Month: September 2021

Some common heterocyclic compound, 4858-85-9, name is 2,3-Dichloropyrazine, molecular formula is C4H2Cl2N2, 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. Product Details of 4858-85-9

Step 1: 2-Chloro-3-(2-phenoxyethylamino)pyrazine. A mixture of 2-phenoxyethylamine (2.65 g, 19.3 mmol), 2,3-dichloropyrazine (2.88 g, 19.3 mmol) and K2CO3 (2.67 g, 19.3 mmol) in acetonitrile (8 mL) was stirred in a sealed tube for 12 h at room temperature, and for a further 9.5 h at 80 C. The reaction mixture was diluted with ether, filtered, and concentrated. The residue was purified by chromatography on silica gel using n-hexane/EtOAc (7:3) as eluent to give 2.36 g (49%) of the title compound as a yellowish oil that solidified on standing: mp 51-53 C.; HRMS m/z calcd for C12H12ClN30 (M)+249.0669, found 249.0659. Anal. (Cl2H12ClN30) C, H, N.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 4858-85-9, its application will become more common.

Reference:
Patent; Biovitrum AB; US6465467; (2002); B1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

24241-18-7, Adding some certain compound to certain chemical reactions, such as: 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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 24241-18-7.

The suspension of 18b (2.51 g, 10.0 mmol), NaCN (0.59 g,12.0 mmol), CuI (0.95 g, 5.0 mmol) and Pd(PPh3)4 (0.14 g,0.1 mmol) were stirred in DMF (20 mL) at 120 C for 10 h under nitrogen protection. After cooling to room temperature, 10% aqueous solution of Na2S2O3(10 mL) and water(50 mL) were added. The mixture was extracted with ethyl acetate (50 mL × 3), washed with water (3 × 50 mL), dried over anhydrous Na2SO4 and concentrated. The residue was purified by chromatography on silica gel eluting with PE/EA (10:1-2:1) to give an off-white solid (1.1 g, yield 55%). 6-Bromo-3-aminopyrazine-2-carbonitrile (19b)Yield: 55%, off-white solid, M.p.: 180-182 C (Lit.183-184 C, Sato et al. 1990a, b). 1H NMR (400 MHz,DMSO-d6): delta 8.45 (s, 1H), 7.62 (s, 2H). 1H NMR (400 MHz,CDCl3):delta 8.30 (s, 1H), 5.28 (s, 2H). 13C NMR (125 MHz,DMSO-d6): delta 156.70, 150.49, 123.64, 115.45, 110.60. EI-MS m/z: 198 (M+, Br79,100), 200 (M+, Br81,98), 171(M+, Br79,-H, -CN, 17), 173 (M+, Br81,-H, -CN, 17),119(M+, -Br, 32), 92 (M+, -Br, -H, -CN, 46).

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 24241-18-7.

Reference:
Article; Guo, Qi; Xu, Mingshuo; Guo, Shuang; Zhu, Fuqiang; Xie, Yuanchao; Shen, Jingshan; Chemical Papers; vol. 73; 5; (2019); p. 1043 – 1051;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, molecular formula is C6H2N2O3, 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

The amine prepared in Example 8 (87.7 mg, 0.172 mmol, 1 eq.) was dissolved in 6 mL acetone cooled to 0C in an ice bath. To this solution was added 2,3-pyrazinedicarboxylic acid anhydride (25.8 mg, 0.172 mmol, 1 eq.). The yellow solution turned into a suspension and was then stirred room temperature for 10 min. The precipitate was filtered off with suction, washed with acetone, dissolved in methanol and concentrated under reduced pressure to afford 54 mg (51%) of the title product as an orange solid. NMR (400 MHz, DMSO-d6) delta 10.23 (s, 1H), 8.92 (t, J= 5.9 Hz, 1H), 8.80 (d, J= 2.4 Hz, 1H), 8.76 (d, J= 3.4 Hz, 1H), 8.75 (d, J= 2.5 Hz, 1H), 8.51 (d, J= 4.0 Hz, 1H), 8.44 (d, J = 4.0 Hz, 2H), 7.71 (td, J= 7.7, 1.7 Hz, 1H), 7.64 (td, J= 7.7, 1.7 Hz, 2H), 7.53 (d, J= 8.4 Hz, 2H), 7.42 (t, J= 9.2 Hz, 2H), 7.33 (d, J= 7.8 Hz, 1H), 7.28 – 7.15 (m, 5H), 3.76 (s, 2H), 3.72 (s, 4H), 3.49 (dd, J= 14.2, 6.5 Hz, 3H), 3.28 (s, 2H), 2.81 (dt, J= 13.7, 8.2 Hz, 4H), 2.65 (t, J = 6.2 Hz, 2H). 13C NMR (101 MHz, DMSO-d6) delta 169.28, 166.90, 165.62, 163.12, 158.66, 158.42, 149.03, 148.75, 147.71, 146.48, 145.66, 144.90, 143.82, 143.43, 136.84, 136.72, 136.46, 134.16, 128.88, 123.13, 122.87, 122.44, 122.16, 119.27, 60.09, 59.53, 58.08, 54.89, 51.65, 51.16, 48.62, 34.30. APCI-HRMS e/z calc. for C35H37N9O2: 615.3070, found 616.3141 [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 4744-50-7, its application will become more common.

Reference:
Patent; UNIVERSITETET I OSLO; GOLDING, Louise; RONGVED, Pal; ASTRAND, Ove Alexander H°gmoen; SAMUELSEN, Ørjan; SCHNAARS, Christian; KILDAHL-ANDERSEN, Geir; (234 pag.)WO2018/33719; (2018); 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. 4858-85-9, name is 2,3-Dichloropyrazine, A new synthetic method of this compound is introduced below., Product Details of 4858-85-9

[00295] Step A: 4-(3-Chloropyrazin-2-yl)-l-naphthonitrileA mixture of 2,3-dichloropyrazine (2.98g, 2mmol), 4-(4,4,5,5-tetramethyl- l,3,2-dioxaborolan-2-yl)-l-naphthonitrile (0.558mmol, 2mmol) palladium tetrakis triphenylphoshine (0.069g, 0.06mmol) and aqueous sodium carbonate solution (2M, 3mL, 6mmol) in dioxane (7mL) was heated to 80C for 12 hours. The reaction mixture cooled to room temperature, washed with water, extracted with ethyl acetate and purified by chromatography to yield 4-(3-chloropyrazin-2-yl)-l-naphthonitrile (0.36g, 68%).

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; ARDEA BIOSCIENCES, INC.; OUK, Samedy; VERNIER, Jean-michel; GUNIC, Esmir; CHEN, Chixu; WO2011/159839; (2011); A2;,
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. 71257-38-0, name is 1,2,3,4-Tetrahydropyrrolo[1,2-a]pyrazine, A new synthetic method of this compound is introduced below., category: Pyrazines

Diisopropylethylamine (12.15 mmole) and di-tert-butyl dicarbonate (8.9 mmole) were added to a solution of the correspondingly 1-substituted 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine (8.1 mmole) in DCM. The reaction mixture was stirred for 16 hours at 25 C. The organic phase was then washed with sodium carbonate solution, water and satd. NaCl solution, dried over Na2SO4 and concentrated by evaporation. The crude product was purified by column chromatography (silica gel, ethyl acetate/DCM, 99:1); 1,2,3,4-Tetrahydro-pyrrolo[1,2-a]pyrazine was dissolved in dichloromethane (90 ml) at to it DIPEA (12.15 mmol) and boc anhydride (8.9 mmol) were added at 0 C. The resulting reaction mixture was allowed to stir for 16 hrs at 25 C. Organic layer was washed with sodium carbonate, water and brine and finally dried over sodium sulfate. Evaporation of the organic layer gave the crude product which was purified by column chromatography (1% ethyl acetate in dichloromethane) or (10% ethyl acetate in hexane); 1,2,3,4-Tetrahydro-pyrrolo[1,2-a]pyrazine which was dissolved in dichloromethane (90 ml) at to it DIPEA (12.15 mmol) and boc anhydride (8.9 mmol) were added at 0 C. The resulting reaction mixture was allowed to stir for 16 hrs at 25 C. Organic layer was washed with sodium carbonate, water and brine and finally dried over sodium sulfate. Evaporation of the organic layer gave the crude product which was purified by column chromatography (1% ethyl acetate in dichloromethane) or (10% ethyl acetate in hexane).

The synthetic route of 71257-38-0 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GRUENENTHAL GmbH; US2009/186899; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 939412-86-9, 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. 939412-86-9 name is (3-Chloropyrazin-2-yl)methanamine hydrochloride, 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.

HATU (15.91 g, 41.8 mmol) was added to a stirred, cooled 0 C mixture of (6R,8aS)-3-oxooctahydroindolizine-6-carboxylic acid (7.3 g, 39.8 mmol), (3- chloropyrazin-2-yl)methanamine hydrochloride (7.89 g, 43.8 mmol) and DIPEA (10.44 ml, 59.8 mmol) in CH2C12 (25 ml) and the mixture was stirred at room temperature for 1 h. and then concentrated. The residue was purified by column chromatography on silica gel (Isco 240 g silica gel), eluting with CH2Cl2/MeOH (50/1) to give (6R,8aS)-N- ((3-chloropyrazin-2-yl)methyl)-3-oxooctahydroindolizine -6-carboxamide (11.15g, 36.1 mmol, 91 % yield) as a white solid. LC-MS: Ret. time 1.09 min; m/z 309.11 (M+H)+; 1HNMR (CDCI3, 500 Hz): 8.38 (1H, d, J = 2 Hz), 8.25 (1H, d, J = 2 Hz), 7.37 (1H, dd, J = 4 and 4.5 Hz), 4.56-4.72 (2H, m,l), 4.29 (1H, dd, J = 13 and 4.5 Hz),3.42-3.47 (m,l), 2.81 (1H, t, J = 13 Hz), 2.35 (2H, t, J = 8 Hz), 2.17-2.23 (1H, m), 2.04 (1H, d, J = 13.5 Hz), 1.94-1.96 (1H, m), 1.74-1.82 (1H, m), 1.55-1.62 (1H, m), 1.16-1.24 (1H, m).

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

Reference:
Patent; MERCK SHARP & DOHME CORP.; WU, Hao; KIM, Ronald M.; LIU, Jian; GAO, Xiaolei; BOGA, Sobhana Babu; GUIADEEN, Deodialsingh; KOZLOWSKI, Joseph; YU, Wensheng; ANAND, Rajan; YU, Younong; SELYUTIN, Oleg B.; GAO, Ying-Duo; LIU, Shilan; YANG, Chundao; WANG, Hongjian; WO2014/114185; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 87486-34-8, A common heterocyclic compound, 87486-34-8, name is 3,5-Dibromo-1-methylpyrazin-2(1H)-one, molecular formula is C5H4Br2N2O, 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 17 A solution of the aminopyrazole (0.28 g, 2.5 mmol) and the dibromopyrazinone (0.74 g, 1.1 equiv) were heated to 120° C. in isopropanol for 1 h. The reaction mixture was cooled to RT, and the product was isolated by filtration (0.43 g, 57percent).

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

Reference:
Patent; Roche Palo Alto LLC; US2010/4231; (2010); 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. 109-08-0, name is 2-Methylpyrazine, A new synthetic method of this compound is introduced below., SDS of cas: 109-08-0

General procedure: A 25 mL Schlenk tube equipped with a magneticstirring bar was charged with2,6-lutidine (0.75 mmol, 3equiv.), p-nitro-benzaldehyde(0.25 mmol), dioxane/water(1:1, 1ml) and [Hmim][H2PO4](1equiv.).The tube was sealed and heated at 100 for 24h. Aftercompletion of the reaction, the resulting solution was extracted with ether (3×10 ml). The organic layer was dried with anhydrous Na2SO4,and concentrated under vacuum. The residue was chromatographed on a silica gelcolumn eluted with a mixture of petroleum ether and ethyl acetate (1:1) to givepure products (92percent).

The synthetic route of 109-08-0 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Zhang, Xue-Yan; Dong, Dao-Qing; Yue, Tao; Hao, Shuang-Hong; Wang, Zu-Li; Tetrahedron Letters; vol. 55; 40; (2014); p. 5462 – 5464;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 1379338-74-5, These common heterocyclic compound, 1379338-74-5, name is 5,7-Dichloropyrido[3,4-b]pyrazine, 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.

Intermediate 18: 1,1-Dimethylethyl (3S)-3-{r(7-chloropyridor3,4-6lpyrazin-5- yl)oxy1methyl)-1-piperidinecarboxylate; 1 , 1-Dimethylethyl (3S)-3-(hydroxymethyl)-1-piperidinecarboxylate (129mg, 0.600mmol) (Apollo Scientific Limited) was taken up in N,N-dimethylformamide (DMF) (3ml), treated with sodium hydride (23.99mg, 0.600mmol) and allowed to stir at room temperature for 20min, a yellow solution resulted. 5,7-dichloropyrido[3,4- £>]pyrazine (100mg, 0.500mmol) was added and the reaction was allowed to stir at room temperature for a further 1 h. The reaction was partitioned between EtOAc (50ml) and NH4CI (50ml). The organic layer was dried using a hydrophobic frit and concentrated to give a brown oil. This oil was purified on silica (25g) using a 0-40% EtOAc/cyclohexane gradient. The appropriate fractions were summed and concentrated to give the title compound as a yellow gum (91 mg).LCMS (Method B): Rt = 1.26min, MH+ = 378.88

Statistics shows that 5,7-Dichloropyrido[3,4-b]pyrazine is playing an increasingly important role. we look forward to future research findings about 1379338-74-5.

Reference:
Patent; GLAXO GROUP LIMITED; ATKINSON, Francis Louis; ATKINSON, Stephen John; BARKER, Michael David; DOUAULT, Clement; GARTON, Neil Stuart; LIDDLE, John; PATEL, Vipulkumar Kantibhai; PRESTON, Alexander G; SHIPLEY, Tracy Jane; WILSON, David Matthew; WATSON, Robert J; WO2012/123312; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 369638-68-6,Some common heterocyclic compound, 369638-68-6, name is tert-Butyl (5-methylpyrazin-2-yl)carbamate, molecular formula is C10H15N3O2, 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.

A. 5-methylpyrazin-2-amine; To a solution tert-butyl 5-methylpyrazin-2-ylcarbamate (1.5 g, 7.17 mmol) in CH2CI2 (20 ml) was added TFA (2.6 mL, 35.86 mmol). The reaction mixture was stirred for 4 hours at room temperature after which, it was concentrated under reduced pressure. The reaction mixture was diluted with CH2CI2 and neutralized with sai.NaHCOs solution. The organic layer was separated and the aqueous layer was extracted with CH2CI2. The combined organic extracts were washed with brine, dried over MgS04, celite filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography using (30% to 50% Ethyl acetate/Hexane) as a solvent to afford title compound (580 mg, 74% yield). MS m/z : 110 [M+l] .

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route tert-Butyl (5-methylpyrazin-2-yl)carbamate, its application will become more common.

Reference:
Patent; DANA-FARBER CANCER INSTITUTE, INC.; GRAY, Nathanael, S.; WO2011/90738; (2011); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem