Month: October 2020

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: (0930) Preparation of (3-chloropyrazin-2-yl)methanamine hydrochloride: (0931) [00352] To a solution of 3-chloropyrazine-2-carbonitrile (10 g) in acetic acid (100 mL) was added Raney Nickel (50% slurry in water, 10 g). The resulting mixture was stirred under 4 bar hydrogen pressure at room temperature for 15 h. The reaction mixture was filtered through celite and the filtrate was concentrated under reduced pressure and co-evaporated with toluene. The remaining brown solid was dissolved in ethyl acetate at 50 C and cooled on an ice-bath. 4M hydrochloric acid in dioxane (50 mL) was added and the reaction mixture was allowed to stir at room temperature for 18 h. The precipitate formed was collected by filtration, washed with diethyl ether and dried under reduced pressure. The product brown solid obtained was dissolved in methanol at 60 C and filtered. The filtrate was partially concentrated, cooled to room temperature and diethyl ether (500 mL) was added. The mixture was allowed to stir at room temperature 18 h. The solids formed were collected by filtration, washed with diethyl ether and dried under reduced pressure to afford the title compound (3-chloropyrazin-2- yl)methanamine hydrochloride (7.67 g, crude) as a brown solid. Calculated (M+H): 144.03; Found (M+H): 144.0

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 55557-52-3, and friends who are interested can also refer to it.

Reference:
Patent; LUC THERAPEUTICS; ANDERSON, David, R.; VOLKMANN, Robert, A.; MENNITE, Frank, S.; FANGER, Christopher; (390 pag.)WO2017/100591; (2017); A1;,
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. 274-79-3 name is Imidazo[1,2-a]pyrazine, 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. 274-79-3

Imidazo[1,2-a]pyrazine 4b (500 mg, 4.20 mmol) was dissolved in 5 mL of 2-methoxyethanol, followed by addition of platinum dioxide (100 mg, 0.36 mmol), and the reactor was purged with hydrogen for three times. After stirring for 12 hours, the reaction mixture was filtered. The filtrate was concentrated under reduced pressure to obtain 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine 4c (200 mg, yield 38.7%) as a yellow oil. MS m/z (ESI): 124.1 [M+1]

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Imidazo[1,2-a]pyrazine, and friends who are interested can also refer to it.

Reference:
Patent; Jiangsu Hansoh Pharmaceutical Co., Ltd.; TANG, Pengcho; LI, Xin; LI, Xiangqin; CHEN, Yang; WANG, Bin; ZHU, Zhe; EP2604610; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6705-33-5, Adding some certain compound to certain chemical reactions, such as: 6705-33-5, name is Pyrazin-2-ylmethanol, 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 6705-33-5.

Example 1018; Step A; To a suspension of triphenylphosphine polystyrene (3 gm, 1 mmol/gm) in dry dichloromethane (20 ml) was slowly added bromine (154 muL). The resulting mixture was stirred at room temperature for 10 min, a solution of commercially available pyrazin-2-yl-methanol (114 mg) in dry dichloromethane (10 ml) was added and stirring at room temperature was continued for 21? h. The mixture was filtered, concentrated under reduce pressure at 20 C. and purified by flash chromatography (silica, cyclohexane/ethyl acetate). The obtained material was dissolved in dry N,N-dimethylformamide (1.5 mL) and added to a suspension of the title compound from Example 1007c (22.3 mg) and potassium carbonate (69.1 mg) in dry N,N-dimethylformamide (1.5 mL). The resulting mixture was stirred at room temperature for 16 h and then concentrated under reduce pressure. The remaining residue was purified by flash chromatography (silica, dichloromethane/methanol) to afford the title compound (6.8 mg; 25%) as a single isomer. [MH]+=539.

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 6705-33-5.

Reference:
Patent; ALANTOS PHARMACEUTICALS, INC.; US2007/155739; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

13301-04-7,Some common heterocyclic compound, 13301-04-7, name is Methyl 3,6-dibromopyrazine-2-carboxylate, molecular formula is C6H4Br2N2O2, 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.

A solution of LiOH (121 mg, 5.07 mmol) in water (1 mL) was slowly added to a solution the pyrazine ester (500 mg, 1.67 mmol) in 1:1 THF/water (8 mL) at 0 C. After stirring at 0 C. for 45 min. The solvent was removed under reduced pressure. The residue was dissolved in a mixture of DCM and 1N aq. HCl. The organic layer was separated and the aqueous extracted twice with DCM. The combined organic extracts were dried (Na2SO4), filtered and concentrated to afford 350 mg (74%) of a cream colored solid. MS m/z (ES): 282 (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 Methyl 3,6-dibromopyrazine-2-carboxylate, its application will become more common.

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

27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, 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. 27398-39-6

To a solution of 3-chloropyrazine-2-carboxylic acid (100 mg, 0.63 mmol) in DCM/MeOH (2 mL : 0.2 mL) was added TMSCH1?2 (0.47 mL, 0.95 mmol) at RT and the resulting mixture was stirred at RT for 2 h. Acetic acid (0.2 mL) was added and the mixture was diluted with water (2 mL) and extracted with DCM (4 mL x 3). The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated in vacuo to give the title compound. LRMS m/z (M+H) 173.0 found, 173.0 required.

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

Reference:
Patent; MERCK SHARP & DOHME CORP.; KIM, Ronald; KUDUK, Scott, D.; LIVERTON, Nigel; ZHUO, Gang; (97 pag.)WO2016/100157; (2016); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6164-79-0, Name is Methyl 2-pyrazinecarboxylate, 6164-79-0, 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.

Methyl 3-oxo-3-(pyrazin-2-yl)propanoate: To a stirred solution of sodium methoxide (25% in MeOH, 27.54 mL, 72.4 mmol, 1 eq) in 90 mL of toluene at 110 C. in a 3-neck flask attached with a mechanical stirrer, condenser and dropping funnel was added a solution of methylpyrazine-2-carboxylate (10 g, 72.4 mmol, 1 eq) in 115 mL of methyl acetate, dropwise, over a period of ?35-40 min. A yellow precipitate was formed. Stirring was continued at 110 C. for 3 hrs. The reaction was cooled and the yellow precipitate was filtered and washed with a small quantity of toluene. This solid was taken into 200 mL of saturated ammonium chloride and 400 mL of EtOAc. The aqueous layer was extracted twice with EtOAc. The combined organic layers were dried over magnesium sulfate, filtered and evaporated to give 6.52 g (50%) of methyl 3-oxo-3-(pyrazin-2-yl)propanoate as a yellow solid.

Statistics shows that Methyl 2-pyrazinecarboxylate is playing an increasingly important role. we look forward to future research findings about 6164-79-0.

Reference:
Patent; Hoffmann-La Roche Inc; Bhagirath, Niala; Brameld, Kenneth Albert; Kennedy-Smith, Joshua; US2013/90334; (2013); A1;,
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. 5521-58-4 name is 5-Methylpyrazin-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. 5521-58-4

To a flask fitted with overhead stirrer, condenser, thermometer and nitrogen line was added 3-{[5-(azetidin-1-ylcarbonyl)pyrazin-2-yl]oxy}-5-[(1S)-2-methoxy-1-methylethoxy]benzoic acid (1.0 eq), and acetonitrile (10 vols) followed by pyridine (3 eq) under a nitrogen atmosphere. Thionyl chloride (1.2 eq) as a solution in acetonitrile (0.225 vols) was added slowly, drop-wise via syringe pump over at least 2 hours. 5-Methylpyrazin-2-amine (1.2 eq) was added to the mixture as a solid. After 2.5 hours the reaction was quenched by adding toluene (10 vols) and 1.0M sodium carbonate solution (2.5 eq). The layers were separated. The organic layer was retained in the flask, then 1.0M hydrochloric acid (1.94 eq) was added. The mixture was agitated for 15 minutes then separated. The organic layer was washed with two aliquots of water (5 vols) then the solvent was removed on the rotary evaporator. Toluene (5 vols) was added to the residue, and warmed to 45 C. Isohexane (1.7 vols) was added, the mixture was seeded, and allowed to cool to ambient temperature overnight. The mixture was cooled to 0 C. for 4 hours, and then cooled to -10 C. for 3 hours. The solid was isolated by filtration then washed with iso-hexane (2.5 vols). After drying in the vacuum oven at 40 C. overnight, the desired product was obtained as a solid (corrected yield 85%).

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

Reference:
Patent; AstraZeneca AB; US2010/210841; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

55557-52-3, 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. 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, This compound has unique chemical properties. The synthetic route is as follows.

Step 7: synthesis of Ethyl 7-aminothieno[2,3-b]pyrazine-6-carboxylate (7)A mixture of 3-chloropyrazine-2-carbonitrile (17.9 g, 128 mmol), sodium carbonate (17.7 g, 167 mmol) and ethyl-2-mercaptoacetate (18.4 mL, 167 mmol) in ethanol (120 mL) was heated to reflux for 4.5h. Quenched with water (1.5 L) and stirred for 30 min. The resulting precipitate was collected and washed with water. The residue was dissolved in diethyl ether and a black precipitate was filtrated off. Ether was evaporated to give pure compound ethyl 7-aminothieno[2,3-b]pyrazine-6-carboxylate 7 (19.6 g, 68.5 %). 1H-NMR (400 MHz, CDC13) 1.42 (t, J= 7.2 Hz, 3H), 4.40 (q, J= 7.2 Hz, 2H), 6.19 (br s, 1H), 8.58 (d, J= 2.2 Hz, 1H), 8.63 (d, J= 2.2 Hz, 1H).

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; N.V. ORGANON; FOLMER, Brigitte, Johanna, Bernita; MAN, de, Adrianus, Petrus, Antonius; GERNETTE, Elisabeth, Sophia; CORTE REAL GONCALVES AZEVEDO, Rita; IBRAHIM, Hemen; WO2011/147764; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

19745-07-4, 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. 19745-07-4, name is 2,5-Dichloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

To a stirred solution of Intermediate 2 (0.2 g, 0.74 mmol) in DMF (5 mL,), TEA (0.5 mL,, 3.70 mmol) and 2,5-dichloro pyrazine (0.11 g, 0.74mmol) was added and stirred at 120¡ãC for 2 h. The reaction mixture was concentrated under vacuum and the resulting crude product was dissolved in DCM. It was washed with water, dried over anhydrous Na2SO4, and concentrated under vacuum. The crude product was purified by flash chromatography to afford the title compound (brown oil). 1H NMR (400 MHz, DMSO-d6): delta 8.23 (s, 1H), 7.81 (s, 1H), 6.88 (d, J = 1.2 Hz, 1H), 6.84 (d, J = 8.0 Hz, 1H), 6.74 (dd, J = 1.6, 8.0 Hz, 1H), 5.97 (s, 2H), 3.54-3.52 (m, 4H), 3.39-3.37 (m, 1H), 2.45-2.44 (m, 2H), 2.39-2.37 (m, 2H), 1.27 (d, J = 6.4Hz, 3H). LCMS: (Method A) 347.0 (M+H), Rt. 3.03 min, 97.9percent (Max). HPLC: (Method A) Rt. 3.05 min, 97.6percent (Max).

The synthetic route of 19745-07-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ASCENEURON SA; QUATTROPANI, Anna; KULKARNI, Santosh S.; GIRI, Awadut Gajendra; (243 pag.)WO2016/30443; (2016); 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. 15707-23-0, name is 2-Ethyl-3-methylpyrazine, This compound has unique chemical properties. The synthetic route is as follows., 15707-23-0

[0239] A mixture of 2-methyl-3-ethylpyrazine (1.0 g, 8.19mmol), selenium dioxide (1.8 g, 16.38 mmol), and diatomaceous earth (1.8 g) in dioxane (20ml) was refluxed for overnight. The mixture was allowed to cool to room temperature. The solid material was removed by filtration through diatomaceous earth. The solvent was evaporated under reduced pressure. The crude product was washed with water (3 x 10 ml), extracted with ethyl acetate (3 x 20 ml), dried with Na2S04 and concentrated. The crude product was used directly for the next step reaction without purification. LC/MS = 137 [M+l].

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; MERCK SHARP & DOHME CORP.; KUANG, Rongze; TING, Pauline; ALI, Amjad; WU, Heping; BERLIN, Michael; STAMFORD, Andrew; WANG, Hongwu; ZHOU, Gang; KIM, David; DENG, Qiaolin; LIM, Yeon-Hee; YU, Younong; (201 pag.)WO2016/81290; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem