Tag: M.W=100-200

274-79-3, A common compound: 274-79-3, name is Imidazo[1,2-a]pyrazine, 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.

Step 1 The indole obtained [1,2-A] pyrazine (10g, 0.08mmol) was dissolved in 100mL of ethylene glycol monomethyl ether, was added 5% palladium on carbon (2G), quickly replaced with hydrogen three times, at room temperature (20-25 ) The reaction was stirred, TLC detection reaction process, the reaction is complete after 30 hours, suction filtered through celite pad, and the filtrate was concentrated by rotary evaporation and purified by column chromatography by chromatography to give 5,6,7,8- hydrogen-imidazo [1,2-A] pyrazine 7g, the the yield of about 68%

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, Imidazo[1,2-a]pyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; shanghai bide pharmatech co. ltd; LI, JINFEI; HUANG, LIANGFU; LI, XINLING; WANG, MINGXIA; (5 pag.)CN103864799; (2016); B;,
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. 3149-28-8, name is 2-Methoxypyrazine, This compound has unique chemical properties. The synthetic route is as follows., 3149-28-8

General procedure: A magnetically stirred solution of xanthate (2.0 equiv) and pyrazine (1.0 equiv) in 1, 2-dichloroethane (1.0mmol/mL according to the xanthate) was refluxed for 15min under a flow of nitrogen. Then dilauroyl peroxide (DLP) was added portionwise (20mol % according to the xanthate) every hour until total consumption of one substrate. The reaction mixture was then cooled to room temperature and the solvent was evaporated under reduced pressure. Unless otherwise specified, the crude product was purified by flash chromatography on silica gel.

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; Huang, Qi; Qin, Ling; Zard, Samir Z.; Tetrahedron; vol. 74; 40; (2018); p. 5804 – 5817;,
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. 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, A new synthetic method of this compound is introduced below., 113305-94-5

Synthesis 1C (S)-tert-Butyl 2-((2-(5-cyanopyrazin-2-ylamino)-5-(trifluoromethyl)pyridin-4-carboxylate S)-tert-Butyl 2-((2-chloro-5-(trifluoromethyl)pyridin-4-ylamino)methyl)morpholine-4- carboxylate (4.67 g, 1 1.8 mmol), 2-amino-5-cyanopyrazine (1.98 g, 16.5 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.86 g, 0.94 mmol), rac-2,2′- bis(diphenylphosphino)-1 ,1 ‘-binaphthyl (0.54 g, 0.87 mmol) and caesium carbonate (7.69 g, 23.6 mmol) were suspended in anhydrous dioxane (108 ml_) under argon. Argon was bubbled through the mixture for 30 minutes, after which the suspension was heated to 100C for 29 hours. The reaction mixture was cooled and diluted with dichloromethane, then absorbed onto silica gel. The pre-absorbed silica gel was added to a 340 g KP-Sil SNAP column which had been equilibrated with 20% ethyl acetate in hexane. Column chromatography, eluting with a gradient of 20-35% ethyl acetate in hexane, gave partially purified material as an orange gum. This was further purified by column chromatography, eluting with 20% ethyl acetate in dichloromethane, to give the title compound as a light tan powder (3.28 g, 58%). H NMR (500 MHz, CDCI3) delta 1.49 (9H, s), 2.73-2.86 (1 H, m), 2.94-3.07 (1 H, m), 3.26- 3.31 (1 H, m), 3.38-3.43 (1 H, m), 3.57-3.61 (1 H, m), 3.70-3.75 (1 H, m), 3.83-4.08 (3H, m), 5.31 (1 H, broad s), 7.12 (1 H, s), 8.13 (1 H, s), 8.23 (1 H, s), 8.57 (1 H, s), 8.87 (1 H, s). LC- MS (Agilent 4 min) Rt 2.90 min; m/z (ESI) 480 [MH+].

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; CANCER RESEARCH TECHNOLOGY LIMITED; COLLINS, Ian; MATTHEWS, Thomas Peter; FARIA DA FONSECA MCHARDY, Tatiana; OSBORNE, James; LAINCHBURY, Michael; WALTON, Michael Ian; GARRETT, Michelle Dawn; WO2013/171470; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

486460-21-3, 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. 486460-21-3, name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine, A new synthetic method of this compound is introduced below.

The dihydroformed product prepared in Example 7 (1.5 g, 3.1 mmol) was added to 60 mL of 2N HCl,Reflux for 12 hours.Ice water bath cooling,The bottom of the yellow oil precipitation,Pour the upper water,The lower oily substance was dissolved in dichloromethane,A small amount of saturated sodium bicarbonate washing,Dispensing,After the organic phase is dried,With a rotary evaporator evaporated to dry yellow liquid,Directly take the next step.Ice water bath,A small amount of the above crude product (0.6 g, 1.4 mmol) was dissolved in dichloromethane (10 mL)Plus DIPEA (Chinese name: N, N-diisopropylethylamine, 452 mg, 3.5 mmol)And 1-hydroxybenzotriazole (19 mg, 0.14 mmol)Trimethylacetyl chloride (210 mg, 1.75 mmol) was then added dropwise.After 0.5 hours,A solution of 3- (trifluoromethyl) -5,6,7,8-tetrahydro- [1,2,4] triazolo [4,3-a] pyrazine (CAS No. 486460-21-3, 296 mg, 1.54 mmol),Continue stirring at room temperature overnight.The next day,Washed,Saturated sodium bicarbonate wash,Organic phase dry,With a rotary evaporator to dry the crude product,1.14 g (yield: 67%, HPLC purity 99%) was obtained by recrystallization (petroleum ether / ethyl acetate = 20/1) as a white solid amidated product.

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; Zhejiang Xinhecheng Co., Ltd.; Zhejiang University; Zhang Yuhong; Yao Jinzhong; Qian Hongsheng; Lin Cong; Lu Guobin; Tang Jiaxing; Shen Chuang; (15 pag.)CN103819475; (2017); B;,
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. 123-32-0, name is 2,5-Dimethylpyrazine, A new synthetic method of this compound is introduced below., 123-32-0

General procedure: Using a nitrogen-filled glove box, an oven-dried Schlenk tube (100mL volume) was charged with a magnetic stirring bar, MnO2 (0.05mmol), KOH (0.5mmol), alcohols (1) (0.55mmol), heteroarenes (2) (0.5mmol) and t-AmOH (1mL). Then the Schlenk tube was closed tightly with a Teflon cap, removed from the glove box. A reflux condenser was evacuated and refilled with dry air and then attached to the Schlenk tube maintaining dry air stream. A bubble counter was attached to the top of the condenser and the whole system was purged with dry air for 15s. The Schlenk tube was immersed into a pre-heated oil bath (design temperature). After design time the reaction was cooled, a small aliquot of the organic phase was analyzed by GC or GC-MS to monitor product formation. Purification of the remainder by column chromatography on silica gel (petroleum ether/ethyl acetate=20/1-5/1) gave the corresponding products in the reported yield.

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; Zhang, Chunyan; Li, Zehua; Fang, Yanchen; Jiang, Shaohua; Wang, Maorong; Zhang, Guoying; Tetrahedron; vol. 76; 11; (2020);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 486460-21-3, name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine, molecular formula is C6H7F3N4, 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. 486460-21-3

Step: 20aSynthesis of 7-(4-Nitro-phenyl)-3-trifluoromethyl-5,6,7,8-tetrahydro-[l,2,4]triazolo[4,3- ajpyrazine.Procedure:K2C03 (4.4g, 0.053mol), followed by l-Fluoro-4-nitro-benzene (1.5g, 0.0177mol) was added to a solution of 3-Trifluoromethyl-5,6,7,8-tetrahydro-[l,2,4]triazolo[4,3- a]pyrazine (3.2g, 0.0230mol) in DMF (15ml), and the flask was stirred for 6hrs at 80C. The reaction was monitored by the TLC (20% ethylacetate in hexane). From the resulting reaction mixture DMF was distilled, the residue was purified by column chromatography (using silica gel of mesh size of 60-120, 20% ethylacetate in hexane as eluant) to afford 1.2g (36.36% yield) of 7-(4-Nitro-phenyl)-3-trifluoromethyl-5,6,7,8-tetrahydro-[l ,2,4]triazolo[4,3- ajpyrazine.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 486460-21-3, its application will become more common.

Reference:
Patent; AURIGENE DISCOVERY TECHNOLOGIES LIMITED; SENGUPTA, Saumitra; RAJAGOPALAN, Srinivasan; BELAVAGI, Ningaraddi; RAMACHANDRA, Muralidhara; WO2012/59932; (2012); 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. 23611-75-8, name is Methyl 6-chloropyrazine-2-carboxylate belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below. 23611-75-8

A solution of 6-chloro-pyrazine-2-carboxylic acid methyl ester (690 mg, 4.0 mmol, l eq), Me6Sn2 (1.0 mL, 4.82 mmol, 1.2 eq) and Pd(PPh3)4 (231 mg, 0.20 mmol, 0.05 eq) in toluene (20 mL) was heated at 80 C for 12 h under nitrogen atmosphere. The mixture was cooled to rt and was concentrated. The residue was purified by chromatography on a silica gel column (EAJ PE = 1/5) to give 6-trimethylstannanyl-pyrazine-2-carboxylic acid methyl ester (360 mg, 30%) as a yellow oil.

The synthetic route of 23611-75-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; LIFESCI PHARMACEUTICALS, INC.; MCDONALD, Andrew; WO2015/103317; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 33332-29-5, name is 2-Amino-5-chloropyrazine, 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 33332-29-5, 33332-29-5

4-(6-chloroimidazo[l,2-a]pyrazin-2-yl)-N,N-dimethylbenzenamine (L21).; In a double necked round bottomed flask equipped with condenser and under nitrogen flow were introduced 5-chloro-2-amino-pyrazine (61 mg, 0.47 mmol), 2-bromo-4′-dimethylamino- acetophenone (170 mg, 0.71 mmol) and anhydrous acetonitrile (7 mL). The reaction mixture was refluxed for 3 hrs. After it cooled down, NaHCO3 (71 mg, 0.85 mmol) was added. The reaction was refluxed for another 6 hrs. The solvent was removed and the crude product (221 mg) was purified by FCC (hex/DCM/AcOEt = 2:2:1), to afford 9 mg (yield 7%) of the product as yellow solid. 1H NMR (270 MHz; CDCl3), delta 8.82 (s, IH, Ar-H), 8.09 (s, IH, Ar- H), 7.822 (s, IH, Ar-H), 7.818 (d, 3JHH = 8.9 Hz, 2H, Ar-H), 6.77 (d, 3JHH = 8.7 Hz, 2H, Ar- H), 3.02 (s, 6H, NCH3). m/z (CI-MS): 273 ([M+l] +), 261, 239 ([M-Cl +I] +).; Imidazopyrazine L21 was synthesized from condensation of chloropyrazine P13 and bromoacetophenone Bl (eq 9). The amine 67 was very unreactive though it is very soluble in acetonitrile. Long reaction time and stronger bases such as triethylamine were examined with limited success

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, 2-Amino-5-chloropyrazine, 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

27398-39-6, Adding a certain compound to certain chemical reactions, such as: 27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, 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 27398-39-6.

3-Chloropyrazin-2-carboxylic acid (1 equiv.) was dissolved in abs. dichloromethane (10 ml/mmol), and triethylamine (3 equiv.) was added. After stirring at room temperature for 5 minutes, N,N-dimethylhydrazine (1.3 equiv.) and 2,4,6-tripropyl-1,3,5,2,4,6-trioxatriphosphorinane 2,4,6-trioxide (1.5 equiv., 50percent solution in tetrahydrofuran) were added. The resulting reaction mixture was stirred at room temperature for a further 30 minutes, and then water, sat. sodium hydrogencarbonate solution and dichloromethane were added. The aqueous phase was repeatedly extracted vigorously with dichloromethane, and the combined organic phases were then dried over magnesium sulfate, filtered and concentrated. Final purification of the resulting crude product by column chromatography gave 3-chloro-N?,N?-dimethylpyrazine-2-carbohydrazide in the form of a colorless solid. 3-Chloro-N?,N?-dimethylpyrazine-2-carbohydrazide (250 mg, 1.25 mmol) was then dissolved in abs. N,N-dimethylformamide (10 ml) under argon, and sodium hydride (60 mg, 1.50 mmol, 60percent purity) was added at room temperature. Stirring at room temperature for 15 minutes was followed by the addition of 3-(2,6-difluorophenyl)propyl bromide (352 mg, 1.50 mmol), and the resulting reaction mixture was stirred under reflux conditions for two hours. After cooling to room temperature, sat. sodium hydrogencarbonate solution, water and dichloromethane were added. The aqueous phase was repeatedly extracted vigorously with dichloromethane, and the combined organic phases were then dried over magnesium sulfate, filtered and concentrated. Final purification of the resulting crude product by column chromatography gave 3-chloro-N-[3-(2,6-difluorophenyl)propyl]-N?,N?-dimethylpyrazine-2-carbohydrazide in the form of a colorless viscous oil (118 mg, 26percent of theory).

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, 3-Chloropyrazine-2-carboxylic acid, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; BAYER CROPSCIENCE AKTIENGESELLSCHAFT; FRACKENPOHL, Jens; BOJACK, Guido; BRUeNJES, Marco; HELMKE, Hendrik; ADELT, Isabelle; LEHR, Stefan; BRUeCHNER, Peter; DITTGEN, Jan; SCHMUTZLER, Dirk; HEINEMANN, Ines; BICKERS, Udo; HILLS, Martin Jeffrey; RUIZ-SANTAELLA, Juan Pedro; STREK, Harry; DESBORDES, Philippe; (119 pag.)US2018/206495; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

19838-07-4, These common heterocyclic compound, 19838-07-4, name is 3-Methylpyrazin-2(1H)-one, 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 solution of 3-methylpyrazin-2-ol (1.5 g, 13.62 mmol) in anhydrous DMF (20 mL) was added N-bromosuccinimide (2.67 g, 14.98 mmol) at 0 C. The reaction mixture was slowly warmed to room temperature and stirred overnight. The resulting mixture was poured into water, and extracted with IPA/DCM (1/5). The combined organics were dried over anhydrous Na2S04, filtered then concentrated. The residue was purified by column chomatography with 80% ethyl acetate/hexanes to give the title compound as white solid (1.97 g, 10.42 mmol, 77% yield).Exact mass calculated for C5H5BrN20: 188.0, found: LCMS m/z = 189.0 [M+H]+; lU NMR (400 MHz, DMSO-i ) delta ppm 2.27 (d, J = 0.5 Hz, 3H), 7.73 (s, 1H), 12.3 (s, 1H).

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 19838-07-4.

Reference:
Patent; ARENA PHARMACEUTICALS, INC.; JONES, Robert M.; HAN, Sangdon; BUZARD, Daniel J.; LEHMANN, Juerg; NARAYANAN, Sanju; YUE, Dawei; WO2011/127051; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem