Month: December 2020

19847-12-2, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 19847-12-2 name is Pyrazinecarbonitrile, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.

Example 3 :f4aS RJaS)-7a-f2-fluoro-5-f2-fpyrazin-2-yl)-lH-imidazol-5-vDphenvn-5-methYl- 4a. .7.7a -t etrah ydro-4 H – f tiro Gamma3 ,4-d] f 1.3]thiazin-2-amineStep 1 : 2-(lH midazol-2-yl)py 2,2-Diethoxyethanamine (3 g, 2.25 mmol) was dissolved in dry methanol (20 mL). To this was added sodium methoxide (1.22 g, 22.5 mmol, as a 25% solution in methanol). After stirring for 25 minutes at room temperature,, pyrazine-2-carbonitrile (2.37 g, 22.5 mmol) and acetic acid (1.35 g, 22.5 mmol) were added and the subsequent solution was stirred at 50C for 1 hour. MeOH (40 mL) and 6N HC1 (12 mL) were added and the reaction was stirred at reflux overnight. The reaction mixture was cooled to room temperature and partitioned between 1 : 1 Et20 and water (60 mL) and the layers were separated. The aqueous layer was basified to pH 9/10 and extracted with 10% MeOH in DCM. The combined organic extracts were dried (MgSOa), filtered and concentrated to give the desired compound ( 1.49 g yellow solid). 1 H NMR (400 MHz, eOH-d,) delta ppm: 7.67 (s, 1 H), 7.09 (d, J=1.8 Hz, 1 H), 6.99 (d, J=2.5 Hz, 1 H), 5.72 (s, 2 H)

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

Reference:
Patent; EISAI R&D MANAGEMENT CO., LTD; DIMOPOULOS, Paschalis; HALL, Adrian; KITA, Yoichi; MADIN, Andrew; SHUKER, Nicola Louise; WO2012/93148; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-25-1, Adding some certain compound to certain chemical reactions, such as: 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, 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 33332-25-1.

. Methyl 5-chloropyrazine-2-carboxylate (2.0 g, 1 eq., 11.6 mmol) was dissolved in MeOH (15 mL) and the solution was cooled to 0C. Sodium borohydride (1.1 g, 2.5 eq., 29 mmol) was slowly added and the reaction mixture was stirred at room temperature for 1 h. The reaction mixture was quenched with a saturated solution of NH4Cl (15 mL) and extracted with DCM (215 mL). The organic extracts were dried over Na2SO4 and concentrated in vacuo to furnish the crude product, which was purified by flash chromatography eluting with cyclohexane/EtOAc (0 to 60%) to give the pure title compound as colourless oil (1.59 g, 95%). 1H NMR (400 MHz, DMSO-d6): delta 8.73 (d, J=1.4 Hz, 1H), 8.54 (d, J=1.3 Hz, 1H), 5.68 (t, J=5.8 Hz, 1H), 4.65 (d, J=5.7 Hz, 2H).

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 33332-25-1.

Reference:
Patent; FONDAZIONE ISTITUTO ITALIANO DI TECNOLOGIA; BERTOZZI, Fabio; BANDIERA, Tiziano; PONTIS, Silvia; REGGIANI, Angelo; GIACOMINA, Francesca; DI FRUSCIA, Paolo; US2019/135778; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 6270-63-9, name is Pyrazin-2(1H)-one, 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. 6270-63-9

General procedure: The appropriate nucleophile (1 equiv.), the epoxide (1-3 equiv.) and a base (1-5 equiv.) were suspended in a solvent and the reaction mixture was heated under the stated conditions. (0735) The reaction was allowed to cool to rt, saturated NH4CI(aq) or water was added and the resulting mixture was extracted using DCM or EtOAc (x 3). The combined organic extracts were dried (phase separator or MgS04), concentrated under reduced pressure and the remaining residue was purified by flash chromatography to give the product.

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 6270-63-9.

Reference:
Patent; ALMAC DISCOVERY LIMITED; ROUNTREE, James Samuel Shane; WHITEHEAD, Steven Kristopher; TREDER, Adam Piotr; PROCTOR, Lauren Emma; SHEPHERD, Steven David; BURKAMP, Frank; COSTA, Joana Rita Castro; O’DOWD, Colin; HARRISON, Timonthy; (333 pag.)WO2019/150119; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, molecular formula is C4H3Br2N3, 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. 24241-18-7.

Making reference to Scheme 5, to a solution of 3,5-dibromopyrazin-2-amine (10 g, 40 mmol), copper(I) iodide (0.91 g, 4.7 mmol), diisopropylethylamine (53 mL, 0.55 mol), and tetrakis(triphenylphosphine)-palladium(0) (2.3 g, 1.9 mmol) in DMF (120 mL) that was de-gassed with Ar was added trimethylsilylacetylene (6.7 mL, 48 mmol). The resulting mixture was stirred under an Ar atmosphere for 1 h at 120C, after which it was evaporated to dryness in vacuo. The residue was subjected to silica gel chromatography eluting with 35% EtOAc in hexanes to give a brown oil that was triturated with hexanes to give the title compound (5.0 g, 47%). XH NMR (CDC13, 300 MHz): delta 8.04 (s, 1H), 5.10 (s, 2 H), 0.28 (s, 9H). HPLC retention time: 2.75 minutes. MS ESI (m/z): 270.0, 272.0 (M+H)+, calc. 269

The synthetic route of 2-Amino-3,5-dibromopyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; UNIVERSITY OF ROCHESTER; BOARD OF REGENTS OF THE UNIVERSITY OF NEBRASKA; GELBARD, Harris A.; DEWHURST, Stephen; GENDELMAN, Howard E.; WO2014/85795; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

875781-43-4, A common heterocyclic compound, 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, molecular formula is C6H4BrN3, 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-bromo-7-iodo-5H-pyrrolof3,2-blpyrazine CIV-E-I); A mixture of III-E-1 (5.0 g, 25 mmol; commercially available from Ark pharma) and freshly ground KOH (5.10 g, 90.9 mmol) in DMF (100 mL) was stirred at RT under N2 for 30 min. Iodine (6.35 g, 25.02 mmol) was then added in one portion and the red mixture was stirred at RT for 2 h when TLC indicated that the reaction was complete. The mixture was poured into water (100 mL) and extracted with EtOAc (3 x 100 mL). The combined organic extracts were dried and concentrated to give IV-E-I (7.74 g, 95%) as a brown solid. 1H NMR (400 MHz, CDCl3) delta 7.67 (s, IH), 8.23 (s, IH).

The synthetic route of 2-Bromo-5H-pyrrolo[2,3-b]pyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; EISAI R & D MANAGEMENT CO. LTD; GRACZYK, Piotr; BHATIA, Gurpreet, Singh; WO2010/15803; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

875781-43-4,Some common heterocyclic compound, 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]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.

Step 1: To a solution of 2-bromo-5H-pyrrolo[2,3-b]pyrazine (1.8 g, 9.09 mmol) in 18 mL of DCM and 18 mL of DMF was added NCS (1.46 g, 10.9 mmol) at RT. The reaction mixture was stirred at RT overnight, then partitioned between EtOAc and brine. The organic layer was dried (MgSO4) concentrated to give 2.98 g of impure 2-bromo-7-chloro-5H-pyrrolo[2,3-b]pyrazine as a yellow oil which was used for the next step without any purification.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, its application will become more common.

Reference:
Patent; Bamberg, Joe Timothy; Hermann, Johannes Cornellius; Lemoine, Remy; Soth, Michael; US2010/144745; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below. 875781-43-4

To a 25 mL microwave vial was added 2-bromo-5H-pyrrolo[2,3-b]pyrazine (0.5 g, 2.52 mmol), 2-fluoropyridin-3-ylboronic acid (600 mg, 4.26 mmol) and sodium carbonate (803 mg, 7.57 mmol) in dioxane (10.0 ml), water (5.00 ml), and EtOH (2.5 ml). The reaction mixture was bubbled through with argon for 10 mins. Pd(PPh3)4 (292 mg, 0.252 mmol). The reaction was bubbled through with argon for 5 mins. The vial was capped and heated in the microwave at 140 C. for 15 min. The reaction mixture was diluted with EtOAc and water. The combined organics were separated, dried (MgSO4), filtered and concentrated. The crude residue dissolved in DCM and treated with silica. The solvent was evaporated and the crude absorbed in silica was purified by SiO2 chromatography eluting with EtOAc/hexane gradient (0% to 60%) to afford 410 mg (76%) of pyrrolopyridine as a light yellow solid. MS m/z (ES): 215 (M+H)+.

In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 875781-43-4, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; de Vicente Fidalgo, Javier; Hermann, Johannes Cornelius; Lemoine, Remy; Li, Hongju; Lovey, Allen John; Sjogren, Eric Brian; Soth, Michael; US2011/59118; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

55557-52-3, 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 55557-52-3 as follows.

Step 1: Into a 2000 mL 4 necked round bottom flask purged and maintained with an inert atmosphere of nitrogen were placed a solution of 3-chloropyrazine-2-carbonitrile (100 g, 716 mmol) in ethanol (660 mL), ethyl 2-sulfanylacetate (112 g, 932 mmol) and sodium carbonate (99 g, 930 mmol). The resulting solution was stirred for 4.5 h at 100 C in an oil bath. The reaction mixture was cooled to room temperature and poured into 7.5 L of water. The solid was collected by filtration. The solid was dissolved in 1500 mL of ethyl ether and filtered. The filtrate was concentrated under reduced pressure. This resulted in ethyl 7-aminothieno[2,3-Z>]pyrazine-6- carboxylate as a solid.

According to the analysis of related databases, 3-Chloropyrazine-2-carbonitrile, the application of this compound in the production field has become more and more popular.

Reference:
Patent; MERCK SHARP & DOHME CORP.; LIM, Jongwon; ALTMAN, Michael, D.; GIBEAU, Craig, R.; (84 pag.)WO2016/144849; (2016); A1;,
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. 95-58-9, name is 2-Chloro-3-methylpyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. 95-58-9

The mixture of 5 g of 2-chloro-3-methylpyrazine, 7.44 mL of benzophenoneimine, 2 g of tris(dibenzylideneacetone)(chloroform)dipalladium (0), 2.48 g of 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl, 5.25 g of sodium t-butoxide, and 150 mL of toluene, was heated overnight under reflux. The reaction mixture was cooled back to room temperature, then diluted with ethyl acetated, and washed with water and with saturated brine in the subsequent order. The organic layer was dried over anhydrous magnesium sulfate. After the insolubles were filtered and the filtrate was concentrated under reduced pressure, 50 mL of 4N hydrogen chloride-1,4-dioxane solution was added to the residue, and the mixture was allowed to stand still for 1 hour. The solution was concentrated under reduced pressure, and the obtained residue was purified by silica gel column chromatography. After the solvent is distilled off, the residue was dissolved in a small amount of chloroform, and hexane was added thereto. The solid thus produced was taken, and dried under reduced pressure to obtain 2.5 g of 3-methyl-2-pyrazineamine [53-1] as an orange solid.

The synthetic route of 95-58-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; BANYU PHARMACEUTICAL CO., LTD.; EP1790650; (2007); 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. 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, A new synthetic method of this compound is introduced below., 55557-52-3

The starting compound 3-chloropyrazine-2-carboxamide was synthesized using two published procedures. The first method was classified as less effective and was based on the homolytic amidation of 2-chloropyrazine. Thus, 2-chloropyrazine (0.17 mol) was dissolved in formamide (3.7 mol), heated to 90 C and ammonium peroxodisulphate (0.18 mol) was added portionwise over one hour period. This mixture reacted for another one hour at 90 C and then it was left to stand for 24 h at laboratory temperature. Dilution with 100 mL of water was followed by filtration and this filtrate was extracted continuously with chloroform for 16 h [34,42]. The mixture of three positional isomers was separated by flash chromatography using silica gel as stationary phase. The second process used 3-chloropyrazine-2-carbonitrile, which was submitted to partial hydrolysis of the nitrile group. The powdered carbonitrile (0.104 mol) was added little by little into the reaction mixture of concentrated hydrogen peroxide (0.95 mol) and water (195 mL) heated to 50 C. The pH was adjusted and regulated around a value of 9 using an 8% solution of sodium hydroxide and the temperature of the reaction was regulated between 55 and 60 C. The reaction was stopped after 2.5 h and was cooled to 5 C. Newly-emerged crystals were removed by suction and recrystallized from ethanol [42].

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:
Article; Jandourek, Ondrej; Dolezal, Martin; Kunes, Jiri; Kubicek, Vladimir; Paterova, Pavla; Pesko, Matus; Buchta, Vladimir; Kralova, Katarina; Zitko, Jan; Molecules; vol. 19; 7; (2014); p. 9318 – 9338;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem