Month: June 2021

Adding a certain compound to certain chemical reactions, such as: 16298-03-6, name is Methyl 2-aminopyrazine-3-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 16298-03-6, COA of Formula: C6H7N3O2

Compound 2 (27.6 g, leq) was added to acetonitrile (276 ml)Stir at room temperature,NBS (25.1 g, 1.01 eq) was added in portions,Stirred at room temperature overnight,TLC showed that after the reaction (20 ~ 30 h)Add water (300 ml)The pH was adjusted to 7 with Na2CO3 solution,Ethyl acetate extraction (3 x 50 ml),Combined organic phase,Dried over anhydrous sodium sulfate and filtered,The solvent was distilled off under reduced pressure,To give crude 3-amino-6-bromopyrazine-2-carboxylic acid methyl ester,30 times the dichloromethane was added (the weight ratio of the crude product to methylene chloride was 1:25 C)50) After refluxing for 0.5 h,Filter,The mother liquor was distilled off to dichloromethane,And then 20 times the ethanol (steamed and ethanol weight ratio of 1:5 to 30) recrystallization,Crystallization at 25 to 30 C gives a pale yellow solid 3,Yield 89%.

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 2-aminopyrazine-3-carboxylate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Central South University; Liu Fengliang; Li Cuiqin; (19 pag.)CN106866553; (2017); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 55557-52-3, The chemical industry reduces the impact on the environment during synthesis 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, I believe this compound will play a more active role in future production and life.

3-Chloro-2-cyanopyrazine (2.24 g, 1.6 eq), 4-amino-2-pyrimidinecarboxylic acid(1.39g, 1eq) and potassium carbonate(4.1g, 3eq) solution in 20mL DMF, stirred and heated to 60 C, reaction for 5h,Cool to room temperature, filter, and refine the solution with (DCM / MeOH = 20:1).Obtained a yellowish solid product 1.73g(Yield: 71%).

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, 3-Chloropyrazine-2-carbonitrile, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Jiangxi Runze Pharmaceutical Co., Ltd.; Liao Niansheng; Hu Xiande; Zhou Liming; Sui Guilan; (22 pag.)CN109568256; (2019); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 160252-31-3, 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. 160252-31-3 name is 1-(5-Chloropyrazin-2-yl)ethanone, 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.

Step 1: 1-(5-(4-fluoro-1H-pyrazol-1-yl)pyrazin-2-yl)ethan-1-one Sodium hydride (60 wt %, 276 mg, 6.90 mmol) was added to a mixture of 1-(5-chloropyrazin-2-yl)ethanone (800 mg, 5.11 mmol) and 4-Fluoro-1H-pyrazole (484 mg, 5.62 mmol) in N,N-dimethylformamide (6.0 mL) at ambient temperature for 10 minutes. The reaction mixture was then poured into water (70 mL) and was sonicated and stirred for 20 minutes. A dark red solid was isolated by filtration, washed with small amounts of water, and dried to 1-(5-(4-fluoro-1H-pyrazol-1-yl)pyrazin-2-yl)ethan-1-one (919 mg, 95% yield). MS: M+1=207.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 1-(5-Chloropyrazin-2-yl)ethanone, and friends who are interested can also refer to it.

Reference:
Patent; BLUEPRINT MEDICINES CORPORATION; Kim, Joseph L.; Kevin, Douglas J.; Brubaker, Jason D.; (57 pag.)US2017/267661; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 78342-42-4, name is (S)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine, 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 78342-42-4, Product Details of 78342-42-4

INTERMEDIATE 2; (3R)-3-f (l, 1-Dimethylethoxycarbonyl) aminol-4-r2-fluoro-4- (trifluoromethyl) phenyll- butanoic acid; Step A. (2R, 5S)-2, 5-Dihydro-3 6-dimethoxy-2-(2′-fluoro-4′- (trifluoromethyl) benzyl)-5-isopropylpyrazine ; To a solution of 3.32 g (18 mmol) of commercially available (2S)-2, 5- dihydro-3,6-dimethoxy-2-isopropylpyrazine in 100 mL of tetrahydrofuran at-70 °C was added 12 mL (19 mmol) of a 1.6M solution of butyllithium in hexanes. After stirring at this temperature for 20 min, 5 g (19.5 mmol) of 2-fluoro-4- trifluoromethylbenzyl bromide in 20 mL of tetrahydrofuran was added and stirring was continued for 3 h before warming the reaction to ambient temperature. The reaction was quenched with water, concentrated in vacuo, and extracted with ethyl acetate. The combined organic phase was washed with brine, dried, and concentrated in vacuo. Purification by flash chromatography (silica gel, 0-5percent ethyl acetate in hexanes) afforded 5.5 g of the title compound. 1H NMR (500 MHz, CDC13) 6 7.33- 7.25 (m, 3H), 4.35-4. 31 (m, 1H), 3.75 (s, 3H), 3.65 (s, 3H), 3.60 (t, 1H, J = 3.4 Hz), 3.33 (dd, 1H, J = 4.6, 13.5 Hz), 3.03 (dd, 1H, J = 7,13. 5 Hz), 2.25-2. 15 (m, 1H), 1.0 (d, 3H, J = 7 Hz), 0.66 (d, 3H, J = 7 Hz).

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; MERCK & CO., INC.; WO2003/82817; (2003); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 25911-65-3, name is 3-Aminopyrazine-2-carbonitrile, A new synthetic method of this compound is introduced below., Formula: C5H4N4

c) 4-Amino-2-[(4-methoxyphenoxy)methyl]pteridine Obtained using the procedure described in section c of Example 2, starting with 9.8 g (0.082 mole) of 3-amino-2-pyrazinecarbonitrile and the above solution of 2-(3-methoxyphenoxy)acetamidine in absolute ethanol. Refluxing time: 2 hours. Yld: 5.5 g (24%), m.p. 238-240 C. (ethanol/N,N-dimethylformamide). NMR (DMSO-d6): delta=3.7 (3H, s); 5.0 (2H, s); 6.9 (4H, s); 8.3 (2H, peak exchangeable with CF3 COOD); 8.8 (1H, d); 9.0 (1H, d).

The synthetic route of 25911-65-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Lipha, Lyonnaise Industrielle Pharmaceutique; US5167949; (1992); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 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.

A mixture of 2,5-dichloropyrazine 3.0 g, sodium hydride (60percent, oil) 880 ml, and NMP 50 ml was added to 2.3 g of benzyl alcohol under ice-cooling. The reaction mixture was warmed to room temperature and stirred at room temperature for 5 hours. The resulting reaction mixture was added with water and extracted with ethyl acetate. The resulting organic layer was washed with saturated brine, dried over sodium sulfate, concentrated under reduced pressure, and the resulting residue was subjected to silica gel column chromatography to give 3. lg of an intermediate of the following formula 1 .

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

Reference:
Patent; SUMITOMO CHEMICAL COMPANY, LIMITED; ORIMOTO, KOHEI; NOKURA, YOSHIHIKO; NAKAJIMA, YUJI; TANABE, TAKAMASA; KIMURA, TAKAHIRO; (305 pag.)TW2017/26631; (2017); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 63286-28-2,Some common heterocyclic compound, 63286-28-2, name is 2-Chloro-3-hydrazinylpyrazine, molecular formula is C4H5ClN4, 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.

Reference Example 141-2 Preparation of N’-(3-chloropyrazin-2-yl)cyclohexanecarbohydrazide To a mixture of 2-chloro-3-hydrazinylpyrazine (1.10 g), triethylamine (1.27 mL), and chloroform (38 mL) in a 200 mL eggplant flask was added cyclohexanecarbonyl chloride (1.13 mL) under ice-cooling, and the resulting mixture was stirred at room temperature for 1 hour. To the reaction mixture were added a saturated aqueous solution of sodium hydrogen carbonate (40 mL), saturated brine (40 mL), and ethyl acetate (120 mL), and the resulting mixture was stirred for a while. The resulting organic layer was separated, washed with saturated brine, dried over anhydrous sodium sulfate, and the insoluble matters were removed by filtration. The resulting filtrate was concentrated under reduced pressure to give the title compound (1.53 g) (yield 79%) as a pale yellow solid. MS(ESI) m/z: 255/257 [M+H]+

The synthetic route of 63286-28-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MITSUBISHI TANABE PHARMA CORPORATION; UBE INDUSTRIES, LTD.; NAKAJIMA, Tatsuo; HAYASHI, Norimitsu; ISHIZAWA, Kouhei; TSUZAKI, Yasunori; IWAMURA, Ryo; TSUBOIKE, Kazunari; US2019/185479; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 91775-62-1, name is 3-Bromo-8-methoxyimidazo[1,2-a]pyrazine, A new synthetic method of this compound is introduced below., Quality Control of 3-Bromo-8-methoxyimidazo[1,2-a]pyrazine

To a degassed mixture of 3-bromo-8-methoxyimidazo[1,2a]pyrazine (1.4g, 6.2mmol), cyclopropylboronic acid (0.8g, 9.3 mmol) potassium phosphate (4.6g, 21.Smmol) in water (5m1) and toluene (30m1), was added Palladium(ii)acetate and tricyclohexyl phosphine. The resulting reaction mixture was stined at 90C for 12h. The reaction mixture was cooled and partitionedbetween ethyl acetate and water. The organic layer was washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure to get the crude product. The crude product was purified by column chromatography (230-400 mesh silica gel and 10- 30% EtOAc in hexane) to obtain 3-cyclopropyl-8-methoxyimidazo[ 1 ,2-a]pyrazine (1 .0g, 91%). ?H NMR (300 MHz,CDC13): oe 7.79 (d, J= 4.8 Hz, 1H), 7.41 (d, J= 4.8 Hz, 1H), 7.33 (s, 1H),4.13 (s, 3H),1.84 – 1.83 (m, 1H), 1.07 – 1.02(m, 2H) 0.77 – 0.73(m,2H); LC-MS: 190.3 [M+H].

The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.

Reference:
Patent; AURIGENE DISCOVERY TECHNOLOGIES LIMITED; KOTRABASAIAH UJJINAMATADA, Ravi; PANDIT, Chetan; (152 pag.)WO2016/185342; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 143591-61-1, name is 3-Bromo-8-chloroimidazo[1,2-a]pyrazine, 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 143591-61-1, SDS of cas: 143591-61-1

A mixture of compound 102 (2.00 g, 8.6 mmol), conc. aqueous NH4OH (60 mL) and 2-propanol (6 mL) was stirred in a closed pressure vessel at 85 C. for 3 days. The reaction mixture was cooled to 25 C., diluted with water (120 mL) and stirred at 25 C. for 10 minutes. The resulting heterogeneous solution was filtered, the solid was washed with water (3×) and air dried overnight. This gave compound 108 as a beige solid 1.50 g (82%). 1H-NMR (400 MHz, DMSO-d6) delta 7.66 (s, 1H), 7.56 (d, 1H), 7.35 (d, 1H), 7.1 (bs, 2H).

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, 3-Bromo-8-chloroimidazo[1,2-a]pyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Schering Corporation; US2007/105864; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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 33332-29-5 as follows. category: Pyrazines

(iii) 2-Amino-5-chloropyrazine (1.7 g) was dissolved in chloroform (190 ml) and pyridine (1.3 ml) was added under an argon atmosphere. The flask and its contents were protected from light and a solution of bromine (0.7 ml) in chloroform (85 ml) was added over a period of 1 hour. After stirring for 2 hours more bromine (0.07 ml) in chloroform (8.5 ml) was added and, after stirring for 30 minutes, pyridine (0.2 ml) was added. The reaction mixture was stirred for a further 30 minutes then washed with water (50 ml) and the organic phase was separated. The solvent was removed by evaporation and the residue was purified by chromatography through a bed of silica (90 g), eluding with hexane (200 ml) followed by dichloromethane. Dichloromethane fractions containing the product were evaporated to give 2-amino-3-bromo-5-chloropyrazine (1.68 g); 1 H NMR (d6 DMSO): 6.94 (br s, 2H), 8.09 (s, 1H); mass spectrum (+ve CI): 208 (M+H)+.

According to the analysis of related databases, 33332-29-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Zeneca Ltd.; US5668137; (1997); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem