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., Formula: C4H2Cl2N2

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

Adding a certain compound to certain chemical reactions, such as: 356783-16-9, name is 3,6-Dichloropyrazine-2-carbonitrile, 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 356783-16-9, Safety of 3,6-Dichloropyrazine-2-carbonitrile

KF (1 g, 6 eq) and TBAB (372.3 mg, 0.4 eq) were dissolved in a mixed solvent of toluene (10 ml) and dimethylsulfoxide (5 ml)After azeotropic removal of water,Compound 6 (500 mg, 1 eq) was added,55 ‘C conditions,Stir for 3 h.TLC shows the raw material reaction is complete,After falling to room temperature,30% H2O2 (0.35 ml) was added under ice bath,Reaction at 27 C for 2 h, add water (1 ml) andNaHCO3 (0.132 g, 1.57 mmol),50 reaction 8.5h,Ice bath with 6N HCl,Adjust pH = 1.0,Ethyl acetate (4 x 5 ml)The organic layer was washed twice with saturated brine,Dried over anhydrous sodium sulfate,The organic solvent was distilled off,Recrystallization from 20 times ethanol (crude weight ratio of ethanol to 1: 5 to 30)Obtained as white solid 7 (favipiravir),The yield was 65% (from the reactants6 is calculated).mp: 175-177 C.

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Reference:
Patent; Central South University; Liu Fengliang; Li Cuiqin; (19 pag.)CN106866553; (2017); 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. 76537-18-3, name is 3-Bromo-5-chloropyrazin-2-amine, A new synthetic method of this compound is introduced below., Recommanded Product: 3-Bromo-5-chloropyrazin-2-amine

3-Bromo-5-chloropyrazin-2-amine (200 mg, 0.96 mmol), triethylamine (290 mg, 2.88mmol), cuprous iodide (5 mg, 0.33 mmol) and palladium(II)bis(triphenylphosphine) dichloride(13 mg, 0.02 mmol) were dissolved in tetrahydrofuran (5 mL). The mixture was stirred at rt, thentrimethylsilylacetylene (0.15 mL, 1.06 mmol) was added dropwise to the mixture. After theaddition, the reaction mixture was warmed to 55 oc and stirred for 1 h. The reaction mixture wascooled to rt, and diluted with ethyl acetate (50 mL). The mixture was filtered. The filtrate wasconcentrated in vacuo, and the residue was purified by silica gel column chromatography(PE/EtOAc (v/v) = 3011) to give the title compound as a light yellow solid (208 mg, 96 %).MS (ESI, pos. ion) m/z: 227.00 [M+Ht;1H NMR (400 MHz, CDCh) 8 (ppm): 7.98 (s, 1H), 5.11 (s, 2H), 0.31 (s, 9H).

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; SUNSHINE LAKE PHARMA CO., LTD.; TANG, Changhua; REN, Qingyun; YIN, Junjun; YI, Kai; LEI, Yibo; WANG, Yejun; ZHANG, Yingjun; (303 pag.)WO2018/108125; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

87486-34-8, Adding some certain compound to certain chemical reactions, such as: 87486-34-8, name is 3,5-Dibromo-1-methylpyrazin-2(1H)-one, 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 87486-34-8.

A solution of 3,5-dibromo-1-methylpyrazin-2-one (500.0 mg, 2.46 mmol), NH3H2O (5.0 mL) in dioxane (30.0 mL) was heated at 105° C. for 20 h. The mixture was concentrated, diluted with EtOAc (50 mL) and filtrated to give the title compound (300.0 mg, 79.0percent) which was carried on without purification. LCMS (M+H)+ 204.

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 87486-34-8.

Reference:
Patent; Bennett, Michael John; Betancort, Juan Manuel; Boloor, Amogh; Kaldor, Stephen W.; Stafford, Jeffrey Alan; Veal, James Marvin; US2015/111885; (2015); 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. 957230-70-5, name is 3,6-Dibromopyrazin-2-amine, A new synthetic method of this compound is introduced below., name: 3,6-Dibromopyrazin-2-amine

Step 2 5 ,8-Diotabromo-3-methyliotamiotadazo[ 1 ,2 ajpyrazine[00298] 2,5-Dibromo-3-aminopyrazme (2 0 g, 7 9 mmol), 2-bromo-l,l -dimethoxypropane (7 25 g, 40 0 mmol) and py?dimum p-toluenesulfonate (2 0 g, 7 9 mmol) are stirred in acetomtrile (65 mL) at reflux for 3 days The mixture is cooled and the solvent evaporated under reduced pressure The residue is partitioned between DCM (150 mL) and water (50 mL) and the layers separated The organic fraction is washed with NaHCtheta3 (sat aq , 50 mL) and b?ne (50 mL) and d?ed over MgStheta4 Evaporation of the solvent under reduced pressure gives a viscous black oil (2 14 g) which is purified by silica chromatography, elutmg with 10% – 20% EtOAc in cyclohexane to afford the title compound as a red-brown solid (280 mg, 1 mmol)

The synthetic route of 957230-70-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GALAPAGOS N.V.; WO2007/131991; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature 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

Application of 4858-85-9, A common heterocyclic compound, 4858-85-9, name is 2,3-Dichloropyrazine, molecular formula is C4H2Cl2N2, 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.

2,3-dichloro-pyrazine (25 g) was dissolved in ethanol (500 mL),Hydrazine monohydrate (16.7 mL) was added, And the mixture was stirred under reflux for 1 hour and a half. Water was added to the reaction solution, and the precipitated solid was dried under reduced pressure after filtering off the resulting solid to give the title compound as white crystals by recrystallization from ethanol (18.12g, 74%).

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; TAIHO PHARMACEUTICAL COMPANY LIMITED; MINAMIGUCHI, KAZUHISA; OKAJIMA, SHIGEO; AOKI, SHINICHI; ASAI, MASANORI; ASAI, TAKAHIRO; YAMANAKA, HIROYOSHI; DOHI, SUGURU; (149 pag.)JP5851663; (2016); B1;,
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. SDS of cas: 74290-65-6

(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

Application of 1286754-14-0,Some common heterocyclic compound, 1286754-14-0, name is Ethyl imidazo[1,2-a]pyrazine-3-carboxylate, molecular formula is C9H9N3O2, 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 – the a] pyrazine -3 – carboxylic acid ethyl ester (780 mg, 4 . 08 mmol) is dissolved under stirring 20 ml in tetrahydrofuran, then add 10% palladium carbon 400 mg, hydrogen under the protection of the 35 C stirring 12 hours, the reaction to remove the catalyst, concentrated under reduced pressure, column chromatography purification to obtain 5, 6, 7, 8 – tetrahydro imidazo [1,2 – the a] pyrazine -3 – carboxylic acid ethyl ester (600 mg, yield: 75.3%, white solid).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Ethyl imidazo[1,2-a]pyrazine-3-carboxylate, its application will become more common.

Reference:
Patent; Sichuan Kelun Pharmaceutical Institute Co., Ltd.; Xie Yinong; You Zejin; Song Zhanbo; Su Ruifei; Deng Zhiwen; Wang Yajun; Chen Xing; Zeng Hong; Song Hongmei; Qi Wei; Wang Lichun; Wang Jingyi; (57 pag.)CN106478631; (2017); 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