Month: May 2021

Application of 89123-58-0,Some common heterocyclic compound, 89123-58-0, name is 5-Bromopyrazine-2,3-diamine, molecular formula is C4H5BrN4, 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.

The title compound of PREPARATION 45 (240 mg, 1.2 mmol) and 1,1?- carbonyldiimidazole (240 mg, 1.5 mmol) were dissolved in 3 ml butyronitrile and the mixture was stirred in a sealed microwave tube for 15 mm at room temperature affording a thick white suspension. The title compound of PREPARATION 73 (220 mg,1.2 mmol) was added and the reaction was heated 18000 under microwave irradiationfor 2 h. The mixture was allowed to cool and was evaporated under reduced pressure. The residue was purified by flash chromatography (methanol-dichloromethane gradient, 0:100 rising to 10:90) to give 240 mg (0.66 mmol, 58% yield) of the title compound as a white solid. Purity 97%.1H NMR (400 MHz, DMSO-d6) oe ppm 8.54 (s, 1H), 8.44 (s, 1H), 8.27 (s, 1H), 5.40 (s,2H), 2.50 (s, 3H).UPLC/MS (3 mm) retention time 0.98 mm.LRMS: mlz 361, 363 (M+1, 1 xBr)

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 5-Bromopyrazine-2,3-diamine, its application will become more common.

Reference:
Patent; ALMIRALL, S.A.; AIGUADE BOSCH, Jose; CONNOLLY, Stephen; EASTWOOD, Paul Robert; ROBERTS, Richard Spurring; SEVILLA GOMEZ, Sara; CATURLA JAVALOYES, Juan Francisco; (110 pag.)WO2017/64068; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 4430-75-5,Some common heterocyclic compound, 4430-75-5, name is Octahydro-2H-pyrido[1,2-a]pyrazine, molecular formula is C8H16N2, 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.

1-fluoro-2-nitrobenzene (1.2 g, 8.56 mmol), Octahydro-1H-pyrido [1, 2-a] pyrazine (1.0 g, 7.13mmol), N,N-Diisopropylethylamine (1.9 mL, 10.7 mmol) were added to N,N-dimethylformamide (20 mL), and the reaction was heated to 90 C for 4 hours under nitrogen. After the reaction was cooled to room temperature, the reaction solution was diluted with water (80 mL), extracted with dichloromethane (30 mL X 3), the organic phases were combined and washed successively with water (50 mL) and brine (50 mL), dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, the obtained crude product was passed through a silica gel chromatography column (petroleum ether: ethyl acetate (V:V) = 5:1) and further purified to give the title compound (yellow oil, 1.74 g, 93.4%).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Octahydro-2H-pyrido[1,2-a]pyrazine, its application will become more common.

Reference:
Patent; Guangdong Dongyangguang Pharmaceutical Co., Ltd.; Jin Chuanfei; Yi Chao; Zhang Yingjun; Duan Zhenfang; Wang Kezhu; (25 pag.)CN108409728; (2018); A;,
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. 723286-80-4, name is tert-Butyl 3-bromo-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate, A new synthetic method of this compound is introduced below., Safety of tert-Butyl 3-bromo-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate

A mixture of pyrazole (33.7 mg, 0.495 mmol) and sodium hydride (19.79 mg, 0.495 mmol) in Lambda/,Lambda/-dimethylformamide (DMF) (1 ml) was cooled to 0 0C and 1 ,1- dimethylethyl 3-bromo-5,6-dihydro[1 ,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate (50 mg, 0.165 mmol, commercially available from e.g. Allichem, Ark Pharm or Bepharm) was added. After completion of the addition, the mixture was stirred at room temp for 30 mins and then at 1 10 0C. After 3 h, the DMF was evaporated and a few drops of NH4CI solution were added followed by ethyl acetate (50 ml). The solution was dried (Na2SO4), filtered and concentrated. The product was purified by MDAP to give desired product in 24.1 mg. LCMS MH+ = 291 (at) 0.79 min (2 min run)

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; GLAXO GROUP LIMITED; DEAN, David Kenneth; MUNOZ-MURIEDAS, Jorge; SIME, Mairi; STEADMAN, Jon Graham Anthony; THEWLIS, Rachel Elizabeth Anne; TRANI, Giancarlo; WALTER, Daryl Simon; WO2010/125102; (2010); 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. 14508-49-7, name is 2-Chloropyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. Application In Synthesis of 2-Chloropyrazine

Using Procedure AU-3 (Table 5) with 2-chloropyrazine the title compound 476 was obtained (4.4 g, 46%) as a yellow solid. MS (m/z): 111.0 (M+H)

The synthetic route of 14508-49-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Forum Pharmaceuticals, Inc.; Rogers, Kathryn; Patzke, Holger; (315 pag.)US2017/749; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 27398-39-6,Some common heterocyclic compound, 27398-39-6, name is 3-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 3-ehioropyrazine-2-earboxyiic acid (100 rng, 0,63 mmoi) in DCM/MeOH (2 mL: 0.2 mL) was added TMSCHN2 (0.47 rnL, 0.95 mrnoi) at RI and theresulting mixture stirred at RT for 2 h. Acetic acid (0.2 mL) was added and the mixture diluted with water (2 mL) and extracted with DCM (4 mL x 3). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo to give the title compound as a oil. LRMS m/z (M+H) 173.0 found, 173.0 required.

The synthetic route of 27398-39-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MERCK SHARP & DOHME CORP.; KUDUK, Scott D.; LIVERTON, Nigel; LUO, Yunfu; SKUDLAREK, Jason; (79 pag.)WO2016/95204; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 59489-71-3, A common heterocyclic compound, 59489-71-3, name is 2-Amino-5-bromopyrazine, molecular formula is C4H4BrN3, 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.

Description 65: 2-bromo-5-iodopyrazine (D65); In a 1000 ml, ice bath cooled round-bottomed flask was dissolved 5-bromo-2-pyrazinamine D64 (11.3 g) in Acetonitrile (125 ml)/water (188 ml). In the mixture HI 67% water solution (45 ml, 401 mmol) was added. To the solution was added dropwise during 150 minutes a solution of sodium nitrite (31.4 g, 455 mmol) in water (125 ml). After the addition the reaction mixture was sealed, was let to warm-up to room temperature and was heated at 50 0C for 30 hours. After cooling the mixture was poured into 800 ml of 20% NaOH and was extracted with Et2O (3 x 800 ml). Gathered Et2O layers were washed with Na2S2Os saturated solution, dried over Na2SO4 and the solvent was evaporated. The crude was purified by Silica Chromatography (Biotage SP – column size 34Og) using DCM 100% to DCM/MeOH 90: 10 as eluent. It was recovered the title compound D65 (896 mg) as yellow powder. 1H NMR (400 MHz, CHLOROFORM-d) delta ppm 8.49 – 8.56 (m, 1 H) 8.65 (d, 1 H)

The synthetic route of 59489-71-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GLAXO GROUP LIMITED; AMANTINI, David; DI FABIO, Romano; WO2010/122151; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 4744-50-7, A common heterocyclic compound, 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, molecular formula is C6H2N2O3, 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.

General procedure: Pyrazine-2,3-dicarboxylic anhydride (1.0 g, 6.7 mmol) was dissolved in tetrahydrofuran (40 mL)in an Erlenmeyer flask and the corresponding substituted aniline (6.7 mmol, 1 equiv.) was added in one dose. The reaction mixture was stirred for 1 hour at laboratory temperature. Water (30 mL) was added into the mixture followed by the saturated aqueous solution of NaHCO3 until pH 6 to form thecorresponding 3-(phenylcarbamoyl)pyrazine-2-carboxylic acid 1-18. Obtained crystals were filtered off and washed with water. The progress of the procedure was monitored by TLC eluted with thesystem water/butanol/acetic acid 5:4:1.

The synthetic route of 4744-50-7 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Semelkova, Lucia; Jano?cova, Petra; Fernandes, Carlos; Bouz, Ghada; Jand?Ourek, Ond?ej; Kone?na, Klara; Paterova, Pavla; Navratilova, Lucie; Kune?, Ji?i; Dole?al, Martin; Zitko, Jan; Molecules; vol. 22; 9; (2017);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 22047-25-2, 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. 22047-25-2, name is Acetylpyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

[Reference Example 6] 1-(6-Methoxy-3-pyridyl)-5-(2-pyrazinyl)-1H-pyrazole-3-carboxylic acid [Show Image] [Show Image] Lithium bis(trimethylsilyl)amide (a 1.0 M solution in tetrahydrofuran, 11.0 mL) was added to a solution of 1-(2-pyrazinyl)-1-ethanone (1.22 g) in tetrahydrofuran (10 mL) under cooling to -78C, and the resultant mixture was stirred for 55 minutes. Diethyl oxalate (2.05 mL) was added thereto, and the mixture was slowly returned to room temperature, and stirred for 6.5 hours. An aqueous 1 N hydrochloric acid solution (11 mL), water and diethyl ether were added to the reaction solution, and the mixture was partitioned. Then, sodium chloride was added to the aqueous layer to be saturated, and then ethyl acetate was added for extraction. The organic layers were combined, and the solvent was evaporated under reduced pressure, to obtain a crude product of 4-(2-pyrazinyl)-2, 4-dioxobutanoic acid ethyl ester (1.83 g, 82%) as a solid. To a suspension of this crude product (1.58 g) in ethanol (20 mL), a solution formed from a suspension of 5-hydrazino-2-methoxypyridine hydrochloride (1.50 g) of Reference Example 1 in ethanol (80 mL) conditioned with triethylamine (1.9 mL), was added, and the mixture was heated to reflux for 19 hours. Acetic acid (5 mL) was further added to the reaction solution, and the mixture was heated to reflux for 1.5 days. After air cooling, ethyl acetate and a saturated aqueous solution of sodium hydrogen carbonate were added to the reaction solution, and the mixture was partitioned. The organic layer was dried over anhydrous sodium sulfate. After separation by filtration, a residue obtained by evaporating the solvent under reduced pressure was purified by silica gel column chromatography (ethyl acetate-hexane), to obtain 1-(6-methoxy-3-pyridyl)-5-(2-pyrazinyl)-1H-pyrazole-3-carboxylic acid ethyl ester (1.05 g, 45%) as a solid. To a solution of this obtained 1H-pyrazole-3-carboxylic acid ethyl ester product (1.05 g) in ethanol (30 mL), an aqueous 1 N sodium hydroxide solution (10.0 mL) was added, and the mixture was stirred for 16 hours at room temperature. An aqueous 1 N hydrochloric acid solution (15 mL), water and ethyl acetate were added to the reaction solution, and the mixture was partitioned. The organic layer was dried over anhydrous magnesium sulfate. After separation by filtration, the solvent was evaporated under reduced pressure, to obtain a crude product of the title compound (0.883 g, 92%) as a solid. This product was supplied to the subsequent reaction without being purified.

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, Acetylpyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; DAIICHI PHARMACEUTICAL CO., LTD.; EP1785418; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 4744-50-7, 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. 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

General procedure: Pyrazine-2,3-dicarboxylic anhydride (1.0 g, 6.7 mmol) was dissolved in tetrahydrofuran (40 mL)in an Erlenmeyer flask and the corresponding substituted aniline (6.7 mmol, 1 equiv.) was added in one dose. The reaction mixture was stirred for 1 hour at laboratory temperature. Water (30 mL) was added into the mixture followed by the saturated aqueous solution of NaHCO3 until pH 6 to form thecorresponding 3-(phenylcarbamoyl)pyrazine-2-carboxylic acid 1-18. Obtained crystals were filtered off and washed with water. The progress of the procedure was monitored by TLC eluted with thesystem water/butanol/acetic acid 5:4:1.

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

Reference:
Article; Semelkova, Lucia; Jano?cova, Petra; Fernandes, Carlos; Bouz, Ghada; Jand?Ourek, Ond?ej; Kone?na, Klara; Paterova, Pavla; Navratilova, Lucie; Kune?, Ji?i; Dole?al, Martin; Zitko, Jan; Molecules; vol. 22; 9; (2017);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 937669-80-2,Some common heterocyclic compound, 937669-80-2, name is 3-Bromopyrazine-2-carboxylic acid, molecular formula is C5H3BrN2O2, 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.

A mixture of 6-(4,6-dimethylpyrimidin-2-yl)-3 ,6-diazabicyclo [3.2.1 ]octane 10-2 (150 mg, 0.69 mmol), 3-bromopyrazine-2-carboxylic acid (167 mg, 0.83 mmol), EDC (198 mg, 1.03mmol), HOAt (140 mg, 1.03 mmol), and N,N-diisopropylethylamine (0.36 mL, 2.06 mmol) in acetonitrile (1 mL) was stirred at room temperature for 24 h. The reaction was concentrated in vacuo and the crude residue was purified by silica gel chromatography (0-100% EtOAc/hexanes, 20 mm) to give 48-1 as an oil. MS (ESI) mlz: 403.3 (M+H).

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

Reference:
Patent; MERCK SHARP & DOHME CORP.; KUDUK, Scott, D.; REGER, Thomas, S.; ROECKER, Anthony, J.; (0 pag.)WO2016/85783; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem