Month: February 2021

Application of 36070-80-1, A common heterocyclic compound, 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, molecular formula is C5H3ClN2O2, 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.

At 0 C., a solution of compound (4-2) (0.89 g. 5 mmol) in dichloromethane (20 mL) is added into a solution of 3-methoxy aniline (0.62 g, 5 mmol) and triethylamine (1.01 g, 10 mmol) in dichloromethane (100 mL) over 30 minutes, and the reaction mixture is heated to room temperature overnight. The reaction mixture is diluted with dichloromethane (100 mL), and the organic phase is washed with water and brine, dried through anhydrous sodium sulfate and filtered. After being evaporated, the residue is purified by silica gel column chromatography to give compound (4-3) (1.1 g, 80%),

The synthetic route of 36070-80-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; HANGZHOU BENSHENG PHARACEUTICALS CO., LTD.; Xu, Rongzhen; Xie, Fuwen; Lai, Hongxi; Rong, Frank; US2013/178470; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 33332-29-5, name is 2-Amino-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 33332-29-5, name: 2-Amino-5-chloropyrazine

(c) 2-Amino-5-chloropyrazine (1.7 g) was dissolved in chloroform (190 ml) and pyridine (1.3 ml) was added under an argon atomosphere. 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. 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. Volatile material was removed by evaporation and 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, 2 H), 8.09 (s, 1 H); mass spectrum (+vc CI): 208 (M+H)+.

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; Zeneca Limited; US5866568; (1999); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 6705-33-5, 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 6705-33-5 as follows.

To a mixture of 5-[4-(trifluoromethoxy)phenyl]-3H-l,3-benzoxazol-2-one (100 mg, 0.34 mmol), pyrazin-2-ylmethanol (111.9 mg, 1.02 mmol) and PPh3 (177.7 mg, 0.68 mmol) in THF (6 mL) was added the DIAD (136.99 mg, 0.68 mmol) at 0 C and the mixture was stirred under N2 at 20 C for 16 hours to give the mixture. The mixture was concentrated to dryness, diluted with H20 (10 mL), and extracted with EtOAc (10 mL chi 2). The combined organic phase was washed with brine (10 mL), dried over Na2SC>4, filtered and the filtrate was concentrated to give the crude product. The crude product was purified by flash chromatography on silica gel (EtOAc in PE = 0% to 35% to 45% to 60%) to give the product (100.9 mg, 260.4 muiotaetaomicron, 77% yield) as an oil. *H NMR DMSO-< 400MHz deltaH = 8.83 (s, 1H), 8.60 - 8.53 (m, 2H), 7.74 (d, 2H), 7.63 (s, 1H), 7.50 - 7.42 (m, 4H), 5.35 (s, 2H). LCMS Rt = 1.52 min in 2 min chromatography, MS ESI calcd. for C19H13F3N3O3 [M+H]+ 388.1, found 388.1. According to the analysis of related databases, 6705-33-5, the application of this compound in the production field has become more and more popular. Reference:
Patent; PRAXIS PRECISION MEDICINES , INC.; REDDY, Kiran; MARTINEZ BOTELLA, Gabriel; GRIFFIN, Andrew, Mark; MARRON, Brian, Edward; (244 pag.)WO2018/148745; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 16298-03-6, 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 16298-03-6 as follows.

Bromine (3.91 g, 24.46 mmol) was added dropwise to a stirred mixture of 3- aminopyrazine-2-carboxylic acid methyl ester (1.27 g, 8.29 mmol) and hydrobromic acid (4.70 mL, 41.5 mmol) at 00C. A solution of sodium nitrite (1.44 g, 20.9 mmol) in water (6 mL) was then added dropwise. The reaction mixture was stirred for 15 min, brought to pH 8 with NaHCO3 (saturated, aqueous), and extracted with ethyl acetate (80 mL) and chloroform (50 mL). The combined organics were dried over MgSO4 and concentrated in vacuoto give 1.13 g (63%) of an orange oil which solidified on standing.

According to the analysis of related databases, 16298-03-6, the application of this compound in the production field has become more and more popular.

Reference:
Patent; BAYER PHARMACEUTICALS CORPORATION; WO2006/121588; (2006); A2;; ; Patent; BAYER PHARMACEUTICALS CORPORATION; WO2006/121860; (2006); A2;; ; Patent; BAYER PHARMACEUTICALS CORPORATION; WO2006/121904; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 4774-14-5, 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. 4774-14-5, name is 2,6-Dichloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

To a mixture of 2,6-dichloropyrazine (12.5 g, 83.91 mmol), 4-methylbenzenesulfonic acid hydrate (32 g, 168.2 mmol), NaI (120 g, 800.6 mmol) and 1,4,7,10,13- pentaoxacyclopentadecane (10 mL, 50.35 mmol) was added thiolane 1 ,1 -dioxide (200 mL) and the mixture heated to 150 0C and stirred for 3 hrs. The mixture was allowed to cool and added water 150 ml and neutralized with solid NaHCtheta3 It was then extracted into ether (3x300ml), washed with Sat. NaHCO3, brine then dried (MgSO4) and concentrated to give an orange solid. The product was washed with water and dried under high vacuum to give 2,6-diiodopyrazine as an orange solid (8.6 g, 31%). ES+ 332. IHNMR (CDCl3) 8.73 (2H, s).

The synthetic route of 2,6-Dichloropyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; VERTEX PHARMACEUTICALS INCORPORATED; JIMENEZ, Juan-Miguel; STUDLEY, John; WO2010/11772; (2010); A2;,
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 23229-26-7 as follows. Computed Properties of C4H2Br2N2

(107d) 2-Bromo-5-(methylsulfonyl)pyrazine 2,5-Dibromopyrazine (270 mg, 1.14 mmol) was dissolved in tetrahydrofuran (10 mL), and sodium thiomethoxide (320 mg, 4.57 mmol) was added at room temperature, followed by stirring at room temperature for 2.5 hours under nitrogen atmosphere. To this reaction solution, water (10 mL) was added, and extraction was carried out with diethyl ether (10 mL). The organic layer was washed with saturated brine, and subsequently dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting residue was purified using silica gel column chromatography (elution solvent: ethyl acetate/hexane=5%-10%) to afford a yellow solid. This was dissolved in methylene chloride (10 mL), and m-chloroperbenzoic acid (approximately 65%, 580 mg, approximately 2.2 mmol) was added at room temperature, followed by stirring at room temperature for 1 hour under nitrogen atmosphere. To this reaction solution, a saturated aqueous sodium hydrogencarbonate solution (10 mL) was added, and extraction was carried out with methylene chloride (10 mL). The organic layer was washed with saturated brine, and subsequently dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting residue was purified using silica gel column chromatography (elution solvent: ethyl acetate/hexane=15%-25%) to afford the desired compound (190 mg, yield 70%) as a white solid. 1H-NMR (CDCl3, 400 MHz): delta 3.26 (3H, s), 8.80 (1H, d, J=1.2 Hz), 9.06 (1H, d, J=1.2 Hz).

According to the analysis of related databases, 23229-26-7, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Daiichi Sankyo Company, Limited; EP2239253; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 21279-62-9, name is 3-Chloropyrazine-2-carboxamide, 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 21279-62-9, name: 3-Chloropyrazine-2-carboxamide

General procedure: Compounds 1-6 were prepared according to conventional organic synthesis methods. 3-Chloropyrazine-2-carboxamide (1.27 mmol) was dissolved in THF (20 mL) in a round bottom flask and after that treated with two equivalents of the corresponding benzylamine and an equimolar amount of triethylamine. The reaction was conducted with continuous stirring and heating (70 C) under reflux in an oil bath for 15 h. Compounds 7-15 were synthesised using a microwave reactor with a focused field. 3-Chloropyrazine-2-carboxamide (1.27 mmol) was put into a thick-walled tube together with the corresponding benzylamine (2.54 mmol), pyridine (1.27 mmol), methanol (approx. 5 mL) and a magnetic stir bar and then sealed with a special cap. The reaction parameters were set according to the previously published paper as follows-140 C, 30 min, 200 W [29]. Reaction progress was checked by TLC (hexane:ethyl acetate-1:1). Regardless of the synthesis method used,all reaction mixtures were adsorbed on silica and subjected to preparative flash chromatography (hexane and ethyl acetate, gradient elution, detection wavelengths 260 nm and 280 nm). Products were recrystallized from ethanol or ethanol and water if necessary. All final substances were chemically characterized (1H-NMR, 13C-NMR, IR, melting point and elemental analysis).

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

Reference:
Article; Jandourek, Ondrej; Tauchman, Marek; Paterova, Pavla; Konecna, Klara; Navratilova, Lucie; Kubicek, Vladimir; Holas, Ondrej; Zitko, Jan; Dolezal, Martin; Molecules; vol. 22; 2; (2017);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 6966-01-4, The chemical industry reduces the impact on the environment during synthesis 6966-01-4, name is Methyl 3-amino-6-bromopyrazine-2-carboxylate, I believe this compound will play a more active role in future production and life.

A mixture of Pd(OAc)2 (146 mg, 0.7 mmol) and 1,1-bis(diphenylphosphino)ferrocene (478 mg, 0.9 mmol) in DMF (65 ml) under an argon atmosphere was stirred at 50 for 15 min and cooled to rt. The reaction mixture was evacuated, then flushed with argon. 3-Amino-6-bromopyrazine-2-carboxylic acid methyl ester (5.0 g, 21.5 mmol), 2-furanboronic acid (2.65 g, 23.7 mmol) and triethylamine (4.3 ml) were added. The reaction mixture was again evacuated, then flushed with argon. The mixture was heated at 90 overnight. After cooling to rt, the black mixture was concentrated to dryness. The residue was dissolved in dichloromethane (800 ml), washed with water, dried over MgSO4, filtered and evaporated. The crude product was purified by silica gel chromatography using a n-heptane /EtOAc gradient for elution, providing the title compound as yellow solid (2.84 g, 60%).MS: M=220.3 (M+H)+

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 3-amino-6-bromopyrazine-2-carboxylate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Bleicher, Konrad; Flohr, Alexander; Groebke Zbinden, Katrin; Gruber, Felix; Koerner, Matthias; Kuhn, Bernd; Peters, Jens-Uwe; Sarmiento, Rosa Maria Rodriguez; US2011/306589; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

63286-28-2, name is 2-Chloro-3-hydrazinylpyrazine, belongs to Pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. Computed Properties of C4H5ClN4

STEP2 Preparation of N’-(3-chloropyrazin-2-yl)-2,2,2-trifluoroacetohydrazide To a solution of 2-chloro-3-hydrazinylpyrazine (4.50 g, 31.1 mmol) in THF (104 mL) was dropwise added TFAA (5.72 mL, 40.5 mmol) at 0 C. The reaction mixture was stirred at room temperature for 1 hour and MeOH:DCMuenched with water. The mixture was extracted DCM, washed with water, dried over Na2SO4, filtered and concentrated in vacuo to afford N’-(3-chloropyrazin-2-yl)-2,2,2-trifluoroacetohydrazide (2.76 g, 37%) as a yellow solid, which was used for the next reaction without further purification. 1H-NMR (DMSO-d6, 400 MHz): delta 11.6 (1H, s), 9.47 (1H, s), 8.18 (1H, d, J=2.8 Hz), 7.88 (1H, d, J=2.4 Hz).

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

Reference:
Patent; HANDOK INC.; Lee, Jin-Hwa; Kim, Seung-Yong; Kim, Do-Ran; Ahn, Koo-Hyeon; Lee, Gwi-Bin; Kim, Doo-Seop; Hwang, Hyun-Sook; (74 pag.)US2017/204101; (2017); 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. 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., Product Details of 33332-25-1

Sodium hydride (60% dispersion in mineral oil) (6.4 g, 0.16 mol) was added portionwise to a solution of 7-hydroxy-1, 2,4, 5-tetrahydro-benzo [DIAZEPINE-3-CARBOXYLIC acid TERT-BUTYL ester (PCT Int. APPL. (2002), WO 02/40471) (40 g, 0.15 mol) in dry dimethylformamide (200 ml) cooled to 5 C over 15 minutes. After 15 minutes, the mixture was allowed to warm to room temperature and stirred for 60 minutes. The mixture was cooled in an ice-water bath and methyl 5-chloro-2-pyrazinecarboxylate (31.2 g, 0.18 mol) was added portionwise. The mixture was allowed to warm to room temperature and stirred for 18 hours. The mixture was poured onto water (500 mi) and ice (500 ml) and stirred until the ice had melted. The resulting solid was collected by filtration, washed with water and dissolved in ethyl acetate (1500 ML). The ethyl acetate layer was washed with brine (200 ML), dried under sodium sulfate and evaporated in vacuo. The crude product was purified by column chromatography eluting with a mixture of ethyl acetate: hexane (1: 2) to afford the title compound (35.07 g).

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; WO2004/56369; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem