Month: July 2021

Synthetic Route of 4430-75-5, A common heterocyclic compound, 4430-75-5, name is Octahydro-2H-pyrido[1,2-a]pyrazine, molecular formula is C8H16N2, 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 A Ethyl 3-(octahydro-2H-pyrido[1,2-a]pyrazin-2-yl)propanoate A solution of 3.5 g of octahydro-2H-pyrido[1,2-a]pyrazine and 8 ml of ethyl acrylate in 50 ml of acetonitrile is refluxed for 24 hours. The solvent is removed in vacuo to yield the expected product.

The synthetic route of 4430-75-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Goldstein, Solo; Poissonnet, Guillaume; Parmentier, Jean-Gilles; Lestage, Pierre; Lockhart, Brian; US2003/195216; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 5521-55-1, A common heterocyclic compound, 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, molecular formula is C6H6N2O2, 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.

EXAMPLE 2 The reaction is carried out, under nitrogen, in a 1 L*4 neck flask equipped with a mechanical stirrer, water condenser (with gas inlet), and a thermocouple. The reactor is charged with 5-methylpyrazinecarboxylic acid (100 g), ethanol,(300 g) and sulfuric acid (2 g). The contents are refluxed for eight hours at 78 C. The reaction mixture is cooled to ambient temperature and sodium bicarbonate (4 g) is added. About 75% of the solvent is removed under reduced pressure and the resulting suspension is allowed to stand overnight. The solids are filtered and washed with cold methanol (2*80 g). Drying under oven (25 inches of Hg) yielded 101.25 g (84%) of 5-methyl-2-pyrazonecarboxylic acid, ethyl ester.

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; ISP INVESTMENTS INC.; US2005/239803; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 768-05-8, 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. 768-05-8, name is Pyrazinoic acid hydrazide belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

General procedure: A mixture of compound 12/13 (1mmol) and hydrazine derivative (1mmol) was taken in ethanol (10mL) in a dry 50mL RB flask. A catalytic amount of conc. H2SO4 was added and the mixture was stirred for 10-15min at RT. After the complete consumption of both starting materials (monitored by TLC), the reaction mixture was poured into ice cold water (10mL). The solid separated was filtered off under suction and washed with ethanol and water.

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, Pyrazinoic acid hydrazide, other downstream synthetic routes, hurry up and to see.

Reference:
Article; Reddyrajula, Rajkumar; Dalimba, Udayakumar; Madan Kumar; European Journal of Medicinal Chemistry; vol. 168; (2019); p. 263 – 282;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 1458-01-1, 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. 1458-01-1, name is Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, This compound has unique chemical properties. The synthetic route is as follows.

A mixture of methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (100 g; 494 mmol), methanol (1 l) and NaOH (6 mol/l in water; 240 mL; 1.44 mol) is refluxed for 3 h.The mixture is allowed to cool to r.t. and then neutralized by addition of hydrochloric acid (6 mol/l in water; approx. 240 mL). Water (200 mL) is added. The precipitate formed is filtered off with suction, washed with water and dried at 60° C. Yield: 99.6 g (107percent of theory) C5H5ClN4O2 .ESI Mass spectrum: m/z=189 [M+H]+; m/z=187 [M-H]-

The chemical industry reduces the impact on the environment during synthesis Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate. I believe this compound will play a more active role in future production and life.

Reference:
Patent; BOEHRINGER INGELHEIM INTERNATIONAL GMBH; HAMPRECHT, Dieter; HECKEL, Armin; KLEY, Joerg; US2013/316981; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 160252-31-3, 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. 160252-31-3, name is 1-(5-Chloropyrazin-2-yl)ethanone belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

Sodium hydride (60 wt.%, 276 mg, 6.90 mmol) was added to a mixture of 1- (5-chloropyrazin-2-yl)ethanone (800 mg, 5.11 mmol) and 4-Fluoro-1H-pyrazole (484 mg, 5.62 mmol) in N,N-dimethylformamide (6.0 mL) at ambient temperature for 10 minutes. The reaction mixture was then poured into water (70 mL) and was sonicated and stirred for 20 minutes. A dark red solid was isolated by filtration, washed with small amounts of water, and dried to 1-(5-(4-fluoro-1H-pyrazol-1-yl)pyrazin-2-yl)ethan-1-one (919 mg, 95% yield). MS: M+1 = 207.

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, 1-(5-Chloropyrazin-2-yl)ethanone, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; BLUEPRINT MEDICINES CORPORATION; BRUBAKER, Jason D.; GUZI, Timothy; WILSON, Kevin J.; DIPIETRO, Lucian V.; ZHANG, Yulian; WILSON, Douglas; FLEMING, Paul E.; (137 pag.)WO2018/17983; (2018); 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. 19847-12-2, name is Pyrazinecarbonitrile, This compound has unique chemical properties. The synthetic route is as follows., Safety of Pyrazinecarbonitrile

(1) preparing a format reagent,Add magnesium, anhydrous polarity to a nitrogen-protected pressure vesselSolvent tetrahydrofuran and elemental iodine, then add methyl chloride to the pressure vessel and stir.After the pressure vessel is heated to 60 C and stirring is continued for 2 hours, a format reagent is prepared;Metal magnesium is newly formed magnesium, and the molar ratio of magnesium metal to chloromethane acid is 1:1.1;The content of elemental iodine is 0.21% × metal magnesium weight; the reaction equation is as follows:(2)Addition reaction, adding 2-cyanopyrazine and tetrahydrofuran to the reactor and heating the reactor to50 C, then add catalysisThe cuprous chloride and the reagents of the above format are then refluxed and condensed.After the end, the remaining part of the reactor is an intermediate product, wherein the addition reaction time is 14h;The molar ratio of 2-cyanopyrazine to the format reagent S1 is1:1.05; the content of cuprous chloride is 2.1% metal magnesium weight;(3)Hydrolyzing, adding water to the remaining intermediate product of the above reactor,The pH of the solution in the reactor was adjusted to 1 with dilute sulfuric acid, and then stirred for 12 hours.Adjusting the pH of the solution in the reactor to neutral with a saturated aqueous solution of sodium carbonate;Finally extracted with toluene three times;(4)After the treatment, the toluene extract is desolvated, and the solid after desolvation is dissolved by heating with ethanol.Add activated carbon, continue heating and reflux for 10 min, and filter.The filtrate was cooled to 5 C to obtain a white solid P1; then the white solid P1 was recrystallized from ethanol.Produced a white solid P2,Drying gives 2-acetylpyrazine;The purity of 2-acetylpyrazine was 98.4%, and the yield of 2-acetylpyrazine was 69%.The reagent polar solvents, elemental iodine, 2-cyanopyrazine, tetrahydrofuran toluene and ethanol were all analytically pure.

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 19847-12-2.

Reference:
Patent; Henan Weiyuan Biological Technology Co., Ltd.; Xuan Bingwu; Xing Xiaodong; Xuan Fuxing; (8 pag.)CN109796416; (2019); 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. 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, This compound has unique chemical properties. The synthetic route is as follows., Recommanded Product: 4744-50-7

In a 250 mL three-necked flask equipped with a mechanical stirrer, a spherical condensed reflux tube was added 15 g in this order 2, 3-pyrazinedicarboxylic anhydride,13 g of 2-amino-5-chloropyridine,0.12 g of 4-dimethylaminopyridine,120 mL of xylene,At 30 C, add 202 g of triethylamine.Heated to 80 C,Reaction 8h; continue to heat up to reflux,Reaction lh.Stop heating,Mechanical stirring naturally down to room temperature,Continue to stir 2h; use ice bath cooling,Control the temperature at 0-5 C,Stir for 2 h.Filtration,The filter cake was washed once with 50 mL of 1 N diluted hydrochloric acid,50 mL of water was again washed,60 C oven drying 8h,Obtained as a white solid 22. lg,Yield 85%Purity 98%,Melting point: 232-235 C.

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 4744-50-7.

Reference:
Patent; Disha Pharmaceutical Group; Weihai Disu Pharmaceutical Co., Ltd; LI, GUANGYUE; DING, YAN; (5 pag.)CN103664952; (2016); B;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 28643-16-5, These common heterocyclic compound, 28643-16-5, name is Methyl 3-amino-5-chloropyrazine-2-carboxylate, 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.

Acid-5: 3-(di-tert-Butoxycarbonyl-amino)-5-difluoromethyl-pyrazine-2-carboxylic acid; a) 3-Amino-5-vinyl-pyrazine-2-carboxylic acid methyl ester; To a mixture of 161 mg (0.86 mmol) 3-amino-5-chloro-pyrazine-2-carboxylic acid methyl ester (GB 1248146) , 0.352 ml (1.204 mmol) tributyl(vinyl)tin and 102 mg (2.498 mmol) lithium chloride in DMF was added 30.2 mg (0.043 mmol) PdCI2(PPh3)2 and the mixture was heated to 85 C for 2.5 h. After cooling to room temperature water was added and the mixture was extracted with EtOAc, the combined organic layers were washed with water and half saturated aq. NaCI, dried with Na2S04 and evaporated. The residue was purified by chromatography on silica gel (cyclohexane to cyclohexane/EtOAc 1 :9) to provide the title compound as yellow solid.HPLC: 0.71 min; ESIMS [M+H]+ = 179.9;1H-NMR (600 MHz, DMSO-cfe): delta 8.04 (s, 1 H), 7.35 (br. s, 1 H), 6.75 (dd, 1 H), 6.38 (d, 1 H), 5.70 (d, 1 H), 3.84 (s, 3H).

The synthetic route of 28643-16-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; NOVARTIS AG; HURTH, Konstanze; LUEOEND, Rainer Martin; MACHAUER, Rainer; NEUMANN, Ulf; RUEEGER, Heinrich; SCHAEFER, Michael; TINTELNOT-BLOMLEY, Marina; VEENSTRA, Siem Jacob; VOEGTLE, Markus; WO2012/95463; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 173253-42-4, name is 2-Amino-5-bromo-6-chloropyrazine, 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 173253-42-4, Application In Synthesis of 2-Amino-5-bromo-6-chloropyrazine

To a solution of 5-bromo-6-chloropyrazin-2-amine (0.600 g, 2.8 mmol, 1 eq.) and benzo[d]thiazol-6-ylboronic acid (0.412 g, 2.3 mmol, 0.8 eq.) in dioxane (8 mL) and water (2 mL) was added Na2CO3 (0.549 g, 5.18 mmol, 2 eq.). The reaction was purged with N2 and PdCl2(dppf)?DCM complex (0.117 g, 5 mol %). The reaction mixture was deoxygenated using N2 atmosphere and the reaction mixture was heated at 100 C. for 16 h under microwave irradiation. The reaction was monitored by TLC and LCMS The reaction mixture was diluted with water and extracted with ethyl acetate (3*100 mL). The separated organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The crude product was purified by normal phase column chromatography to afford desired product (0.210 g, 28%).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2-Amino-5-bromo-6-chloropyrazine, and friends who are interested can also refer to it.

Reference:
Patent; GiraFpharma LLC; PHAM, Son Minh; CHEN, Jiyun; ANSARI, Amantullah; JADHAVAR, Pradeep S.; PATIL, Varshavekumar S.; KHAN, Farha; RAMACHANDRAN, Sreekanth A.; AGARWAL, Anil Kumar; CHAKRAVARTY, Sarvajit; (120 pag.)US2019/23666; (2019); 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. 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., Computed Properties of C6H5ClN2O2

To a solution of methyl 5-chloropyrazine-2-carboxylate (I, 30.0 g, 0.174 mol) in acetonitrile (120 mL) TMSBr (45.1 mL, 0.348 mol) was added under nitrogen atmosphere. The mixture was stirred and heated at 80 C for 5 h while volatile component (105 mL) was distilled away under reduced pressure (atmospheric pressure to 800 hPa). After the mixture was cooled to 0 C, water (150 mL) was added while keeping the internal temperature at 0 to 8 C, and the mixture was stirred at 0 C for 1 h. The precipitated solids were collected by filtration, washed with water (120 mL), and dried under reduced pressure at 50 C to provide 35.0 g of the title compound (II) (93% yield) as brown solids. The ratio of I and II was 1.1 :98.9 by its HPLC analysis.

The synthetic route of 33332-25-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; EISAI R&D MANAGEMENT CO., LTD.; YOSHIZAWA, Kazuhiro; OMORI, Masayuki; WATANABE, Yuzo; NAGAI, Mitsuo; TAKAHASHI, Masabumi; FANG, Frank; WO2013/162065; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem