Pyrazines

These common heterocyclic compound, 40155-43-9, name is 5-Aminopyrazine-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. name: 5-Aminopyrazine-2-carboxylic acid

The starting 5-chloropyrazine-2-carboxylic acid (317 mg, 2 mmol) was converted to5-aminopyrazine-2-carboxylic acid (1) by substitution reaction with 25% (m/m) aqueous solutionof ammonia (3 mL). The reaction was carried out 10 mL microwave pressurized vials with stirring(reaction temperature: 100 C, reaction time: 30 min, power output: 80 W). The reaction was repeated20 times to yield reasonable quantity of the starting acid. Once the reaction was completed, the vials content was put onto Petri dish and heated above a water bath with intermittent stirring until a drysolid was obtained (ammonium salt of the product). To get the free acid form, the ammonium salt wasdissolved in water and drop-wise acidified with 10% hydrochloric acid to reach pH of 4. The mixturewas then left to cool down in room temperature for 5 min then kept in the fridge for 15 min. The formedfree acid crystals were filtered off by filtration paper with suction and left to dry overnight. After itwas dried, the resulting 5-aminopyrazine-2-carboxylic acid (1) was esterified in several microwavepressurized vials; 3 mL of anhydrous propanol and 2 drops of concentrated sulfuric acid were added to278 mg (2 mmol) of compound 1 in each vial. The esterification was carried out in microwave reactor(reaction temperature: 100 C, reaction time: 1 h, power output: 80 W). The completion of reaction wasmonitored by TLC in system hexane/ethyl acetate (EtOAc) (1:3). The ester was then purified by flashchromatography using gradient elution 40 to 100% EtOAc in hexane.

The synthetic route of 5-Aminopyrazine-2-carboxylic acid has been constantly updated, and we look forward to future research findings.

Reference:
Article; Bouz, Ghada; Juhas, Martin; Niklova, Pavlina; Jand?ourek, Ond?ej; Paterova, Pavla; Ek, Ji?i Janou; T?mova, Lenka; Kovalikova, Zuzana; Kastner, Petr; Dole al, Martin; Zitko, Jan; Molecules; vol. 22; 10; (2017);,
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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. 72788-94-4, name is 2-Chloro-5-(hydroxymethyl)pyrazine, A new synthetic method of this compound is introduced below., Recommanded Product: 72788-94-4

2) In N,N-dimethylacetamide (6.4 mL) and 2M aqueous sodium carbonate solution (6.4 mL) were suspended (5-chloropyrazin-2-yl)methanol (460 mg) and methyl 2,2- dimethyl-3-[4-(4,4,5,5-tetramethyl- 1 ,3,2-dioxaboloran-2-yl)phenoxy]propanoate ( 1.600 g), palladium chloride (dppf) methylene chloride complex (261 mg) was added to the suspension, and the mixture was stirred at 80C overnight. To the reaction mixture were added ethyl acetate and water, and the mixture was filtered through Celite. The organic layer was separated, and the aqueous layer was extracted twice with ethyl acetate. The organic layers were combined, washed twice with water, washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (n- hexane:ethyl acetate=70:30 to 40:60 to 0: 100) to obtain methyl 3-{4-[5-(hydroxyl- methyl)pyrazin-2-yl]phenoxy}-2,2-dimethylpropanoate (660 mg).MS (m/z): 317 [M+H] +

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; MITSUBISHI TANABE PHARMA CORPORATION; SAKURAI, Osamu; SARUTA, Kunio; HAYASHI, Norimitsu; GOI, Takashi; MOROKUMA, Kenji; TSUJISHIMA, Hidekazu; SAWAMOTO, Hiroaki; SHITAMA, Hiroaki; IMASHIRO, Ritsuo; WO2012/81736; (2012); A1;,
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Reference of 22047-25-2, These common heterocyclic compound, 22047-25-2, name is Acetylpyrazine, 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: A 2-neck round bottom flask attached with calcium chloride guard tube was charged with MeOH (30mL). Then, 2-acetylpyrazine (1.47g, 2mmol) followed by KOH pellets (0.675g, 2mmol) were added and initiated magnetic stirring. To this mixture, distilled water (2mL) was added and continued stirring for 10min. Now, the resulting solution was added the respective n,n?,n?-trimethoxyphenyl benzaldehydes (1.0g, 1mmol) under stirring at room temperature slowly and then 6mL of ammonia solution was added. The reaction mixture was stirred further for 4h. The reaction was monitored by TLC. On completion of reaction by TLC, the reaction mass was filtered and washed with methanol (3×10 mL) and then diethyl ether (3×10 mL) to obtain a white precipitate of respective compounds. Each of the above precipitates was recrystallised in a mixture of CHCl3 and MeOH (1:1) at room temperature for 48h. The resulting colourless single crystals of 1-3 were collected by filtration.

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

Reference:
Article; Ramesh; Sharath Kumar; Raghavendra Kumar; Suchetan; Devaraja; Sabine, Foro; Nagaraju; Journal of Molecular Structure; vol. 1200; (2020);,
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Electric Literature of 33332-29-5,Some common heterocyclic compound, 33332-29-5, name is 2-Amino-5-chloropyrazine, molecular formula is C4H4ClN3, 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 2: 2,5-Dichloropyrazine; 5-Chloro-2-pyrazinamine (product of E1, step 1) (2.41g, 18.6mmole) was dissolved in concentrated hydrochloric acid (24ml), cooled in an ice-acetone bath and treated with a solution of sodium nitrite (2.63g, 38.1 mmole) in water (1 8ml) dropwise over a period of 1 hour. The mixture was cooled in an ice-water bath and left to stir for 1 hour. The mixture was allowed to warm to room temperature over 1 hour, neutralised by addition of sodium hydroxide solution (2M) and extracted with dichloromethane ( x 4). The dichloromethane layers were combined, dried under magnesium sulfate and evaporated in vacuo. The resulting residue was purified by column chromatography (1: 9 ethyl acetate: pentane) to afford the title compound (0.33g). 1H NMR (CDCl3) 8.40 (2H, s).

The synthetic route of 33332-29-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GLAXO GROUP LIMITED; WO2005/97778; (2005); A1;,
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Reference of 173253-42-4, These common heterocyclic compound, 173253-42-4, name is 2-Amino-5-bromo-6-chloropyrazine, 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 1. 5,6-Bis(4-fluorophenyl)pyrazin-2-amine A mixture of 5-bromo-6-chloropyrazin-2-amine (2 g, 9.66 mmol, 1.00 equiv), 4-fluorophenylboronic acid (3.38 g, 24.14 mmol, 2.50 equiv), Pd(PPh3)4 (1.11 g, 0.96 mmol, 0.10 equiv), K3PO4 (8.19 g, 38.66 mmol, 4.00 equiv), and 1,4-dioxane (10 mL) was stirred overnight at 100 C. in an oil bath. The resulting mixture was concentrated in vacuo, and the residue was purified via silica gel column chromatography (ethyl acetate: petroleum ether (1:20)), resulting in 1.7 g (62%) of 5,6-bis(4-fluorophenyl)pyrazin-2-amine as a brown solid.LC-MS (ES, m/z): 284 [M+H]+ 1H-NMR (300 MHz, CDCl3, ppm) delta 8.059 (s, 1H), 7.505-7.233 (m, 4H), 7.037-6.930 (m, 4H), 4.763 (s, 1H)

The synthetic route of 173253-42-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; BIOENERGENIX; US2012/225846; (2012); A1;,
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Electric Literature of 69214-34-2,Some common heterocyclic compound, 69214-34-2, name is 8-Bromoimidazo[1,2-a]pyrazine, molecular formula is C6H4BrN3, 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 mixture of 8.-hrornoirnidazo[ I ,2apyrazine (100 mg, 0.51 rnrnol) and selectfluor (214mg, 0.61 rnmol) in MeCN (5 mL) was heated to 70 C for 1 hour, After LCMS, it was indicatedthat starting material disappeared. The mixture was then concentrated, and the residue was purified by Prep-HPLC to give the title compound (40 mg) as a yellow solid. LRMS miz (M+H) 216.1, 218.1 found, 216.1, 218.1 required.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 8-Bromoimidazo[1,2-a]pyrazine, its application will become more common.

Reference:
Patent; MERCK SHARP & DOHME CORP.; LIVERTON, Nigel; KUDUK, Scott D.; BESHORE, Doug C.; MENG, Na; LUO, Yunfu; (127 pag.)WO2016/101119; (2016); A1;,
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Application of 100047-56-1, A common heterocyclic compound, 100047-56-1, name is 5-Bromo-3-methylpyrazin-2-ol, molecular formula is C5H5BrN2O, 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 solution of (lR,3s,5S)-tert-butyl 3-((ls,4S)-4-hydroxycyclohexyloxy)-8- azabicyclo[3.2.1]octane-8-carboxylate (100 mg, 0.307 mmol), 5-bromo-3-methylpyrazin-2-ol (69.69 mg, 0.369 mmol), triethylamine (42.83 mu?, 0.307 mmol) and triphenylphosphine (88.65 mg, 0.338 mmol) in THF (2 mL) at ice -water bath under nitrogen was added DIAD (0.123 mL, 0.369 mmol) dropwise. The reaction mixture was slowly warmed to room temperature and stirred overnight, then concentrated. The residue was purified by semi preparative HPLC (35- 95% CH3CN/H20 over 30 min) then neutralized to give the title compound (36 mg, 72.52 muiotaetaomicron?, 23.6% yield) as oil. Exact mass calculated for CzsI^Br^C^: 495.2, found LCMS m/z = 497.6 [M+H]+; ‘H NMR (CDC13 , 400 MHz) delta ppm 1.48 (s, 9H), 1.42-1.65 (m, 8H), 1.82-1.96 (m, 6H), 2.05-2.12 (m, 2H), 2.41 (d, = 0.6 Hz, 3H), 3.42-3.48 (m, 1H), 3.75-3.86 (m, 1H), 4.10- 4.30 (m, 2H), 4.92-5.00 (m, 1H), 7.97 (d, = 0.6 Hz, 1H).

The synthetic route of 100047-56-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ARENA PHARMACEUTICALS, INC.; JONES, Robert M.; BUZARD, Daniel J.; HAN, Sangdon; KIM, Sun Hee; LEHMANN, Juerg; ZHU, Xiuwen; WO2013/55910; (2013); A1;,
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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. 25680-54-0, name is 3-Ethylpyrazin-2(1H)-one, A new synthetic method of this compound is introduced below., Safety of 3-Ethylpyrazin-2(1H)-one

2. 2-Iodo-3-ethylpyrazine This was prepared from 2-hydroxy-3-ethyl-pyrazine by the procedure of Hirschberg and Spoerri, J. Org. Chem., 1961, 1907.

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; Merck Sharp & Dohme Limited; US5260293; (1993); A;,
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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. 41110-38-7, name is Methyl 6-methylpyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., Quality Control of Methyl 6-methylpyrazine-2-carboxylate

INTERMEDIATE 71 PREPARATION OF (6-METHYLPYRAZIN-2-YL)METHANOL To a solution of 6-methylpyrazine-2-carboxylic acid (8.00 g, 58.0 mmol) in N,N- dimethylformamide (50 mL) were added Cs2CO3 (37.8 g, 116 mmol) and iodomethane (12.3 g, 87.0 mmol). After being stirred overnight at room temperature, the reaction mixture was quenched with water (100 mL) and extracted with EtOAc (5 x 150 mL). The combined organic layers were washed with brine (100 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was then diluted with water (50 mL). NaBH4 (12.5 g, 330 mmol) was added portionwise at 0 C. After addition, the resulting mixture was stirred at room temperature for 30 min, cooled to 0 C, diluted with water (150 mL) and extracted with EtOAc (8 x 100 mL). The combined organic layers were washed with brine (200 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to afford the title compound (2.9 g, crude) as a yellow solid.1H NMR (400 MHz, DMSO-d6) delta 8.50 (s, 1H), 8.42 (s, 1H), 5.55 (t, J = 5.8 Hz, 1H), 4.59 (d, J = 5.5 Hz, 2H), 2.47 (s, 3H).

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; DENALI THERAPEUTICS INC.; BONANOMI, Giorgio; ESTRADA, Anthony A.; FENG, Jianwen A.; FOX, Brian; LESLIE, Colin Philip; LYSSIKATOS, Joseph P.; NAPOLITANO, Carmela; POZZAN, Alfonso; SUDHAKAR, Anantha; SWEENEY, Zachary K.; TONELLI, Federica; DE VICENTE FIDALGO, Javier; (232 pag.)WO2017/96301; (2017); A1;,
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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. 5521-61-9, name is 6-Methylpyrazine-2-carboxylic acid, A new synthetic method of this compound is introduced below., HPLC of Formula: C6H6N2O2

Example 14: 6-.Meth lA^(1^ yl)pyrazjne~2-carboxamideExample 14 was prepared from intermediate 2-A by amidation reaction with 6-meih lpyrazine- 2-carboxylic acid, as follows:To a solution of 2-A (80 nig, 0.35 nimol) and 6~nieih> pymzine-2-carboxylic acid (58 mg, 0.42 mmol) in DMF (5 ml.) was added DOHA (92 mg, 0.70 mmol) and HATU (338 mg, 0.70 mmol) under a. After stirring at room iemperature for an hour, the reaction was quenched with brine and extracted with ethyl acetate (3 x 20 ml..). The combined organic phase was washed with brine, dried over NajS(¾ and concentrated under reducced pressure. The residue was purified by Prep HPLC to yield 78 mg (64percent) of the title ompound, 6-raefh Iota-lambda’-((1 R,5S)-5-(r ridm-2- as an off-white solid. .H NMR (500 MHz, CDCI3); S 9.18 (s, 1 E), 8.60 (s, IH), 8.55 (4 J * 4.7 Hz, 1.H), 7.94 (s. 1 H), 7.62 (m, 1 H), 7.38 (d,J- 7.8 Hz, IH), 7.19 (m, 1 H), 2.60 (s, 3H), 2.53 {<1, J- 10.7 ¾ I H), 2.25 (m, IH), 2.18 - 1.70 (in, 10H); RSI-MS m/z: 347 (M+B)'*'. The synthetic route of 5521-61-9 has been constantly updated, and we look forward to future research findings. Reference:
Patent; H. LUNDBECK A/S; LI, Guiying; DOLLER, Dario; WO2013/40535; (2013); A2;,
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