Month: September 2021

Application of 59489-32-6, These common heterocyclic compound, 59489-32-6, name is 5-Chloro-2,3-dimethylpyrazine, 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.

Description 86: 2,3-dimethyl-5-[(phenylmethyl)oxy]pyrazine (D86); Potassium tert-butoxide (413 mg, 3.68 mmol) was added to a solution of 5-chloro-2,3- dimethylpyrazine D85 (350 mg) and benzyl alcohol (0.638 ml, 6.14 mmol) in 1,4-Dioxane (12 ml). The resulting yellow suspension was stirred at 98 0C for 20 minutes and then the temperature was allowed to reach 23 0C. Water (5 ml) and EtOAc (20 ml) were added, the aqueous phase was extracted with EtOAc (3 x 10 ml) and the collected organic layers washed with brine (2 x 5 ml), dried over Na2SO4, filtered and evaporated under reduced pressure to give a yellow oil.This was purified by column chromatography on silica gel (SNAP KP-SiI 5Og; eluted with Cy/EtOAc 90:10) and an orange solid was obtained. It resulted to be not pure and it was further purified by silica gel chromatography (SNAP KP-SiI; eluted with n- hexane/Et2O 90:10). Evaporated fractions gave the title compound D86 as yellow solid(175 mg).UPLC (IPQC): rt = 1.10 minutes, peak observed: 215 (M+l) C13Hi4N2O requires 214.

Statistics shows that 5-Chloro-2,3-dimethylpyrazine is playing an increasingly important role. we look forward to future research findings about 59489-32-6.

Reference:
Patent; GLAXO GROUP LIMITED; AMANTINI, David; DI FABIO, Romano; WO2010/122151; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 54608-52-5, name is 2-Hydrazinopyrazine, molecular formula is C4H6N4, 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. HPLC of Formula: C4H6N4

To a solution of 2-hydrazinylpyrazine (0.485 g, 4.40 mmol) in HOAc (6 mL) was added (2- (hydroxyimino)-l -phenylbutane-l ,3-dione (0.765 g, 4.00 mmol) in small portions over 2 minutes. The mixture was stirred for 5 minutes and the resulting light orange suspension was stirred at 60 C for 6 hours. EtOH (1 mL) was added and the mixture was heated at 60 C for an additional 6 hours. The resulting dark green suspension was cooled to ambient temperature and the mixture was diluted with H20 (30 mL). The green suspension was stirred for 1 hour and the solid was collected via vacuum filtration. The collected solid was washed with H20 and dried in vacuum. The solid was suspended in EtOH (25 mL) and concentrated HC1 (500 mu) was added. The mixture was heated at reflux for 20 hours, cooled to ambient temperature and diluted with chilled 0 (75 mL). The mixture was treated with 1M NaOH to pH=7 and was extracted with Et20 (3X). The combined extracts were washed with saturated NaCl and dried over MgS04. The dried solution was filtered through packed Celite and concentrated. The residual green-yellow solid was purified on a Si02 column using step gradient elution (25% CH2CI2, 50% EtOAc/hexanes) to furnish the title compound as a turquoise solid (325 mg, 31%). MS (apci) m/z = 266.1 (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 54608-52-5, its application will become more common.

Reference:
Patent; ARRAY BIOPHARMA INC.; ALLEN, Shelley; BLAKE, James F.; BRANDHUBER, Barbara J.; JIANG, Yutong; KOLAKOWSKI, Gabrielle R.; XU, Rui; WINSKI, Shannon L.; WO2014/78328; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 356783-16-9, A common heterocyclic compound, 356783-16-9, name is 3,6-Dichloropyrazine-2-carbonitrile, molecular formula is C5HCl2N3, 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.

EXAMPLE II-29 In 60 mL of dimethyl sulfoxide was dissolved 3.0 g of 3,6-dichloro-2-pyrazinecarbonitrile. After adding 3.0 g of potassium fluoride, the mixture thus obtained was stirred at 90-100 C. for 2 hours. The reaction mixture was returned to room temperature, to which were successively added 2.1 g of 2-methyl-1,3-cyclopentandione and 7.2 ml of triethylamine. The mixture thus obtained was stirred at room temperature for one hour. The reaction mixture was added to a mixture of 50 mL of ethyl acetate and 200 mL of water, and the organic layer was separated. The organic layer thus obtained was washed successively with water and saturated aqueous solution of sodium chloride and dried on anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. The residue thus obtained was purified by silica gel column chromatography [eluent: n-hexane:ethyl acetate=2:1] to obtain 1.7 g of 6-fluoro-3-[(2-methyl-3-oxo-1-cyclopenten-1-yl)oxy]-2pyrazinecarbonitrile as a yellow-colored solid product. IR (KBr) cm-1: 2238, 1707, 1676 1H-NMR (CDCl3) delta: 1.72(3H,t,J=1.8 Hz), 2.58-2.68(2H,m), 2.76-2.91(2H,m), 8.29(1H,d,J=8.1 Hz)

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; Toyama Chemical Co., Ltd.; US2003/130213; (2003); 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. 5049-61-6, name is Pyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows., Quality Control of Pyrazin-2-amine

Example 9; Preparation of (5R), (6Z)-6- (7-Methyl-5. 6, 7, 8-tetrahydroimidazor1, 2-alpyrazin-2- vlmethylene)-7-oxo-4-thia-1-aza-bicyclor3. 2. Olhept-2-ene-2-carboxylic acid, sodium salt Step 1 : Imidazo [1, 2-a] pyrazine-2-carboxylic acid ethyl ester: Ethyl bromopyruvate (62.9 g) was added to the DME (258 mL) solution of 2- aminopyrazine (24.8 g) at room temperature and stirred for 2.5 h. The reaction mixture was cooled to 0 C and stirred for 30 min to afford a pale brown precipitate. The precipitate was filtered and washed with Et20 to give pale brown crystals. The suspension of the precipitate (66.1 g) in EtOH (1.29 L) was heated at reflux temperature to turn to clear solution. After refluxing for 2h, the reaction mixture was concentrated under reduced pressure, then mixed with CHCI3 and saturated NaHCO3aq. The mixture was filtered through a pad of Celite and the separated organic layer was dried (MgS04) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCI3- MeOH (99/1-97/3), and collected fractions were concentrated under reduced pressure followed by recrystallization from CHC13-Et20. The titled compound was obtained as pale pink crystals. Yield : 10.9 g, 22%). ‘H NMR (CDCI3) d 1.46 (t, 3H, J = 7.2 Hz), 4.49 (q, 2H, J = 7.2 Hz), 7.96 (d, 1 H, J = 4.7 Hz), 8.08 (dd, 1H, J= 1.2, 4.7 Hz), 8.26 (s, 1H), 9.21 (d, 1 H, J = 1.2 Hz).

According to the analysis of related databases, 5049-61-6, the application of this compound in the production field has become more and more popular.

Reference:
Patent; WYETH; WO2003/93277; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 957344-74-0, name is 5,8-Dibromoimidazo[1,2-a]pyrazine, molecular formula is C6H3Br2N3, 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. Recommanded Product: 957344-74-0

A mixture of known compound 7 (2.75g, 9.90mmol), cyclopropylamine (3.4mL, 49.50mmol) and N, N-diisopropylethylamine (3.5mL, 19.80mL) in 1,4-dioxane (33mL) was stirred at 100C for 16h. The reaction mixture was cooled to room temperature, diluted with ethyl acetate and washed with saturated aqueous NaHCO3. The organic phase was dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated in vacuo. The residue was purified by column chromatography (Hexanes:EtOAc=1:2) to afford the title compound 9 (2.3g, 92%). 1H NMR (300MHz, DMSO-d6) delta 7.88 (s, 1H), 7.82 (br, 1H), 7.58 (s, 1H), 7.49 (s, 1H), 2.85 (m, 1H), 0.68 (m, 2H), 0.63 (m, 2H).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 957344-74-0, its application will become more common.

Reference:
Article; Kang, Seok Jong; Lee, Jung Wuk; Chung, Shin Hyuck; Jang, Sun Young; Choi, Jaeyul; Suh, Kwee Hyun; Kim, Young Hoon; Ham, Young Jin; Min, Kyung Hoon; European Journal of Medicinal Chemistry; vol. 163; (2019); p. 660 – 670;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 486424-37-7, name is 3-Amino-6-bromopyrazine-2-carboxylic acid, 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. Safety of 3-Amino-6-bromopyrazine-2-carboxylic acid

Step 1. Synthesis of tert-butyl (l-(2-(3-amino-6-bromopyrazine-2-carboxamido)pyridin- 3-yl)-4-methylpiperidin-4-yl)carbamate. In a 100 mL round bottom flask equipped with a magnetic stirrer HBTU (2.23 gm, 5.87 mmol), 3-amino-6-bromopyrazine-2-carboxylic acid (1.17 gm, 5.39 mmol), and N-ethyl-N- isopropylpropan-2-amine (1.28 mL, 7.34 mmol) were allowed to stir in DMF (15 ml) for 15 minutes whereupon tert-butyl (l-(2-aminopyridin-3-yl)-4-methylpiperidin-4-yl)carbamate (1.5 gm, 4.9 mmol) was added in one portion. Reaction was allowed to stir for 16hr. Reaction was then poured into DMF and extracted thrice with 50 mL ethyl acetate. Organic extracts were combined and dried with brine followed by anhydrous sodium sulfate. The residue was purified by silica gel using gradient chromotography ethanol – ethyl acetate 0 -10% which yielded pure tert-butyl (l-(2-(3-amino-6-bromopyrazine-2-carboxamido)pyridin-3-yl)-4-methylpiperidin-4- yl)carbamate (1.86 gm, 67.5% yield) upon evaporation of fractions containing the desired product. LC-MS (Acidic method): ret.time= 1.17 min, M+H = 508.3.

The synthetic route of 3-Amino-6-bromopyrazine-2-carboxylic acid has been constantly updated, and we look forward to future research findings.

Reference:
Patent; NOVARTIS AG; LUZZIO, Michael Joseph; PAPILLON, Julien; VISSER, Michael Scott; (213 pag.)WO2016/20864; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

87486-34-8, name is 3,5-Dibromo-1-methylpyrazin-2(1H)-one, 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. COA of Formula: C5H4Br2N2O

A mixture of tert-butyl 4-(4-aminophenyl)piperidine-l-carboxylate (2.5 g, 9.06 mmol) and 3,5-dibromo-l-methylpyrazin-2(lH)-one (2.2 g, 8.23 mmol) in isopropanol (30 mL) was heated at 85 °C for 15 h. After the reaction was finished, it was filtered and the solid was washed with isopropanol to afford 282a as a white solid (2.9 g, 80 ).LCMS: (M+H)+ 463

The synthetic route of 87486-34-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GILEAD CONNECTICUT, INC.; GENENTECH, INC.; BARBOSA, Antonio, J., M.; BLOMGREN, Peter, A.; CURRIE, Kevin, S.; KRISHNAMOORTHY, Ravi; KROPF, Jeffrey, E.; LEE, Seung H.; MITCHELL, Scott A.; ORTWINE, Daniel; SCHMITT, Aaron, C.; WANG, Xiaojing; XU, Jianjun; YOUNG, Wendy; ZHANG, Honglu; ZHAO, Zhongdong; ZHICHKIN, Pavel E.; WO2011/140488; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 21943-17-9,Some common heterocyclic compound, 21943-17-9, name is 5-Bromo-3-chloropyrazin-2(1H)-one, molecular formula is C4H2BrClN2O, 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.

General procedure: A solution of 56 (1.50 g, 7.16 mmol), the appropriate secondary amine (8.59 mmol, 1.20 equiv) and diisopropylethylamine (1.50 mL, 8.59 mmol) in n-butanol (15 mL)was heated in a microwave reactor using variable wattage to 140 C for 1 h. The mixture was concentrated and purified by flash column chromatography on silica, eluting with 9:1 dichloromethane/methanol, to give gave 58-63.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 5-Bromo-3-chloropyrazin-2(1H)-one, its application will become more common.

Reference:
Article; Caldwell, John J.; Veillard, Nicolas; Collins, Ian; Tetrahedron; vol. 68; 47; (2012); p. 9713 – 9728,16;; ; Article; Caldwell, John J.; Veillard, Nicolas; Collins, Ian; Tetrahedron; vol. 68; 47; (2012); p. 9713 – 9728;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 74290-67-8, 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. 74290-67-8 name is 2-Amino-5-bromo-3-methylpyrazine, 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.

A solution of 5-bromo-3-methyl-pyrazin-2-amine (1000 mg, 5.32 mmol), phenol (650 mg, 6.91 mmol), Cs2C03 (2600 mg, 7.98 mmol), Cul (203 mg, 1.06 mmol), and Nu,Nu-dimethylgly cine (110 mg, 1.06 mmol) in dioxane (5 mL) was degassed and heated to 90 C under N2 for 12 h. After cooling to room temperature, the mixture was diluted with EtOAc (100 mL) and water (100 mL) and the organic phase collected. The aqueous layer was extracted again with EtOAc (100 mL) and the combined organic layers were dried over anhydrous MgSC^ and concentrated to dryness. The residue was purified by flash column chromatography to give the title compound as a yellow oil (533 mg, 49.8% yield). MS (ESI): mass calcd. for CnHnN30, 201.1; m/z found, 202.1 [M+H]+.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2-Amino-5-bromo-3-methylpyrazine, and friends who are interested can also refer to it.

Reference:
Patent; JANSSEN PHARMACEUTICA NV; ARORA, Nidhi; BACANI, Genesis M.; BARBAY, Joseph Kent; BEMBENEK, Scott D.; CAI, Min; CHEN, Wei; DECKHUT, Charlotte Pooley; EDWARDS, James P.; GHOSH, Brahmananda; HAO, Baoyu; KREUTTER, Kevin; LI, Gang; TICHENOR, Mark S.; VENABLE, Jennifer D.; WEI, Jianmei; WIENER, John J. M.; WU, Yao; ZHU, Yaoping; ZHANG, Feihuang; ZHANG, Zheng; XIAO, Kun; (1000 pag.)WO2017/100668; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 41110-28-5, name is 3-Methylpyrazine-2-carboxylic acid, 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. category: Pyrazines

Example 1.1: Preparation of 3-methyl-pyrazine-2-carboxylic acid ethyl esterTo a solution of 3-methyl-pyrazine-2-carboxylic acid (10 g) (commercially available) and jV,7V-dimethylformamide (“DMF”) (1 drop) in dichloromethane (20 ml) at ambient temperature was added drop wise oxalyl chloride (2.57 ml). The reaction mixture was stirred at ambient temperature for 1 hour. The reaction mixture was concentrated and the residue dissolved in dichloromethane (20 ml). Triethylamine (4.04 ml) was added to this solution followed by drop wise addition of ethanol (10 ml). The reaction mixture was stirred at ambient temperature for one hour and then concentrated. The residue was purified by chromatography on silica gel (eluent: 0-10% v/v ethyl acetate in zso-hexane) to give 3- methyl-pyrazine-2-carboxylic acid ethyl ester (9.85 g). MH+ = 167, RT = 0.73 min (Method A). IH-NMR (400 MHz, CDCl3): 8.61 (d, IH), 8.54 (d, IH), 4.49 (q, 2H), 2.85 (s, 3H), 1.46 (t, 3H) ppm.

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

Reference:
Patent; SYNGENTA LIMITED; WILLETTS, Nigel, James; MULHOLLAND, Nicholas, Phillip; WORTHINGTON, Paul, Anthony; AVERY, Alaric, James; WO2010/130970; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem