Pyrazines

33332-29-5, 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. 33332-29-5, name is 2-Amino-5-chloropyrazine, This compound has unique chemical properties. The synthetic route is as follows.

Description 5 2,5-Dichloropyrazine (D5); 5-Chloro-2-pyrazinamine (D4) (753 mg, 5.81 mmol) was dissolved in concentrated hydrochloric acid (8 ml), cooled in an ice-acetone bath and treated with a solution of sodium nitrite (822 mg, 11.9 mmol) in water (6 ml) dropwise over a period of 1 hour. The mixture was transferred to an ice-water bath and left to stir for 1 hour. The mixture was allowed to warm to room temperature over 2 hours, neutralised by addition of an aqueous 50% sodium hydroxide solution and extracted with dichloromethane (x 4). The dichloromethane layers were combined, dried under magnesium sulfate and evaporated. The resulting residue was purified by Biotage column chromatography eluting with 10% ethyl acetate in pentane to afford the title compound (112 mg). ?H NMR (CDCI3) 8.40 (2H, s).

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; GLAXO GROUP LIMITED; WO2005/123723; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, 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. 5049-61-6, name is Pyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows.

Ethyl bromopyruvate (62.9 g) was added to the DME (258 mL) solution of 2-aminopyrazine (24.8 g) at room temperature and stirred for 2.5 h. The reaction mixture was cooled to 0 C. and stirred for 30 min to afford a pale brown precipitate. The precipitate was filtered and washed with Et2O to give pale brown crystals. The suspension of the precipitate (66.1 g) in EtOH (1.29 L) was heated at reflux temperature to turn to clear solution. After refluxing for 2 h, the reaction mixture was concentrated under reduced pressure, then mixed with CHCl3 and saturated NaHCO3aq. The mixture was filtered through a pad of Celite and the separated organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCl3-MeOH (99/1~97/3), and collected fractions were concentrated under reduced pressure followed by recrystallization from CHCl3-Et2O. The titled compound was obtained as pale pink crystals. Yield: 10.9 g, 22%). 1H NMR(CDCl3)delta d 1.46(t, 3H, J=7.2 Hz), 4.49(q, 2H, J=7.2 Hz), 7.96(d, 1H, J=4.7 Hz), 8.08(dd, 1H, J=1.2, 4.7 Hz), 8.26(s, 1H), 9.21 (d, 1H, J=1.2 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; Wyeth; US2006/276445; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

4858-85-9, 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 4858-85-9 as follows.

2,3-Dichloropyrazine A-1 (15 g; 100.68 mmol) and hydrazine hydrate 65 % (15.509 ml; 201.37 mmol) are dissolved in 45 ml ethanol and stirred for 1 h at 80 C. While cooling down, a precipitate is formed. It is slurred up with a small amount of water and filtered off. It is washed with water and then dried to afford the product. Yield: 93% (13.6 g; 94.07mmol) HPLC-MS: (M+H)+ = 145/147; tRet = 0.34 min; method FECB5

According to the analysis of related databases, 2,3-Dichloropyrazine, the application of this compound in the production field has become more and more popular.

Reference:
Patent; BOEHRINGER INGELHEIM INTERNATIONAL GMBH; ENGELHARDT, Harald; WO2015/67770; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 5521-58-4, name is 5-Methylpyrazin-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. 5521-58-4

1-Chloro-N,N,2-trimethyl-l-propenylamine (0.86 g, 6.56 mmol) was added to a solution of 3- [4-(azetidin-1-ylcarbonyl)-2-fluorophenoxy]-5-(( 15)-2- {(tert-butyl( dimethyl)silyl]oxy} -1- methylethoxy)benzoic acid (3 g, 5.96 mmol) in DCM (100 mL) and stirred at RT for Ihour. 2- Amino-5-methylpyrazine (1.3 g, 11.9 mmol) and pyridine (0.94 mL, 11.9 mmol) were added and the reaction stirred for a further 30 mins. The solvent was removed in vacuo. Water (100 mL) was added and the mixture extracted with ethyl acetate (3 x 50 mL). The extracts were combined and washed with water (100 mL), brine (100 mL), dried (MgS04), filtered, and evaporated in vacuo to give the crude product which was chromatographed on silica, eluting with a gradient of 50-100% ethyl acetate in isohexane, to give the desired compound (3.6 g). ?H NMR No. (CDC13): 0.00 (s, 3H), 0.03 (s, 3H), 0.81 (s, 9H), 1.30 (d, 3H), 2.32 (quin, 2H), 2.51 (s, 3H), 3.60-3.80 (m, 2H), 4.20-4.39 (brm, 4H), 4.45 (m, 1H), 6.75 (m, 1H), 7.03 (d, 2H), 7.21 (s, 1 H), 7.40 (d, 1 H), 7.50 (d, 1 H), 8.10 (s, 1 H), 8.27 (s, 1 H), 9.48 (s, 1 H). m/z 595 (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, 5521-58-4, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2005/121110; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6863-73-6, A common compound: 6863-73-6, name is 3-Chloropyrazin-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.

EXAMPLE 1; Tert-butyl 4-(8-(2-fluoro-4-(methylsulfonyl)phenylamino)imidazo[l,2- a]pyrazin-3-yl)-5,6-dihydropyridine-l(2H)-carboxylateStep 1: 8-Chloroimidazo[l,2-a]pyrazine[0313] 3-chloropyrazin-2-amine (21.0 g, 161.54 mmol, 1.00 equiv) was dissolved in isopropyl alcohol (200 mL) in a 500 mL round-bottom flask equipped with a reflux condenser. To this solution was added 2-bromo-l,l-diethoxyethane (160.3 g, 813.71 mmol, 5.00 equiv) in small portions over 10 minutes. The resulting mixture was then allowed to reflux for 2 hours in an oil bath. The reaction was monitored by TLC (EtOAc/PE = 1:1). The mixture was cooled down to room temperature and filtered off to give a yellow cake. The solid was added to a saturated solution of NaHCC>;3 (200 mL) and DCM (IL). Aqueous layer was separated from organic phase and re-extracted with DCM (2x 250 mL). The combined organics were dried over MgSO4, filtered and evaporated to dryness affording 8-chloroimidazo[l,2-a]pyrazine (25 g) as a yellow solid.

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-Chloropyrazin-2-amine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; KALYPSYS, INC.; KAHRAMAN, Mehmet; SMITH, Nicholas, D.; BONNEFOUS, Celine; NOBLE, Stewart, A.; PAYNE, Joseph, E.; WO2010/88518; (2010); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

23688-89-3, Adding some certain compound to certain chemical reactions, such as: 23688-89-3, name is 6-Chloropyrazine-2-carboxylic acid, 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 23688-89-3.

To a 100 ml round bottom flask, 6-chloropyrazine-2-carboxylic acid (Ig, 6.31 mmol) was suspended in dry CH2Cl2 (30ml). Oxalyl chloride (3.78 ml, 7.57 mmol) was added along with a few drop of DMF, the mixture was stirred at room temperature for 12 hrs, N, O- Dimethylhydroxylamine hydrochloride (0.800 g, 8.20 mmol) was added, the resulting mixture was cooled down to 5C, TEA (2.64 ml, 18.92 mmol) was added via a droping funal, the reaction mixture was stirred at room temperature for 30 minutes, filtered and the filter cake was washed with EtOAc, the combinded filtrate was washed with saturated sodium bicarbonate and brine, concentrated to an oil, purified on silica gel with Hexanes/EtOAc solventsto give product (1.06g). MS (ES) MH+: 202 for C7H8ClN3O2

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 23688-89-3.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; BARVIAN, Kevin; BASARAB, Gregory, Steven; GOWRAVARAM, Madhusudhan, Reddy; HAUCK, Sheila, Irene; ZHOU, Fei; WO2010/43893; (2010); 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. 6966-01-4, name is Methyl 3-amino-6-bromopyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., 6966-01-4

K2CO3 (0.89 g, 6.46 mmol) was added to a solution of methyl 3-amino-6-bromopyrazine- 2-carboxylate (0.75 g, 3.23 mmol) in anhydrous DME (15 ml) in a pressure tube. Trimethylboroxine (0.99 ml, 3.56 mmol) was added then the resulting brown suspension was de-gassed by bubbling a stream of nitrogen through the reaction mixture for 5 min. Pd(dppf)2C (0.13 g, 0.16 mmol) was added then the pressure tube was flushed with nitrogen and sealed. The reaction was stirred at 100 C for 16 h then allowed to cool to RT. The resulting suspension was filtered then the solid thus obtained was washed with EtOAc (20 ml). The combined filtrate was concentrated in vacuo. The crude material was purified by flash column chromatography on a silica column (50 g). The column was eluted with EtOAc: heptane, increasing the gradient linearly from 0:100 to 50:50 over 10 column volumes. The desired fractions were combined and evaporated to yield the product as a light yellow solid (470 mg, 87%).1H NMR (250 MHz, DMSO-de) delta 8.18 (s, 1 H), 7.11 (s, 2H), 3.83 (s, 3H), 2.33 (s, 3H). LC/MS (System A): m/z (ESI+) = 168 [MH+], Rt = 0.68 min, UV purity = 100%.

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; ENTERPRISE THERAPEUTICS LIMITED; MCCARTHY, Clive; HARGRAVE, Jonathan David; HAY, Duncan Alexander; SCHOFIELD, Thomas Beauregard; WENT, Naomi; (111 pag.)WO2017/221008; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 132426-19-8, name is 2-Bromo-1-(pyrazin-2-yl)ethanone, 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 132426-19-8, 132426-19-8

Example 76N-(2-amino-phenyl)-4-[4-(4-pyrazin-2-yl-1H-imidazol-2-yl)-tetrahydro-pyran-4-yl]-benzamide; 4-(4-Cyano-tetrahydro-pyran-4-yl)-benzoic acid methyl ester (1.0 g, 4.08 mmol) was suspended in 4.0N NaOH and heated at 110 C. for 1 hour. After the reaction was complete, 2N HCl was slowly added to form a precipitate. The precipitate was then filtered, dried under vacuum, and used for next step without purification. 4-(4-Carboxy-phenyl)-tetrahydro-pyran-4-carboxylic acid (0.4 g, 1.6 mmol) was dissolved in NMP. HATU (1.28 g, 2.1 eq) and DIPEA (0.8 mL, 3.0 eq) were added and stirred at 50 C. for 1 hour. The reaction mixture was cooled down to room temperature and benzyl alcohol (172 mg, 1.0 eq) was added. The reaction mixture was stirred at room temperature overnight. Saturated aqueous solution of NaHCO3 was added to the mixture and was then extracted with EtOAc. The organic phase was dried, evaporated and used for next step without further purification.To a solution of 4-(4-benzyloxycarbonyl-phenyl)-tetrahydro-pyran-4-carboxylic acid (0.3 g, 0.88 mmol) and 2-bromo-1-pyrazin-2-yl-ethanone (210 mg, 1.2 eq) in acetonitrile, TEA (0.18 mL, 1.2 eq) was added and heated in the microwave at 80 C. for 1 hour. The reaction mixture was evaporated and purified by silica gel chromatography (Hex:EtOAc 25:75). 4-(4-benzyloxycarbonyl-phenyl)-tetrahydro-pyran-4-carboxylic acid 2-oxo-2-pyrazin-2-yl-ethyl ester (0.3 g, 0.65 mmol), NH4OAc (110 mg, 2.2 eq) and 3 molecular sieves were mixed together in xylene and heated in the microwave at 160 C. for 1 hour. After the reaction was done, it was extracted with EtOAc and the organic phase was dried and evaporated to be used in the next step without further purifications.Hydrogenation of 4-[4-(4-pyrazin-2-yl-1H-imidazol-2-yl)-tetrahydro-pyran-4-yl]-benzoic acid benzyl ester (0.2 mg, 0.45 mmol) in EtOH, was carried out in the presence of excess Pd/C (10%, dry basis) at a pressure of 1 atmosphere. After 16 hours, the reaction mixture was filtered through a celite pad and washed with hot ethanol. The solution was evaporated and used for next step without further purification.The above acid was then coupled with 1,2-phenylenediamine in the presence of HATU and DIPEA in DMF and purified by reverse phase chromatography to give the title compound. MS found for C25H24N6O2 as (M+H)+ 441.21 1H NMR (400 MHz, dmso-d6): 1H-NMR (DMSO) delta: 10.42 (s, 1H), 9.32 (s, 1H), 8.68-8.64 (m, 2H), 8.37 (s, 1H), 8.07 (d, J=8.4 Hz, 2H), 7.54 (d, J=8.4 Hz, 2H), 7.46-7.28 (m, 5H), 3.82-3.79 (m, 2H), 3.52-3.46 (m, 2H), 2.98-2.95 (m, 2H), 2.40-2.29 (m, 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, 2-Bromo-1-(pyrazin-2-yl)ethanone, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Melvin, JR., Lawrence S.; Graupe, Michael; Venkataramani, Chandrasekar; US2010/22543; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 113305-94-5, name is 5-Aminopyrazine-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. 113305-94-5

A solution of thiophosgene (1.86 g, 15 mmol) in THF (4 mL) is added dropwise to a solution of 5-aminopyrazine-2-carbonitrile (1.20 g, 10 mmol) and pyridine (2 mL) in CH2Cl2 (200 mL) and THF (25 mL) at room temperature. The reaction mixture is stirred at room temperature for 3 h. The mixture is concentrated and the crude product is diluted with ethyl acetate, filtered and concentrated to give the title compound.

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, 113305-94-5, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Farouz, Francine S.; Holcomb, Ryan Coatsworth; Kasar, Ramesh; Myers, Steven Scott; US2011/144126; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, molecular formula is C6H6N2O2, 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. 5521-55-1

A solution of compound 20-12 (0.2 g, 0.2 mmol) in isopropanol (2 mL) was cooled to 0 C, and a solution of HC1 in isopropanol (40%, 5 mL) was added. The mixture was stirred until no more gas evolution. The mixture was filtered to afford a white solid; the solid was washed with EtOAc (5 mL). A round-bottom flask was charged with the white solid, compound 22-1 (0.1 g, 0.7 mmol), EDCI (0.2 g, 1.5 mmol) and HOAT (0.15 g, 1.1 mmol), and then DCM (10 mL) was added under N2. The mixture was cooled to 0 C, and DIPEA (0.5 mL, 3 mmol) was added slowly. The mixture was stirred at 30 C for 6 hours. After the reaction was complete, the mixture was quenched with water (10 mL). The resulting mixture was extracted with DCM (10 mL) twice. The combined organic layers were washed with saturated aqueous NaC1 (10 mL), dried over anhydrous Na2SO4, and then concentrated in vacuo. The residue was purified by silica gel column chromatography eluted with PE : EtOAc (V:V) = 2:1 to give compound 20-2 (0.163 g, 70%) as a white solid.MS (ESI, pos.ion) m/z: 900.4[M+1] and ?HNMR (600 MHz, CDC13): (510.25 (s, 1H), 9.07 (s, 1H), 8.43 (s, 1H), 8.17 (d, J= 6.8 Hz,1H), 7.86-7.78 (m, 2H), 7.48 (s, 1H), 7.05 (s, 1H), 6.95 (d, J 9.1 Hz, 1H), 5.74 (dd, J 18.0,8.6 Hz, 1H), 5.51 (s, 1H), 5.02 (t, J= 9.5 Hz, 1H), 4.72-4.65 (m, 2H), 4.51 (d, J= 11.4 Hz, 1H),4.14-4.11 (m, 1H), 3.78 (s, 3H), 3.26-3.19 (m, 2H), 2.74-2.69 (m, 1H), 2.67-2.55 (m, 9H),2.29 (dd, J= 17.3, 8.6 Hz, 1H), 2.07 -2.00 (m, 2H), 1.95 – 1.89 (m, 2H), 1.78 (t, J= 10.0 Hz,1H), 1.64 (dd, J= 9.2, 5.9 Hz, 1H), 1.50 (s, 3H), 1.41 (d, J= 6.9 Hz, 7H), 1.27 (d, J= 3.5 Hz,2H), 1.20 (s, 3H), 0.92- 0.75 (m, 3H) ppm.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 5521-55-1, its application will become more common.

Reference:
Patent; SUNSHINE LAKE PHARMA CO., LTD.; ZHANG, Yingjun; LUO, Huichao; REN, Qingyun; XIONG, Zhimin; LIU, Yang; LEI, Yibo; XIONG, Jinfeng; ZHANG, Jiancun; (123 pag.)WO2016/127859; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem