Tag: M.W=0-100

Reference of 4949-13-7, These common heterocyclic compound, 4949-13-7, name is 2-Fluoropyrazine, 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.

2-fluoropiperidine4a (6 mL, 74.20 mmol) and cyclopropyl nitrile (5.74 mL, 77.9 mmol) were dissolved in dry toluene (60 mL).Nitrogen protection, 0 C, Sodium bis(trimethylsilyl)amide (39 mL, 78 mmol) was slowly added, and the reaction was naturally stirred at room temperature for 4 hours. The reaction was quenched by dropwise addition of saturated aqueous ammonium chloride (100 mL), and extracted with ethyl acetate (300 mL×2). The combined organic phase was washed with saturated sodium chloride solution (200 mL×2) Sodium drying, suction filtrationThe residue was purified by silica gel column chromatography (EtOAc/EtOAc (EtOAc)A pale yellow solid 4b (1.34 g, yield 12%) was obtained.

Statistics shows that 2-Fluoropyrazine is playing an increasingly important role. we look forward to future research findings about 4949-13-7.

Reference:
Patent; Guangdong Dongyangguang Pharmaceutical Co., Ltd.; Li Jianhao; Gu Zheng; Tang Wanjun; Kang Panpan; (43 pag.)CN109721555; (2019); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 4949-13-7, name is 2-Fluoropyrazine, belongs to pyrazines compound, 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 4949-13-7, SDS of cas: 4949-13-7

Reagent 142-Fluoro-3-(tributylstannyl)pyrazineA clear solution of 2,2,6,6-tetramethylpiperidine (4.1 ml, 24.29 mmol) in tetrahydrofuran (150 mL) was cooled to -30 C and treated with n-butyl lithium (9.0 ml, 22.50 mmol). The internal temperature (IT) rose from -37 to -26 C. The reaction mixture was stirred at room temperature (IT=15 C) for 0.5 hours and then placed in a N2(1)/MeOH bath and cooled to an internal temperature of -122 C. A solution of 2-fluoropyrazine (2.0889 g, 21.30 mmol) in tetrahydrofuran (50 ml) was added via cannula over 4 minutes (IT=103). After 5 min, the tributyltin chloride (7 ml, 25.81 mmol) was added and the mixture was maintained at -100 C for 1 hr 40 minutes. The dark brown solution was quenched with 1:4:5 35% aqueous HCl:EtOH:THF, allowed to warm to room temperature over 35 minutes, made slightly basic with sodium bicarbonate, concentrated to a residue, and then partitioned between methylene chloride and water. The aqueous layer was extracted with methylene chloride (3×150 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated to afford the crude product as a light brown oil which was purified on silica gel using a gradient of 100:0 to 60:40 hexanes:ethyl acetate over 35 minutes to afford the desired product as a clear oil (2.26 g, 27%).

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

Reference:
Patent; ASTRAZENECA AB; US2008/318943; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 5049-61-6, 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. 5049-61-6, name is Pyrazin-2-amine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

Initial attempt showed that the reaction gave a lot of black polymers after a few min., with the main product being 3,5-dichloro-2-amino pyrazine. Only small amount of 5- chloro-2-aminopyrazine was isolated (eq 7). This reaction could not be scaled up because it was not reproducible.

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, Pyrazin-2-amine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; THE GOVERNMENT OF THE UNITED STATES, as represented by the secretary of HEALTH AND HUMAN SERVICES; WO2007/124345; (2007); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 109-08-0,Some common heterocyclic compound, 109-08-0, name is 2-Methylpyrazine, molecular formula is C5H6N2, 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.

Compound 17: (E)-2-[2-(Pyrazin-2-yl)vinyl)benzamide hydrochloride: n-Butyl lithium (2.5 M in hexanes, 4.8 mL, 12.0 mmol, 1.2 eq.) was added dropwise to a solution of diisopropylamine (1.83 mL, 1.32 g, 13.0 mmol, 1.3 eq.) in dry tetrahydrofuran (25 mL) at -78 °C. The mixture was stirred at -78 °C for 10 min and 2-methylpyrazine (0.91 mL, 0.94 g, 10.0 mmol, 1.0 eq.) was added dropwise. The resulting mixture was stirred at -78 °C for 30 min. A solution of 2-cyanobenzaldehyde (1.31 g, 10.0 mmol, 1.0 eq.) in dry THF (10 mL) was added dropwise and the mixture was allowed to slowly warm up to room temperature over 2 h while stirring. The reaction was quenched by addition of water (20 mL). The pH was adjusted to -10 by careful addition of cone. HCl and the mixture was extracted with dichloromethane (3 x 25 mL). The combined organic extracts were washed with brine (25 mL), dried over sodium sulfate and evaporated in vacuo. The crude product was purified by column chromatography (SiO2, 1:9 methanol-ethyl acetate) providing 2-(1-hydroxy-2-(pyrazin-2-yl)ethyl)benzamide (1.06 g, 44percent yield) as a clear yellow oil. 1,8-Diazabicyclo[5.4.0]undec-7-ene (1.61 mL, 1.69 g, 11.1 mmol, 2.5 eq.) was dropwise to a stirred solution of 2-[1-hydroxy-2-(pyrazin-2-yl)ethyl]benzamide (1.00 g, 4.4 mmol, 1.0 eq.) in dichloromethane (25 mL). The mixture was stirred at room temperature for 16 h. Water (25 mL) was added and the layers were separated. The aqueous layer was extracted with dichloromethane (2 x 25 mL) and the combined organic extracts washed with brine (25 mL), dried over sodium sulfate and concentrated in vacuo. The residue was taken up in ethyl acetate (20 mL) and filtered. The solids were washed with ethyl acetate (2 x 5 mL) and dried in vacuo providing (E)-2-[2-(pyrazin-2-yl)vinyl]benzamide (0.21 g, 21percent yield) as a fine off-white solid. A solution of hydrochloric acid (2.0 M in diethyl ether, 0.53 mL, 1.07 mmol, 1.2 eq.) was added dropwise to a stirred suspension of (E)-2-[2-(pyrazin-2-yl)vinyl]benzamide (0.20 g, 0.09 mmol, 1.0 eq.) in dry diethyl ether (7.5 mL). The mixture was stirred at room temperature for 1 h and was filtered. The solids were washed with diethyl ether (2 x 5 mL) and dried in vacuo providing (E)-2-[2-(pyrazin-2-yl)vinyl]benzamide hydrochloride (0.20 g, 86percent yield) as a fine yellow solid; 1H NMR (400 MHz, DMSO-d6) delta 7.33-7.55 (m, 5H, 2Ar+NH2+C=CH), 7.88-7.96 (m, 2H, Ar), 8.11 (d, J = 16.0 Hz, 1H, C=CH), 8.51 (s, 1H, Ar), 8.64 (s, 1H, Ar), 8.71 (s, 1H, Ar).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2-Methylpyrazine, its application will become more common.

Reference:
Patent; UNIVERSITY COLLEGE DUBLIN – NATIONAL UNIVERSITY OF IRELAND, DUBLIN; THE PROVOST, FELLOWS, FOUNDATION SCHOLARS, AND THE OTHER MEMBERS OF BOARD, OF THE COLLEGE OF THE HOLY AND UNDIVIDED TRINITY OF QUEEN ELIZABETH, NEAR DUBLIN; KENNEDY, Breandan; REYNOLDS, Alison; O’SULLIVAN, Jacintha; BAXTER, Andrew, Douglas; WO2015/107122; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 5049-61-6,Some common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, molecular formula is C4H5N3, 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 solution of 2-aminopyrazine 1 (4.5 g, 47.4 mmol) in 50 mL DMF/MeCN solvent mixture (1:3) and a solution of l,3-dibromo-5,5-dimethylhydantoin 2 (13.6 g, 47.6 mmol, 2 eq. of “Br”) in 40 mL DMF/MeCN solvent mixture (1:3) were simultaneously added (using two syringe needles) to a solution of MeCN (100 mL) at 0C. The reaction mixture was stirred for one hour, quenched with aqueous sodium thiosulfate (I N, 200 mL) and concentrated under vacuum. The crude product (>99% conversion, 8 g) was dissolved in EtOAc and filtered through celite/charcoal and recrystallized from acetonitrile (4.0 g, 50% recovery). The reaction was scaled up to 12.0 g in two batches and the desired product 3 was analyzed by NMR and LC-MS. IH NMR (500 MHz, CDC13) delta 7.99 (s, IH); 13C NMR (126 MHz, CDC13) delta 151.92, 143.16, 142.99, 123.95, 123.56.

The synthetic route of 5049-61-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; DOW GLOBAL TECHNOLOGIES LLC; ROHM AND HAAS ELECTRONIC MATERIALS KOREA LTD.; ONDARI, Mark E.; WELSH, Dean M.; FROESE, Robert DJ; NA, Hong-Yeop; (38 pag.)WO2016/209895; (2016); 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. 5049-61-6, name is Pyrazin-2-amine, A new synthetic method of this compound is introduced below., Quality Control of Pyrazin-2-amine

Step 1: 2-amino-5-bromopyrazine. To a stirred, cooled (0 C) solution of amino pyrazine (5.0 g, 52.6 mmol) in methylene chloride (200 mL) was added N-bromosuccinimide (9.39 g, 52.8 mmol). After stirring for 24 hours, the reaction was washed with aqueous 10% sodium carbonate (3*50 mL), water (50 mL), then dried (MgSO4), and filtered. The filtered material was concentrated under reduced pressure, taken up in minimal ethyl acetate (5 mL) followed by hexanes (200 mL). Yellow crystals formed which were filtered and dried. (56 % yield).

The synthetic route of 5049-61-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Keegan, Kathleen S.; Kesicki, Edward A.; Gaudino, John Joseph; Cook, Adam Wade; Cowen, Scott Douglas; Burgess, Laurence Edward; US2003/69284; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 5049-61-6,Some common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, molecular formula is C4H5N3, 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.

Synthesis of 206-A. A mixture of ethyl 3-bromo-2-oxopropanoate (10.8 g, 55.3 mmol) and pyrazin-2-amine (5.0 g, 52.6 mmol) in DME (150 mL) was stirred at room temperature for 5 h. The precipitate was collected by filtered. Then the cake was dissolved in EtOH (100 mL) and stirred at 80 oC for 2 h. The solvent was removed in vacuo. The residue was purified by column chromatography on silica gel (PE : EtOAc = 2 : 1~ 1 : 2) to give 206-A (2.0 g, 20%) as a yellow solid.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Pyrazin-2-amine, its application will become more common.

Reference:
Patent; RODIN THERAPEUTICS, INC; JEFSON, Martin, R.; LOWE, John, A., III; DEY, Fabian; BERGMANN, Andreas; SCHOOP, Andreas; FULLER, Nathan, Oliver; (165 pag.)WO2017/7756; (2017); 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. 4949-13-7, name is 2-Fluoropyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. SDS of cas: 4949-13-7

Butyl lithium solution (2.5 M in hexane, 881 mL, 2.01 mol) and 1.5 L of dry THF were charged into a flame-dried 5.0 L round bottomed flask. The flask was cooled to -50 0C and 2,2,6,6-tetramethylpiperidine (312.0 mL, 2.20 mol) was added dropwise . The reaction mixture was warmed to 0 0C without taking the cold bath away and kept at that temperature for 20 min. The reaction was then cooled to -78 0C, and 2-fluoropyrazine (180 g, 1.84 mol) in 150 mL of THF was added dropwise. The mixture was kept at -78 0C for 5 min. Iodine (464 g, 1.84 mol) in 500 mL of THF was added dropwise and the reaction mixture was kept at -78 0C for 1 h. The reaction was quenched with the addition of 250 mL of concentrated HCl, 250 mL MeOH and 250 mL THF at -78 0C. The cold bath was then removed, and aqueous sodium bisulfite was added to get rid of traces of unreacted iodine. The solvent was evaporated and the residue was diluted with water and adjusted to pH 8. The mixture was extracted with ethyl acetate (3 x 1.5 L). Combined ethyl acetate layer was dried over sodium sulfate and concentrated. The crude product was purified by column chromatography (Silica: 100-200 mess, solvent: 10% EtOAc/hexanes) to give the title compound as a white solid.

The synthetic route of 4949-13-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; AMGEN INC.; ALLEN, Jennifer R.; BOURBEAU, Matthew P.; CHEN, Ning; HU, Essa; KUNZ, Roxanne; RUMFELT, Shannon; WO2010/57121; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 2423-65-6, A common heterocyclic compound, 2423-65-6, name is Pyrazine 1-oxide, molecular formula is C4H4N2O, 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: Synthesis of meso-substituted calixarenes 4a-f (general procedure). A 1.6 M solution of BunLi in hexane (1.44 mL, 2.3 mmol) was added to a vigorously stirred solution of TMEDA (0.43 mL, 2.9 mmol) in anhydrous THF (4 mL) cooled to -78 C. After 40 min of stirring, a solution of 25,26,27,28-tetramethoxycalix[4]arene (480.5 mg, 1.0 mmol) in anhydrous THF (5 mL) was added, the reaction mixture was warmed up to room temperatures and stirred for another 2 h. The solution of formed 2-lithium-25,26,27,28-tetramethoxycalix[4]arene (1) was cooled to -78 C, and a solution of the corresponding azine N-oxide 2a-f (2.0 mmol) in anhydrous THF (6 mL) was added. The reaction mixture was stirred at room temperature for 1 h, followed by the addition of AcCl (0.14 mL, 2.0 mmol). The mixture was concentrated at reduced pressure. The residue was subjected to column chromatography on SiO2, the eluate was concentrated dry in vacuo.

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:
Article; Varaksin; Chupakhin; Charushin; Khlamkin; Utepova; Russian Chemical Bulletin; vol. 64; 5; (2015); p. 1093 – 1096; Izv. Akad. Nauk, Ser. Khim.; 5; (2015); p. 1093 – 1096,4;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 5049-61-6, 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. 5049-61-6 name is Pyrazin-2-amine, 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.

Step 1 ) Formation of 5-Bromopyrazin-2-amine N-bromosuccinimide (22.4 g, 0.126 mol) was added portionwise to a stirred solution of 2-Aminopyrazine (15 g, 157 mmol) in CCI4 (500 ml.) at O0C. The reaction mixture was stirred at RT under nitrogen atmosphere. After 3 hours, the reaction mixture was filtered and the filtrate was concentrated under vacuum. The crude material was purified by flash chromatography on silica (PE:EtOAc) to give the title compound as a yellow solid. LC/MS (Atlantis), M+(ESI): 173.8.1H-NMR (DMSO-d6, 400 MHz) delta 8.01 (1 H, s), 7.66-7.67 (1 H, s), 6.63 (2H, brs).

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

Reference:
Patent; MERCK SERONO S.A.; SWINNEN, Dominique; JORAND-LEBRUN, Catherine; GRIPPI-VALLOTTON, Tania; GERBER, Patrick; GONZALEZ, Jerome; SHAW, Jeffrey; JEYAPRAKASHNARAYANAN, Seenisamy; WO2010/100144; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem