Month: November 2020

These common heterocyclic compound, 4858-85-9, name is 2,3-Dichloropyrazine, 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. 4858-85-9

To a 1.0 M solution of LiHMDS in toluene (14.8 mL, 14.8 mmol) under nitrogen at 0 C was added 2,3-dichloropyrazine (0.699 mL, 6.71 mmol) and ethyl acetate (0.725 mL, 7.38 mmol). The mixture was stirred overnight for 18 hours, allowing the ice bath to warm to room temperature. The mixture was poured into saturated ammonium chloride (100 mL), and extracted with diethyl ether (3×100 mL). The combined ether extracts were washed with brine, dried (sodium sulphate) and evaporated. The residue was chromatographed (40 g silica cartridge, 0-25% ethyl acetate/petroleum benzine 40-60 C) to give the title compound (199) (0.414 g, 31 % yield) as a pale yellow oil; 1 H NMR (400 MHz, CDCI3) delta 8.46 (d, J = 2.5 Hz, 1 H), 8.31 (d, J = 2.5 Hz, 1 H), 4.22 (q, J = 7.1 Hz, 2H), 4.03 (s, 2H), 1.27 (t, J = 7.1 Hz, 3H). LCMS Method C: rt 5.16 min.

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 4858-85-9.

Reference:
Patent; CANCER THERAPEUTICS CRC PTY LTD; DEVLIN, Mark Graeme; STREET, Ian Philip; TONG, Warwick Bonner; WO2014/27199; (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. 1458-18-0, name is Methyl 3-amino-5,6-dichloropyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., 1458-18-0

Under an argon atmosphere,Isoamyl nitrite (26.6 mL, 200 mmol) was added to a THF solution of methyl 3-amino-5,6-dichloropyrazine-2-carboxylate (4.44 g, 20.0 mmol) in THF (30 mL). The reaction mixture was stirred at 80 C. for 17 hours. After standing to cool, the low boiling point compound was distilled off to obtain a crude product. This crude product was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 100/0 to 90/10) to obtain methyl 5,6-dichloropyrazine-2-carboxylate (2.29 g, 55% ) As a white solid.

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; TOSOH CORPORATION; SAGAMI CHEMICAL RESEARCH INSTITUTE; AIHARA, HIDENORI; SHONO, TOMOHIRO; (23 pag.)JP2015/140319; (2015); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 5049-61-6, name is Pyrazin-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. 5049-61-6

Stage 1. 3, 5-Dibromopyrazin-2-amine To a solution of aminopyrazine (11.36 g, 0.12 mol) in DCM (700 mL) at 0C was added N-bromosuccinimide (44.64 g, 0.25 mol) portion-wise. The reaction was stirred for 2 hrs. The reaction was washed with sat Na2CO3 (3 x 200 mL), dried over Mg504, filtered and concentrated in vacuo before purification by column chromatography (20% EtOAc/heptane) to give the title compound as a yellow solid (15.9 g, 53%). LCMS: m/z 252/254/256 [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 5049-61-6.

Reference:
Patent; CHROMA THERAPEUTICS LTD; DAVIES, Stephen John; PINTAT, Stephane; NORTH, Carl Leslie; MOFFAT, David Festus Charles; WO2014/1802; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

55557-52-3, 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. 55557-52-3, name is 3-Chloropyrazine-2-carbonitrile, A new synthetic method of this compound is introduced below.

Preparation 228N-(3-Cyanopyrazin-2-yl)-N-methylbenzenesulfonamide10721] To a solution of 2-chloro-3-cyanopyrazine (5 g,35.94 mmol) and Cs2CO3 (16.27 g, 50 mmol) in acetonitrile(75 mE) was added N-methylbenzenesulfonamide (7.37 g, 43mmol) and the reaction heated to 80 C. for 3 hours. The reaction mixture was concentrated in vacuo and the residue partitioned between water and EtOAc. The organic layer was collected, dried, concentrated in vacuo and purified by silica gel column chromatography eluting with 50% EtOAc in hexanes to afford the title compound (7.2 g, 73%). ?H NMR (400 MHz, DMSO-d5): oe ppm 3.12 (s, 3H), 7.64 (m, 4H), 7.76 (m, 1H), 8.80 (d, 1H), 8.85 (d, 1H).

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; Pfizer Inc.; Coe, Jotham Wadsworth; Dehnhardt, Christoph Martin; Jones, Peter; Sabnis, Yogesh Anil; Strohbach, Joseph Walter; Wakenhut, Florian Michel; Whitlock, Gavin Alistair; (180 pag.)US2015/329542; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

The chemical industry reduces the impact on the environment during synthesis 486424-37-7, name is 3-Amino-6-bromopyrazine-2-carboxylic acid, I believe this compound will play a more active role in future production and life. 486424-37-7

(Step 2) (1084) To a solution of 3-amino-6-bromopyrazine-2-carboxylic acid (10 g, 45.87 mmol) in DMF (50 mL) were added HATU (26.16 g, 68.8 mmol) and DIEA (80.1 mL, 458.7 mmol) at room temperature. Ethylamine (2 mol/L, THF solution, 114.65 mL, 229.3 mmol) was added thereto at room temperature, and the mixture was stirred at room temperature for 20 hr. The reaction mixture was concentrated under reduced pressure, to the residue was added ethyl acetate, and the solution was washed with water. The aqueous layer was extracted with ethyl acetate (x3). The organic layer was washed with water and saturated brine, and dried over sodium sulfate, and the solvent was evaporated under reduced pressure. The obtained residue was purified by silica gel column chromatography (solvent; 15% ethyl acetate/hexane) to give 3-amino-6-bromopyrazine-2-carboxylic acid ethylamide (6.60 g, 59%) as a pale yellow solid. 1H-NMR(400MHz,DMSO-d6) :delta1.10(t,3H,J=7.20Hz),3.24-3.30(m,2H),7.69(brs,2H),8.33(s,1H),8.60(t-like,1H,J=5.44Hz).

The chemical industry reduces the impact on the environment during synthesis 486424-37-7. I believe this compound will play a more active role in future production and life.

Reference:
Patent; Takeda Pharmaceutical Company Limited; YAMAMOTO, Satoshi; SHIRAI, Junya; FUKASE, Yoshiyuki; SATO, Ayumu; KOUNO, Mitsunori; TOMATA, Yoshihide; OCHIDA, Atsuko; YONEMORI, Kazuko; ODA, Tsuneo; IMADA, Takashi; YUKAWA, Tomoya; (238 pag.)EP2975031; (2016); 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. 132426-19-8, name is 2-Bromo-1-(pyrazin-2-yl)ethanone, This compound has unique chemical properties. The synthetic route is as follows., 132426-19-8

To a solution of 1-(pyrazin-2-yl)ethan-1-one (250 mg, 2.03 mmol) in AcOH (5 mL), pyridinium bromide perbromide(780 mg, 2.4 mmol) was added and allowed the mixture to stir at room temperature for 48hours. After TLC showed completion, diluted the mixture with EtOAc (20 mL) and washedwith water (3 x 10 mL). The organic layer was dried over Na2SO4 and concentrated to obtaincrude 2-bromo-1-(pyrazin-2-yl)ethan-1-one, which was used in next step without further purification(300 mg, crude). To a solution of 1-(2,6-dimethylphenyl)thiourea (134 mg, 0.7 mmol)in DMF (5 mL), crude 2-bromo-1-(pyrazin-2-yl)ethan-1-one (300 mg, 0.7 mmol) and triethylamine(0.31 mL, 2.2 mmol) were added successively and heated the mixture at 70C for 2hours. After TLC showed completion, reaction mixture was diluted with EtOAc (20 mL) andwashed with water (3 x 10 mL). The organic layer was dried over Na2SO4 and concentrated.The resulting residue was purified by column chromatography (silicagel, 100-200) and thedesired product was eluted with 20% EtOAc in hexane. Concentration of the pure fractionsafforded 52 (135 mg, 32% yield), as a pale yellow solid; 1H NMR: (400 MHz, DMSO-d6): delta 2.23(s, 6H), 7.14-7.20 (m, 3H), 7.45 (s, 1H), 8.54 (d, J = 2.4 Hz, 1H), 8.61 (t, J = 1.6 Hz, 1H), 8.99 (d, J = 1.6 Hz, 1H), 9.43 (1H, s); 13C NMR: (300 MHz, CDCl3) delta 18.1, 107.7, 128.1, 128.9, 137.0,137.4, 142.5, 142.7, 143.8, 148.3, 148.8, 171.0; LCMS m/z (M+H) 283.08, purity 99.8%; HRMSMS ESI m/z calcd for C15H14N4S (M+H)+ 283.1012, found 283.1001 (Delta 1.1 ppm).

If you are interested in these compounds, you can also browse my other articles.Thank you for taking the time to read this article. I hope you enjoyed it.

Reference:
Article; Kesicki, Edward A.; Bailey, Mai A.; Ovechkina, Yulia; Early, Julie V.; Alling, Torey; Bowman, Julie; Zuniga, Edison S.; Dalai, Suryakanta; Kumar, Naresh; Masquelin, Thierry; Hipskind, Philip A.; Odingo, Joshua O.; Parish, Tanya; PLoS ONE; vol. 11; 5; (2016);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below. 33332-25-1

To a solution of methyl 5-chloropyrazine-2-carboxylate (601 mg, 3.48 mmol) in THF (11.6 mL) was added 1-cyclohexene-l-yl-boronic acid (656 mg, 5.21 mmol), K3PO4 (1.47 g, 6.91 mmol), Pd(OAc)2 (39.2 mg, 0.175 mmol), SPhos (144 mg, 0.350 mmol) and H2O (0.13 mL, 7.2 mmol) at room temperature. After stirring for 15 h at 40 C, the reaction was quenched by adding water. The crude products were extracted with EtOAc (3X), and the combined organic extracts were washed with brine, dried (MgS04), and concentrated in vacuo. The residue was purified by flash column chromatography (hexane/EtOAc = 9/1 to 4/1) to afford methyl 5-(cyclohex-l-en-l-yl)pyrazine-2-carboxylate (736 mg, 97%) as a pale yellow solid. NMR (300 MHz, CDCh) delta 9.21 (d, J= 1.2 Hz, 1H), 8.81 (d, J= 1.2 Hz, 1H), 6.98-7.01 (m, 1H), 4.05 (s, 3H), 2.55-2.60 (m, 2H), 2.34-2.38 (m, 2H), 1.81-1.89 (m, 2H), 1.70-1.77 (m, 2H).

In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 33332-25-1, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; UNIVERSITY OF HAWAII; TURKSON, James; YUE, Peibin; TIUS, Marcus; BROTHERTON-PLEISS, Christine; LOPEZ TAPIA, Francisco, Javier; (420 pag.)WO2018/136935; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 6270-63-9 name is Pyrazin-2(1H)-one, 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. 6270-63-9

The ethyl 1-(2-fluoro-4-methoxyphenyl)-6-(4-iodophenyl)-7-oxo-spiro[5H-pyrazolo[3,4-c]pyridine-4,1-cyclopropane]-3-carboxylate (8D) (2.0g, 3 . 6mmol) and pyrazine-2-one (513 mg, 5 . 3mmol) dissolved in 1,4-dioxane (10 ml) in, under the protection of nitrogen, by adding potassium phosphate (1.5g, 7 . 2mmol), cuprous iodide (68 mg, 0 . 36mmol) and trans-(1R, 2R)-N, N’ -dimethyl -1,2-cyclo hexanediamine (51 mg, 0 . 36mmol), microwave 150 C reaction 1 hour. The reaction solution is poured into water (50 ml) in, with ethyl acetate (50 ml ¡Á 2) extraction, combined organic phase, the organic phase with saturated salt water (80 ml) washing, dry anhydrous sodium sulfate, concentrated, the residue is separation and purification of silica gel column chromatography (ethyl acetate: petroleum ether (v/v) =1:1-1:0) to obtain the title compound ethyl 1-(2-fluoro-4-methoxyphenyl)-7-oxo-6-[4-(2-oxopyrazin-1-yl)phenyl]spiro[5H-pyrazolo[3,4-c]pyridine-4,1-cyclopropane]-3-carboxylate(26A), white solid (1.3g, yield 68%).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Pyrazin-2(1H)-one, and friends who are interested can also refer to it.

Reference:
Patent; SICHUAN HAISCO PHARMACEUTICAL CO LTD; WEI, YONGGANG; QIU, GUANPENG; LEI, BAILIN; LU, YONGHUA; (120 pag.)CN104395312; (2016); B;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

27398-39-6, A common heterocyclic compound, 27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, molecular formula is C5H3ClN2O2, 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.

General procedure: To a solution of ethyl 5-(piperazin-1-yl) benzofuran-2-carboxylate (1 mmol) in dry dichloromethane (3 mL) was added triethylamine (2 mmol) and corresponding acid (1 mmol) at 0¡ãC. Propylphosphonic anhydride solution (50 wtpercent in ethyl acetate; 2.5 mmol) was then added drop wise to the reaction mixture and was stirred at rt for 6 h (monitored by TLC & LCMS for completion). The reaction mixture was then washed with water (2 mL), brine (2 mL), and dried over anhydrous sodium sulfate and evaporated in vacuo. The residue obtained was then recyrstallised from diethyl ether.

The synthetic route of 27398-39-6 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Renuka, Janupally; Reddy, Kummetha Indrasena; Srihari, Konduri; Jeankumar, Variam Ullas; Shravan, Morla; Sridevi, Jonnalagadda Padma; Yogeeswari, Perumal; Babu, Kondra Sudhakar; Sriram, Dharmarajan; Bioorganic and Medicinal Chemistry; vol. 22; 17; (2014); p. 4924 – 4934;,
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. 486460-21-3, name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., 486460-21-3

Comparative Example 1: Preparation of Compound of formula 2 wherein R is Boc, according to the method disclosed in U.S. Patent No. 6,699,871, Example 7, STEP A [42] (R)-3-Boc-amino-4-(2,4,5-trifluorophenyl)-butanoic acid (50.1mg, 0.15mmol) was dissolved in dichloromethane (2.5ml) and 3-(trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-alpha]pyrazine (39.2mg, 0.20mmol) was added thereto. While maintaining a temperature of 0 to 5C, HOBT (17.2mg, 0.21mmol) was added to the mixture, followed by reaction for 10 minutes. Thereafter, EDC (48.3mg, 0.25mmol) was added at 0C, and the reaction mixture was warmed to room temperature and stirred for 14 hours. After the reaction was completed, the reaction liquid was concentrated under reduced pressure and a desired compound was purified by column chromatography eluting with 100% ethyl acetate to afford 29mg (yield: 47.5%) of the title compound as a solid.

If you are interested in these compounds, you can also browse my other articles.Thank you for taking the time to read this article. I hope you enjoyed it.

Reference:
Patent; ST PHARM CO., LTD.; LIM, Geun Gho; CHANG, Sun Ki; BYEON, Chang Ho; WO2012/99381; (2012); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem