Pyrazines

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. 274-79-3, name is Imidazo[1,2-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., Quality Control of Imidazo[1,2-a]pyrazine

Imidazo[1 ,2-a]pyrazine(l1 ) (4.38 g, 36.8 mmol) was dissolved in methanol (100 mL) and hydrogenated at 1 atm/25 0C hydrogen over platinum(IV) oxide (0.522 g, 1.838 mmol) for 24 h. The catalyst was filtered and the filtrate concentrated to afford afford product in 4.8 g that was used without further purification. LC/MS = 124 (M+H)+, retention time = 0.34 minutes (2 minute method (high pH)).

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 274-79-3.

Reference:
Patent; GLAXO GROUP LIMITED; DEAN, David Kenneth; MUNOZ-MURIEDAS, Jorge; SIME, Mairi; STEADMAN, Jon Graham Anthony; THEWLIS, Rachel Elizabeth Anne; TRANI, Giancarlo; WALL, Ian David; WALTER, Daryl Simon; WO2010/125101; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 22047-25-2, A common heterocyclic compound, 22047-25-2, name is Acetylpyrazine, molecular formula is C6H6N2O, 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.

Preparation 8; 1-Pyrazin-2-yl-ethyl Amine; The synthetic procedure used in this preparation is outlined below in Scheme J. To a solution of 1-pyrazin-2-yl-ethanone (2.0 g, 15.85 mmol) and ammonium acetate (19.337 g, 158.5 mmol) in methanol (50 mL) was added sodium cyanoborohydride (0.7 g, 11.1 mmol) in one portion. The reaction mixture was stirred overnight at room temperature. After removal of methanol, water (20 mL) was added to the residue and the resulting solution was basified by addition of sodium hydroxide to pH=13. The aqueous solution was extracted with dichloromethane and the combined organic phase was dried over sodium sulfate. Removal of the solvent under reduced pressure afforded 14.62 g of 1-pyrazin-2-yl-ethylamine, yield: 75%. MS (M+H)=124.

The synthetic route of 22047-25-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Roche Palo Alto LLC; US2009/163502; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 1060814-53-0,Some common heterocyclic compound, 1060814-53-0, name is (5-Chloropyrazin-2-yl)methanamine, molecular formula is C5H6ClN3, 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.

Example 2544-N-[(5-chloropyrazin-2-yl)methyl]-6-(2, 3-di methyl phenyl)pyri midine-2,4-diam me.4-Chloro-6-(2,3-dimethylphenyl)pyrimidin-2-amine (12 mg, 0,050 mmol), (5- chloropyrazin-2-yl)methanamine (14 mg, 0,10 mmol), Et3N (0,040 mL, 0,30 mmol) and 1-butanol (0,20 mL) were stirred at 100C for 20 hours. MeOH (1 mL) was added and the mixture was purified by preparative HPLC to give the desiredproduct. LCMS [M+H] 341.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route (5-Chloropyrazin-2-yl)methanamine, its application will become more common.

Reference:
Patent; THOMAS HELLEDAYS STIFTELSE FOeR MEDICINSK FORSKNING; SCOBIE, Martin; HELLEDAY, Thomas; KOOLMEISTER, Tobias; JACQUES, Sylvain; DESROSES, Matthieu; JACQUES-CORDONNIER, Marie-Caroline; WO2014/84778; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, This compound has unique chemical properties. The synthetic route is as follows., Product Details of 109838-85-9

1.1) (2S,5R)-2-[5-(5-Chloro-thiophen-2-yl)-isoxazol-3-ylmethyl]-5-isopropyl-3,6-dimethoxy-2,5-dihydro-pyrazine (Intermediate 1):Commercially available (R)-2-isopropyl-3,6-dimethoxy-2,5-dihydro-pyrazine (2.Og, 10.86 mmol) in dry THF (12ml) under argon was cooled to -75°C. n-BuLi (8 ml, 13.03 mmol, 1.6M solution in hexanes) was added slowly and stirring was continued for 30 min. After that 3-bromomethyl-5-(5-chloro-thiophen-2-yl)-isoxazole (3.628 g, 13.03 mmol), (preparation described in J. Med. Chem. 2005, 4511-4525; Bioorg. Med. Chem. Lett. 2004, 4191-4195), in THF (15 ml) was added dropwise under stirring and stirring was continued for 30 min at -75 °C. Then the mixture was warmed to 0 °C and stirred for 1h before it was quenched with sat. aq. NaHCO3-solution. The mixture was extracted with ethyl acetate, the organic layers were combined and dried with MgSO4, filtered and evaporated to dryness. A crude oil was obtained (4.1 g) and the diastereomeric excess (d.e.: 88 percent) was determined by H-NMR from that crude mixture. The mixture was separated by column chromatography on silica gel (n- heptane-ethyl acetate 6:1). Yield: 3.3 g, 80 percent.

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; SANOFI-AVENTIS; WO2009/103439; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 870787-06-7, These common heterocyclic compound, 870787-06-7, name is 3-(Trifluoromethyl)pyrazine-2-carboxylic acid, 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.

Diphenylphosphoryl azide (3.47g, 12.6mmol) was added to a stirred solution of 3- trifluoromethylpyrazine-2-carboxylic acid (1.92g, 9.70mmol) and triethylamine (1 .28g, 12.6mmol) in tert-butanol (9.6ml, l OOmmol) and toluene (19.2ml). The resulting mixture was heated at 90C for 4 hours and then allowed to cool. It was washed with 2M aqueous sodium bicarbonate, then dried through a phase-separation filter and concentrated under reduced pressure. The residue was purified by chromatography on silica gel using a gradient of ethyl acetate in isohexane as eluent to give tert-butyl N-(3- trifluoromethylpyrazin-2-yl)-carbamate (2.0g) as a colourless oil which slowly crystallised to give a white solid. (0268) 1H NMR (400MHz, CDCI3) delta 8.65 (d, 1 H), 8.40 (d, 1 H), 7.15 (br s, 1 H), 1 .55 (s, 9H).

Statistics shows that 3-(Trifluoromethyl)pyrazine-2-carboxylic acid is playing an increasingly important role. we look forward to future research findings about 870787-06-7.

Reference:
Patent; SYNGENTA PARTICIPATIONS AG; WAILES, Jeffrey, Steven; CARTER, Neil, Brian; CLOUGH, John, Martin; WILLIAMS, John; (57 pag.)WO2019/57723; (2019); 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., Application In Synthesis of Methyl 5-chloropyrazine-2-carboxylate

Dissolve 5-chloro-pyrazine-2-carboxylic acid methyl ester (10.0 g, 57.9 mmol) in THF (65 mL) and MeOH (65 mL). Cool the solution to 0 0C before adding IN NaOH (63.7 mL) with stirring. Warm the mixture to room temperature and stir for 5 h. Concentrate the mixture in vacuo to 1/3 volume. Quench with IN HCl (75 mL) to form a white precipitate. Dilute with CH2Cl2 (200 mL) and filter. Wash the filter cake with water and CH2Cl2. Separate the phases, dry the organic phase over MgSO4, filter, and concentrate. Add the aqueous layer to the concentrated organic residue and concentrate. Purify by silica gel flash column chromatography, eluting with 40% ethyl acetate/n-hexane, followed by 10% MeOH, 3% acetic acid and 87% EPO CH2Ch- Collect the mixed fractions and concentrate. Take up the resulting solid with CH2CI2 (50 mL) and H2O (50 mL) and stir. Filter the solid and add it to the first filter cake. Add 5.0N NaOH to the filtrate to make the solution basic. Separate the two layers. Discard the organic layer, add 5.0N HCl to the aqueous layer until acidic. Extract with CH2Cl2 (3 x 100 mL). Dry the organic layer over Na2SO4, filter, and concentrate. Add the solid to the pure fractions from the column. Combine the pure filter cakes with the pure fractions from the column, yielding the desired product (8.46 g, 92%). mass spectrum (exact mass): 157.99.

The synthetic route of 33332-25-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ELI LILLY AND COMPANY; WO2006/66173; (2006); 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 33332-29-5 as follows. COA of Formula: C4H4ClN3

General procedure: Method B is a modification of Method A and was performed under nitrogen atmosphere andwith extended work-up. Substituted benzoyl chloride (1.5 mmol, 1.2 equiv) was placed into the askunder nitrogen, diluted with dry DCM (5 mL) and dry pyridine (400 mg, 5 mmol, 4 equiv) was added.The mixture was mixed for 5 min under nitrogen. Then, 5-chloropyrazin-2-amine (162 mg, 1.25 mmol,1 equiv) dissolved in DCM (10 mL) was added dropwise over 10 min under nitrogen ow. The askwas closed by septum and stirred for additional 6 h. After reaction, the mixture was diluted with DCMto the final volume of 40 mL and washed with water (1 30 mL), 5% (m/m) aqueous NaHCO3 solution(1 30 mL), and brine (1 30 mL). The organic layer was dried over anhydrous Na2SO4 and adsorbedon silica (4 g) by evaporating the solvents under reduced pressure. Automated flash chromatographywas run using same conditions as described in Method A. If needed, the products were recrystallizedfrom hot EtOH (crystallization initiated by cooling and dropwise addition of cold water).

According to the analysis of related databases, 33332-29-5, the application of this compound in the production field has become more and more popular.

Reference:
Article; Zitko, Jan; Mindlova, Al?b?ta; Vala?ek, Ond?ej; Jand’ourek, Ond?ej; Paterova, Pavla; Janou?ek, Ji?i; Kone?na, Klara; Dole?al, Martin; Molecules; vol. 23; 9; (2018);,
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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 117719-17-2 as follows. Formula: C8H11BrN4O

Preparation of Intermediate I-57. A mixture of Intermediate I-02 (8.17 g, 31.52 mmol) and 1,3-dichloroacetone (6.0 g, 47.29 mmol) in 2-propanol (15 mL) was heated in a sealed tube at 55 C. for 2 days. On cooling, the mixture was filtered and rinsed with Et2O and MeOH. The solid was purified by flash chromatography on silica gel (MeOH:DCM, 5:95) and the product obtained was washed with MeOH and dried to give Intermediate I-57 (3.97 g, 38%).

According to the analysis of related databases, 117719-17-2, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Centro Nacional De Investigaciones Oncologicas (CNIO); US2012/83492; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 622392-04-5, name is 2-Bromo-5-iodopyrazine, This compound has unique chemical properties. The synthetic route is as follows., Formula: C4H2BrIN2

Description 66: 2-bromo-5-(trifluoromethyl)pyrazine (D66); Potassium fluoride (238 mg, 4.09 mmol) and copper(I) iodide (779 mg, 4.09 mmol) were mixed and heated under vacuum using heat gun (temperature 360 0C, on display of heating gun) for 20 minutes (until a greenish colour of the mixture appeared). After cooling at room temperature, DMF (4 ml) and NMP (4.00 ml) were added followed by (trifluoromethyl)trimethylsilane (0.603 ml, 3.77 mmol) and 2-bromo-5-iodopyrazine D65 (896 mg). The resulting mixture was stirred at room temperature for 5 hours. The reaction mixture was poured in 200 ml of 6N NH3 water solution and was extracted twice with Et2O(3 x 50 ml). Gathered Et2O layers were dried over Na2SO4.Diethyl ether was distilled by Claisen apparatus. It was recovered the title compound D66(586 mg).1H NMR (400 MHz, CHLOROFORM- d) delta ppm 8.73 – 8.81 (m, 1 H) 8.84 (s, 1 H)

According to the analysis of related databases, 622392-04-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; GLAXO GROUP LIMITED; AMANTINI, David; DI FABIO, Romano; WO2010/122151; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 55557-52-3, name is 3-Chloropyrazine-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 55557-52-3, Safety of 3-Chloropyrazine-2-carbonitrile

(a). (3-Chloropyrazin-2-yl)methanamine hydrochloride was prepared as follows. To a solution of 3-chloropyrazine-2-carbonitrile (160 g, 1 .147 mol) in acetic acid (1.5 L) was added Raney Nickel (50% slurry in water, 70 g, 409 mmol). The resulting mixture was stirred under 4 bar hydrogen at room temperature overnight. Raney Nickel was removed by filtration over decalite and the filtrate was concentrated under reduced pressure and co-evaporated with toluene. The remaining brown solid was dissolved in ethyl acetate at 50C and cooled on an ice-bath. 2M hydrogen chloride solution in diethyl ether (1 .14 L) was added in 30 min. The mixture was allowed to stir at room temperature over weekend. The crystals were collected by filtration, washed with diethyl ether and dried under reduced pressure at 40C. The product brown solid obtained was dissolved in methanol at 60C. The mixture was filtered and partially concentrated, cooled to room temperature and diethyl ether (1000 ml) was added. The mixture was allowed to stir at room temperature overnight. The solids formed were collected by filtration, washed with diethyl ether and dried under reduced pressure at 40C to give 153.5 g of (3-chloropyrazin-2- yl)methanamine.hydrochloride as a brown solid (74.4 %, content 77 %).

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

Reference:
Patent; ACERTA PHARMA B.V.; HAMDY, Ahmed; ROTHBAUM, Wayne; IZUMI, Raquel; LANNUTTI, Brian; COVEY, Todd; ULRICH, Roger; JOHNSON, Dave; BARF, Tjeerd; KAPTEIN, Allard; (732 pag.)WO2016/24230; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem