Category: Pyrazines

117103-53-4, name is 2-Bromo-5-nitropyrazine, 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. HPLC of Formula: C4H2BrN3O2

Example 13 2 (R)- (3-CHLORO-4-METHANESULFONYL-PHENYL)-3-CYCLOPENTYL-N- (5- METHANESULFONYLAMINO-PYRAZIN-2-YL)-PROPIONAMIDE [000164] A solution of molten acetamide (1.58 g, 26.7 mmol) heated to 90C was treated with a mixture of 2-bromo-5-nitropyrazine (1.34 g, 6.58 MMOL), METHANESULFONAMIDE (1.88 g, 19.7 mmol), and potassium carbonate (2.30 g, 16.6 mmol). The resulting mixture was quickly brought to 145C. The resulting solution was stirred at 145C for 30 min. At this time, the reaction was cooled to 25C and then was treated with water (4 mL). This solution was cooled to 0C and then was treated with a IN aqueous hydrochloric acid solution until the pH of the solution was adjusted to pH=8. This solution was treated with charcoal and was filtered through a pad of celite (90/10 methylene chloride/methanol wash). The filtrate was partitioned, and the aqueous layer was extracted with a solution of 90/10 methylene CHLORIDE/METHANOL. The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60,230-400 mesh, ethyl acetate) afforded N- (5-nitro- PYRAZIN-2-YL)-METHANESULFONAMIDE (583.9 mg, 40.6%) as a yellow solid: mp 204-207C ; EI-HRMS m/e calcd for C5H6N404S (M+H) + 219. 0183, found 219.0185.

The synthetic route of 117103-53-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; WO2004/52869; (2004); 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. 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, A new synthetic method of this compound is introduced below., Formula: C6H4BrN3

Weigh 50g of 3-ethynyl-4-methyl benzoic acid methyl ester,56.9 g of 5-bromopyrrolo [2,3-b] pyrazine and 58 g of triethylamine in a reaction vessel,Add 500mL of N, N-dimethylacetamide dissolved,50 C,Under argon atmosphere, 8.0 g of PdCl2 (PPh3) 2 and 2.2 g of CuI were added,The reaction was heated to 80 for 24h.After the reaction,The reaction solution was slowly poured into aqueous ammonium chloride (35g of ammonium chloride dissolved in 700mL of purified water)After stirring 0.5h centrifugation,Drying gave the title compound,Yield 88%.

The synthetic route of 875781-43-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Nanjing Shenghe Pharmaceutical Co., Ltd.; Wang Yong; Sha Xiangyang; Li Erna; Zhao Liwen; (10 pag.)CN106632347; (2017); A;,
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Pyrazine | C4H4N2 – PubChem

Electric Literature of 109838-85-9, A common heterocyclic compound, 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, molecular formula is C9H16N2O2, 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.

Step B – Preparation of Compound Int-16cTo a 500 mL flame dried flask was added (R)-2-isopropyl-3, 6-dimethoxy-2,5- dihydropyrazine (10.0 g, 54.3 mmol) and anhydrous THF (200 mL). The solution was cooled to -78 ¡ãC. “-BuLi (2.5M in hexane, 24.0 mL, 59.7 mmol) was added dropwise. After the solution was allowed to stir at -78 ¡ãC for 30 minutes, compound Int-16b (in 5 mL anhydrous THF) was added dropwise. After the solution was allowed to stir at -78 ¡ãC for 1 hour, it was allowed to warm up to room temperature in two hours. Water (100 mL) and Et20 (150 mL) were added. The organic layer was separated and the aqueous layer was extracted with Et20 (100 mL) twice. The organic layers were combined, washed with brine, dried over Na2S04, filtered and concentrated in vacuo. The residue obtained was purified using Si02 chromatography (40 g, eluted with Et20 in Hexane: 0percent to 3percent) to provide compound Int-16c (10.43 g, 58.0percent).

The synthetic route of 109838-85-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MERCK SHARP & DOHME CORP.; DWYER, Michael P; KEERTIKAR, Kartik M; COBURN, Craig A; WU, Hao; HU, Bin; ZHONG, Bin; ZHANG, Chengren; DAN, Zhigang; WO2012/40924; (2012); A1;,
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Application of 32974-92-8, 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. 32974-92-8, name is 1-(3-Ethylpyrazin-2-yl)ethanone, This compound has unique chemical properties. The synthetic route is as follows.

General procedure: The ligands L1-L4 were synthesized by reflux method. Shown in Scheme 1, 5mM of 2-Acetyl-3-ethylpyrazine and thiosemicarbazides (L1), 5mM of 2-Acetyl-3-ethylpyrazine and 4-methylthiosemicarbazide (L2), 5mM of 2-Acetyl-3-ethylpyrazine and 4-phenylthiosemicarbazide (L3), and 5mM of 2-Acetyl-3-ethylpyrazine and 3-pyrrolethiosemicarbazide (L4) were stirred in CH3OH for 3 h at 65C. The ligands were precipitated and filtered. L1-L4 were characterized by infrared spectroscopy, electrospray ionization mass spectrometry (ESI-MS), 1H NMR, and 13C NMR (Supplementary Figs S4- S31).

The chemical industry reduces the impact on the environment during synthesis 1-(3-Ethylpyrazin-2-yl)ethanone. I believe this compound will play a more active role in future production and life.

Reference:
Article; Khan, Muhammad Hamid; Cai, Meiling; Li, Shanhe; Zhang, Zhenlei; Zhang, Juzheng; Wen, Xiaoan; Sun, Hongbin; Liang, Hong; Yang, Feng; European Journal of Medicinal Chemistry; vol. 182; (2019);,
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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. 41110-29-6, name is Methyl 3-methylpyrazine-2-carboxylate, This compound has unique chemical properties. The synthetic route is as follows., HPLC of Formula: C7H8N2O2

In a 1 -L flask, the methyl 3-methylpyrazine-2- carboxylate (265A, 16.08 g, 106 mmol) was suspended in CHCl3 (300 mL). 3- Chlorobenzoperoxoic acid (Aldrich, 24.62 g, 143 mmol) was added. The reaction mixture was heated to 70 C for 16 h. The reaction mixture was quenched with saturated NaHCO3 (200 mL). The layers were separated, and the aqueous layer was further extracted with DCM (2 x 100 mL). The combined organic layers were dried over MgSO4, and the filtrate was concentrated to afford crude 3-(methoxycarbonyl)-2-methylpyrazine 1 -oxide (17.77 g). MS m/z=169 [M+H]+. In a 1 -L flask, the crude 3-(methoxycarbonyl)-2-methylpyrazine 1 -oxide (17.77 g, 106 mmol) was dissolved in DMF (300 mL). Neat phosphoryl trichloride (29.6 mL, 317 mmol) was added. The reaction mixture was heated to 100 C. After 1 h, the reaction mixture was concentrated to remove most of the DMF. The flask was cooled in an ice water bath, and 1 M aqueous Na2CO3 (300 mL) was added slowly, followed by 80% EtOAc-hexane (400 mL). The mixture was filtered through Celite filter aid. The resulting filtrate was partitioned and the aqueous phase was extracted further with 80% EtOAc-hexane (2 x 250 mL). The combined organic layers were dried over MgSO4 and concentrated. The material was purified through silica gel using 11 % EtOAc-hexane to afford methyl 5-chloro-3-methylpyrazine-2-carboxylate (265B, 4.29 g, 23 mmol, 22%). MS m/z=187 [M+H]+.

According to the analysis of related databases, 41110-29-6, the application of this compound in the production field has become more and more popular.

Reference:
Patent; AMGEN INC.; ALLEN, Jennifer R.; AMEGADZIE, Albert; BOURBEAU, Matthew P.; BROWN, James A.; CHEN, Jian J.; CHENG, Yuan; FROHN, Michael J.; GUZMAN-PEREZ, Angel; HARRINGTON, Paul E.; LIU, Longbin; LIU, Qingyian; LOW, Jonathan D.; MA, Vu Van; MANNING, James; MINATTI, Ana Elena; NGUYEN, Thomas T.; NISHMURA, Nobuko; NORMAN, Mark H.; PETTUS, Liping H.; PICKRELL, Alexander J.; QIAN, Wenyuan; RUMFELT, Shannon; RZASA, Robert M.; SIEGMUND, Aaron C.; STEC, Markian M.; WHITE, Ryan; XUE, Qiufen; (759 pag.)WO2016/22724; (2016); A1;,
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Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 1458-01-1, name is Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, 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. Formula: C6H7ClN4O2

4-(4-Aminophenyl)ethylamidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride (83) A mixture of 1-H-pyrazolecarboxamidine hydrochloride (2.8 g, 19 mmol), 4-aminoethylaniline (1.3 mL, 9 mmol) and diisopropylethylamine (1.3 ml) were stirred in dry DMF (5 mL) under argon for 18 h. After this time, ether (30 ml) was added to produce a clear oil. The obtained oil (82) was washed with ether and dried under vacuum (40 mTorr) overnight. After drying 70 mg of oil was taken into dry methanol (3 mL) and 25percent NaOH (0.14 mL) was added. The reaction volume was decreased to 1.0 mL and 3,5-diamino-6-chloropyrazine-2 carboxylic acid methyl ester (0.1 g, 0.5 mmol) was added. The mixture was stirred at room temperature overnight. Another portion of 82 (0.1 g) was dissolved in methanol (1 mL), treated with 25percent NaOH (0.15 mL) and the resulting solution was added to the reaction mixture. The reaction mixture was stirred 3 h at reflux, then cooled to room temperature and the solvent was removed under reduced pressure. The residue was dissolved in a minimal volume of DMF and separated by preparative HPLC. The obtained fractions were analyzed by LC/MS. The fractions containing product with M+H=349 were collected and the solvent was removed under reduced pressure. The residue was dissolved in 10percent HCl and evaporated to dryness to produce 83 (23.5 mg, 11percent) as a yellow solid. 1H NMR (360 MHz, DMSO-d6) delta 2.91 (m, 2H), 3.59 (m, 2H), 7.31 (d, 2H), 7.42 (m, 4H), 9.02 (br s, 2H), 9.41 (br s., 1H), 10.56 (s, 1H). 13C NMR (90 MHz, DMSO-d6) 33.1, 42.0, 108.9, 119.6, 120.7, 129.9 (2 C), 131.0 (2 C), 153.1, 154.1, 155.8, 165.2. API MS m/z=349 [C14H17ClN8O+H]+.

The synthetic route of Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PARION SCIENCES, INC.; JOHNSON, Michael Ross; (49 pag.)US2015/376146; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 23229-26-7, These common heterocyclic compound, 23229-26-7, name is 2,5-Dibromopyrazine, 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.

To a flask, an appropriate pyrazine, pyrimidine or thiazole (1.0 equivalent) and a nucleophile (Nu), such as amine, alcohol or thio-derivatives in one equivalence or an exess amount were combined in a solvent such as THF, DMF or alcohol, with or without an addition of NaH. The reaction was either stirred at room temperature or under heating for one to three days. After all the solvents were removed, the residue was partitioned between saturated NaHCO3 and EtOAc. The aqueous layer was extracted with ethyl acetate and the combined extracts were concentrated in vacuo to give a residue, which was purified by silica gel chromatography to afford the desired product.

The synthetic route of 23229-26-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Wang, Tao; Zhang, Zhongxing; Meanwell, Nicholas A.; Kadow, John F.; Yin, Zhiwei; Xue, Qiufen May; Regueiro-Ren, Alicia; Matiskella, John D.; Ueda, Yasutsugu; US2004/110785; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 113305-94-5,Some common heterocyclic compound, 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, molecular formula is C5H4N4, 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 solution of 2-amino-5-cyanopyrazine (500.0 mg, 4.162 mmol) in 1,4- dioxane (8.3 ML) was treated with 4- (dimethylamino) pyridine (305.1 mg, 2.497 mmol), N, N, N’, N’-TETRAMETHYLETHYLENEDIAMINE (241.8 mg, 2.081 mmol), and di-tert-butyl dicarbonate (2.9 mL, 12.49 mmol). The reaction stirred at 25C for 20 h and then was concentrated in vacuo. Biotage chromatography (FLASH 40M, Silica, 10% ethyl acetate/hexanes) afforded 5- [ [BIS [ (L, 1-dimethylethoxy) carbonyl] ] amino]-2- pyrazinecarbonitrile as a white solid: mp 67-68C ; (ES) +-HRMS m/e calcd for CISH2ON404 (M+Na) + 343. 1377, found 343.1379.

The synthetic route of 113305-94-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; WO2004/52869; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 109-08-0, name is 2-Methylpyrazine, molecular formula is C5H6N2, 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. Computed Properties of C5H6N2

Step C??Synthesis of mt 7-3 10347] To a solution of 2-methylpyrazine (272 mg, 2.9 mmol) and HMPA (520 mg, 2.9 mmol) in THF (2.5 mE) was added EDA (1.6 mE, 3 mmol) at ?78¡ã C. dropwise. The mixture was allowed to stir at ?78¡ã C. for 30 minutes before a solution of mt 7-2 (600 mg, 2.45 mmol) in 2 mE of THF was added. The mixture was allowed to warm to room temperature for 3 hours before it was quenched with 10 mE of saturated NH4C1 solution. The resulting mixture was extracted with EtOAc (3×10 mE) and the combined organic washings were dried over sodium sulfate, filtered and in vacuo. The resulting residue was purified using column chromatography (25percent EtOAc/petroleum ether) to provide mt 7-3 (100 mg, 12percent). MS (ESI): mlz (M+H) 339.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 109-08-0, its application will become more common.

Reference:
Patent; Coburn, Craig A.; Maletic, Milana; Soll, Richard; Li, Chunsing; Luo, Yunfu; Qi, Zhiqi; US2014/5103; (2014); A1;,
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Pyrazine | C4H4N2 – PubChem

Related Products of 21943-12-4,Some common heterocyclic compound, 21943-12-4, name is 2-Amino-3-bromopyrazine, molecular formula is C4H4BrN3, 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: Step 1: A vial equipped with a magnetic stir bar was charged with the ortho-haloaminopyridine and BrettPhos G1 precatalyst (6 mol %). The vial was sealed with a teflon screw cap, and evacuated and backfilled with argon three times. The amine (1 to 1.5 mol eq) was added via syringe, followed by LiHMDS solution (1M in THF, 2.5 mol eq). Amines that were solid at room temperature were added with the catalyst. The reaction mixture was stirred at 40 C for 4-18 h, until LC/MS indicated complete conversion of the starting material. The mixture was cooled to room temperature, diluted with dichloromethane, and poured into water. The organic phase was separated and the aqueous phase was extracted twice more with dichloromethane. The combined organic phases were dried over Na2SO4. The solvent was removed under reduced pressure.

The synthetic route of 21943-12-4 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Li, Chaomin; Chen, Lily; Steinhuebel, Dietrich; Goodman, Andrew; Tetrahedron Letters; vol. 57; 25; (2016); p. 2708 – 2712;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem