 mmol) of hexabutylditin and 250 mg (1.32 mmol) of 2,3-diamino-5-bromopyrazine were added. Subsequently, 422 mg (0.60 mmol) of bis(triphenylphosphine)palladium(II) chloride were added and the reaction mixture was heated to reflux overnight. Thereafter, the mixture was cooled to RT and filtered through Celite, and the filtrate was concentrated. The residue was admixed with methanol, and the solids were filtered off and discarded. The filtrate was taken up in methanol-dichloromethane, absorbed onto diatomaceous earth and purified on silica gel (eluent: cyclohexane-ethyl acetate 2:1, 1:1). This gave 151 mg (31% purity, 11% of theory) of the title compound. The crude product was converted further without further purification. LC-MS (method 3): Rt=0.91 min MS (ESIpos): m/z=336 (M+H)+

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

Reference:
Patent; BAYER INTELLECTUAL PROPERTY GMBH; Follmann, Markus; Stasch, Johannes-Peter; Redlich, Gorden; Ackerstaff, Jens; Griebenow, Nils; Knorr, Andreas; Wunder, Frank; Li, Volkhart Min-Jian; Baerfacker, Lars; Weigand, Stefan; US2014/148433; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference 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.

A solution of 3,5-dibromopyrazin-2-amine X-9a (0.60 g, 2.37 mmol) and NaOMe (0.15 g, 2.78 mmol) in MeOH (15 mL) was heated to reflux for 1 h. Progress of the reaction was monitored by TLC and LCMS. After completion, the reaction mixture was cooled to room temperature. The precipitated solid was purified by column chromatography (silica, 100- 200 mesh, 10% EtOAc in hexane) to afford 5-bromo-3-methoxy-pyrazin-2-amine X-9 (0.295 g) as a white solid. (0843) Yield: 61 %. (0844) Basic LCMS Method 2 (ES+): 204 (M+H)+, 100% purity. 1 H NMR (400 MHz, DMSO-cfe) d 3.87 (s, 3H), 6.52 (brs, 2H), 7.57 (s, 1 H)

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; 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

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. 91476-80-1, name is 5,6,7,8-Tetrahydroimidazo[1,2-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., HPLC of Formula: C6H9N3

Example 32 (5,6-Dihydro-8H-imidazo[1,2-a]pyrazin-7-yl)-(4-{4-[4-(3-methanesulfonyl-propoxy)-indol-1-yl]-pyrimidin-2-ylamino}-cyclohexyl)-methanone A mixture of sodium 4-{4-[4-(3-methanesulfonyl-propoxy)-indol-1-yl]-pyrimidin-2-ylamino}-cyclohexanecarboxylate (0.3 g) and 5,6,7,8-tetrahydro-imidazo[1,2-a]pyrazine (0.24 g). HBTu (0.4 g), DIEA (1 mL), THF (3 mL) and DMA (3 mL) was stirred at room temperature for three hours. The reaction mixture was then partitioned between EtOAc and water, the organic layer washed with saturated NaHCO3 and water, dried over Na2SO4 and concentrated in vacuo. The residue was purified via prep. TLC (10% MeOH/DCM) to give 56 mg of (5,6-dihydro-8H-imidazo[1,2-a]pyrazin-7-yl)-(4-{4-[4-(3-methanesulfonyl-propoxy)-indol-1-yl]-pyrimidin-2-ylamino}-cyclohexyl)-methanone. MS (M+H)=578.

According to the analysis of related databases, 91476-80-1, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Gong, Leyi; Tan, Yun-Chou; US2011/301170; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 55557-52-3,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.

EXAMPLE 13.1 (+-)-3-[(6R,8aS)[[(3-chlorophenyl)ethynyl]hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl] pyrazine-2-carbonitrile A mixture of (+-)-(6R,8aS)-6-[(3-chlorophenyl)ethynyl]octahydropyrrolo[1,2-a]pyrazine (40 mg, 0.15 mmol), 2-chloro-3-cyanopyrazine(30 mg, 0.22 mmol), Et3N (0.1 mL) and THF (1.5 mL) was stirred at 80 C. for 4 h. The resulting mixture was concentrated and purified on silica gel column to provide product (44 mg, 81%). 1H NMR (300 MHz, CDCl3): delta (ppm) 1.62 (m, 1H), 1.85-2.25 (m, 5H), 3.02 (dd, 1H), 3.24-3.48 (m, 3H), 4.61 (dt, 2H), 7.29 (m, 3H), 7.45 (s, 1H), 8.02 (d, 1H), 8.27 (d, 1H).

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

Reference:
Patent; AstraZeneca AB; NPS PHARMACEUTICALS; US2007/37817; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 21279-62-9, name is 3-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. Recommanded Product: 3-Chloropyrazine-2-carboxamide

General procedure: The starting compound (1.27 mmol) was treated with 18 aliphatic amines, alicyclic amines or saturated heterocycles containing at least one nitrogen atom (2.54 mmol). Four reactions were completed by conventional heating methods. The conditions were 110 C, toluene as a solvent and pyridine (1.27 mmol) as a base. The reaction time was set to one hour. Then the reactions were completed using the microwave reactor with focused field and conditions used for syntheses were 140 C, 30 min,120 W, methanol used as a solvent and pyridine (1.27 mmol) as a base. They were set experimentally with respect to prior experience. The progress of reaction was monitored with TLC in system hexane/ethyl acetate (1:1). Then the mixture was separated by flash column chromatograph using gradient elution. Mobile phases were hexane and ethyl acetate again.

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

Reference:
Article; Jandourek, Ondrej; Dolezal, Martin; Kunes, Jiri; Kubicek, Vladimir; Paterova, Pavla; Pesko, Matus; Buchta, Vladimir; Kralova, Katarina; Zitko, Jan; Molecules; vol. 19; 7; (2014); p. 9318 – 9338;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 5521-55-1, A common heterocyclic compound, 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, molecular formula is C6H6N2O2, 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.

5-Methyl-pyrazine-2-carboxylic acid (691 mg, 5 mmol) was stirred in toluene (15 mL) and treated with TEA (765 mL, 5.5 mmol) followed by diphenylphosphoryl azide (1.0 mL, 5.0 mmol). The resulting solution was stirred for 30 min, then used directly.A solution of 5-methyl-pyrazine-2-carbonyl azide (1.0 mmol) in toluene was heated at 900C for 10 min. The reaction flask was removed from the heating bath and the brown solution was treated with 2- (1,4- dimethyl-piperazin-2-ylmethoxy) -5-methyl-phenylamine EPO (0.25 g, 1.0 iranol) . The flask was returned to the heating bath and heated at 40C for 4 h. The mixture was allowed to cool, then filtered to give the product as a tan powder. 1H-NMR (400 MHz, CDCl3) delta 10.90 (s, 1, H), 8.4 (s, 1, H), 8.2 (m, 3, H), 6.8 (m, 2, H), 4.2 (dd, 1, H), 3.9 (t, 1, H),.3.1 (d, 1, H), 2.8 (br d, 1, H), 2.6 (m, 2, H), 2.5 (s, 3, H), 2.4 (m, 1, H), 2.4 (s, 3, H), 2.3 (S, 3, H), 2.25 (m, 1, H), 2.2 (s, 3, H), 2.1 (m, 1, H). LRMS (esi, positive) m/e 385.30 (M+l) .

The synthetic route of 5521-55-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ICOS CORPORATION; WO2006/105262; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 36070-80-1,Some common heterocyclic compound, 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, molecular formula is C5H3ClN2O2, 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 5-chloropyrazine-2-carboxylic acid (3 g, 18.9 mmol) in dichloromethane (60 mL) was added oxalyl dichloride (2.52 g, 1.7 mL, 19.9 mmol) dropwise at 0C. Then to the mixture was added 2 drops of DMF and the mixture was stirred at room temperature for 2 hours. After the reaction was completed, the mixture was concentrated in vacuo to give 5- chloropyrazine-2-carbonyl chloride (3.4 g, 100%) as a white solid.

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

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; HOFFMANN-LA ROCHE INC.; FENG, Song; LIANG, Chungen; LIU, Yongfu; SHEN, Hong; TAN, Xuefei; WU, Jun; CHEN, Dongdong; LI, Chao; WANG, Li; (156 pag.)WO2020/53249; (2020); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

19745-07-4, A common heterocyclic compound, 19745-07-4, name is 2,5-Dichloropyrazine, molecular formula is C4H2Cl2N2, 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.

Into a 250 ml 3-necked round bottom flask, was placed 45percent hydriodic acid (60 ml). To this was added sodium iodide (25 g, 0.17 mol). To the mixture was added XV-B-86 (10.5 g, 0.07 mol). The resulting solution was allowed to react at room temperature. Adjustment of the pH to >8 was accomplished by the addition of 20 g NaOH in 50 g ice to afford XV-C-86.

The synthetic route of 19745-07-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Kalypsys, Inc.; US2005/234046; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 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.

Ethyl bromopyruvate (2.15 g, 11.04 mmol) was added to stirred solution of 2-aminopyrazine (1 g, 10.5 mmol) in 1,2-Dimethoxy ethane (10 mL). The reaction mixture was stirred at 20-35 C. for 2 h. The mixture was then filtered to obtain a solid precipitate which was dried well, dissolved in EtOH (10 mL) and refluxed for 2 h. This mixture was concentrated, diluted with aqueous saturated sodium bicarbonate solution, extracted with chloroform.-The chloroform layer was washed with water followed by brine solution, dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford the crude product, which was purified by column chromatography (using 60-120 silica gel and 60% EtOAc in Hexane as eluent) to afford 450 mg of the title compound. 1H NMR (400 MHz, CDCl3) delta ppm 9.22 (1H, s), 8.28 (1H, s), 8.12-8.08 (1H, m), 8 (1H, d, J=4.8 Hz), 4.52-4.47 (2H, m), 1.5 (3H, t).

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; DR. REDDY’S LABORATORIES LTD.; Sasmal, Pradip Kumar; Ahmed, Shahadat; Prabhu, Ganesh; Tehim, Ashok; Paradkar, Vidyadhar; Dattatreya, Marahanakuli Prasanna; Mavinahalli, Nanjegowda Jagadeesh; US2015/5280; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 912773-21-8, name is 2-Bromo-5-chloropyrazine, 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 912773-21-8, COA of Formula: C4H2BrClN2

A mixture of 2-bromo-5-chloro-pyrazine (229.4 mg, 1.19 mmol), [5-fluoro-6-(2,2,2- trifluoro-1-methyl-ethoxy)-3-pyridyl]boronic acid (300 mg, 1.19 mmol), Pd(dppf)Cl2 (130.16 mg, 0.18 mmol) and CS2CO3 (772.77 mg, 2.37 mmol) in 1,4-dioxane (10 mL) and water (1 mL) was stirred at 60 C for 5 hours under N2. After cooling to r.t., the mixture was diluted with _0 (30 mL), and the mixture was extracted with EtOAc (50 mL x 2). The combined organic phase was washed with water (20 mL x 2) and brine (20 mL), dried over Na2S04, filtered and concentrated to give the crude product. The crude product was purified by flash chromatography on silica gel (EtOAc in PE = 0% to 1% to 3% ) to give the product (210 mg, 0.64 mmol) as a solid. The product was analyzed by SFC to show two peaks (Peak 1: Rt = 2.02 min, Peak 2: Rt = 2.28 min). Method: Column: Chiralpak AD-3 150 x 4.6mm I.D, 3_ Mobile phase: A: C02 B:ethanol (0.05% DEA), Gradient: from 5% to 40% of B in 5 min and hold 40% for 2.5 min, then 5% of B for 2.5 min Flow rate: 2.5mL/min Column temp.: 35 C. 1H NMR (400MHz CDC13) _ = 8.77 (d, 1H), 8.65 (d, 1H), 8.53 (d, 1H), 8.08 (dd, 1H), 5.95 – 5.85 (m, 1H), 1.63 -1.48 (m, 3H). LCMS Rt = 0.92 min in 1.5 min chromatography, 5-95AB, purity 98.54%, MS ESI calcd. for Ci2H9ClF4N30 [M+H]+ 322.0, found 321.9

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; PRAXIS PRECISION MEDICINES, INC.; REDDY, Kiran; MARTINEZ BOTELLA, Gabriel; GRIFFIN, Andrew, Mark; MARRON, Brian, Edward; (364 pag.)WO2018/98499; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem