Category: Pyrazines

33332-29-5, A common compound: 33332-29-5, name is 2-Amino-5-chloropyrazine, 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.

To a solution of 5-chloropyrazin-2-amine (2.5 g, 19.3 mmol) in IPA (25 mL) was added 2-chloroacetaldehyde (5.68 g, 28.95 mmol). The resulting mixture was stirred at 100 C for 16 hours to give a black suspension. The reaction solution was cooled to room temperature and concentrated to give a residue. The residue was dissolved in EtOAc (150 mL) and K2C03 aqueous (60 mL). After separatation, the organic layer was washed with brine (50 mL x 2), dried over anhydrous Na2504, filtered and concentrated to give a crude product. The crudeproduct was purified by silica gel column with EtOAc in PE = (10% to 50%) to give 6- chloroimidazo[1,2-alpyrazine (1000 mg, 33% yield) as a solid. ?H NMR (400 MHz, CDC13) oe11 8.94 (s, 1H), 8.20 (s, 1H), 7.88 (s, 1H), 7.73 (s, 1H). LCMS R = 0.174 mm in 1.5 mm chromatography, MS ESI calcd. for C6H5C1N3 [M+H1 154.0, found 153.8.

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, 2-Amino-5-chloropyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; PRAXIS PRECISION MEDICINES, INC.; REDDY, Kiran; MARTINEZ BOTELLA, Gabriel; GRIFFIN, Andrew Mark; MARRON, Brian Edward; (168 pag.)WO2018/98500; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

875781-43-4,Some common heterocyclic compound, 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, molecular formula is C6H4BrN3, 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: 2-Bromo-5H-pyrrolo[3,2-b]pyrazine(4; 0.471 g,2.39 mmol), 4-pyridylboronic acid (0.58 g, 4.72 mmol), dichloro 1,1′-bis(diphenylphosphino)ferrocenepalladium (II) dichloromethane adduct (0.097 g, 0.12 mmol), acetonitrile(3 mL) and 1M sodium carbonate (3 mL) were placed in a 10 mL CEM microwavevial. The vial was capped and irradiated in a CEM microwave reactor for 30minutes at 150 C.Water (3 mL) and ethyl acetate (9 mL) were added the layers were partitioned. Theaqueous layer was extracted with ethyl acetate (2 x 10 mL). The combined organicextracts were washed with saturated sodium chloride (5 mL), dried over MgSO4and concentrated under reduced pressure. The residue was purified by preparativereverse phase HPLC to give 2-(pyridin-4-yl)-5H-pyrrolo[2,3-b]pyrazine(14; 0.28 g,60%) as an off white solid: 1H NMR (400 MHz, DMSO-d6) delta 12.24 (s, 1H), 9.00(s, 1H), 8.69 (dd, J = 4.5, 1.6 Hz, 2H), 8.12 (dd, J = 4.5, 1.6Hz, 2H), 7.98 (d, J = 3.6 Hz, 1H), 6.74 (d, J = 3.6 Hz, 1H); ESMSm/z 197.1 (M+1).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, its application will become more common.

Reference:
Article; Burdick, Daniel J.; Wang, Shumei; Heise, Christopher; Pan, Borlan; Drummond, Jake; Yin, Jianping; Goeser, Lauren; Magnuson, Steven; Blaney, Jeff; Moffat, John; Wang, Weiru; Chen, Huifen; Bioorganic and Medicinal Chemistry Letters; vol. 25; 21; (2015); p. 4728 – 4732;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-25-1, 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 33332-25-1 as follows.

Methyl 5-[(oxan-4-yl)amino]pyrazine-2-carboxylate Methyl 5-chloro-2-pyrazinecarboxylate (507 mg, 2.94 mmol), Et3N (1.08 mL, 7.64 mmol) and 4-aminotetrahydropyran (395 uL, 3.82 mmol) were dissolved in dioxane (5 mL) and heated in a microwave reactor at 100 C. for 20 min. Water (50 mL) and brine (25 mL) were added and the reaction mixture was extracted into EtOAc (2*100 mL), dried (MgSO4) and concentrated in vacuo to give the title compound (236 mg, 33.9%) as a yellow oil. LCMS (ES+): 238.2 [MH]+.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 33332-25-1, and friends who are interested can also refer to it.

Reference:
Patent; Proximagen Limited; Espensen, Max; Savory, Edward; US2015/258101; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

875781-43-4, 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. 875781-43-4 name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, 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.

The compound 2-bromo-5H-pyrrolo [2,3-b] pyrazine (3.00 g, 15.0 mmol) was dissolved in 1,4-dioxane(60 mL), sodium hydroxide solution (2.0 M, 15.0 mL) and formaldehyde solution (37%, 11.4 mL) were added successively, and the mixture was stirred at room temperature night. The reaction solution was concentrated to give a brown oil which was adjusted to pH = 7 with HCl (1.0 M), precipitated with a pale yellow solid, filtered, The filtrate was extracted with EtOAc / MeOH (v / v) = 5/1, 20 mL x 2) and the organic phase was concentrated and the cake was combined and evaporated to dryness to give 4.0 g of yellow Color solid, yield: 99.0%.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, and friends who are interested can also refer to it.

Reference:
Patent; Guangdong East Sunshine Pharmaceutical Co., Ltd; Liu, Bing; Huang, Jiuzhong; Zhang, Yingjun; Xue, Yaping; Xing, Wei; Xu, Juan; Wu, Zuping; Yu, Tianxi; (106 pag.)CN106432246; (2017); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, molecular formula is C4H5N3, 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. 5049-61-6.

To a solution of 2-amino pyrazine (2Og, 210 mmol) in dimethoxy ethane (400 ml) was added ethyl bromopyruvate (32.8 ml) at 25C and the resulting reaction mixture was allowed to stir at the same temperature for 4 hrs . It was then cooled to O0C and stirred for 30 minutes. The separated solid was filtered and washed with ether. Solid residue was taken in ethanol (1000ml) and refluxed for 4hrs. Solvent was removed completely, residue taken in chloroform (1000ml), saturated sodium bicarbonate solution (700 ml) was added to it and the mixture was allowed to stir for 45 minutes . The mixture was filtered through celite bed, washed several times with chloroform and filtrate was dried over sodium sulfate. Evaporation of the organic layer under reduced pressure gave the crude mass, which was purified by crystallization using ether-methanol mixture. Yield : 20%

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; GRUeNENTHAL GMBH; WO2009/90055; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-25-1, 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. 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, This compound has unique chemical properties. The synthetic route is as follows.

. Methyl 5-chloropyrazine-2-carboxylate (2.0 g, 1 eq., 11.6 mmol) was dissolved in MeOH (15 mL) and the solution was cooled to 0C. Sodium borohydride (1.1 g, 2.5 eq., 29 mmol) was slowly added and the reaction mixture was stirred at room temperature for 1 h. The reaction mixture was quenched with a saturated solution of NH4Cl (15 mL) and extracted with DCM (215 mL). The organic extracts were dried over Na2SO4 and concentrated in vacuo to furnish the crude product, which was purified by flash chromatography eluting with cyclohexane/EtOAc (0 to 60%) to give the pure title compound as colourless oil (1.59 g, 95%). 1H NMR (400 MHz, DMSO-d6): delta 8.73 (d, J=1.4 Hz, 1H), 8.54 (d, J=1.3 Hz, 1H), 5.68 (t, J=5.8 Hz, 1H), 4.65 (d, J=5.7 Hz, 2H).

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; FONDAZIONE ISTITUTO ITALIANO DI TECNOLOGIA; BERTOZZI, Fabio; BANDIERA, Tiziano; PONTIS, Silvia; REGGIANI, Angelo; GIACOMINA, Francesca; DI FRUSCIA, Paolo; US2019/135778; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 1458-03-3, name is Methyl 3-amino-6-chloropyrazine-2-carboxylate, molecular formula is C6H6ClN3O2, 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. 1458-03-3.

Into a 500 ml three-necked flask, 100 mL of acetic acid was added, and Compound 2 (20 g, 0.11 mol) was added dropwise to a 100 mL aqueous solution of 40% hydrogen bromide at 0C. The reaction was completed after 30 minutes of dropwise addition. A 50 ml aqueous solution of sodium nitrite (20.7 g, 0.33 mol) was added dropwise at a controlled temperature of 0C. After 30 minutes of reaction, the reaction is complete and it is quenched by the dropwise addition of 30 ml of 10% sodium bisulfite solution. Ethyl acetate extraction (200ml¡Á2), dried over 20g of anhydrous sodium sulfate, The mixture was concentrated by suction filtration to obtain a white solid compound 3 (23.3 g, yield 87%).

The synthetic route of Methyl 3-amino-6-chloropyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Shaoyuan Science And Technology (Shanghai) Co., Ltd.; Shanghai Shaoyuan Reagent Co., Ltd.; Wei Yuanbo; Guo Tao; Wu Yong; (8 pag.)CN108101857; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

24241-18-7, A common compound: 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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.

A mixture of 3,5-dibromopyrazin-2-amine (214 mg, 0.83 mmol) and phenyl boronic acid (100 mg, 0.8 mmol) in toluene (8 mL) was degassed and backfilled with nitrogen 3 times. Pd(PPtLs)4 (46 mg) was added followed by 2M K3PO4 (0.8 mL) and EtOH (1 mL). The mixture was heated at reflux for 18 h. The solution was cooled to room temperature, partitioned between EtOAc (25 mL) and water (5 mL). The layers were separated and the organic layer dried over Na2SO4, filtered and concentrated to an oil which was purified via silica gel chromatography (15% EtOAc/heptane) to afford the product (187 mg, 95% yield)

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, 2-Amino-3,5-dibromopyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; BRISTOL-MYERS SQUIBB COMPANY; WO2009/155388; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, 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. 27398-39-6

Intermediate 17 (50 mg, 0.079 mmol) was dissolved in NMP (300 uL) and N-ethyl-N- isopropylpropan-2-amine (41.3 mu, 0.237 mmol) and 3-chloropyrazine-2-carboxylic acid (13.78 mg, 0.087 mmol) were added, followed by HATU (36.1 mg, 0.095 mmol). The reaction was allowed to stand for 10 min and then analysed by LCMS and found to be complete. 2,2,2-Trifluoroacetic acid (151 mu, 1.975 mmol) was added and the mixture heated at 120 ¡ãC for 20 min. The mixture was poured into water and extracted with DCM. The organics were dried, filtered and evaporated to give a gum which was purified by RP HPLC (solvent B – minimum 10percent, intermediate 55percent, maximum 95percent) to give compound 48 as a white solid (10 mg, 24percent).

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 27398-39-6.

Reference:
Patent; JANSSEN PHARMACEUTICA NV; VAN BRANDT, Sven, Franciscus, Anna; GIJSEN, Henricus, Jacobus, Maria; VOS, Ann, Marleen; OEHLRICH, Daniel; (77 pag.)WO2018/162445; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 5049-61-6

Example 2 Synthesis of 3,5-dibromopyrazine-2-ylamine 11.2 ml of bromine in 38 ml of acetic acid were slowly added at 15 C., while stirring, to a solution of 2-aminopyrazine (9.5 g, 100 mmol) and sodium acetate trihydrate (32.6 g) in 150 ml of acetic acid. The addition required about 1-2 hours and it was carried out in the dark. The reaction mixture was stirred at room temperature overnight. The solution was concentrated in vacuo and the brown viscous residue was poured into ice water (150 ml) under stirring. Aqueous 20% sodium hydroxide was added in order to obtain a pH of 8 and extracted with ethyl acetate (4*75 ml). The combined organics were washed with water (2*50 ml) and brine (1*50 ml), dried and concentrated. The crude product was purified by column chromatography (2:1 hexanes and ethyl acetate) to provide the desired compound. HPLC: 8.7 min (98% pure) MS: MH+=251.8 C4H3Br2N3=250.8 g/mol

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, 5049-61-6, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Nuss, John M.; Ramurthy, Savithri; US2001/34051; (2001); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem