Tag: M.W=200-300

24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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. 24241-18-7

A solution of 2-amino-3,5-dibromopyrazine (obtained as described in Gazz. Chim. Ital., 1960, 90, 1807) (1.26 g) and sodium ethoxide (0.4 g) in ethanol (50 ml) was heated under reflux for 4 hours. Volatile material was removed by evaporation and the residue was partitioned between water (20 ml) and ethyl acetate (50 ml). The organic layer was separated and dried (MgSO4). Volatile material was removed by evaporation to give 2-amino-5-bromo-3-ethoxypyrazine (0.95 g); 1 H NMR (d6 -DMSO): 1.4 (t, 3H), 4.3 (q, 2H), 6.4 (br s, 2H), 7.6 (s, 2H); mass spectrum (+ve CI): 218 (M+H)+.

Statistics shows that 24241-18-7 is playing an increasingly important role. we look forward to future research findings about 2-Amino-3,5-dibromopyrazine.

Reference:
Patent; Zeneca Limited; US5861401; (1999); A;,
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. 23229-25-6, name is 2,6-Dibromopyrazine, This compound has unique chemical properties. The synthetic route is as follows., 23229-25-6

the molar ratio of Sodiummethoxide and dibromopyrazine is 5:1 placed into three-necked flask with astirrer and a thermometer, added 500ml of Distilled water, start the mixer andwith speed of 200r / min it was stirredfor 10min; After the mixing the mixture was placed at reflux apparatus , heatedup to 60 C, refluxed for 2h, , the collected reflux liquid was put into abeaker then placed in an ice-water bath , at 4 C under ice the precipitatewas allowed to stand for 2h, filtered toobtain precipitate and spare after rotary evaporation drying; The massconcentration of concentrated sulfuric acid is 98% and after drying as mentioned above the precipitatemass ratio is 12: 1 were mixed andtogether poured into a beaker of 500mL, after stirred with a glass rod for10min placed on the shaker and Oscillating reaction for 2 h ,then againadded 50mL of nitric acid solution with a mass concentration of 95% , continues to oscillate the reaction for 20minto obtain a mixed solution; The ratio of the mixed liquid and ammonia water is1:5, the ammonia water was poured into the above mentioned mixed solution, placedthe reaction solution on a magnetic stirrer, with speed of 600r / min it was stirred for 10s , afterwards reduce speed to200r / min and continue to stir for 30min. After completion of the stirring,400ml of anhydrous ethanol added into the mixture solution, placed intoultrasonic vibration device, ultrasonic vibration reaction for 1h, thentransferred to a distillation apparatus, heated to 60 C, ethanol was removedby distillation,for drying used vacuum freeze-drying machine and after crushingof solid particles; Take 1g of the above mentioned solid particles and put into100ml of beaker , added 15ml of glacial acetic acid and 10ml of hydrogenperoxide with a mass concentration of 30%, water bath warmed to 40 C, andafter the 6hrs of reaction filtrated to obtain precipitate and dried to obtain 2,6-diamino-3,5-dinitro-1-oxidepyrazine.

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; Changzhou University; CHEN, Xing-quan; (5 pag.)CN105399690; (2016); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 1458-16-8 as follows. 1458-16-8

To a mixture under argon of 0.5 mmol of intermediate -if-,0.025 mmol of Cul and 1 mmol of potassium carbonate in a small thick glass reactor (Ace Tube) , are successively added 1 mL of isopropanol, 1 mmol of ethylene glycol and 0.75 mmol of thiophenol. The reactor is sealed with a Teflon stopper, placedunder magnetic stirring and heated two hours at 80C. The reaction mixture is cooled to room temperature and the thus obtained precipitate isolated through filtration, washed and recrystallized from hot methanol (yield : 88%)LCMS (IE, m/z): (M+1) 248; ?H NMR: oH ppm 400 MHz, DMSO: 7.19 -7.14 (3H, m, CHarom.) , 7.30-7.26 (2H, m, CHarom.) , 7.97 (1H, 5,CHarom)

According to the analysis of related databases, 1458-16-8, the application of this compound in the production field has become more and more popular.

Reference:
Patent; PIERRE FABRE MEDICAMENT; KALOUN, El Bachir; BEDJEGUELAL, Karim; MORDANT, Celine; RABOT, Remi; TAMBURLIN, Isabelle; FOURNIER, Emmanuel; SCHMITT, Philippe; (74 pag.)WO2016/207345; (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. 1458-18-0, name is Methyl 3-amino-5,6-dichloropyrazine-2-carboxylate, This compound has unique chemical properties. The synthetic route is as follows., 1458-18-0

The pyrazine (24.8 gm, 9.66 X 10″2 moles) was stirred in pyridine (200 mL) as benzoyl chloride (33.9 gm, 0.241 moles) was added in 3 portions. This solution was stirred at 65C overnight. After cooling, the pyridine was removed under reduced pressure and the remaining material was dissolved in methylene chloride (400 mL) and water (200 mL) was added. To this mixture was added potassium carbonate until the aqueous was basic to litmus. The methylene chloride solution was isolated and washed with 2% HCl (250 mL.). The solution was then dried over magnesium sulfate. After filtration, the solvents were removed under reduced pressure. The remaining material was stirred with diethyl ether (200 mL) causing the product to crystallize. The solid product was isolated by filtration. After washing with diethyl ether and drying the imide was obtained as a grey solid in a yield of 36.8 gm (82%).

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; JANUS BIOTHERAPEUTICS, INC.; LIPFORD, Grayson, B.; ZEPP, Charles, M.; WO2012/167046; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 132426-19-8, name is 2-Bromo-1-(pyrazin-2-yl)ethanone, 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 132426-19-8, 132426-19-8

Example 76N-(2-amino-phenyl)-4-[4-(4-pyrazin-2-yl-1H-imidazol-2-yl)-tetrahydro-pyran-4-yl]-benzamide; 4-(4-Cyano-tetrahydro-pyran-4-yl)-benzoic acid methyl ester (1.0 g, 4.08 mmol) was suspended in 4.0N NaOH and heated at 110 C. for 1 hour. After the reaction was complete, 2N HCl was slowly added to form a precipitate. The precipitate was then filtered, dried under vacuum, and used for next step without purification. 4-(4-Carboxy-phenyl)-tetrahydro-pyran-4-carboxylic acid (0.4 g, 1.6 mmol) was dissolved in NMP. HATU (1.28 g, 2.1 eq) and DIPEA (0.8 mL, 3.0 eq) were added and stirred at 50 C. for 1 hour. The reaction mixture was cooled down to room temperature and benzyl alcohol (172 mg, 1.0 eq) was added. The reaction mixture was stirred at room temperature overnight. Saturated aqueous solution of NaHCO3 was added to the mixture and was then extracted with EtOAc. The organic phase was dried, evaporated and used for next step without further purification.To a solution of 4-(4-benzyloxycarbonyl-phenyl)-tetrahydro-pyran-4-carboxylic acid (0.3 g, 0.88 mmol) and 2-bromo-1-pyrazin-2-yl-ethanone (210 mg, 1.2 eq) in acetonitrile, TEA (0.18 mL, 1.2 eq) was added and heated in the microwave at 80 C. for 1 hour. The reaction mixture was evaporated and purified by silica gel chromatography (Hex:EtOAc 25:75). 4-(4-benzyloxycarbonyl-phenyl)-tetrahydro-pyran-4-carboxylic acid 2-oxo-2-pyrazin-2-yl-ethyl ester (0.3 g, 0.65 mmol), NH4OAc (110 mg, 2.2 eq) and 3 molecular sieves were mixed together in xylene and heated in the microwave at 160 C. for 1 hour. After the reaction was done, it was extracted with EtOAc and the organic phase was dried and evaporated to be used in the next step without further purifications.Hydrogenation of 4-[4-(4-pyrazin-2-yl-1H-imidazol-2-yl)-tetrahydro-pyran-4-yl]-benzoic acid benzyl ester (0.2 mg, 0.45 mmol) in EtOH, was carried out in the presence of excess Pd/C (10%, dry basis) at a pressure of 1 atmosphere. After 16 hours, the reaction mixture was filtered through a celite pad and washed with hot ethanol. The solution was evaporated and used for next step without further purification.The above acid was then coupled with 1,2-phenylenediamine in the presence of HATU and DIPEA in DMF and purified by reverse phase chromatography to give the title compound. MS found for C25H24N6O2 as (M+H)+ 441.21 1H NMR (400 MHz, dmso-d6): 1H-NMR (DMSO) delta: 10.42 (s, 1H), 9.32 (s, 1H), 8.68-8.64 (m, 2H), 8.37 (s, 1H), 8.07 (d, J=8.4 Hz, 2H), 7.54 (d, J=8.4 Hz, 2H), 7.46-7.28 (m, 5H), 3.82-3.79 (m, 2H), 3.52-3.46 (m, 2H), 2.98-2.95 (m, 2H), 2.40-2.29 (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, 2-Bromo-1-(pyrazin-2-yl)ethanone, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Melvin, JR., Lawrence S.; Graupe, Michael; Venkataramani, Chandrasekar; US2010/22543; (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. 6966-01-4, name is Methyl 3-amino-6-bromopyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., 6966-01-4

K2CO3 (0.89 g, 6.46 mmol) was added to a solution of methyl 3-amino-6-bromopyrazine- 2-carboxylate (0.75 g, 3.23 mmol) in anhydrous DME (15 ml) in a pressure tube. Trimethylboroxine (0.99 ml, 3.56 mmol) was added then the resulting brown suspension was de-gassed by bubbling a stream of nitrogen through the reaction mixture for 5 min. Pd(dppf)2C (0.13 g, 0.16 mmol) was added then the pressure tube was flushed with nitrogen and sealed. The reaction was stirred at 100 C for 16 h then allowed to cool to RT. The resulting suspension was filtered then the solid thus obtained was washed with EtOAc (20 ml). The combined filtrate was concentrated in vacuo. The crude material was purified by flash column chromatography on a silica column (50 g). The column was eluted with EtOAc: heptane, increasing the gradient linearly from 0:100 to 50:50 over 10 column volumes. The desired fractions were combined and evaporated to yield the product as a light yellow solid (470 mg, 87%).1H NMR (250 MHz, DMSO-de) delta 8.18 (s, 1 H), 7.11 (s, 2H), 3.83 (s, 3H), 2.33 (s, 3H). LC/MS (System A): m/z (ESI+) = 168 [MH+], Rt = 0.68 min, UV purity = 100%.

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; ENTERPRISE THERAPEUTICS LIMITED; MCCARTHY, Clive; HARGRAVE, Jonathan David; HAY, Duncan Alexander; SCHOFIELD, Thomas Beauregard; WENT, Naomi; (111 pag.)WO2017/221008; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

87486-34-8, Adding some certain compound to certain chemical reactions, such as: 87486-34-8, name is 3,5-Dibromo-1-methylpyrazin-2(1H)-one, 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 87486-34-8.

A solution of 3,5-dibromo-1-methylpyrazin-2-one (500.0 mg, 2.46 mmol), NH3H2O (5.0 mL) in dioxane (30.0 mL) was heated at 105¡ã C. for 20 h. The mixture was concentrated, diluted with EtOAc (50 mL) and filtrated to give the title compound (300.0 mg, 79.0percent) which was carried on without purification. LCMS (M+H)+ 204.

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 87486-34-8.

Reference:
Patent; Bennett, Michael John; Betancort, Juan Manuel; Boloor, Amogh; Kaldor, Stephen W.; Stafford, Jeffrey Alan; Veal, James Marvin; US2015/111885; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 957344-74-0, name is 5,8-Dibromoimidazo[1,2-a]pyrazine, molecular formula is C6H3Br2N3, 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. 957344-74-0

Step 3 4-(5-Bromoimidazo[l,2-a]pyrazin-8-ylamino)-N-(2-diethylaminoethyl) benzene sulfonamide[00262] A mixture of 5,8-dibromoimidazo[l,2-a]pyrazine (1.Og, 3 6mmol), 4-amino-N-(2- diethylaminoethyl)benzenesulfonamide (109mg, 0 4mmol), Pd2(dba)3 (7mg, 0.007mmol), Xantphos(8.4mg, 0.015mmol) and Cs2CO3 (167mg, 0 52mmol) in dioxane is heated at 850C under nitrogen for 18 hours The reaction is cooled to room temperature then evaporated to dryness The residue is chromatographed on silica gel, elutmg with DCM then 98 2 DCM NH3 (7N m MeOH), and the fractions containing the title compound are combined and evaporated to afford a dark oil This oil contains an impurity, but is used in the subsequent step without further purification

The chemical industry reduces the impact on the environment during synthesis 5,8-Dibromoimidazo[1,2-a]pyrazine. I believe this compound will play a more active role in future production and life.

Reference:
Patent; GALAPAGOS N.V.; WO2007/131991; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

1458-16-8, 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. 1458-16-8 name is Methyl 3-amino-6-iodopyrazine-2-carboxylate, 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.

Example 3b: 3-amino-6-iodopyrazine-2-carboxamide 30 ml of ammonia in water is added under magnetic stirring to 15 g (53.8 mmol) of a solution of methyl 3-amino-6-iodopyrazine-2-carboxylate in 150 ml of methanol. The reaction medium is stirred at 25C for 48 hours. After evaporation of the solvents, the precipitate obtained is filtered, rinsed with water and then dried at 50C to yield 12.50 g of 3-amino-6-iodopyrazine-2-carboxamide (88%) in the form of a beige solid. LCMS (EI, m/z): (M+l) 265.02 1H NMR: deltaEta ppm (400 MHz, DMSO): 8.35 (1H, s, CHarom), 7.85 (1H, bs, NH), 7.60 (3H, bs, NH), 3.25 (3H, s, CH3).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Methyl 3-amino-6-iodopyrazine-2-carboxylate, and friends who are interested can also refer to it.

Reference:
Patent; PIERRE FABRE MEDICAMENT; KRUCZYNSKI, Anna; CREANCIER, Laurent; KALOUN, El Bachir; BEDJEGUELAL, Karim; RABOT, Remi; WO2014/16434; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem