Category: Pyrazines

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. 486460-21-3, name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., 486460-21-3

To a solution of (R)-3-[(tert-butyloxycarbonyl)amino]-4-(2,4,5-trifluorophenyl)- butanoic acid (1.36 g, 4.080 mmol) in acetonitrile (20 ml) was added Diisopropylethylamine (2.47 g, 19.12 mmol) and 1 ,1-Carbonyl diimidazole (0.94 g, 5.82 mmol) at room temperature. The reaction mixture was stirred for 30 min at room temperature. S-iTrifluoromethylJ-S.ej.e-tetrahydro-l ,2,3-triazolo[4,3- a]pyrazine (0.750 g, 3.88 mmol) was added to the above reaction mixture at room temperature. The reaction mixture was heated to 65-70C for 22 h. After completion of the reaction, the mixture was concentrated under vacuum and the crude mass was dissolved in ethyl acetate (15 ml) and washed with 5% aqueous NaHC03 solution followed by twice with water (2 x 30 ml). The ethyl acetate layer was concentrated under reduced pressure to get crude mass and recrystallized from mixture of 10 % ethyl acetate and petroleum ether (50 ml) to get 1.5 g (82%) of tert-butyl{(1 R)-3-oxo-1 -(2,4,5-trifluorobenzyl)-3-[3-(trifluoromethyl)-5-6- dihydro[1 ,2,4] triazole[4,3-a]pyrazin-7(8H)-yl]propyl}carbamate.

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; PANACEA BIOTEC LTD; JAIN, Rajesh; RAO, Jagadeeshwar, R; RAO, Siripragada, Mahender; WO2012/35549; (2012); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, molecular formula is C5H2ClN3, 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. 55557-52-3

A.1.11. Synthesis of 3-aryl-pyrazine-2-carboxylic acids:; A.1.11.1 3-p-Tolyl-pyrazine-2-carboxylic acid; 3-Chloropyrazine-2-carbonitrile (3.0 g; 21.5 mmol) was dissolved in dimethoxyethane (65 ml) and 4-tolylboronic acid (3.2 g; 23.65 mmol) was added, followed by the addition of K2CO3 (8.2 g; 59 mmol) and water (30 ml). The reaction mixture was deoxygenized with N2 (g) for 3 minutes followed by the addition of triphenylphosphine (842 mg; 3.2 mmol) and palladium(II)acetate (237 mg; 1.06 mmol). The reaction mixture was heated to 900C for 14 h, cooled to rt, diluted with EtOAc, filtered over a plug of celite and dried with magnesiumsulfate. The organic solvent was evaporated under reduced pressure to give 5.3 g of S-p-tolyl-pyrazine-l-carbonitrile. The intermediate nitrile was dissolved in MeOH (110 ml) followed by the addition of 4M aq NaOH (180 ml). The resulting mixture was heated to 85C for 14 h, cooled to rt and the MeOH was evaporated under reduced pressure. The residual aq. phase was acidified to pH=2 by the addition of cone. HCl and the precipitated product was filtered off, dissolved in DCM / EtOAc and dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 2.30 g of 3-p- tolyl-pyrazine-2-carboxylic acid. LC-MS: tR = 0.40 min; [M-H]+ = 213.14.

The chemical industry reduces the impact on the environment during synthesis 3-Chloropyrazine-2-carbonitrile. I believe this compound will play a more active role in future production and life.

Reference:
Patent; ACTELION PHARMACEUTICALS LTD; WO2009/104155; (2009); 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. 274-79-3, name is Imidazo[1,2-a]pyrazine, A new synthetic method of this compound is introduced below., 274-79-3

Stage 2. The imidazo [1 , 2-a] pyrazine (7.2 g, 60.44 mmole) was dissolved in 2-methoxyethanol (100 ml) and Pttheta2 (1.2 g, 5.13 mmole) was added. The reaction mixture was stirred overnight at RT in an autoclave under a hydrogen atmosphere (4 bar). The autoclave was then flushed with nitrogen, the reaction mixture was filtered through filter earth, concentrated, and the solvent residues were then extracted with toluene. Purification was carried out by column chromatography on silica gel (DCM / 7 N NH3 in methanol, 95:5)

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; GRUeNENTHAL GMBH; WO2009/90055; (2009); 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. 1458-01-1 name is Methyl 3,5-diamino-6-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. 1458-01-1

A mixture of methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (100 g; 494 mmol), methanol (1 I) 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¡ãC. Yield: 99.6 g (107percent of theory) ESI Mass spectrum: m/z = 189 [M+H]+; m/z = 187 [M-H]”

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, and friends who are interested can also refer to it.

Reference:
Patent; BOEHRINGER INGELHEIM INTERNATIONAL GMBH; HAMPRECHT, Dieter; HECKEL, Armin; KLEY, Joerg; WO2013/174757; (2013); 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. 6705-33-5, name is Pyrazin-2-ylmethanol, This compound has unique chemical properties. The synthetic route is as follows., 6705-33-5

a) To a stirred and cooled (?5 C.) solution of 8.3 parts of 2-pyrazinemethanol, 13.3 parts of ethyl 4-hydroxybenzoate and 20.2 parts of triphenylphosphine in 178 parts of tetrahydrofuran was added dropwise a solution of 13.93 parts of diethyl azodicarboxylate in 45 parts of tetrahydrofuran. Upon completion, the reaction mixture was stirred over weekend. After evaporation, the residue was taken up in water and the product was extracted with dichloromethane. The extract was dried, filtered and evaporated. The residue was stirred in 2,2′-oxybispropane. The precipitate was filtered off and the filtrate was evaporated. The residue was crystallized from 2-propanol, yielding 7.5 parts (38.7%) of ethyl 4-(2-pyrazinylmethoxy)benzoate; mp. 76.1 C. (interm. 9).

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; Janssen Pharmaceutica N.V.; US5070090; (1991); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 486460-21-3, name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-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 486460-21-3, 486460-21-3

Step 1: Preparation of 1-[4-(3-trifluoromethyl-5,6-dihydro-8H-[1,2,4]triazolo[4,3-a]pyrazin-7-yl)-phenyl]-3-aza-bicyclo[3.1.0]hexane-3-carboxylic acid tert-butyl esterTo a solution of 1-(4-bromo-phenyl)-3-aza-bicyclo[3.1.0]hexane-3-carboxylic acid tert-butyl ester (Intermediate I, 400 mg, 1.18 mmol) in anhydrous toluene (5 mL) were added Pd2(dba)3 (5.4 mg, 0.006 mmol), BINAP (11.0 mg, 0.018 mmol), sodium tert-butoxide (227 mg, 2.34 mmol) and 3-trifluoromethyl-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine (prepared by the procedure as described in reference J. Med. Chem., 2005, 48, 141-151) (340 mg, 1.77 mmol) at r.t. and reaction mixture was refluxed for 6 h. Reaction mixture was then concentrated and the crude product was purified by column chromatography (silica gel, 6:4 EtOAc:Pet. ether) to afford the title compound as white solid (330 mg, 62%).ESIMS (m/z): 472.9 (M+23), 451.9 (M+2), 450.8 (M+1).

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, 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; PANACEA BIOTEC LTD.; US2012/165320; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6705-33-5,Some common heterocyclic compound, 6705-33-5, name is Pyrazin-2-ylmethanol, molecular formula is C5H6N2O, 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.

16A. Preparation of 3-chloro-4-(pyrazin-2-ylmethoxy)-phenylamine To a mixture of pyrazin-2-yl-methanol (62 mg, 0.56 mmol), 4-amino-2-chloro-phenol (80.8 mg, 0.56 mmol) and triphenylphosphine (148 mg, 0.56 mmol) in THF (3 ml) was added DIAD (0.11 ml, 0.56 mmol) and the mixture was stirred at rt for 20 h. The mixture was concentrated in vacuo, diluted with 1N HCl (30 ml), washed with EtOAc (3*20ml) and basified to pH 12 by 1N NaOH. The mixture was extracted with EtOAc (4*40 ml) and the combined EtOAc extracts were washed with brine (1*20 ml), dried (MgSO4), filtered and concentrated in vacuo to give 16A (43.3 mg, 33% pure)

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 6705-33-5, its application will become more common.

Reference:
Patent; Gavai, Ashvinikumar V.; Han, Wen-Ching; Chen, Ping; Ruediger, Edward H.; Mastalerz, Harold; Fink, Brian E.; Norris, Derek J.; US2005/197339; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

486460-21-3, Adding a certain compound to certain chemical reactions, such as: 486460-21-3, name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-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 486460-21-3.

In a 50 ml round bottom flask,0.17 g (0.90 mmol)(Trifluoromethyl) -5,6,7,8-tetrahydro [1,2,4]Triazolo [4,3-alpha] piperazine,2.0 g of a formaldehyde aqueous solution having a mass fraction of 37% and 15 ml of absolute ethanol, stirred at room temperature for 15 minutes,Followed by the addition of 4 – ((R 2 -methylene) amino) -5-R1-2,4-dihydro-3H-1,2,4-triazole-After stirring at room temperature for 1 h,Filter,Washed with absolute ethanol,To obtain the desired solid product.

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, 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Nankai University; Wang, Baolei; Li, Zhengming; Zhang, Yan; (13 pag.)CN106749262; (2017); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

5049-61-6, 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. 5049-61-6, name is Pyrazin-2-amine, A new synthetic method of this compound is introduced below.

Step 1: Imidazo[1,2-a]pyrazine A round bottom set up with reflux condenser was charged with pyrazin-2-amine (1000 mg, 10.52 mmol), 2-chloroacetaldehyde (-50% wt) (2.03 ml, 31.55 mmol), and EtOH (23 mL) and heated under reflux overnight. Next day LC/MS showed completion. The mixture was concentrated and passed through a plug of silica (solvent used: 1% MeOH/DCM) to afford imidazo[1,2-a]pyrazine as off-white solid. MS [M+H]=120.1; Calc’d for C6H5N3: 119.1

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; CEE, Victor J.; DEAK, Holly L.; DU, Bingfan; GEUNS-MEYER, Stephanie D.; HUA, Zihao; MARTIN, Matthew W.; MARX, Isaac; NGUYEN, Hanh Nho; OLIVIERI, Philip R.; PANTER FABER, Kathleen; ROMERO, Karina; SCHENKEL, Laurie; WHITE, Ryan; US2014/336182; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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. 24241-18-7

A solution of 2-amino-3,5-dibromopyrazine (obtained as described in Gazz. Chim. Ital., 1960, 90, 1807) (1.26 g) and sodium ethoxide (0.4 g) in ethanol (50 ml) was heated under reflux for 4 hours. Volatile material was removed by evaporation and the residue was partitioned between water (20 ml) and ethyl acetate (50 ml). The organic layer was separated and dried (MgSO4). Volatile material was removed by evaporation to give 2-amino-5-bromo-3-ethoxypyrazine (0.95 g); 1 H NMR (d6 -DMSO): 1.4 (t, 3H), 4.3 (q, 2H), 6.4 (br s, 2H), 7.6 (s, 2H); mass spectrum (+ve CI): 218 (M+H)+.

Statistics shows that 24241-18-7 is playing an increasingly important role. we look forward to future research findings about 2-Amino-3,5-dibromopyrazine.

Reference:
Patent; Zeneca Limited; US5861401; (1999); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem