Month: June 2021

14508-49-7, name is 2-Chloropyrazine, 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. Application In Synthesis of 2-Chloropyrazine

20.0 g (174.6 mmol) 2-chloropyrazine are added dropwise to 60.0 ml (61.7 g, 1.2 mol) hydrazine hydrate. The mixture is stirred at a bath temperature of 120 C. for 45 min. For working up, the cooled reaction mixture is left to stand at 2 C. for 12 h, the crystals which have precipitated out are filtered off and the residue on the filter is washed twice with petroleum ether. The residue is then recrystallized from toluene.Yield: 6.5 g (34% of th.)LC-MS (Method 1): Rt=0.49 min; MS (ESIpos): m/z=111 [M+H]+;1H-NMR (400 MHz, DMSO-d6): delta=8.11 (s, 1H), 7.94 (s, 1H), 7.90 (s, 1H), 7.70 (d, 1H), 4.29 (br. s, 2H).

The synthetic route of 14508-49-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; BAYER SCHERING PHARMA AKTIENGESELLSCHAFT; US2010/305085; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 22047-25-2, name is Acetylpyrazine, 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

PZEH was synthesized by the condensation reaction of2-acetylpyrazine with hydrazine hydrate, with the loss of awater molecule. Hydrazine hydrate (0.1 ml, 2.05 mmol) wasadded to an ethanolic solution (10 ml) of 2-acetylpyrazine(0.251 g, 2.05 mmol). The solution was heated under reflux forabout 4 h with constant stirring and was then left to cool toroom temperature overnight to give a cream-coloured solid.The crude product was filtered off, dried in the air andrecrystallized from an EtOH/MeCN mixture to affordcolourless crystals that were suitable for X-ray diffraction. It isworth mentioning that PZEH will undergo further condensationto form the azine on standing at room temperature(yield 0.105 g, 37%; m.p. 394-395 K). Analysis calculated forC6H8N4 (%): C 52.93, H 5.92, N 41.15; found (%): C 52.95, H4.96, N 39.61; IR (cm1, KBr pellet): 3394 (s, N-H), 3318 (m,N-H), 3182 (s, aryl C-H), 2913 (m, alkyl C-H), 1657 (s,C N), 1592 (s, aryl C C), 1511 (s), 1100 (s); 1H NMR(CDCl3): 9.19 (1H, s, Ar-H), 8.43-8.42 (1H, m, Ar-H), 8.38(1H, d, Ar-H), 5.73 (2H, s, -N-NH2), 2.20 (3H, s, -C-CH3);13C NMR (CDCl3): 151.73 (C N), [144.85, 142.57, 142.48,142.36] (py-C), 8.89 (-CH3); MS/EI (m/z) (I, %) for C6H8N4: 136 [M]+ (100), 107 [C6H7N2]+ (59), 79 [C4H3N2]+ (83), 57[C2H5N2]+ (89), 52 [C2N2]+ (68).

The synthetic route of Acetylpyrazine has been constantly updated, and we look forward to future research findings.

Reference:
Article; Kassim, Muhammad Arif; Yassin, Ubaidullah H. M.; Tan, Ai Ling; Usman, Anwar; Hamid, Malai Haniti S. A.; Acta Crystallographica Section C: Structural Chemistry; vol. 74; 4; (2018); p. 424 – 427;,
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. 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, This compound has unique chemical properties. The synthetic route is as follows., name: 2-Amino-3,5-dibromopyrazine

The compound 3,5-dibromo-2-aminopyrazine 1a (20.0 g, 106 mmol) was added to aqueous ammonia (100 mL), and the reaction mixture was reacted at 110 ° C overnight, and the reaction was monitored by LCMS.Pour the reaction system into water (300 mL), extracted with ethyl acetate (500mLx2), the combined organic phases were saturated brine (200mL), dried over anhydrous sodium sulfate and concentrated.The crude product by column (v / v, petroleum ether / ethyl acetate = 30: 1-2: 1) to give the title compound 1b (9.0g, 47.8mmol), 60percent yield

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:
Patent; Shanghai Huahuituo Pharmaceutical Technology Co., Ltd.; Zhejiang Huahai Pharmaceutical Co., Ltd.; Xu Xin; Zhang Tian; Li Yunfei; Wang Guan; Zhu Weibo; Li Qiang; Qu Minkai; Zhang Linli; Song Jinqian; Liu Lei; Chen Haiji; Liu Qiang; Wang Yijin; Ge Jian; (67 pag.)CN109535164; (2019); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 51171-02-9, These common heterocyclic compound, 51171-02-9, name is Methyl 3-Bromo-2-pyrazinecarboxylate, 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.

(a) 3-(4-chlorophenylamino)-pyrazine-2-carboxylic acid methyl ester A mixture of 21.7 g 3-bromo-pyrazine-2-carboxylic acid methyl ester and 25.5 g 4-chloroaniline in 150 ml ethyl acetate is boiled 4 days at reflux. The solution is washed with 4 N hydrochloric acid, water and then with 2 N sodium carbonate. The organic phase is dried over sodium sulphate and evaporated to give the heading compound (recrystallized from isopropanol) m.p. 135-136.

Statistics shows that Methyl 3-Bromo-2-pyrazinecarboxylate is playing an increasingly important role. we look forward to future research findings about 51171-02-9.

Reference:
Patent; Sandoz Ltd.; US4337198; (1982); A;,
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. 1174321-06-2, name is 5-(Difluoromethyl)pyrazine-2-carboxylic acid, A new synthetic method of this compound is introduced below., HPLC of Formula: C6H4F2N2O2

Example 211 N-(3-((4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-oxazin-4-yl)-5-chloro-4-fluorophenyl)-5-(difluoromethyl)pyrazine-2-carboxamide The title compound was synthesized by procedures and steps analogous to those described in Method A2, Example 206 above, but using 5-(difluoromethyl)pyrazine-2-carboxylic acid (Aurigene Discovery Technologies Ltd.) in step 10. MS m/z=482.1 [M+H]+. Calculated for C18H14ClF6N5O2: 481.779 1H NMR (400 MHz, CHLOROFORM-d) delta=9.61 (br. s., 1H), 9.51 (s, 1H), 8.91 (s, 1H), 8.18 (dd, J=2.5, 6.1 Hz, 1H), 7.44-7.35 (m, 1H), 7.02-6.60 (m, 1H), 4.35 (br. s., 2H), 4.11-3.96 (m, 1H), 2.80 (dd, J=2.2, 13.9 Hz, 1H), 1.92 (t, J=13.2 Hz, 1H), 1.65 (s, 3H)

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; MINATTI, Ana Elena; LOW, Jonathan D.; ALLEN, Jennifer R.; CHEN, Jian; CHEN, Ning; CHENG, Yuan; JUDD, Ted; LIU, Qingyian; LOPEZ, Patricia; QIAN, Wenyuan; RUMFELT, Shannon; RZASA, Robert M.; TAMAYO, Nuria A.; XUE, Qiufen; YANG, Bryant; ZHONG, Wenge; US2014/249104; (2014); A1;,
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. 41110-28-5, name is 3-Methylpyrazine-2-carboxylic acid belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. Recommanded Product: 3-Methylpyrazine-2-carboxylic acid

To a stirred solution of MeOH (50 mL) was added SOCl2(8.6 g, 72.4 mmol) dropwise at 0C. Then 3-methylpyrazine-2-carboxylic acid (5 g, 36.2 mmol) was added to the reaction. The mixture was stirred at 60 C overnight. The mixture was concentrated under reduced pressure and the residue was dissolved into EA (50mL) . The organic phase was washed with saturated aq.NaHCO3(50 mL) . The organic phase was washed with brine, dried over Na2SO4and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluted with: EA/PE = 1/1) to afford the title compound as yellow solid (3.9g, yield: 70.9%) . MS: M/e 153 (M+1)+.

The synthetic route of 41110-28-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; BEIGENE, LTD.; ZHANG, Guoliang; SUN, Hanzi; ZHOU, Changyou; (253 pag.)WO2020/20097; (2020); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 27825-21-4, 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. 27825-21-4, name is Methyl 3-chloropyrazine-2-carboxylate belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

Methyl 3-chloropyrazine-2-carboxylate (504 mg, 2.9 mmol, 1 eq.), O-benzylhydroxylamine (1073 mg, 8.72 mmol, 3 eq.), Dimethyl sulfoxide (3 mL) and N,N-diisopropylethylamine (1.44 mL, 8.72 mmol, 3 eq.) were added to a microwave reaction tube, and microwave reaction was performed at 100 C for one hour. After the reaction, the reaction solution was transferred to a separating funnel, 30 mL of ethyl acetate and 30 mL of a saturated sodium chloride solution were added, the organic phase was separated, and the aqueous layer was extracted twice with ethyl acetate. The organic phases were combined, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated and sampled with 100-200 mesh silica gel. After purification by 200-300 mesh silica gel column chromatography (eluent EA: PE = 1: 4), crude intermediate 2 was obtained. The crude product was recrystallized from petroleum ether / n-hexane to obtain intermediate 3-((benzyloxy)amino)pyrazine-2-carboxylic acid methyl ester (2, yield: 16%).

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, Methyl 3-chloropyrazine-2-carboxylate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Shandong University; Liu Xinyong; Sun Lin; Zhan Peng; Gao Ping; Cheng Xiqiang; Li Yanqi; Wang Xueshun; (24 pag.)CN108299428; (2019); B;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 143591-61-1,Some common heterocyclic compound, 143591-61-1, name is 3-Bromo-8-chloroimidazo[1,2-a]pyrazine, molecular formula is C6H3BrClN3, 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 149; The mixed halo-products (3:1 Cl:Br) from Preparative Example 102 (3.67 g, 15.0 mmol), were combined with N,N-dimethyl-m-phenylenediamine.2HCl (4.71 g, 22.5 mmol), i-Pr2NEt (15.7 mL, 90.2 mmol), and NMP solvent (75 mL). The reaction was heated in an oil bath at 160 C. for 18 hours. The reaction was cooled and concentrated under vacuum. The crude material was purified by column chromatography; 2 columns using a gradient of 20% EtOAc/Hexanes increasing to 50% EtOAc/Hexanes. The product 149 was isolated in 95% purity as determined by 1H NMR (400 MHz DMSO-d6,) 9.36 (s, 1H), 7.77 (s, 1H), 7.74 (d, J=4.4 Hz, 1H), 7.54 (d, J=4.8 Hz, 1H), 7.47 (m, 1H), 7.42 (t, J=2.0 Hz), 7.09 (t, J=8.0 Hz, 1H), 6.40 (dd, J=8.0 Hz, 2.0 Hz, 1H), 2.87 (s, 6H). Product was isolated in 77% yield, 3.83 g.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3-Bromo-8-chloroimidazo[1,2-a]pyrazine, its application will become more common.

Reference:
Patent; Schering Corporation; US2007/117804; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, 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. HPLC of Formula: C6H2N2O3

General procedure: Pyrazine-2,3-dicarboxylic anhydride (1.0 g, 6.7 mmol) was dissolved in tetrahydrofuran (40 mL)in an Erlenmeyer flask and the corresponding substituted aniline (6.7 mmol, 1 equiv.) was added in one dose. The reaction mixture was stirred for 1 hour at laboratory temperature. Water (30 mL) was added into the mixture followed by the saturated aqueous solution of NaHCO3 until pH 6 to form thecorresponding 3-(phenylcarbamoyl)pyrazine-2-carboxylic acid 1-18. Obtained crystals were filtered off and washed with water. The progress of the procedure was monitored by TLC eluted with thesystem water/butanol/acetic acid 5:4:1.

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

Reference:
Article; Semelkova, Lucia; Jano?cova, Petra; Fernandes, Carlos; Bouz, Ghada; Jand?Ourek, Ond?ej; Kone?na, Klara; Paterova, Pavla; Navratilova, Lucie; Kune?, Ji?i; Dole?al, Martin; Zitko, Jan; Molecules; vol. 22; 9; (2017);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 87885-43-6, 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. 87885-43-6, name is 2-Chloro-3-nitropyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

EXAMPLE 1 1-(3-Nitro-2-pyrazinyl)piperazin-3-one A solution of 2-chloro-3-nitropyrazine (9.1 g, 57 mmol) in chloroform (100 ml) was added dropwise over 45 minutes to a cooled solution of piperazine-2-one (5.71 g, 57 mmol) and triethylamine (8.0 ml, 57 mmol) in isopropanol (120 ml). After addition was complete, the reaction mixture was allowed to warm to 20-25 and was stirred at this temperature for 20 hours. The precipitate was removed by filtration and recrystallized from methanol-ethyl acetate-hexane to give 6.96 g (54.7%) of product, m.p. 178-179.

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

Reference:
Patent; Merck & Co., Inc.; US4619927; (1986); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem