Tag: M.W=100-200

Application of 32710-14-8, A common heterocyclic compound, 32710-14-8, name is 3-Aminopyrazine-2-carbaldehyde, molecular formula is C5H5N3O, 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 77 Pyrido[2,3-b]pyrazine-6,7-dicarboxylic acid, diethyl ester STR163 Diethyl oxalacetate, (4.7 g, 0.025 mol) and piperidine (1.66 g, 1.93 mL) are added to 3-aminopyrazine-2-carboxaldehyde (2.4 g, 0.0195 mol) dissolved in 250 mL of toluene. After the reaction mixture is refluxed for two hours, the toluene is removed under reduced pressure to give a dark red oily residue. The product is purified by column chromatography on silica gel (hexane:EtOAc, 4:1), affording 3.1 g (58% yield), of the crude desired product. Crystallization from ether-hexane (4:1) gives analytically pure compound 1.5 g (28%) having a melting point 83-85 C.

The synthetic route of 32710-14-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; American Cyanamid Company; US5252538; (1993); A;,
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. 19847-12-2, name is Pyrazinecarbonitrile, This compound has unique chemical properties. The synthetic route is as follows., Formula: C5H3N3

2-Cyanopyrazine (1.0g, 9.5mmol) was dissolved in dry methanol (50mL) with stirring at room temperature. Metallic sodium (0.12g, 5.2mmol) was added and the mixture refluxed for 2h. The clear yellow solution of the in situ iminoester was brought to neutral pH with glacial acetic acid resulting in a clear orange solution. 2-(Hydoxyimino)-propanehydrazone [14,15] (1.1g, 9.3mmol) was added and the resulting solution refluxed for 1h, and stirred at room temperature overnight. The white solid formed was separated by suction filtration and washed with methanol and diethylether (Yield: 1.85g, 90%). 1H NMR (300MHz, DMSO-d6, 298K) delta (ppm) 11.72 (s, 1H, N-OH), 10.03 (s, 1H, NH), 9.27 (d, 1H, CH(pyz)), 8.70 (d, 1H, CH(pyz)), 8.64 (dd, 1H, CH(pyz)), 6.99 (s, 2H, NH2), 1.95 (s, 3H, CH3). 13C{1H} NMR (75.4MHz, DMSO-d6, 298K) delta (ppm) 160.52 (C=O), 150.66, 146.14 (C=N), 146.04 (C(pyz)), 145.01, 142.86, 142.72 (CH(pyz)), 10.20 (CH3). Selected IR data (cm-1): 3247 br (nu N-H), 1650 s (nu C=O), 1621 s, (nu C=N), 1045 s (nu N-Ooxime). M. pt. 240-242C.

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 19847-12-2.

Reference:
Article; Drover, Marcus W.; Tandon, Santokh S.; Anwar, Muhammad U.; Shuvaev, Konstantin V.; Dawe, Louise N.; Collins, Julie L.; Thompson, Laurence K.; Polyhedron; vol. 68; (2014); p. 94 – 102;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 33332-29-5, 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 33332-29-5 as follows.

(iii) 2-Amino-5-chloropyrazine (1.7 g) was dissolved in chloroform (190 ml) and pyridine (1.3 ml) was added under an argon atmosphere. The flask and its contents were protected from light and a solution of bromine (0.7 ml) in chloroform (85 ml) was added over a period of 1 hour. After stirring for 2 hours more bromine (0.07 ml) in chloroform (8.5 ml) was added and, after stirring for 30 minutes, pyridine (0.2 ml) was added. The reaction mixture was stirred for a further 30 minutes then washed with water (50 ml) and the organic phase was separated. The solvent was removed by evaporation and the residue was purified by chromatography through a bed of silica (90 g), eluding with hexane (200 ml) followed by dichloromethane. Dichloromethane fractions containing the product were evaporated to give 2-amino-3-bromo-5-chloropyrazine (1.68 g); 1 H NMR (d6 DMSO): 6.94 (br s, 2H), 8.09 (s, 1H); mass spectrum (+ve CI): 208 (M+H)+.

According to the analysis of related databases, 33332-29-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Zeneca Ltd.; US5668137; (1997); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 41110-29-6, 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. 41110-29-6 name is Methyl 3-methylpyrazine-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.

A solution of mixture of 2-(methoxycarbonyl)-3-methylpyrazine 1-oxide compound with 3-(methoxycarbonyl)-2-methylpyrazine 1-oxide (1:1) (5.1 g, 15.17 mmol) in toluene (50 mL) was cooled to 0 C. To the mixture was added phosphorus oxychloride (2.78 ml, 30.3 mmol) under nitrogen followed by n,n?-dimethylformamide (0.117 ml, 1.517 mmol). The reaction mixture was stirred at room temperature for 4 h and then was heated to 65 C. for 18 h. The mixture was cooled to room temperature, diluted with EtOAc and washed with saturated NaHCO3 solution. The aqueous layer was back-extracted with EtOAc. The combined organic extracts were dried (MgSO4), filtered and concentrated in vacuo. The mixture was purified with ISCO (0% to 50% EtOAc/Hexanes) to afford both isomers: methyl 5-chloro-3-methylpyrazine-2-carboxylate (0.68 g, 48.1% yield) and methyl 6-chloro-3-methylpyrazine-2-carboxylate (1.5 g, 106% yield).

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

Reference:
Patent; WHITE, Ryan; ALLEN, Jennifer R.; EPSTEIN, Oleg; HONG, Fang-Tsao; HUA, Zihao; HUMAN, Jason Brooks; LOPEZ, Patricia; OLIVIERI, Philip R.; ROMERO, Karina; SCHENKEL, Laurie; STELLWAGEN, John; TAMAYO, Nuria A.; ZHENG, Xiao Mei; US2014/213581; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 13134-38-8, These common heterocyclic compound, 13134-38-8, name is 3,6-Dimethylpyrazin-2-amine, 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.

[0093] To a stuffed solution of 280 mg (2.0 mmol) of thiophene-2,5-dicarbaldehyde in 6 mL of THF and 0.2 mL of water was added sodium borohydride (54 mg, 1.4 mmol). The reaction was stirred for 20 mm at rt. Water (5 mL) was added and the mixture was stirred for 10 mm and extracted with EtOAc (3 x). The combined organic layers were dried over Na2504, filtered and evaporated. The crude material was diluted with 10 mL of acetonitrile and cooled to 0 C. Triethylamine (0.89 mL) and methanesulfonyl chloride (0.40 mL) were added and the mixture was stilTed for 1 h at 0 C and then 1 h at rt. The mixture was treated with satd. aq. NaHCO3 and extracted with EtOAc (3 x). The combined organic layers were dried over Na2SO4, filtered and evaporated to provide 657 mg of crude thiophene-2,5-diylbis(methylene) dimethanesulfonate. A mixture of 62.1 mg of the crude mesylate, 114 mg of K2C03, and 50 mg of 3,6-dimethylpyrazin-2-amine in 1 mL of DMF was heated at 110 C in a sealed tube with stirring for 48 h. The mixture was cooled to rt, diluted with water, and extracted with EtOAc (3x). The combined organic layers were dried over Na2SO4, filtered and evaporated. Purification by column chromatography (100% EtOAc) provided 7.3 mg of the title compound. MS (ESj:[M+H] 355.3; [M+Na] 377.4; MS (ES): [M-H] 353.3.

The synthetic route of 13134-38-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; NEUROPORE THERAPIES, INC.; WRASIDLO, Wolfgang; STOCKING, Emily, M.; (53 pag.)WO2016/40780; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 109838-85-9,Some common heterocyclic compound, 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, molecular formula is C9H16N2O2, 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.

[00374] 100 g (0.543 mol) of 1 (100 g, 5.4 mol) was taken up in THF (1000 mL) and cooled to -78 ¡ãC. 228 mL (0.570 moles) of n-BuLi (2.5M in THF) was added dropwise over 30 minutes. Then the solution was stirred vigorously for an additional 30 minutes. 81 g of methyl iodide (0.57 mol) was diluted to 250 mL with THF and cooled to -78 ¡ãC. The methyl iodide was then added dropwise over 30 minutes. Following completion of the addition of methyl iodide, the reaction was stirred at -78 ¡ãC for 2 hours. 1L of diethyl ether was then added to the mixture, followed by 500 mL of H20. The reaction was then warmed to room temperature. The aqueous layer was extracted multiple times with diethyl ether and the organic layer were combined, washed with saturated sodium thiosulfate, once with brine, and dried over MgSC>4. The organics were concentrated under vaccum to give residue which was purified by chromatography with gradient of 50: 1 to 20: 1 petroleum ether: diethyl ether to yield 110 g (80.5percent) of 2 (pale yellow oil). XH NMR: (400 MHz, CDC13-J) ppm 0.60 – 0.72 (m, 3 H), 0.94 – 1.03 (m, 3 H), 1.26 – 1.35 (m, 3 H), 2.07 – 2.30 (m, 1 H), 3.53 – 3.70 (m, 6 H), 3.89 (br. s., 2 H).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, its application will become more common.

Reference:
Patent; PRESIDENT AND FELLOWS OF HARVARD COLLEGE; VERDINE, Gregory, L.; HILINSKI, Gerard; WO2014/159969; (2014); 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. 33332-28-4, name is 2-Amino-6-chloropyrazine, A new synthetic method of this compound is introduced below., HPLC of Formula: C4H4ClN3

Example 5 N-(6-Chloro-pyrazin-2-yl)-7-fluoro-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide 4.1 g (15 mmols) of methyl 7-fluoro-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylate-1,1-dioxide and 2.3 g (18 mmols) of 2-amino-6-chloropyrazine were reacted in 200 ml of xylene analogous to Example 2 and worked up in analogy thereto. 3.8 g (66percent of theory) of N-(6-chloro-pyrazin-2-yl)-7-fluoro-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide were obtained. IR (KBr): 1645 cm-1 (CO amide).

The synthetic route of 33332-28-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Dr. Karl Thomae Gesellschaft mit beschrankter Haftung; US4533664; (1985); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 939412-86-9, A common heterocyclic compound, 939412-86-9, name is (3-Chloropyrazin-2-yl)methanamine hydrochloride, molecular formula is C5H7Cl2N3, 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.

To a mixture of compound V (49.8 g), DCM (500 mL) and DMF (5 mL) in a 500 mL three-neck flask, oxalyl chloride (38 g, 1.5 eq) was added at 0~10 C. The reaction mixture was warmed to RT. After completion of the reaction, the solvent was removed by concentration. DCM (200 mL) was added to obtain the compound VI solution in DCM. (0099) To a mixture of compound VII (30 g), DCM (240 mL) and TEA (6 eq) in a 1000 mL three-neck flask at 0~10 C, the solution of compound VI in DCM obtained from the above step was added dropwise, the reaction mixture was warmed to RT. After the reaction was completed, water (300 mL) was added to quench the reaction. The organic phase was washed with IN HCI aqueous solution (500 mL), saturated NaHC03 aqueous solution (500 mL) and water (500 mL). The organic phase was concentrated under vacuum. The crude product was recrystallized from IPAc/Heptane to afford compound VIII (61 g, 98% yield, 99.7% chiral purity).

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; WANG, Peng; LI, Pixu; GU, Xiangyong; GE, Yadong; WANG, Zhong; GAO, Feng; DU, Qiangqiang; (25 pag.)WO2019/90269; (2019); 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. 40155-43-9, name is 5-Aminopyrazine-2-carboxylic acid, A new synthetic method of this compound is introduced below., category: Pyrazines

5-aminopyrazine-2-carboxylic acid (493 mg, 3.54 mmol; Ark Pharm, Inc., Libertyville, IL) was stirred in dry Lambda/,Lambda/-dimethylformamide (3.0 mL) at room temperature under nitrogen. Solid potassium carbonate (742 mg, 5.37 mmol) was added, followed by benzyl bromide (0.43 mL, 3.6 mmol). The mixture was stirred for 22 hours and then diluted with ethyl acetate and water. The layers were separated, and the aqueous layer was extracted with ethyl acetate. The combined organics were washed with brine, dried over sodium sulfate, filtered, and evaporated. The residue was purified by silica chromatography using a 4Og pre-packed column, eluting with ethyl acetate. The product fractions were combined, evaporated, and dried under high vacuum to afford (I- 22a) (161 .2 mg, 0.70 mmol, 20%): m/z 229.9 (M+H)+.

The synthetic route of 40155-43-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PFIZER INC.; BENBOW, John William; LOU, Jihong; PFEFFERKORN, Jeffrey Allen; TU, Meihua Mike; WO2010/29461; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 113305-94-5, 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. 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, This compound has unique chemical properties. The synthetic route is as follows.

Imidazo[1,2-a]pyrazine-6-carbonitrile (5-2) To a solution of 5-aminopyrazine-2-carbonitrile (5-1) (350 mg, 2.92 mmol) in ethanol (15 mL) was added 2-chloroacetaldehyde (4 mL, 40% in water). The mixture was stirred at 110 C. overnight. The solution was concentrated, then purified by chromatography on silica gel to afford the title compound (280 mg). MS (m/z): 145.1 (M+H)+.

The chemical industry reduces the impact on the environment during synthesis 5-Aminopyrazine-2-carbonitrile. I believe this compound will play a more active role in future production and life.

Reference:
Patent; SU, Wei-Guo; JIA, Hong; DAI, Guangxiu; US2012/245178; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem