Month: September 2021

274-79-3,Some common heterocyclic compound, 274-79-3, name is Imidazo[1,2-a]pyrazine, molecular formula is C6H5N3, 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.

Imidazo[1,2-a]pyrazine (420 mg, 3.53 mmol) was dissolved in acetonitrile (10 mL).N-bromosuccinimide (691 mg, 3.88 mmol) was added thereto, and the mixture was reacted at room temperature overnight.After the reaction is completed, a saturated sodium hydrogencarbonate solution is added thereto.Extract with dichloromethane, dry the organic phase with anhydrous sodium sulfate, filter, and then dry the solvent.The residue was purified by silica gel column chromatography to give a yellow solid,619mg.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Imidazo[1,2-a]pyrazine, its application will become more common.

Reference:
Patent; Shanghai Pharmaceutical Group Co., Ltd.; Wan Huixin; Li Chunli; Shi Chen; Liu Haiyan; Li Ping; Shen Jingkang; (50 pag.)CN104341425; (2018); B;,
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

These common heterocyclic compound, 1458-01-1, name is Methyl 3,5-diamino-6-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. name: Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate

4-(4-Aminophenyl)ethylamidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride (83) A mixture of 1-H-pyrazolecarboxamidine hydrochloride (2.8 g, 19 mmol), 4-aminoethylaniline (1.3 mL, 9 mmol) and diisopropylethylamine (1.3 ml) were stirred in dry DMF (5 mL) under argon for 18 h. After this time, ether (30 ml) was added to produce a clear oil. The obtained oil (82) was washed with ether and dried under vacuum (40 mTorr) overnight. After drying 70 mg of oil was taken into dry methanol (3 mL) and 25percent NaOH (0.14 mL) was added. The reaction volume was decreased to 1.0 mL and 3,5-diamino-6-chloropyrazine-2 carboxylic acid methyl ester (0.1 g, 0.5 mmol) was added. The mixture was stirred at room temperature overnight. Another portion of 82 (0.1 g) was dissolved in methanol (1 mL), treated with 25percent NaOH (0.15 mL) and the resulting solution was added to the reaction mixture. The reaction mixture was stirred 3 h at reflux, then cooled to room temperature and the solvent was removed under reduced pressure. The residue was dissolved in a minimal volume of DMF and separated by preparative HPLC. The obtained fractions were analyzed by LC/MS. The fractions containing product with M+H=349 were collected and the solvent was removed under reduced pressure. The residue was dissolved in 10percent HCl and evaporated to dryness to produce 83 (23.5 mg, 11percent) as a yellow solid. 1H NMR (360 MHz, DMSO-d6) delta 2.91 (m, 2H), 3.59 (m, 2H), 7.31 (d, 2H), 7.42 (m, 4H), 9.02 (br s, 2H), 9.41 (br s., 1H), 10.56 (s, 1H). 13C NMR (90 MHz, DMSO-d6) 33.1, 42.0, 108.9, 119.6, 120.7, 129.9 (2 C), 131.0 (2 C), 153.1, 154.1, 155.8, 165.2. API MS m/z=349 [C14H17ClN8O+H]+.

The synthetic route of Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PARION SCIENCES, INC.; JOHNSON, Michael Ross; (49 pag.)US2015/376146; (2015); 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. 486424-37-7, name is 3-Amino-6-bromopyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., Recommanded Product: 3-Amino-6-bromopyrazine-2-carboxylic acid

-Amino-6-bromopyrazine-2-carboxylic acid (53.59 g, 0.229 mol) and 4-hydroxy-3-aminopyridine (33.64 g, 0.275 mol) were mixed in THF (500 mL) and triethyl amine (115.86 g, 1.145 mol) was added. The mixture was stirred at 25 for 10 min. The temperature was raised to 55 C. and T3P (218.90 g, 0.344 mol) was added. The mixture was stirred at 55 C. for 30 min. Water (150 mL) was added at 55 C. and the mixture was stirred for 2 h at 55 C. Solvents were distilled of until fractions at 55-80 C. was removed.Acetonitrile (500 mL) was added followed by water (350 mL) while maintaining the temperature at 75 C. The mixture was stirred for 2 h at 75 C. The solid was isolated by filtration. The solid was washed with water (250 mL) followed by acetonitrile (250 mL). The solid was dried under vacuum at 80 C. for 5 h to give the title compound (84.5%)1HNMR (400 MHz, DMSO-d6): 11.64 (s, 1H) 10.26 (s, 1H) 8.78 (s, 1H) 8.45 (s, 1H) 7.78 (s, 2H) 7.72 (d, 1H) 6.31 (d, 1H).MS (ESI+) m/z 310 [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 486424-37-7.

Reference:
Patent; ASTRAZENECA AB; US2011/118275; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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