Month: November 2020

5049-61-6, 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. 5049-61-6 name is Pyrazin-2-amine, 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.

Preparation of 3,5-dibromopyrazin-2-amine Intermediate BA) [0322] To a stirred solution of aminopyrazine (8.21 g, 86.4 mmol) in anhydrous methylene chloride (215 mL) cooled to 0C was added N-bromosuccinimide (32.3 g, 181 mmol) in portions over a six hour period, during which time the temperature of the reaction was kept below 0C. The resulting mixture was stored at 4C overnight, after which it was stirred vigorously and quenched with H20 (100 mL). The organic layer was separated, after which it was washed with saturated aqueous NaHC03, washed with brine, dried over MgS04, filtered, and evaporated in vacuo to yield a residue that was triturated with 20% EtOAc in hexanes to yield the title compound (10.3 g, 47%) as a yellow/brown powder. 1H NMR (CDC13, 300MHz) delta 8.02 (s, 1H), 5.05 (bs, 2H); HPLC retention time: 1.99 minutes; MS ESI (m/z): 252.0/254.0/256.2 (M+l)+, calc. 251.

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

Reference:
Patent; UNIVERSITY OF ROCHESTER; GELBARD, Harris, A.; DEWHURST, Stephen; GOODFELLOW, Val, S.; WIEMANN, Torsten; RAVULA, Satheesh, Babu; LOWETH, Colin, J.; WO2011/149950; (2011); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

36070-80-1, Adding a certain compound to certain chemical reactions, such as: 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, 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 36070-80-1.

Step 1: 5-chloro-N-[(lS)-2,2,2-trifluoro-l-methylethyl]pyrazine-2-carboxamideN,N-Diisopropylethylamine (1.3 mL, 7.5 mmol) was added to a mixture of 5- chloropyrazine-2-carboxylic acid (0.40 g, 2.5 mmol), N,N,N’,N’-tetramethyl-0-(7- azabenzotriazol-l-yl)uronium hexafluorophosphate (1.0 g, 2.8 mmol) and (2S)-1,1,1- trifluoropropan-2-amine (0.28 g, 2.5 mmol) (Oakwood: Cat.No.44272) in methylene chloride (10 mL). The reaction mixture was stirred at room temperatureovernight. The reaction mixture was worked up with saturated aqueous NaHCC , and extracted with ethyl acetate (3x 20 mL). The combined organic layers were washed with brine, dried over MgS04, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography on a silica gel column with ethyl acetate in hexanes (0-15%) to afford the desired product (0.64 g, 73%). LCMS (M+H) +: m/z = 253.9/255.9.

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

Reference:
Patent; INCYTE CORPORATION; YAO, Wenqing; BURNS, David M.; ZHUO, Jincong; WO2012/177606; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, 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. 5049-61-6, name is Pyrazin-2-amine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

[Referential Example 11] 1-(5-Methoxy-2-pyrazinyl)-5-(2-pyridyl)-1H-pyrazole-3-carboxylic acid; [Show Image] [Show Image] 1) 5-Chloro-2-hydrazinopyrazine; A solution of 5-chloro-2-hydroxpyrazine (1.84 g) synthesized from aminopyrazine by the method of Palamidessi et al. (J.Org.Chem., vol.29, pp 2491-2492, 1964) in phosphorus oxychloride (28ml) was placed in a sealed tube, and the solution was stirred at an outer temperature of 130C for 6 hours. After cooling with air, ice cold water and dichloromethane were added to the reaction liquid, then the phases were separated. The organic layer was dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure. Hydrazine monohydrate (1.39 ml) was added to a solution of the residue in ethanol (14 ml), and the mixture was stirred at room temperature for 150 minutes and for another 15 minutes at 80C. After cooling with air, the reaction liquid was evaporated under reduced pressure, and to the residue was added water and a mixed solvent of chloroform and methanol (1:10), then the phases were separated. The organic layer was dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure to give 5-chloro-2-hydrazinopyrazine(0.325 g, 16%) as a solid. 1H-NMR (400 MHz, DMSO-d6)delta: 4.32 (2H, br s), 7.92 (1H, s), 7.99 (1H, s), 8.13 (1H, s). EI-MSm/z: 144 (M+).

The synthetic route of 5049-61-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; DAIICHI PHARMACEUTICAL CO., LTD.; EP1698626; (2006); 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. 4858-85-9, name is 2,3-Dichloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. 4858-85-9

To a solution of l-(quinolin-2-yl)piperidin-4-ol (see PREPARATION Pl . l ; 2.0 g, 8.7 mmol) in DMF (30 mL) at room temperature was added sodium hydride (60% wt in mineral oil) (0.47 g, 17.4 mmol) at 0 C. The mixture was stirred at room temperature for 60 min and then 2, 3-dichloro-pyrazine (1.2 g, 8.7 mmol) was added. The reaction mixture was heated to 90 C overnight and then diluted with water (60 mL) and extracted with EtOAc (2 x 50 mL). The combined organic extracts were washed with water (40 mL) and brine (40 mL), dried over Na2S04, and filtered. The filtrate was evaporated in vacuo and the residue was purified by flash column chromatography on silica gel (10% to 30% EtOAc in petroleum ether) to give the title product ( 2.0 g, 5.8 mmol, 70% yield ) as white solid. ESI-MS (M+l): 341 calc. for

The synthetic route of 4858-85-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; AMGEN INC.; ALLEN, Jennifer; HORNE, Daniel B.; HU, Essa; KALLER, Matthew R.; MONENSCHEIN, Holger; NGUYEN, Thomas T.; REICHELT, Andreas; RZASA, Robert M.; WO2011/143495; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

19745-07-4, 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. 19745-07-4, name is 2,5-Dichloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

Step C: To a solution of (S)-3-(2,5-difluoro-4-(methylsulfonyl)phenylamino)- l-(piperidin-4-yl)pyrrolidin-2-one (Table 2, compound 1; 1.5 g, 4.02 mmol) and DIEA (3.50 mL, 20.1 mmol) in DMF (15mL) was added 2,5-dichloropyrazine (1.20 g, 8.03 mmol) . This mixture was heated to 100 ¡ãC for 3 hours under nitrogen. The mixture was poured into brine (150 mL) and extracted into ethyl acetate (3 x 500 mL). The combined organic layers were dried over MgS04, filtered and concentrated in vacuo to give an oil. Ether (100 mL) was added and a precipitate formed overnight. The ether was decanted and the solid was triturated using ethanol (100 mL) at reflux with stirring for 5 minutes. The material was purified by column chromatography using 50percent to 100percent ethyl acetate/hexane. The resulting solid was dried over the weekend under high vacuum to provide the title compound (0.83 g, 39percent yield). Mass spectrum (apci) m/z = 486.1 (M+H).

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

Reference:
Patent; ARRAY BIOPHARMA INC.; AICHER, Thomas Daniel; BENCSIK, Josef Roland; BOYD, Steven Armen; CONDROSKI, Kevin Ronald; FELL, Jay Bradford; FISCHER, John P.; HINKLIN, Ronald Jay; PRATT, Scott Alan; SINGH, Ajay; TURNER, Timothy M.; WO2011/146335; (2011); 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

General procedure: alpha,beta-unsaturated tosylhydrazones 1 (0.11 mmol, 1.1 equiv), heteroaryl chlorides 2 (0.1 mmol, 1 equiv), Cs2CO3 (0.25 mmol, 2.5 equiv) and MeCN (1 mL) were added to a tube. The mixture was stirred at 60 C until the heteroaryl chlorides was completely disappeared for 4-8h. After cooling to room temperature, the mixture was quenched with NH4Cl (2 mL, saturated aqueous solution) and extracted with CH2Cl2 (3 ¡Á 2 mL). The combined organic phases were dried over Na2SO4 and solvents removed in vacuo. The residue was purified by flash column chromatography on silica gel with ethyl acetate/petroleum ether (1:10-1:4, V/V) as the eluent, affording the desired product 3 and 4.

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:
Article; Zeng, Lin; Guo, Xiao-Qiang; Yang, Zai-Jun; Gan, Ya; Chen, Lian-Mei; Kang, Tai-Ran; Tetrahedron Letters; vol. 60; 33; (2019);,
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. 3149-28-8, name is 2-Methoxypyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. 3149-28-8

1.9 g (0.017 mol) of 30 % hydrogen peroxide are added to a solution of 1.1 g (0.01 mol) of 2-methoxy-pyrazine in 3 ml of glacial acetic acid and the resulting solution is heated at 65-68C for 17 hours. The solution is concentrated to 1/3 of the original volume, diluted with the same amount of water and concentrated again. The residue is extracted with chloroform and the combined organic phases are washed with saturated sodium chloride solution and dried over sodium sulfate. After concentration, two amounts, each of 25 ml, of toluene are added to the residue obtained and are concentrated again. The desired title compound, which can be used directly for further reactions, is obtained in a yield of 0.98 g (77 % of theory). ‘H NMR (300 MHz, CDCI3) : 7.988 ppm (d (J=4.2 Hz), 1 H) ; 7.766-7. 773 ppm (m, 1 H) ; 7.745 ppm (dxd (J=4.2 and 1.5 Hz), 1 H) ; 3.995 ppm (s, 3H).

The synthetic route of 3149-28-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SYNGENTA PARTICIPATIONS AG; WO2003/87067; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, 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. 55557-52-3

Step 7: synthesis of Ethyl 7-aminothieno[2,3-b]pyrazine-6-carboxylate (7) A mixture of 3-chloropyrazine-2-carbonitrile (17.9 g, 128 mmol), sodium carbonate (17.7 g, 167 mmol) and ethyl-2-mercaptoacetate (18.4 mL, 167 mmol) in ethanol (120 mL) was heated to reflux for 4.5 h. Quenched with water (1.5 L) and stirred for 30 min. The resulting precipitate was collected and washed with water. The residue was dissolved in diethyl ether and a black precipitate was filtrated off. Ether was evaporated to give pure compound ethyl 7-aminothieno[2,3-b]pyrazine-6-carboxylate 7 (19.6 g, 68.5%). 1H-NMR (400 MHz, CDCl3) 1.42 (t, J=7.2 Hz, 3H), 4.40 (q, J=7.2 Hz, 2H), 6.19 (br s, 1H), 8.58 (d, J=2.2 Hz, 1H), 8.63 (d, J=2.2 Hz, 1H).

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, 55557-52-3, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Folmer, Brigitte Johanna Bernita; Man, de Adrianus Petrus Antonius; Gernette, Elisabeth Sophia; Corte Real Goncalves Azevedo, Rita; Ibrahim, Hemen; US2013/79341; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, molecular formula is C4H3Br2N3, 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. 24241-18-7

A 500ml three-neck flask, was added morpholine (9.6g, 0.11mol) and 2-amino-3,5-dibromo-pyrazine (25.3g, 0.1mol) and N- methylpyrrolidinone (100ml), and at 80 reaction 6h, TLC tracking, cooled to room temperature, add water 400ml, stirring, suction filtered and dried to give a yellow solid 22.5g, a yield of 86.7%.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 24241-18-7, its application will become more common.

Reference:
Patent; Hubei University of Technology; Liu, Mingxing; Jiang, Weidong; Wang, Wanxia; (6 pag.)CN105622526; (2016); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 4858-85-9, name is 2,3-Dichloropyrazine, 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. 4858-85-9

To a flame dried 25 mL flask with zinc dust (217 mg, 3.31 mmol) and N,N-dimethylacetamide (2 mL) was added chlorotrimethylsilane (33.5 muL, 0.265 mmol) and 1,2- dibromoethane (22.83 muL, 0.265 mmol). The resulting slurry was stirred 15 min, then tert-butyl 3-iodoazetidine-l-carboxylate (753 mg, 2 66 mmol) was added to the above mixture (mild exotherm). The suspension was stirred at rt 30 min. [00422] The zinc solution was added via syringe to a solution of 2,3-dichloropyrazine (277 mg, 1.862 mmol), (dppf)PdCl2-CH2Cl2 (65.2 mg, 0.080 mmol), and copper(I) iodide (30.4 mg, 0.160 mmol) in N,N-dimethylacetamide (1.0 mL) that was degassed with N2 (3 x). The solution was heated to 80 0C and stirred 1 h. The reaction was quenched with NH4Cl (10 mL) and extracted with EtOAc (3 x 10 mL). The combined organic fractions were dried (MgSO4), concentrated, and purified by ISCO (40 g SiO2, 10-100% EtOAc/Hexane) to give tert-butyl 3-(3- chloropyrazin-2-yl)azetidine-l-carboxylate (262 mg, 0.971 mmol, 36.5 % yield) as a clear, colorless oil.

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 4858-85-9.

Reference:
Patent; AMGEN INC.; ALLEN, Jennifer R.; BOURBEAU, Matthew P.; CHEN, Ning; HU, Essa; KUNZ, Roxanne; RUMFELT, Shannon; WO2010/57121; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem