Pyrazines

Synthetic Route of 126069-70-3,Some common heterocyclic compound, 126069-70-3, name is 2-(Trifluoromethyl)-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine, molecular formula is C7H8F3N3, 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.

2-(Trifluoromethyl)-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazine (I4) (287 mg, 1.5 mmol) and DIPEA (0.314 ml_, 1.800 mmol) were dissolved at 0 0C in dichloromethane (DCM) (15 ml_). 2-chloro-4-fluorobenzoyl chloride (290 mg, 1.500 mmol, commercially available from e.g. Sigma-Aldrich, Maybridge or Apollo ) dissolved in DCM (5 ml.) was added dropwise and the solution stirred to room temperature over 4 h. Solvents were removed in vacuo and the residue was partitioned between dichloromethane (50 ml.) and saturated sodium bicarbonate solution (25 ml_). The aqueous phase was extracted with dichloromethane (3 x 50 ml.) and the combined extracts were washed with water (50 ml_), brine (50 ml_), dried over anhydrous sodium sulfate and concentrated in vacuo to afford a crude oil (759 mg). The crude product was purified by flash chromatography (Isolera, 25 g, 0-100% 2M ammonia in methanokdichloromethane (1 :9)/dichloromethane) to afford crude product. Concentration of the waste afforded material which was also identified as product. Samples were combined to afford crude product. This was purified by MDAP, product containing fractions concentrated and loaded directly on to an SCX cartridge (Varian, 10 g). The column was washed with methanol and the product eluted with 2M ammonia methanol. The solvents were evaporated in vacuo to afford the desired product in 318 mg. LC/MS = 348/350 (M+H)+, retention time = 0.94 minutes (2 minute method)

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2-(Trifluoromethyl)-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine, its application will become more common.

Reference:
Patent; GLAXO GROUP LIMITED; DEAN, David Kenneth; MUNOZ-MURIEDAS, Jorge; SIME, Mairi; STEADMAN, Jon Graham Anthony; THEWLIS, Rachel Elizabeth Anne; TRANI, Giancarlo; WALL, Ian David; WALTER, Daryl Simon; WO2010/125101; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 87486-33-7, name is 3,5-Dichloro-1-methylpyrazin-2(1H)-one, molecular formula is C5H4Cl2N2O, 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. Computed Properties of C5H4Cl2N2O

EXAMPLE 2 3-Amino-5-chloro-1-methyl-2(1H)-pyrazinone A solution of 3,5-dichloro-1-methyl-2(1H)-pyrazinone (7.16 g, 0.040 mol) in dioxane (120 mL) was treated with a concentrated aqueous solution of ammonia (28%, 16 mL, 0.24 mol). After stirring at room temperature for three days a suspension of solid had formed. The solid was collected, rinsed with a little water, ether, and hexanes and air dried. The product, 3-amino-5-chloro-1-methyl-2(1H)-pyrazinone, was obtained as a white crystalline powder (4.81 g) melting above 250 C. PMR (DMSO-d6, 200 MHz): delta 7.16 (broad s, 2H, NH2); 6.99 (s, 1H, Het-H); 3.34 (s, 3H, N–CH3). IR (Nujol mull): 3310 (w, NH); 3170 (w, NH); 1660 (s, C=O) cm-1.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 87486-33-7, its application will become more common.

Reference:
Patent; E. I. Du Pont de Nemours and Company; US4802908; (1989); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 143591-61-1, 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. 143591-61-1, name is 3-Bromo-8-chloroimidazo[1,2-a]pyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

EXAMPLE 50;Tert-butyl 4-(3-(2-fluoro-4-(methylsulfonyl)phenylamino)imidazo[l,2- a]pyrazin-8-yl)piperazine-l-carboxylateStep 1: Tert-butyl 4-(3-bromoimidazo[l,2-a]pyrazin-8-yl)piperazine-l-carboxylate[0382] A mixture of tert-butyl piperazine-1-carboxylate (9.7 mmol) and 3- bromo-8-chloroimidazo[l,2-a]pyrazine (4.3 mmol) in 10 mL DMSO was heated to 100 0C for 45 minutes. The reaction mixture was cooled down to room temperature, and quenched with water. The mixture was rinsed into a seperatory funnel and extracted with ethyl acetate (3×50 mL). Combined organics were washed with water, brine and dried over Na2SO4, filtered and concentrated in vacuo to give tert-butyl 4-(3-bromoimidazo[l,2-a]pyrazin-8-yl)piperazine-l-carboxylate as tan solid (1.5 g).

The synthetic route of 3-Bromo-8-chloroimidazo[1,2-a]pyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Patent; KALYPSYS, INC.; KAHRAMAN, Mehmet; SMITH, Nicholas, D.; BONNEFOUS, Celine; NOBLE, Stewart, A.; PAYNE, Joseph, E.; WO2010/88518; (2010); 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. 486424-37-7, name is 3-Amino-6-bromopyrazine-2-carboxylic acid belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. category: Pyrazines

Block B can be prepared according to scheme 2 in FIG. 2. Referring to FIG. 2, the synthesis of Block B can be performed as described below. (0164) Intermediate 6 Block B [0029] To a solution of Intermediate 6 (6.0 g, 27.4 mmol) in DMSO (30 mL) was added CDI (8.9 g, 54.8 mmol), DIPEA (3.8 g, 30.1 mmol) and DMAP (0.17 g, 1.37 mmol). The solution was stirred at rt for 4 hours. Aniline (2.5 g, 27.4 mmol) was added and the mixture was stirred at rt overnight. Water was added and the formed solid was collected by filtration. The crude product was purified by silica-gel column to afford 2.5 g of Block B (31 %) as yellow solid. (0165) [0030] LC-MS (M+l): 293.2; 1H MR (400 MHz, DMSO-d6) 510.28 (s, 1H), 8.42 (s, 1H), 7.78 (d, J = 8.0 Hz, 2H), 7.74 (s, 2H), 7.36 (t, J = 8.0 Hz, 2H), 7.13 (t, J = 7.6 Hz, 1H) .

The synthetic route of 486424-37-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MERRIMACK PHARMACEUTICALS, INC.; DRUMMOND, Dary| C.; GENG, Bolin; KIRPOTIN, Dmitri B.; TIPPARAJU, Suresh, K.; KOSHKARYEV, Alexander; ALKAN, Ozan; (142 pag.)WO2017/123588; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 870787-06-7, name is 3-(Trifluoromethyl)pyrazine-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 870787-06-7, Recommanded Product: 3-(Trifluoromethyl)pyrazine-2-carboxylic acid

PREPARATION EXAMPLE 7: 3-trifluoromethyl-pyrazine-2-carboxylic acid ri-(5-bromo-3-50 mg of C-[1 -(5-bromo-3-chloro-pyridin-2-yl)-cyclopropyl]-methylamine (step 1 of PREPARATION EXAMPLE 2) was dissolved in 0.9 ml of dichloromethane and 0.085 ml of triethylamine was added at ambient temperature. Then 383 mg of 3- (trifluoromethyl)pyridine-2-carboxylic acid, 54 mg of HOBT hydrate, 76 mg of EDCI.HCI and 37 mg of 3-trifluoromethyl-pyrazine-2-carboxylic acid were added sequentially. The reaction mixture was stirred at ambient temperature for 14 hours and then water was added, the phases were separated and the aqueous phase was extracted withdichloromethane. The organic phases were combined, dried with anhydrous sodium sulphate, filtered and concentrated. Crude material was obtained as a yellow sticky solid, which was purified by flash chromatography on silica gel with cyclohexane/ethyl acetate (1 :1 ) as a solvent. Thus, 76 mg of 3-trifluoromethyl-pyrazine-2-carboxylic acid [1 -(5-bromo- 3-chloro-pyridin-2-yl)-cyclopropylmethyl]-amide was obtained as a sticky solid. . 1H-NMR (CDCIs): 8.80 ppm (s, 1 H), 8.75 ppm (s, 1 H), 8.65 ppm (s, 1 H), 7.95 ppm (s, 1 H), 7.70 ppm (m, 1 H), 3.72 ppm (d, 2H), 1 .18 ppm (m, 4H).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-(Trifluoromethyl)pyrazine-2-carboxylic acid, and friends who are interested can also refer to it.

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

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. COA of Formula: C4H6N4

General procedure: p-TsOH (9.5 mg, 55 mumol, 5 mol %) and MnO2 (348 mg, 4.00 mmol) were added to a stirred solution of heterocyclic hydrazine 1a-d (1 mmol) and aldehyde 2a-k (1.2 mmol) in PhMe (10 ml). The mixture was heated at 80C until the starting material was completely consumed (monitored by TLC, 40-55 min) and then cooled down to room temperature. After filtration and evaporation of solvent from the filtrate, the resulting residue was purified by silica gel column chromatography affording pure products.

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; Bhatt, Ashish; Singh, Rajesh K.; Kant, Ravi; Chemistry of Heterocyclic Compounds; vol. 54; 12; (2018); p. 1111 – 1116; Khim. Geterotsikl. Soedin.; vol. 54; 12; (2018); p. 1111 – 1116,6;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 4949-13-7, A common heterocyclic compound, 4949-13-7, name is 2-Fluoropyrazine, molecular formula is C4H3FN2, 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.

10264] To a 2.5 M solution of n-butyllithium (40 mE, 0.1 mol) in anhydrous THF (250 mE) cooled to -78 C. under N2 protection was added TMP (2,2,6,6-tetramethylpiperidine, 15 g, 0.106 mol) dropwise over a period of 20 minutes. The mixture was warmed to 0 C. by replacing the dry ice/acetone bath with an ice bath and stirred for 1.5 h. The mixture was cooled back to -78C. and a solution of 9a (3 g, 0.03 mol) and tributyltin chloride (10 g, 0.03 mol) in SOmE of dry THF was added over 10 mm. The mixture was stirred at -78 C. for 6 h, then warmed to -40 C. by replacing the dry ice/acetone bath with an dry ice/acetonitrile bath. A solution of 35% HC1, ethanol and THF (1:4:5) was added. The mixture was warmed to room temperature and washed with saturated NaHCO3 solution (100 mE) and extracted with EtOAc (3×100 mE). The combined organic layers were dried over anhydrous Na2504 and concentrated under reduced pressure. The residue was purified by column chromatography (silica, EtOAc:petroleum ether=1:15) to provide 9b (3.4 g, 29% yield) as light yellow oil. ?H-NMR (CDC13, 300 MHz): oe=8.41 (d, 1H), 8.17 (d, 1H), 1.8-0.53 (m, 27H).

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; Helsinn Healthcare SA; Giuliano, Claudio; Garcia Rubio, Silvina; Daina, Antoine; Guainazzi, Angelo; Pietra, Claudio; US2015/252021; (2015); 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

Application of 55557-52-3, 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. 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

General procedure: In a degassed solution of DME/H2O (2:1) (12mL/mmol of diazine), were successively introduced S-Phos (10mol%) and Pd(OAc)2 (5mol%). The solution was heated at 80C for 10min then sodium carbonate (4.0equiv), appropriate boronic acid (1.05 or 1.5equiv) and appropriate diazine (1.0equiv) were added. The solution was then refluxed (15min or overnight) under Ar. The resulting mixture was filtered on Celite and washed with ethyl acetate and water. The aqueous phase was then extracted three times with ethyl acetate. The combined organic phase was dried over MgSO4 and evaporated to dryness. The residue was purified by column chromatography (eluent: PE/EtOAc) to give the desired product.

The synthetic route of 3-Chloropyrazine-2-carbonitrile has been constantly updated, and we look forward to future research findings.

Reference:
Article; Fresneau, Nathalie; Cailly, Thomas; Fabis, Frederic; Bouillon, Jean-Philippe; Tetrahedron; vol. 69; 26; (2013); p. 5393 – 5400;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, molecular formula is C4H5N3, 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. Formula: C4H5N3

To a solution of pyrazin-2-amine(A70, 2.0 g, 2.10 mmol) and ethyl 3- bromo-2-oxopropanoate(A15, 3.0 mL, 2.30 mmol) in ethanol(15.0 mL) was added Cone., HC1(1.0 mL) at 0 C and stirred for 12 h at 95 C. The reaction mixture was concentrated under reduced pressure followed by addition of water(10 mL), the mixture was then extracted with DCM and the organic layer was washed with saturated NaHC03 solution and brine, dried over sodium sulphate, filtered and concentrated under reduced pressure. The obtained crude was purified by combi-flash purifier with 3% methanol in dichloromethane as eluent to afford the desired product A71 as yellow solid(0.4 g, 10 %). 1H NMR (DMSO-d6, 400 MHz) d 1.31(t, / = 7.2 Hz, 3H), 4.33(q, / = 7.2 Hz, 2H), 7.96(d, J = 4.4 Hz, 1H), 8.57(d, J = 4.0 Hz, 1H), 8.66(s, 1H), 9.15(s, 1H); MS(ESI) m/z = 192.1(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 5049-61-6, its application will become more common.

Reference:
Patent; JUBILANT BIOSYS LIMITED; VADIVELU, Saravanan; RAJAGOPAL, Sridharan; BURRI, Raghunadha Reddy; GARAPATY, Shivani; SIVANANDHAN, Dhanalakshmi; THAKUR, Manish Kumar; NATARAJAN, Tamizharasan; SWAMY, Indu N; NAGARAJU, Nagendra; KANAGARAJ, Subramaniam; MOHD, Zainuddin; SARKAR, Sayantani; SAMANTA, Swapan Kumar; ., Hariprakash; (284 pag.)WO2019/102494; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem