Month: July 2021

Adding a certain compound to certain chemical reactions, such as: 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, 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 5521-55-1, HPLC of Formula: C6H6N2O2

General procedure: To the dipeptide salt (7 or 11, 1 mmol) in Schemes 2 and 3 wasadded a solution of 7 N NH3 in CH3OH (10 mL) and reaction mixturewas stirred for 10 min at 0 C. The solvent was evaporatedunder reduced pressure to afford free peptides, which was dissolvedin DMF (4 mL) and cooled to 4 C. To this reaction mixturerequisite carboxylic acid (1 mmol), DIC (1.1 mmol) and HOBt(1.1 mmol) was added and stirring continued at 4 C for 36 h. Thesolvent was removed under reduced pressure and the resultingresidue purified by column chromatography over neutral alumina using CHCl3/CH3OH (4:1) as eluant to afford desired peptides.The peptides were checked for their homogeneity on aShimadzu SPD-M20A HPLC system using a Supelcosil LC-8(25 cm 4.6 mm ID) column. The peptides were analyzed by usingan isocratic solvent system of CH3CN-H2O-TFA (70:30:0.8%) usinga SUPELCOSIL C-18 column with a flow rate of 1 mL/min

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:
Article; Meena, Chhuttan L.; Thakur, Avinash; Nandekar, Prajwal P.; Sangamwar, Abhay T.; Sharma, Shyam S.; Jain, Rahul; Bioorganic and Medicinal Chemistry; vol. 23; 17; (2015); p. 5641 – 5653;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 4774-14-5, These common heterocyclic compound, 4774-14-5, name is 2,6-Dichloropyrazine, 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. Preparation of (2-chlorophenyl)-(3,5-dichloropyrazin-2-yl)-methanol. To a -20 C. solution of n-butyllithium (2.5 M in hexane, Aldrich, 26.5 mmol) in dry tetrahydrofuran (200 mL) under argon was added 2,2,6,6-tetramethylpiperidine (Aldrich, 11.5 mL, 66.5 mmol, 1.22 eq). The resulting solution was warmed to 0 C. over 0.5 hour period. The solution was then cooled to -78 C., and a solution of 2,6-dichloropyrazine (Aldrich, 8.24 g, 55.3 mmol, 1.0 eq) in tetrahydrofuran was slowly added via a syringe. After addition was complete, the resulting mixture was stirred at -78 C. for an additional 1 hour after which 2-chlorobenzaldehyde (Aldrich, 9.3 mL, 83 mmole, 1.5 eq) was added drop wise via a syringe. The reaction mixture was stirred for an additional 1 hour, quenched with hydrochloric acid (18 mL, 220 mmol, 4 eq)/ethanol (75 mL)/tetrahydrofuran (90 mL) mixture, and then warmed to room temperature. The reaction mixture was diluted with aqueous saturated sodium bicarbonate solution and extracted with ether. The organic layer was separated and washed with brine, dried over sodium sulfate, filtered, and concentrated to give a crude oil which was purified via chromatography using dichloromethane/hexanes (1:1) as the eluent to give (2-chlorophenyl)-(3,5-dichloropyrazin-2-yl)methanol (12.8 g, 44 mmol, 80% yield). Mass spec M+1=290.

Statistics shows that 2,6-Dichloropyrazine is playing an increasingly important role. we look forward to future research findings about 4774-14-5.

Reference:
Patent; Arora, Nidhi; Billedeau, Roland Joseph; Dewdney, Nolan James; Gabriel, Tobias; Goldstein, David Michael; O’Yang, Counde; Soth, Michael; US2005/197340; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 36070-79-8, name is 6-Chloropyrazine-2-carboxamide, 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 36070-79-8, name: 6-Chloropyrazine-2-carboxamide

General procedure: 150 mg (0.952 mmol) of 5-Cl-PZA (1) or 6-Cl-PZA (2) was dissolved in ethanol together with triethylamine (1 eq., 96 mg, 0.952 mmol). Three equivalents of corresponding alkylamine were added to the reaction mixture and refluxed in ethanol generally for 6 hours. The completion of the reaction was checked by TLC chromatography (eluent: hexane/ethyl acetate, 1:2). The crude product was absorbed on silica by solvent evaporation and purified by flash chromatography (hexane/ethyl acetate gradient elution).

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:
Article; Servusova, Barbora; Paterova, Pavla; Mandikova, Jana; Kubicek, Vladimir; Kucera, Radim; Kunes, Jiri; Dolezal, Martin; Zitko, Jan; Bioorganic and Medicinal Chemistry Letters; vol. 24; 2; (2014); p. 450 – 453;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 25911-65-3, A common heterocyclic compound, 25911-65-3, name is 3-Aminopyrazine-2-carbonitrile, molecular formula is C5H4N4, 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.

c) 4-Amino-2-(methoxymethoxymethyl)pteridine Obtained using the procedure described in section c of Example 2, starting with 12.0 g (0.10 mole) of 3-amino-2-pyrazinecarbonitrile and 18.0 g (0.15 mole) of 2-(methoxymethoxy)acetamidine in 400 ml of absolute ethanol. Refluxing time: 4 hours. Yld: 15.8 g (71%), m.p. 129-131 C. (ethanol). NMR (DMSO-d6): delta=3.3 (3H, s); 4.5 (2H, s); 4.7 (2H, s); 8.2 (2H, peak exchangeable with CF3 COOD); 8.7 (1H, d); 8.9 (1H, d).

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; Lipha, Lyonnaise Industrielle Pharmaceutique; US5167949; (1992); A;,
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 23688-89-3 as follows. name: 6-Chloropyrazine-2-carboxylic acid

The preparation method is:0.185 g (ie 1.0 mmol) of 2-phenoxyaniline, 0.158 g (ie 1.0 mmol) of 6-chloropyrazine-2-carboxylic acid and 30 ml of dichloromethane were added to the reaction flask. Then 0.202 g (ie 2.0 mmol) of Et3N was added, followed by 0.287 mg (1.5 mmol) of EDCl, 0.20 g (ie 1.5 mmol) of HOBt,After reacting at 25 C for 2.5 hours, the reaction was completed by TLC, and the reaction was completed. The reaction solution was washed twice with water and once with saturated brine. The organic phase is dried over anhydrous sodium sulfate and de-solued to give a crude product. Recrystallization of ethanol to give a brick red solid is 6-chloro-N-(2-phenoxyphenyl)pyrazine-2-carboxamide, m.p (melting point): 138-140 C, yield: 79.0%;

According to the analysis of related databases, 23688-89-3, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Shanghai Kaiai Network Technology Co., Ltd.; Xu Liyong; (8 pag.)CN108892646; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 886860-50-0, 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. 886860-50-0, name is 2-Amino-5-iodopyrazine, This compound has unique chemical properties. The synthetic route is as follows.

Step 1. methyl 3-(5-aminopyrazin-2-yl)propiolate To a 5 mL of microwave vial was added 5-iodopyrazin-2-amine (100 mg, 0.452 mmol), methyl propiolate (161 muL, 1.810 mmol), potassium carbonate (125 mg, 0.905 mmol), copper (I) iodide (3.45 mg, 0.018 mmol), and THF (1508 muL). The reaction mixture was heated at 65 C. for 2 h. The reaction mixture was diluted with water and extracted with EtOAc. The organic layer was dried over anhydrous sodium sulfate, filtered, and evaporated in vacuo. The crude product was purified by flash chromatography (20% EtOAc in DCM) yielding methyl 3-(5-aminopyrazin-2-yl)propiolate (38%). LCMS (m/z): 178.4 (MH+), 0.48 min.

The chemical industry reduces the impact on the environment during synthesis 2-Amino-5-iodopyrazine. I believe this compound will play a more active role in future production and life.

Reference:
Patent; Novartis AG; Bagdanoff, Jeffrey T.; Ding, Yu; Han, Wooseok; Huang, Zilin; Jiang, Qun; Jin, Jeff Xianming; Kou, Xiang; Lee, Patrick; Lindvall, Mika; Min, Zhongcheng; Pan, Yue; Pecchi, Sabina; Pfister, Keith Bruce; Poon, Daniel; Rauniyar, Vivek; Wang, Xiaojing Michael; Zhang, Qiong; Zhou, Jianguang; Zhu, Shejin; (366 pag.)US9242996; (2016); B2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, molecular formula is C9H16N2O2, 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. Computed Properties of C9H16N2O2

General procedure: n-Butyllithum (500 muL, 1.6 M in hexane) was added dropwise to a stirred solution of (2R)-2,5 -dihydro-2-isopropyl-3,6-dimethoxypyrazine( 150 jiL, 0.83 mmol) in 3 mL dry THF at -78°C under argon atmosphere. The resultant mixture was allowed to be stirred for additional 5 mm. The obtained yellow solution was subsequently transferred via a double-tipped needle to stirred slurry of copper (I) cyanide (38 mg, 0.42 mmol) in 2 mL THF at -78°C under argon. This mixture was stirred at 0 °C for around 1.5 mm to afford cyanocuprate as a tan colored solution. The reaction was then immediately cooled down to-78 °C. A solution of the iodide 6 (0.28 mmol) in 10 mL dry THF was then added dropwise. The reaction mixture was stirred at -78 °C for 30 mm and then for 16 h at -25 °C under argon. The reaction was quenched by adding a 1:9 mixture of aqueous ammonia/saturated aqueous ammonium chloride (15 mL). The aqueous phase was further extracted with diethyl ether (3 x20 mL). The organic layer was combined and then washed with the 1:9 mixtures of concentrated aqueous ammonia/saturated aqueous ammonium chloride, followed by brine, and then dried with anhydrous Na2SO4. After removing the volatile components with rotavapor, the crude product was purified by silica gel flash chromatography (hexane:EtOAc = 4:1 then 3:1) afforded the desired product 7 as colorless oil. [0066] 7b R = Et, 79percent yield. [CL]D179 +6.75(c 1.01, CHC13); 1H-NMR (600 MHz, DMSO-d6,64°C): delta 0.65(d, 3H,J= 6.8 Hz), 0.99(d, 3H,J= 6.8 Hz), 1.10(t, 3H,J= 7.0 Hz), 1.25(s,3H), 1.37(s, 3H), 1.45-1.48(m, 1H), 1.50-1.60(m, 3H), 1.71-1.75(m, 1H), 1.82-1.85(m, 1H),2.15-2.20(m, 1H), 3.14-3.19(m, 2H), 3.25(s, 3H), 3.60(s, 3H), 3.61(s, 3H), 3.89(t, 1H, J 3.6Hz), 3.98(dd, 1H, J= 10.8Hz, 4.0 Hz), 3.99-4.01(m, 2H), 4.53(d, 1H, J 5.9 Hz), 4.55(d, 1H,J= 5.9 Hz), 4.86(s, 1H), 5.09(s, 2H), 7.30-7.31(m, 1H), 7.33-7.36(m, 4H); 13C-NMR (150MHz, DMSO-d6 rotamers): delta 14.20, 15.17, 16.38, 19.01, 24.64, 26.23, 27.90, 30.73, 31.03,37.52, 37.88, 52.07, 53.83, 54.03, 54.27, 59.77, 65.81, 66.13, 83.29, 83.41, 83.66, 83.70,84.90, 109.05, 109.22, 111.32, 127.22, 127.60, 127.68, 128.21, 128.36, 136.97, 137.26,155.52, 162.76, 163.03, 163.11; MS(ESI) mlz: 590 [M+H] HRMS: calculated forC31H48N308 ([M+H]+) 590.3441, found 590.3440.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 109838-85-9, its application will become more common.

Reference:
Patent; MEMORIAL SLOAN-KETTERING CANCER CENTER; ZHENG, Weihong; LUO, Minkui; IBANEZ SANCHEZ, Glorymar del Valle; WO2013/63417; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 4774-15-6, 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. 4774-15-6, name is 2,6-Dimethoxypyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

the molar ratio of Sodiummethoxide and dibromopyrazine is 5:1 placed into three-necked flask with astirrer and a thermometer, added 500ml of Distilled water, start the mixer andwith speed of 200r / min it was stirredfor 10min; After the mixing the mixture was placed at reflux apparatus , heatedup to 60 C, refluxed for 2h, , the collected reflux liquid was put into abeaker then placed in an ice-water bath , at 4 C under ice the precipitatewas allowed to stand for 2h, filtered toobtain precipitate and spare after rotary evaporation drying; The massconcentration of concentrated sulfuric acid is 98% and after drying as mentioned above the precipitatemass ratio is 12: 1 were mixed andtogether poured into a beaker of 500mL, after stirred with a glass rod for10min placed on the shaker and Oscillating reaction for 2 h ,then againadded 50mL of nitric acid solution with a mass concentration of 95% , continues to oscillate the reaction for 20minto obtain a mixed solution; The ratio of the mixed liquid and ammonia water is1:5, the ammonia water was poured into the above mentioned mixed solution, placedthe reaction solution on a magnetic stirrer, with speed of 600r / min it was stirred for 10s , afterwards reduce speed to200r / min and continue to stir for 30min. After completion of the stirring,400ml of anhydrous ethanol added into the mixture solution, placed intoultrasonic vibration device, ultrasonic vibration reaction for 1h, thentransferred to a distillation apparatus, heated to 60 C, ethanol was removedby distillation,for drying used vacuum freeze-drying machine and after crushingof solid particles; Take 1g of the above mentioned solid particles and put into100ml of beaker , added 15ml of glacial acetic acid and 10ml of hydrogenperoxide with a mass concentration of 30%, water bath warmed to 40 C, andafter the 6hrs of reaction filtrated to obtain precipitate and dried to obtain 2,6-diamino-3,5-dinitro-1-oxidepyrazine.

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, 2,6-Dimethoxypyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Changzhou University; CHEN, Xing-quan; (5 pag.)CN105399690; (2016); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 25911-65-3, 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. 25911-65-3, name is 3-Aminopyrazine-2-carbonitrile belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

EXAMPLE 4 Synthesis of 3-Amino-6-bromopyrazine-2-carbonitrile (Intermediate 3) To a solution of intermediate 2 (1.7 g, 14 mmol) in acetic acid (40 mL) at RT was added bromine (0.95 mL, 19 mmol) slowly. The resulting mixture was heated at 60 C. for 30 min and then cooled to RT. The mixture was poured into ice water and the resulting solid filtered. After thoroughly washed with water, the title compound was obtained as a yellow solid (2.3 g, 83%). 1H NMR (500 MHz, DMSO-d6): delta 8.44 (s, 1H), 7.60 (br s, 2H). MS (ES+): m/z 199 (M+H)+.

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

Reference:
Patent; TargeGen, Inc.; US2007/259876; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 33332-25-1, 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. 33332-25-1 name is Methyl 5-chloropyrazine-2-carboxylate, 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.

To a mixture of methyl 5-chloropyrazine-2-carboxylate (1 g, 5.79 mmol) and 2,2,2-trifluoroethanol (2.111 ml, 29.0 mmol) was added potassium carbonate (0.801 g, 5.79 mmol). The reaction was stirred at ambient temperature for 16 hrs. The reaction was partitioned between ethyl acetate and water. The organic portion was concentrated and purified in 10-60% EtOAc/Heptane to give the title compound (1.1 g, 4.66 mmol, 80%). MS m/z=237.1 (M+H).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Methyl 5-chloropyrazine-2-carboxylate, and friends who are interested can also refer to it.

Reference:
Patent; WHITE, Ryan; ALLEN, Jennifer R.; EPSTEIN, Oleg; HONG, Fang-Tsao; HUA, Zihao; HUMAN, Jason Brooks; LOPEZ, Patricia; OLIVIERI, Philip R.; ROMERO, Karina; SCHENKEL, Laurie; STELLWAGEN, John; TAMAYO, Nuria A.; ZHENG, Xiao Mei; US2014/213581; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem