Month: February 2021

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. 16298-03-6, name is Methyl 2-aminopyrazine-3-carboxylate, A new synthetic method of this compound is introduced below., name: Methyl 2-aminopyrazine-3-carboxylate

Example 3a: methyl 3-amino-6-iodopyrazine-2-carboxylate 1.5 equivalents of N-iodosuccinimide are added at room temperature to 5 g (32.7 mmol) of a methyl 3-aminopyrazine-2-carboxylate solution in 25 ml of dimethylformamide. The reaction medium is heated at 65 ¡ãC for 1 hour, added together with 0.5 equivalents of N-iodosuccinimide and maintained at 65¡ãC for 24 hours. After returning to room temperature, the solvent is evaporated and then the product is extracted several times with dichloromethane. The organic phases are combined, washed with 10percent sodium bisulfite solution, dried on magnesium sulfate and concentrated to yield 8 g (88percent) of methyl 3-amino-6-iodopyrazine-2-carboxylate in the form of a yellow solid. LCMS (EI, m/z): (M+l) 280 1H NMR: deltaEta ppm (400 MHz, DMSO): 8.50 (1H, s, CHarom), 7.50 (2H, bs, NH2), 3.20 (3H, s, CH3).

The synthetic route of 16298-03-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PIERRE FABRE MEDICAMENT; SOKOLOFF, Pierre; CACHOUX, Frederic; WO2014/16433; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 22047-25-2, The chemical industry reduces the impact on the environment during synthesis 22047-25-2, name is Acetylpyrazine, I believe this compound will play a more active role in future production and life.

Preparation 4 1-Pyrazin-2-yl-ethyl amine The synthetic procedure used in this preparation is outlined below in Scheme F. 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 dicholromethane 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.

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, Acetylpyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Roche Palo Alto LLC; US2009/170874; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 622392-04-5, 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. 622392-04-5, name is 2-Bromo-5-iodopyrazine, This compound has unique chemical properties. The synthetic route is as follows.

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)

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

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

These common heterocyclic compound, 14508-49-7, name is 2-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. Safety of 2-Chloropyrazine

Step 1: tert-Butyl 4-(pyrazin-2-yl)piperazine-1-carboxylate Into a 1 L flask equipped with a condenser and a magnetic stir bar was added 2-chloropyrazine (20.6 g, 180 mmol), tert-butyl piperazine-1-carboxylate (33.5 g, 180 mmol), potassium carbonate (29.8 g, 216 mmol), dioxane (225 mL) and DMF (225 mL). The mixture was heated to 120 C. for 3 days. The mixture was cooled and poured into a 1 L separatory funnel containing brine (600 mL) and extracted with Et2O (3*200 mL). The combined organic layers were washed with brine, dried over MgSO4, filtered and concentrated under reduced pressure. Purification by column chromatography through silica gel, eluting with 50:50 hexanes:EtOAc to 20:80 hexanes:EtOAc as a gradient, afforded the title compound as a yellow solid.

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

Reference:
Patent; Isabel, Elise; Lachance, Nicolas; Leclerc, Jean-Philippe; Leger, Serge; Oballa, Renata M.; Powell, David; Ramtohul, Yeeman K.; Roy, Patrick; Tranmer, Geoffrey K.; Aspiotis, Renee; Li, Lianhai; Martins, Evelyn; US2011/301143; (2011); 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. 123-32-0, name is 2,5-Dimethylpyrazine, This compound has unique chemical properties. The synthetic route is as follows., HPLC of Formula: C6H8N2

1), in 125 ml in the reaction bottle, by adding 1.08g (10mmol) 2, 5-dimethyl-pyrazine, 1.13g (4mol) FeSO4¡¤ 7H2O, by adding 30 ml of water (i.e., 3 ml/1mmol), stirring in the ice bath, then measure 0.1mol (6 ml) 98% concentrated sulfuric acid to constant pressure dropping funnel slowly dropping, the temperature change in the process of dropping the attention, to maintain the temperature of the reaction bottle too high (i.e., to control the temperature to 60 C the following can be). After concentrated sulfuric acid instillment , on a rectifier 22mmol (7.5 ml) hydrogen peroxide, PV drop instillment , and to continue the reaction in the ice bath, dripping at any time in the process of observing reaction bottle temperature change (i.e., to control the temperature to 60 C the following can be). After dripping adding 240uL (3mmol) is propionaldehyde, slowly elevated temperature so as to control the temperature to 50-60C, in the reaction 1h, 2h, 3h, 4h are respectively adding 240uL is propionaldehyde. In the reaction process and reaction conditions for TLC, reaction conditions estimated raw material, when the raw material after the reaction is complete can stop the reaction (about 6h).2), stop heating after the reaction, cooling to room temperature, with 30 ml ethyl acetate extraction, the aqueous phase (the lower) the quality of the diluted for the fraction of 20% NaOH to adjust the pH to 8, in the process the alkali adjusting full stirring, not to allow the temperature of the solution is too high (i.e., not to exceed 60 C). Then extracting with ethyl acetate three times, combined with the phase (the upper), pressure-reducing (pressure -0.08–0.10 MPa) concentrated to dry, yellow oily substance is about 1.532 g. Finally through the column chromatography the 2-ethyl -3, 6-dimethyl-pyrazine separated.As follows:The silica gel chromatography (built-in 200-300 purpose silica gel 30g), the resulting 1.532g for column chromatography yellow oily substance; for the mobile phase ethyl acetate: petroleum ether = 1:20 of the mixed solution, the total consumption of mobile phase about 500 ml; final 1.245g product—2-ethyl -3, 6-dimethyl-pyrazine (the purity is 95.6%). Yield 90.88%.

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 123-32-0.

Reference:
Patent; Zhejiang University; Cheng, Jingli; Wang, Likun; Zhao, Yang; Zhao, Jinhao; (9 pag.)CN105237486; (2016); A;,
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. 1379338-74-5, name is 5,7-Dichloropyrido[3,4-b]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., COA of Formula: C7H3Cl2N3

(A) (S)-terf-butyl 3-((7-chloropyrido[4,3-ib]pyrazi n-5-ylami no)methyl)piperidi ne- 1 -carboxylate.[0123] A solution of (S)-teri-butyl 3-(aminomethyl)piperidine-1 -carboxylate (100 mg, 0.5 mmol), 5,7-dichloropyrido[4,3-¡ê>]pyrazine (100 mg, 0.5 mmol) and DIPEA (77 mg, 0.6 mmol) in THF (5 ml_) was stirred at room temperature for 4 hours. The volatiles were removed under reduced pressure, and the residue was treated with ethyl acetate, with brine, and concentrated to give the crude title compound.

According to the analysis of related databases, 1379338-74-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; HUTCHISON MEDIPHARMA LIMITED; SU, Wei-Guo; DENG, Wei; JI, Jianguo; WO2012/167423; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 69214-33-1, name is 8-Chloroimidazo[1,2-a]pyrazine, 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 69214-33-1, Quality Control of 8-Chloroimidazo[1,2-a]pyrazine

To the solution of compound 9 (6.47 g, 42.13 mmol) indichloromethane (140 ml) N-bromosuccinimide (7.50 g,42.13 mmol) was added and the mixture was stirred at roomtemperature for 3 h. The reaction mixture was diluted withdichloromethane and stirred with 10% aqueous sodium carbonatesolution for 1 h before the layers were separated. The organic layerwas washed with water (2), dried over sodium sulphate, filteredand concentrated under reduced pressure. The crude product was triturated with diisopropyl ether and filtered to give the titlecompound (14.40 g)

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; Garamvoelgyi, Rita; Dobos, Judit; Sipos, Anna; Boros, Sandor; Illyes, Eszter; Baska, Ferenc; Kekesi, Laszlo; Szabadkai, Istvan; Szantai-Kis, Csaba; Keri, Gyoergy; Oerfi, Laszlo; European Journal of Medicinal Chemistry; vol. 108; (2016); p. 623 – 643;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 36070-80-1,Some common heterocyclic compound, 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, molecular formula is C5H3ClN2O2, 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.

5-Chloropyrazine-2-carboxylic acid (27, 7.84 g), N,N-dimethylformamide(120 mL), ethyl piperidine-4-carboxylate (16.0 mL),and N,N-diisopropylethylamine (25.0 mL) were mixed, followed bystirring at 90 C for 8 h. The reaction mixture was cooled to roomtemperature and ethyl acetate was added. The mixture was washedwith a dilute hydrochloric acid solution and dried over anhydrous sodium sulfate. The insoluble materials were separated by filtration andthe filtrate was concentrated under reduced pressure. The obtainedsolid was washed with diisopropyl ether and dried to obtain 28 (6.80 g,49%) as a milky white solid: 1H NMR (CDCl3) delta 1.27 (3H, t,J = 7.0 Hz), 1.74-1.86 (2H, m), 2.02-2.11 (2H, m), 2.66 (1H, tt,J = 10.5, 4.1 Hz), 3.20-3.30 (2H, m), 4.17 (2H, q, J = 7.1 Hz),4.33-4.42 (2H, m), 8.02 (1H, d, J = 1.3 Hz), 8.86 (1H, d, J = 1.3 Hz);ESI-MS m/z 280 [(M+H)+].

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 5-Chloropyrazine-2-carboxylic acid, its application will become more common.

Reference:
Article; Inagaki, Yusuke; Ino, Katsutoshi; Ishizu, Kenichiro; Koike, Takanori; Maeda, Jun; Negoro, Kenji; Shimoshige, Yukinori; Takahashi, Taisuke; Tanaka, Hiroaki; Tsukamoto, Issei; Yokoyama, Kazuhiro; Bioorganic and medicinal chemistry; (2020);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 4774-14-5, name is 2,6-Dichloropyrazine, 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 4774-14-5, name: 2,6-Dichloropyrazine

Step 1 [0666] To a solution of fert-butyl azetidin-3-ylcarbamate hydrochloride (LXIII) (2 g, 9.58 mmol) in dry DMF (19.2 mL) was added DIPEA (8.37 ml, 47.9 mmol). To this mixture was added 2,6-dichloropyrazine (LXIV) (1.428 g, 9.58 mmol) and the reaction was stirred at 95C for 3 h. The reaction was quenched with water (20 mL) and extracted with EtOAc. The organic layer was dried over anhydrous NaaSO/t, filtered and concentrated. The residue was purified by silica gel column chromatography (40 g) (100% hexanes?hexanes:EtOAc 1 : 1) to yield fert-butyl (l-(6-chloropyrazin-2-yl)azetidin-3-yl)carbamate (LXV) (2.2882 g, 8.04 mmol, 84 % yield) as a white solid. ESIMS found for C12H17CIN4O2 mlz 285.1 (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, 2,6-Dichloropyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; SAMUMED, LLC.; KC, Sunil Kumar; WALLACE, David Mark; CAO, Jianguo; CHIRUTA, Chandramouli; HOOD, John; (254 pag.)WO2017/23980; (2017); A1;,
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 54608-52-5 as follows. HPLC of Formula: C4H6N4

General procedure: Sodium (0.70 g, 30.44 mmol) was dissolved in 50 mL of anhydrous ethanol, and 2-chloro-6-hydrazinylpyrazine (2a) (4.00 g, 27.67 mmol) was added. The reaction solution was heated to 60 C until the mixture was totally dissolved. Keep the temperature of the reaction below 40 C, and diethyl maleate (4.77 g, 27.67 mmol) was added dropwise. The reaction was heated to 45 C and cooled to room temperature after 5 h. The reaction was quenched with glacial acetic acid (1.83 g, 30.44 mol) and stirred for 1 h. The resulting solution was evaporated in vacuo, dissolved in 50 mL of water, extracted with CH2Cl2 (3¡Á50 mL). The extracts was washed with brine, dried with anhydrous MgSO4 and evaporated to give the crude product, which was further purified with recrystallization (diehyl ether) as a yellow solid, 4.25 g.

According to the analysis of related databases, 54608-52-5, the application of this compound in the production field has become more and more popular.

Reference:
Article; Liu, Weijie; Li, Jiao; He, Kai; Huang, Fangfang; Ma, Yi; Li, Yuxin; Li, Qingshan; Xu, Fengbo; Chinese Chemical Letters; (2019); p. 417 – 420;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem