Pyrazines

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. 4858-85-9, name is 2,3-Dichloropyrazine, A new synthetic method of this compound is introduced below., Safety of 2,3-Dichloropyrazine

To a solution of 2,3-dichloro-pyrazine (10 g) (commercially available) and N,N- dimethylformamide (“DMF”) (80 ml) was added diethylmalonate (26.87 g) and potassium carbonate (23.19 g). The reaction mixture was heated to 1 10C for 8 hours. The reaction mixture was cooled to ambient temperature, filtered and the filtrate concentrated. The residue was purified by chromatography on silica gel (eluent 5-95% ethyl acetate in isohexane) to give 2-(3-Chloro-pyrazin-2-yl)-malonic acid diethyl ester (12.93 g). 1 H- NMR (400MHz, CDCI3): 8.50 (s, 1 H), 8.40 (s, 1 H), 5.20 (s, 1 H), 4.30 (q, 4H), 1.30 (t, 6H) ppm.

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; SYNGENTA LIMITED; SYNGENTA PARTICIPATIONS AG; AVERY, Alaric; DE MESMAEKER, Alain; MULHOLLAND, Nicholas; WILLETTS, Nigel; WORTHINGTON, Paul; WO2012/62531; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 5049-61-6, These common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, 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: In a stainless reactor bomb, the respective aromatic amine (1.0mmol), 4c (0.50 mol%), K2CO3 (5.0 mol%), and MeOH (1.0 mL) were placed. Then, the reactor was sealed with a stainless stopper, and the mixture was stirred for 17 h at 120 C. After removing MeOH under reduced pressure, the products were isolated by silica gel column chromatography.

The synthetic route of 5049-61-6 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Toyooka, Genki; Tuji, Akiko; Fujita, Ken-Ichi; Synthesis; vol. 50; 23; (2018); p. 4617 – 4626;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 13515-06-5,Some common heterocyclic compound, 13515-06-5, name is 5,6-Dimethylpyrazine-2-carboxylic acid, molecular formula is C7H8N2O2, 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.

5,6-Dimethylpyrazine acid (0.27 mmol, prepared as Example 2), EDCI (0.35mmol) And DMAP (0.027 mmol) were dissolved in dry methylene chloride (20 mL). The compound hederagenin alcohol (140 mg, 0.27 mmol, prepared as Example 3) was dissolved in dichloromethane (20 mL). This solution was dropped into 5,6-methylpyrazine acid solution within 20 minutes, and stirred at room temperature for 12 hours. The reaction mixture was then diluted with dichloromethane (20 mL), washed with saturated aqueous NaCl solution, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain a white powder, H-11. Yield: 25% (after chromatograph with DCM / MeOH, 1% -2%) as a white powder, m.p .: 146.2 C.

The synthetic route of 13515-06-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Xinhuo Zhiyao (Beijing) Technology Co., Ltd.; Fang Kang; Guo Wenbo; Wang Penglong; Cheng Gang; (26 pag.)CN110964078; (2020); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 109838-85-9, 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 109838-85-9 as follows.

Preparation 34: ((lS,2RV3-amino-l-(3,5-difluorotenzyl)-2-hydroxy-propyl)carbamic acid t-butyl esterStepA: (2S,5R)-2-(3,5-difluorobenzyl)-5-isopropyl-3,6-dimethoxy-2,5-dihvdropyrazine(R)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine was dissolved THF and n-BuLi was added thereto at -78 °C, followed by addition of difluorobenzyl chloride. After the reaction was complete, NH4Cl was added to the reaction mixture, followed by extraction with EtOAc. The organic extract was dried over MgSO4 and concentrated under reduced pressure. The residue was purified by column chromatography (eluent: EtOAc: n-Hex = 1/1) to afford the title compound (339 mg, 80percent).MSbetaVI+l] = 313 (M+l)

According to the analysis of related databases, 109838-85-9, the application of this compound in the production field has become more and more popular.

Reference:
Patent; LG LIFE SCIENCES, LTD.; WO2009/38412; (2009); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 1458-18-0,Some common heterocyclic compound, 1458-18-0, name is Methyl 3-amino-5,6-dichloropyrazine-2-carboxylate, molecular formula is C6H5Cl2N3O2, 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 stirred solution of methyl 3-amino-5, 6-dichloropyrazine-2-carboxylate (500 mg, 2.25 mol, 1 equiv) and 2- (tributylstannyl) -1, 3-oxazole (806.5 mg, 2.25 mol, 1.00 equiv) in 1, 4-dioxane (20 mL) were added LiCl (190.9 mg, 4.50 nMol, 2 equiv) , tricyclohexylphosphane (126.3 mg, 0.45 nMol, 0.2 equiv) and Pd 2 (dba) 3. CHCl 3 (466.2 mg, 0.45 nMol, 0.20 equiv) in portions at room temperature under nitrogen atmosphere. The resulted mixture was stirred for 4h at 140 under nitrogen atmosphere with microwave irritation. The resulted mixture was concentrated under reduced pressure. The residue was purified by Prep-TLC (CH 2Cl 2 /MeOH 20: 1) to afford methyl 3-amino-6-chloro-5- (1, 3-oxazol-2-yl) pyrazine-2-carboxylate (160 mg, 27.9%) as a yellow solid. LCMS: m/z (ESI) , [M+H] + = 255.1.

The synthetic route of 1458-18-0 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; DIZAL (JIANGSU) PHARMACEUTICAL CO., LTD.; QI, Changhe; TSUI, Honchung; ZENG, Qingbei; YANG, Zhenfan; ZHANG, Xiaolin; (399 pag.)WO2020/35052; (2020); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 54013-07-9, 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. 54013-07-9, name is 5-Methoxypyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows.

General procedure: Isoquinolin-3-amine (3.23 g, 22.4 mmol) was added to a solution of 1,1′-thiocarbonyldipyridin-2(1H)-one (5.20 g, 22.4 mmol) in dichloromethane (50 mL) at room temperature. The reaction was stirred for 2 h, then purified by flash chromatography on silica gel (0-10% ethyl acetate in hexanes). Product fractions were combined and concentrated in vacuo to give 3-isothiocyanatoisoquinoline(3.9 g, 93 %) as a white solid.

The chemical industry reduces the impact on the environment during synthesis 5-Methoxypyrazin-2-amine. I believe this compound will play a more active role in future production and life.

Reference:
Article; Iwuagwu, Christiana; King, Dalton; McDonald, Ivar M.; Cook, James; Zusi, F. Christopher; Hill, Matthew D.; Mate, Robert A.; Fang, Haiquan; Knox, Ronald; Gallagher, Lizbeth; Post-Munson Amy Easton, Debra; Miller, Regina; Benitex, Yulia; Siuciak, Judy; Lodge, Nicholas; Zaczek, Robert; Morgan, Daniel; Bristow, Linda; Macor, John E.; Olson, Richard E.; Bioorganic and Medicinal Chemistry Letters; vol. 27; 5; (2017); p. 1261 – 1266;,
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. 74290-65-6, name is 3-Bromo-5-methylpyrazin-2-amine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. Quality Control of 3-Bromo-5-methylpyrazin-2-amine

(ii) 2-Amino-3-bromo-5-methylpyrazine (0.374 g) was added to a freshly prepared solution of sodium methoxide in methanol (made by addition of sodium (0.115 g) to methanol (6 ml). The reaction mixture was heated under reflux for 18 hours, cooled to ambient temperature and the solvent removed by evaporation. Water (5 ml) was added to the residue and extracted with dichloromethane (3*20 ml). The combined organic extracts were dried (MgSO4) and the solvent removed by evaporation. The residue was purified by chromatography on silica gel, eluding with dichloromethane to give 2-amino-3-methoxy-5-methylpyrazine as a white crystalline solid (0.208 g, 75%), m.p. 67-69 C.; mass spectrum (+ve CI): 140 (M+H)+.

The synthetic route of 74290-65-6 has been constantly updated, and we look forward to future research findings.

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

Some common heterocyclic compound, 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, molecular formula is C6H2N2O3, 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. Product Details of 4744-50-7

The amine prepared in Example 8 (87.7 mg, 0.172 mmol, 1 eq.) was dissolved in 6 mL acetone cooled to 0C in an ice bath. To this solution was added 2,3-pyrazinedicarboxylic acid anhydride (25.8 mg, 0.172 mmol, 1 eq.). The yellow solution turned into a suspension and was then stirred room temperature for 10 min. The precipitate was filtered off with suction, washed with acetone, dissolved in methanol and concentrated under reduced pressure to afford 54 mg (51%) of the title product as an orange solid. NMR (400 MHz, DMSO-d6) delta 10.23 (s, 1H), 8.92 (t, J= 5.9 Hz, 1H), 8.80 (d, J= 2.4 Hz, 1H), 8.76 (d, J= 3.4 Hz, 1H), 8.75 (d, J= 2.5 Hz, 1H), 8.51 (d, J= 4.0 Hz, 1H), 8.44 (d, J = 4.0 Hz, 2H), 7.71 (td, J= 7.7, 1.7 Hz, 1H), 7.64 (td, J= 7.7, 1.7 Hz, 2H), 7.53 (d, J= 8.4 Hz, 2H), 7.42 (t, J= 9.2 Hz, 2H), 7.33 (d, J= 7.8 Hz, 1H), 7.28 – 7.15 (m, 5H), 3.76 (s, 2H), 3.72 (s, 4H), 3.49 (dd, J= 14.2, 6.5 Hz, 3H), 3.28 (s, 2H), 2.81 (dt, J= 13.7, 8.2 Hz, 4H), 2.65 (t, J = 6.2 Hz, 2H). 13C NMR (101 MHz, DMSO-d6) delta 169.28, 166.90, 165.62, 163.12, 158.66, 158.42, 149.03, 148.75, 147.71, 146.48, 145.66, 144.90, 143.82, 143.43, 136.84, 136.72, 136.46, 134.16, 128.88, 123.13, 122.87, 122.44, 122.16, 119.27, 60.09, 59.53, 58.08, 54.89, 51.65, 51.16, 48.62, 34.30. APCI-HRMS e/z calc. for C35H37N9O2: 615.3070, found 616.3141 [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 4744-50-7, its application will become more common.

Reference:
Patent; UNIVERSITETET I OSLO; GOLDING, Louise; RONGVED, Pal; ASTRAND, Ove Alexander H°gmoen; SAMUELSEN, Ørjan; SCHNAARS, Christian; KILDAHL-ANDERSEN, Geir; (234 pag.)WO2018/33719; (2018); 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. 71257-38-0, name is 1,2,3,4-Tetrahydropyrrolo[1,2-a]pyrazine, A new synthetic method of this compound is introduced below., name: 1,2,3,4-Tetrahydropyrrolo[1,2-a]pyrazine

Diisopropylethylamine (12.15 mmole) and di-tert-butyl dicarbonate (8.9 mmole) were added to a solution of the correspondingly 1-substituted 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine (8.1 mmole) in DCM. The reaction mixture was stirred for 16 hours at 25 C. The organic phase was then washed with sodium carbonate solution, water and satd. NaCl solution, dried over Na2SO4 and concentrated by evaporation. The crude product was purified by column chromatography (silica gel, ethyl acetate/DCM, 99:1); 1,2,3,4-Tetrahydro-pyrrolo[1,2-a]pyrazine was dissolved in dichloromethane (90 ml) at to it DIPEA (12.15 mmol) and boc anhydride (8.9 mmol) were added at 0 C. The resulting reaction mixture was allowed to stir for 16 hrs at 25 C. Organic layer was washed with sodium carbonate, water and brine and finally dried over sodium sulfate. Evaporation of the organic layer gave the crude product which was purified by column chromatography (1% ethyl acetate in dichloromethane) or (10% ethyl acetate in hexane); 1,2,3,4-Tetrahydro-pyrrolo[1,2-a]pyrazine which was dissolved in dichloromethane (90 ml) at to it DIPEA (12.15 mmol) and boc anhydride (8.9 mmol) were added at 0 C. The resulting reaction mixture was allowed to stir for 16 hrs at 25 C. Organic layer was washed with sodium carbonate, water and brine and finally dried over sodium sulfate. Evaporation of the organic layer gave the crude product which was purified by column chromatography (1% ethyl acetate in dichloromethane) or (10% ethyl acetate in hexane).

The synthetic route of 71257-38-0 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GRUENENTHAL GmbH; US2009/186899; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 274-79-3,Some common heterocyclic compound, 274-79-3, name is Imidazo[1,2-a]pyrazine, molecular formula is C6H5N3, 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 imidazo[1,2-a]pyrazine (7.2 g, 60.44 mmole) was dissolved in 2-methoxyethanol (100 ml) and PtO2 (1.2 g, 5.13 mmole) was added. The reaction mixture was stirred overnight at RT in an autoclave under a hydrogen atmosphere (4 bar). The autoclave was then flushed with nitrogen, the reaction mixture was filtered through filter earth, concentrated, and the solvent residues were then extracted with toluene. Purification was carried out by column chromatography on silica gel (DCM/7 N NH3 in methanol, 95:5)

The synthetic route of 274-79-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GRUENENTHAL GmbH; US2009/186899; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem