Tag: M.W=100-200

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

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

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

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

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

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

123-32-0, 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. 123-32-0, name is 2,5-Dimethylpyrazine, A new synthetic method of this compound is introduced below.

In a 500-L reactor equipped with a reflux condenser, 250 kg of water and 20 kg of 2,5-dimethylpyrazine were added.Potassium permanganate 4.0kg, heated to 82C, kept at 80C for 1.6h, the solution purple faded and cooled to 76C,Then add 4.0kg of potassium permanganate, slowly warming to 82C, and hold at 82C for 1.6h.The solution purple faded and then incubated for 2.5 hours, and the temperature was reduced to 22 DEG C.; the filter cake was filtered, the filter cake was washed with 12 kg of water, and the filtrate was combined;The combined filtrate is first concentrated under normal pressure, distilled out of water and pyrazine solution (recovery application), after about 82% steaming,Diverted under reduced pressure to dryness; which distilled out of the filtrate 250kg, containing 2,5-dimethyl pyrazine 17kg;Add 15kg of water to the steamed kettle and raise the temperature to 52C to fully dissolve it; then pump it to a neutralization kettle., Adjust the pH to 2.5 with 1+1 sulfuric acid at about 6Kg, and extract with butanone (80Kg x 3) 3 times at 52 C to combine the organic phases;The organic phase was allowed to stand for 24 hours and a small amount of water was removed in the lower layer. The upper organic layer was degassed to dryness at atmospheric pressure.Add 10kg of water to heat and dissolve it, and while it is hot, the filtrate is cooled to 0C, crystallized, and suction filtered.The crude product was dried to 3.6kg; recrystallized from butanone to give 3.2kg of light yellow crystalline powder of 5-methylpyrazine-3-carboxylic acid.The yield was 81.6% and the purity was 99.4%.

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; Changzhou Engineering Polytechnic College; Chen Huiru; Chen Wenhua; Huang Yibo; Zhang Yuxiu; (7 pag.)CN108017586; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 4858-85-9 name is 2,3-Dichloropyrazine, 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. 4858-85-9

2,3-Pyrazinedithiol (pdt) was synthesized according to a literature procedure [15,26-28]. 2,3-Dichloropyrazine (12.02g, 0.07668mol) was dissolved in 200mL MeOH under inert atmosphere. NaSH¡¤xH2O (23.49g, 0.2133mol) was dissolved in 100mL H2O under inert atmosphere. The solutions were combined, and the yellow reaction mixture was brought to reflux at 90C for 15h. 100mL of a 1.21M HCl (aq) solution was slowly added to the reaction mixture. The mixture slowly turned red, and some dark red precipitate was visible. The mixture was cooled to -20C for 3h, after which the precipitate (4.972g, 42.7%) was filtered and washed with cold MeOH. 1H NMR (CDCl3): 13.50ppm (2H), 6.85ppm (2H). IR (neat): nu/cm-1=3083, 2893, 1630, 1547, 1528, 1480, 1316, 1290, 1148, 1133, 1071, 1051, 852, 828, 820, 803, 726, 668, 623. Element. Anal. Calc. for H4C4N2S2: H, 2.80; C, 33.31; N, 19.42; S, 44.47. Found: H, 2.83; C, 32.92; N, 19.05; S, 44.23%.

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

Reference:
Article; Kennedy, Steven R.; Kozar, Morgan N.; Yennawar, Hemant P.; Lear, Benjamin J.; Polyhedron; vol. 103; (2016); p. 100 – 104;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 4858-85-9 name is 2,3-Dichloropyrazine, 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. 4858-85-9

Preparation of 2-Amino-3-Chloropyrazine A mixture of 2,3-dichloropyrazine (Lancaster) and ammonium hydroxide was heated in a sealed tube at 100 C. for 24 h resulting in a white precipitate. The precipitate was collected by filtration and dried under vacuum to afford 2-amino-3-chloropyrazine of sufficient purity for immediate conversion to 2-chloro-3-nitropyrazine.

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

Reference:
Patent; Konradi, Andrei W.; Pleiss, Michael A.; Thorsett, Eugene D.; Ashwell, Susan; Welmaker, Gregory S.; Kreft, Anthony; Sarantakis, Dimitrios; Dressen, Darren B.; Grant, Francine S.; Semko, Christopher; Xu, Ying-Zi; Stappenbeck, Frank; US2002/52375; (2002); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

873-40-5, 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. 873-40-5, name is 2,3,5-Trichloropyrazine, This compound has unique chemical properties. The synthetic route is as follows.

General procedure: Under nitrogen gas stream 2,3,5-trichloropyrazine of 28g (152.65mmol),2-chlorophenylboronic acid of 23.8g (152.65mmol),Put THF / H2O and K2CO3 of 800ml / 200ml 63.3g (457.9mmol) and stirred. At 40 into the Pd (PPh3) 4 of 5.3g (4.58mmol) was stirred at 80 for 12 hours.After completion of the reaction, which was then extracted with dichloromethane. The organic layer was dried over MgSO4 filtered under reduced pressure. The filtered organic layer was evaporated under reduced pressure to a back by column chromatography the desired compound 2,5-dichloro-3- (2-chlorophenyl) pyrazine 12g (yield: 30%) was obtained.

If you are interested in these compounds, you can also browse my other articles.Thank you for taking the time to read this article. I hope you enjoyed it.

Reference:
Patent; Doosan Corporation; Kim, Tae Hyung; Bae, Hyung Chan; Son, Hyo Suk; Baek, Young Mi; Patk, Ho Chul; (54 pag.)KR101488560; (2015); B1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem