Category: Pyrazines

5049-61-6, 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. 5049-61-6, name is Pyrazin-2-amine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

[Referential Example 11] 1-(5-Methoxy-2-pyrazinyl)-5-(2-pyridyl)-1H-pyrazole-3-carboxylic acid; [Show Image] [Show Image] 1) 5-Chloro-2-hydrazinopyrazine; A solution of 5-chloro-2-hydroxpyrazine (1.84 g) synthesized from aminopyrazine by the method of Palamidessi et al. (J.Org.Chem., vol.29, pp 2491-2492, 1964) in phosphorus oxychloride (28ml) was placed in a sealed tube, and the solution was stirred at an outer temperature of 130C for 6 hours. After cooling with air, ice cold water and dichloromethane were added to the reaction liquid, then the phases were separated. The organic layer was dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure. Hydrazine monohydrate (1.39 ml) was added to a solution of the residue in ethanol (14 ml), and the mixture was stirred at room temperature for 150 minutes and for another 15 minutes at 80C. After cooling with air, the reaction liquid was evaporated under reduced pressure, and to the residue was added water and a mixed solvent of chloroform and methanol (1:10), then the phases were separated. The organic layer was dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure to give 5-chloro-2-hydrazinopyrazine(0.325 g, 16%) as a solid. 1H-NMR (400 MHz, DMSO-d6)delta: 4.32 (2H, br s), 7.92 (1H, s), 7.99 (1H, s), 8.13 (1H, s). EI-MSm/z: 144 (M+).

The synthetic route of 5049-61-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; DAIICHI PHARMACEUTICAL CO., LTD.; EP1698626; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

36070-80-1, Adding a certain compound to certain chemical reactions, such as: 36070-80-1, name is 5-Chloropyrazine-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 36070-80-1.

Step 1: 5-chloro-N-[(lS)-2,2,2-trifluoro-l-methylethyl]pyrazine-2-carboxamideN,N-Diisopropylethylamine (1.3 mL, 7.5 mmol) was added to a mixture of 5- chloropyrazine-2-carboxylic acid (0.40 g, 2.5 mmol), N,N,N’,N’-tetramethyl-0-(7- azabenzotriazol-l-yl)uronium hexafluorophosphate (1.0 g, 2.8 mmol) and (2S)-1,1,1- trifluoropropan-2-amine (0.28 g, 2.5 mmol) (Oakwood: Cat.No.44272) in methylene chloride (10 mL). The reaction mixture was stirred at room temperatureovernight. The reaction mixture was worked up with saturated aqueous NaHCC , and extracted with ethyl acetate (3x 20 mL). The combined organic layers were washed with brine, dried over MgS04, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography on a silica gel column with ethyl acetate in hexanes (0-15%) to afford the desired product (0.64 g, 73%). LCMS (M+H) +: m/z = 253.9/255.9.

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, 5-Chloropyrazine-2-carboxylic acid, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; INCYTE CORPORATION; YAO, Wenqing; BURNS, David M.; ZHUO, Jincong; WO2012/177606; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, 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. 5049-61-6 name is Pyrazin-2-amine, 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.

Preparation of 3,5-dibromopyrazin-2-amine Intermediate BA) [0322] To a stirred solution of aminopyrazine (8.21 g, 86.4 mmol) in anhydrous methylene chloride (215 mL) cooled to 0C was added N-bromosuccinimide (32.3 g, 181 mmol) in portions over a six hour period, during which time the temperature of the reaction was kept below 0C. The resulting mixture was stored at 4C overnight, after which it was stirred vigorously and quenched with H20 (100 mL). The organic layer was separated, after which it was washed with saturated aqueous NaHC03, washed with brine, dried over MgS04, filtered, and evaporated in vacuo to yield a residue that was triturated with 20% EtOAc in hexanes to yield the title compound (10.3 g, 47%) as a yellow/brown powder. 1H NMR (CDC13, 300MHz) delta 8.02 (s, 1H), 5.05 (bs, 2H); HPLC retention time: 1.99 minutes; MS ESI (m/z): 252.0/254.0/256.2 (M+l)+, calc. 251.

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

Reference:
Patent; UNIVERSITY OF ROCHESTER; GELBARD, Harris, A.; DEWHURST, Stephen; GOODFELLOW, Val, S.; WIEMANN, Torsten; RAVULA, Satheesh, Babu; LOWETH, Colin, J.; WO2011/149950; (2011); A2;,
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. 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. 113305-94-5

4G. Benzyl-(2-{4-[(Z)-3-(5-cyano-yrazin-2-ylamino)-3-methylsulfanyl-acryloyl]-3- methoxy-henyl}-ethyl)-carbamic acid tert-butyl esterA solution of 2-amino-5-cyanopyrazine (0.12 g, 0.92 mmol) was added in portions to a stirred slurry of NaH (60% in mineral oil) (0.040 g, 0.92 mmol) in THE (3 mL) at room temperature. The mixture was stirred for 30 minutes then benzyl-{2-[4-(3,3-bis- methylsulfanyl-acryloyl)-3-methoxy-phenyl]-ethyl}-carbamic acid tert-butyl ester (0.30 g, 0.62 mmol) was added and the reaction mixture was then heated to 65C for 12hours. The solution was allowed to cool to room temperature then water (10 mL) was carefully added and the mixture extracted with EtOAc (3 x 20 mL). The combined organic extracts were washed with brine (10 mL), dried (Na2SO4) and evaporated under reduced pressure to leave a residue that was purified by column chromatography on neutral silica gel (60-120 mesh) using 15-30% EtOAc/hexanes asthe eluent to give the title compound (0.17 g, 49%).

The synthetic route of 113305-94-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ONCOTHYREON INC.; BOYLE, Robert, George; WALKER, David, Winter; BOYCE, Richard, Justin; PETERSON, Scott; FAROUZ, Francine; VO, Cong, Hung; WO2015/120390; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 41270-66-0, name is 5-Chloro-2,3-diphenylpyrazine, molecular formula is C16H11ClN2, 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. 41270-66-0

Under the protection of nitrogen,Add 3-methyl-2-chloro-quinoxaline (532 mg, 2.00 mmol) to cis-5-(isopropylaminomethyl)tetrahydrofuran-2-yl)methanol (1.04 g, 6.00 mmol)N-methylpyrrolidone(50mL) solution,The reaction was heated to 190 C for 15 h, and the reaction was monitored by LC-MS.The reaction was cooled, and ice water was added to the mixture, and ethyl acetate (50mL*3)The organic mixed phase was washed with water (50 mL) and saturated brine (50 mL*2).Filtration, solvent removal under reduced pressure, purification by chromatography on silica gel column, and collected under reduced pressure.Drying in vacuo gave 641.5 mg of Compound VIII as a white solid.Yield: 79.6%

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 41270-66-0, its application will become more common.

Reference:
Patent; Chengdu Yuandong Bio-pharmaceutical Co., Ltd.; Zeng Yanqun; Yan Shengyong; Zhang Tao; Wang Ying; (17 pag.)CN108623541; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-29-5, Name is 2-Amino-5-chloropyrazine, 33332-29-5, belongs to Pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows.

General procedure: Method B is a modification of Method A and was performed under nitrogen atmosphere andwith extended work-up. Substituted benzoyl chloride (1.5 mmol, 1.2 equiv) was placed into the askunder nitrogen, diluted with dry DCM (5 mL) and dry pyridine (400 mg, 5 mmol, 4 equiv) was added.The mixture was mixed for 5 min under nitrogen. Then, 5-chloropyrazin-2-amine (162 mg, 1.25 mmol,1 equiv) dissolved in DCM (10 mL) was added dropwise over 10 min under nitrogen ow. The askwas closed by septum and stirred for additional 6 h. After reaction, the mixture was diluted with DCMto the final volume of 40 mL and washed with water (1 30 mL), 5% (m/m) aqueous NaHCO3 solution(1 30 mL), and brine (1 30 mL). The organic layer was dried over anhydrous Na2SO4 and adsorbedon silica (4 g) by evaporating the solvents under reduced pressure. Automated flash chromatographywas run using same conditions as described in Method A. If needed, the products were recrystallizedfrom hot EtOH (crystallization initiated by cooling and dropwise addition of cold water).

Statistics shows that 2-Amino-5-chloropyrazine is playing an increasingly important role. we look forward to future research findings about 33332-29-5.

Reference:
Article; Zitko, Jan; Mindlova, Al?b?ta; Vala?ek, Ond?ej; Jand’ourek, Ond?ej; Paterova, Pavla; Janou?ek, Ji?i; Kone?na, Klara; Dole?al, Martin; Molecules; vol. 23; 9; (2018);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

24241-18-7, These common heterocyclic compound, 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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.

To a solution of intermediate I-82 (10 g, 40 mmol, 1.0 eq) in DMF (115 mL) was added neat triethylamine (53 mL), Pd(PPh3)4 (2.3 g, 2.0 mmol, 0.05 eq) and CuI (0.90 g, 4.7 mmol, 0.12 eq) followed by drop wise addition of ethynyltrimethylsilane (6.7 mL, 48 mmol, 1.2 eq) and the reaction mixture was stirred for 30 minutes at 120 C. The crude reaction mixture was concentrated by evaporation and the crude reaction product was purified by silica gel column chromatography to give intermediate I-83 (3.0 g, 17%) as yellow oil. MS (ESI): m/z 271 (M+H+).

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 24241-18-7.

Reference:
Patent; Chytil, Milan; Engel, Sharon R.; Fang, Qun Kevin; Spear, Kerry L.; US2010/204214; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

41270-66-0, Name is 5-Chloro-2,3-diphenylpyrazine, 41270-66-0, belongs to Pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows.

2-[4-(tert-butoxycarbonyl)(isopropyl)aminobutoxy]-N-(methylsulfonyl)acetamide (20.0 g, 0.055 mol)And dissolved in methanol (110 mL),Trifluoroacetic acid (6.8 g, 0.06 mol) was added and the reaction stirred at 65 C for 6 hours until the reaction was complete. The reaction mixture was added dropwise to stirred water (200 mL), cooled to 0 C for 3 hours and filtered to give the intermediate compound 2- [4- (isopropyl) aminobutoxy] -N- (methylsulfonyl) acetamide) and then dissolved in methanol (40 mL)5-Chloro-2,3-diphenylpyrazine (16.0 g, 0.06 mol)N, N-diisopropylethylamine (15.5 g, 0.12 mol),The reaction mixture was stirred for 8 hours at 100 C. The reaction mixture was allowed to cool to room temperature. Water (40 mL) was added and the mixture was cooled to -10 C for 3 hours. The resulting mixture was filtered to give a solution of celecoxib (25.0 g) , The reaction of this step is as follows

Statistics shows that 5-Chloro-2,3-diphenylpyrazine is playing an increasingly important role. we look forward to future research findings about 41270-66-0.

Reference:
Patent; Hunan Ouya Biological Co., Ltd.; Li Xingmin; (10 pag.)CN105949135; (2016); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

27398-39-6, Name is 3-Chloropyrazine-2-carboxylic acid, 27398-39-6, belongs to Pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows.

Step 4: 3-chloro-N-[[1 -r3-chloro-5-r2-(trifluoromethyl)cvclopropyll-2-Pyridyllcvclopropyllmethyllpyrazine-2-carboxamide (compound A.1 1 1 )147 mg [1 -[3-chloro-5-[2-(trifluoromethyl)cyclopropyl]-2-pyridyl]cyclopropyl]methanamine (step 3) was dissolved in 3 ml of dichloromethane and 0.142 ml triethylamine was added. After cooling to 0¡ãC, 193 mg 3-(ethyliminomethyleneamino)-N,N-dimethyl-propan-1-amine hydrochloride, 84 mg 3-chloropyrazine-2-carboxylic acid and 141 mg 1- hydroxybenzotriazole were added. The mixture was stirred overnight at ambient temperature. Then water was added. The layers were separated, the organic layer was dried over anhydrous sodium sulphate, filtered and concentrated. Crude material was obtained as an orange oil, which was purified by flash chromatography on silica gel with heptane/ethyl acetate as a solvent. Thus, 161 mg of 3-chloro-N-[[1-[3-chloro-5-[2- (trifluoromethyl)cyclopropyl]-2-pyridyl]cyclopropyl]methyl]pyrazine-2-carboxamide was obtained as a yellow sticky solid. 1H-NMR (CDCI3): 8.42 ppm (d, 1 H), 8.38 ppm (d, 1 H), 8.18 ppm (s, 1 H), 7.78 ppm (s, 1 H, broad), 7.31 ppm (s, 1 H), 3.66 ppm (d, 1 H), 2.26 ppm (m, 1 H), 1 .78 ppm (m, 1 H), 1.57 ppm (m, 1 H), 1.39 ppm (m, 1 H), 1.18 ppm (m, 4H).

Statistics shows that 3-Chloropyrazine-2-carboxylic acid is playing an increasingly important role. we look forward to future research findings about 27398-39-6.

Reference:
Patent; SYNGENTA PARTICIPATIONS AG; SYNGENTA LIMITED; PITTERNA, Thomas; LOISELEUR, Olivier; WORTHINGTON, Paul, Anthony; O’SULLIVAN, Anthony, Cornelius; LUKSCH, Torsten; BOBOSIK, Vladimir; WO2013/64521; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5900-13-0, 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 5900-13-0 as follows.

5-bromo-3-methoxy-2-pyrazinamme (13.5g), hexane-2,5-dione (9g) and para- toluenesulphonic acid hydrate (0.5g) in toluene (200ml) was heated under reflux using a Dean and Stark trap to collect the water. After 16h, the solution was allowed to cool, EPO concentrated to 50ml and passed through a pad of silica gel eluting with dichloromethane to collect the subtitle compound. Yield 17g.1H NMR (D6-DMSO):8.25 (IH, s), 5.92 (2H, s), 4.02 (3H, s), 2.02 (6H, s)

According to the analysis of related databases, 5-Bromo-3-methoxypyrazin-2-amine, the application of this compound in the production field has become more and more popular.

Reference:
Patent; ASTRAZENECA AB; WO2007/35154; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem