Month: November 2020

113305-94-5, The chemical industry reduces the impact on the environment during synthesis 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, I believe this compound will play a more active role in future production and life.

To a stirred mixture of 5-aminopyrazine-2-carbonitrile (131 mg, 1.09 mmol) in THF (8 mL) was slowly added sodium hydride (73 mg, 1.82 mmol) below 15 C. The resulting mixture was stirred at room temperature for 1 hour and compound 207 (302 mg, 0.91 mmol) was added. The reaction mixture was then stirred at 60 C for 4 hours, quenched with ice-water, and extracted with ethyl acetate. The organic layer was dried over Na2504 and concentrated to afford the title compound 208 (280 mg, crude) as a yellow solid.

The chemical industry reduces the impact on the environment during synthesis 113305-94-5. I believe this compound will play a more active role in future production and life.

Reference:
Patent; PHARMAENGINE, INC.; CAI, Xiong; QIAN, Changgeng; WANG, Yanong Daniel; (98 pag.)WO2017/132928; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

6705-33-5, The chemical industry reduces the impact on the environment during synthesis 6705-33-5, name is Pyrazin-2-ylmethanol, I believe this compound will play a more active role in future production and life.

To a solution of pyrazin-2-ylmethanol (550 mg, 5 mmol, 1 equiv) and triethylamine (1.52 mL, 11 mmol, 2.2 equiv) in DCM (15 mL) was added MsCl (1.26 g, 11 mmol, 2.2 equiv) dropwise. The resulting mixture was stirred at room temperature for 2 hours. The reaction mixture was diluted with water and extracted with DCM (3*50 mL). The combined organic phase were dried over MgSCL and concentrated in vacuo to afford the title compound pyrazin-2-ylmethyl methanesulfonate as a yellow solid which was used for the next step without any further purification (940 mg crude). LC-MS: m/z 189.0 (M+H)+

The chemical industry reduces the impact on the environment during synthesis Pyrazin-2-ylmethanol. I believe this compound will play a more active role in future production and life.

Reference:
Patent; ANNAPURNA BIO INC.; TANG, Haifeng; BOYCE, Sarah; HANSON, Michael; NIE, Zhe; (213 pag.)WO2019/169193; (2019); 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. 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, A new synthetic method of this compound is introduced below., 875781-43-4

Step 1. 2-Bromo-5-trityl-5H-pyrrolo[2,3-b]pyrazine. At 40 C., a solution of 2-bromo-5H-pyrrolo[2,3-b]pyrazine (725 mg, 3.66 mmol) and cesium carbonate (3250 mg, 9.95 mmol) in DMF (20.0 mL) was treated with trityl chloride (925 mg, 3.32 mmol). After 2 hours, the reaction mixture was cooled to ambient temperature and poured onto water (150 mL). The mixture was filtered and the filter cake was triturated with water (250 mL) for 1 hour. The solid was isolated and recrystallized from hot ethanol to afford 2-bromo-5-trityl-5H-pyrrolo[2,3-b]pyrazine (750 mg, 52%) as a colorless crystalline solid. LC/MS (M+H) 440.16.

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; Thorarensen, Atli; Brown, Matthew Frank; Casimiro-Garcia, Agustin; Che, Ye; Coe, Jotham Wadsworth; Flanagan, Mark Edward; Gilbert, Adam Matthew; Hayward, Matthew Merrill; Langille, Jonathan David; Montgomery, Justin Ian; Telliez, Jean-Baptiste; Unwalla, Rayomand Jal; US2015/158864; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 5049-61-6, name is Pyrazin-2-amine, 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. 5049-61-6

Example 2 Synthesis of 3,5-dibromopyrazine-2-ylamine 11.2 ml of bromine in 38 ml of acetic acid were slowly added at 15 C., while stirring, to a solution of 2-aminopyrazine (9.5 g, 100 mmol) and sodium acetate trihydrate (32.6 g) in 150 ml of acetic acid. The addition required about 1-2 hours and it was carried out in the dark. The reaction mixture was stirred at room temperature overnight. The solution was concentrated in vacuo and the brown viscous residue was poured into ice water (150 ml) under stirring. Aqueous 20% sodium hydroxide was added in order to obtain a pH of 8 and extracted with ethyl acetate (4*75 ml). The combined organics were washed with water (2*50 ml) and brine (1*50 ml), dried and concentrated. The crude product was purified by column chromatography (2:1 hexanes and ethyl acetate) to provide the desired compound. HPLC: 8.7 min (98% pure) MS: MH+=251.8 C4H3Br2N3=250.8 g/mol

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, 5049-61-6, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Nuss, John M.; Ramurthy, Savithri; US2001/34051; (2001); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, 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. 27398-39-6

Intermediate 17 (50 mg, 0.079 mmol) was dissolved in NMP (300 uL) and N-ethyl-N- isopropylpropan-2-amine (41.3 mu, 0.237 mmol) and 3-chloropyrazine-2-carboxylic acid (13.78 mg, 0.087 mmol) were added, followed by HATU (36.1 mg, 0.095 mmol). The reaction was allowed to stand for 10 min and then analysed by LCMS and found to be complete. 2,2,2-Trifluoroacetic acid (151 mu, 1.975 mmol) was added and the mixture heated at 120 ¡ãC for 20 min. The mixture was poured into water and extracted with DCM. The organics were dried, filtered and evaporated to give a gum which was purified by RP HPLC (solvent B – minimum 10percent, intermediate 55percent, maximum 95percent) to give compound 48 as a white solid (10 mg, 24percent).

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 27398-39-6.

Reference:
Patent; JANSSEN PHARMACEUTICA NV; VAN BRANDT, Sven, Franciscus, Anna; GIJSEN, Henricus, Jacobus, Maria; VOS, Ann, Marleen; OEHLRICH, Daniel; (77 pag.)WO2018/162445; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

24241-18-7, A common compound: 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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.

A mixture of 3,5-dibromopyrazin-2-amine (214 mg, 0.83 mmol) and phenyl boronic acid (100 mg, 0.8 mmol) in toluene (8 mL) was degassed and backfilled with nitrogen 3 times. Pd(PPtLs)4 (46 mg) was added followed by 2M K3PO4 (0.8 mL) and EtOH (1 mL). The mixture was heated at reflux for 18 h. The solution was cooled to room temperature, partitioned between EtOAc (25 mL) and water (5 mL). The layers were separated and the organic layer dried over Na2SO4, filtered and concentrated to an oil which was purified via silica gel chromatography (15% EtOAc/heptane) to afford the product (187 mg, 95% yield)

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-3,5-dibromopyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; BRISTOL-MYERS SQUIBB COMPANY; WO2009/155388; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 1458-03-3, name is Methyl 3-amino-6-chloropyrazine-2-carboxylate, molecular formula is C6H6ClN3O2, 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. 1458-03-3.

Into a 500 ml three-necked flask, 100 mL of acetic acid was added, and Compound 2 (20 g, 0.11 mol) was added dropwise to a 100 mL aqueous solution of 40% hydrogen bromide at 0C. The reaction was completed after 30 minutes of dropwise addition. A 50 ml aqueous solution of sodium nitrite (20.7 g, 0.33 mol) was added dropwise at a controlled temperature of 0C. After 30 minutes of reaction, the reaction is complete and it is quenched by the dropwise addition of 30 ml of 10% sodium bisulfite solution. Ethyl acetate extraction (200ml¡Á2), dried over 20g of anhydrous sodium sulfate, The mixture was concentrated by suction filtration to obtain a white solid compound 3 (23.3 g, yield 87%).

The synthetic route of Methyl 3-amino-6-chloropyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Shaoyuan Science And Technology (Shanghai) Co., Ltd.; Shanghai Shaoyuan Reagent Co., Ltd.; Wei Yuanbo; Guo Tao; Wu Yong; (8 pag.)CN108101857; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-25-1, 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. 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, This compound has unique chemical properties. The synthetic route is as follows.

. Methyl 5-chloropyrazine-2-carboxylate (2.0 g, 1 eq., 11.6 mmol) was dissolved in MeOH (15 mL) and the solution was cooled to 0C. Sodium borohydride (1.1 g, 2.5 eq., 29 mmol) was slowly added and the reaction mixture was stirred at room temperature for 1 h. The reaction mixture was quenched with a saturated solution of NH4Cl (15 mL) and extracted with DCM (215 mL). The organic extracts were dried over Na2SO4 and concentrated in vacuo to furnish the crude product, which was purified by flash chromatography eluting with cyclohexane/EtOAc (0 to 60%) to give the pure title compound as colourless oil (1.59 g, 95%). 1H NMR (400 MHz, DMSO-d6): delta 8.73 (d, J=1.4 Hz, 1H), 8.54 (d, J=1.3 Hz, 1H), 5.68 (t, J=5.8 Hz, 1H), 4.65 (d, J=5.7 Hz, 2H).

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; FONDAZIONE ISTITUTO ITALIANO DI TECNOLOGIA; BERTOZZI, Fabio; BANDIERA, Tiziano; PONTIS, Silvia; REGGIANI, Angelo; GIACOMINA, Francesca; DI FRUSCIA, Paolo; US2019/135778; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 5049-61-6, name is Pyrazin-2-amine, molecular formula is C4H5N3, 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.

To a solution of 2-amino pyrazine (2Og, 210 mmol) in dimethoxy ethane (400 ml) was added ethyl bromopyruvate (32.8 ml) at 25C and the resulting reaction mixture was allowed to stir at the same temperature for 4 hrs . It was then cooled to O0C and stirred for 30 minutes. The separated solid was filtered and washed with ether. Solid residue was taken in ethanol (1000ml) and refluxed for 4hrs. Solvent was removed completely, residue taken in chloroform (1000ml), saturated sodium bicarbonate solution (700 ml) was added to it and the mixture was allowed to stir for 45 minutes . The mixture was filtered through celite bed, washed several times with chloroform and filtrate was dried over sodium sulfate. Evaporation of the organic layer under reduced pressure gave the crude mass, which was purified by crystallization using ether-methanol mixture. Yield : 20%

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; GRUeNENTHAL GMBH; WO2009/90055; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

875781-43-4, 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. 875781-43-4 name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, 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.

The compound 2-bromo-5H-pyrrolo [2,3-b] pyrazine (3.00 g, 15.0 mmol) was dissolved in 1,4-dioxane(60 mL), sodium hydroxide solution (2.0 M, 15.0 mL) and formaldehyde solution (37%, 11.4 mL) were added successively, and the mixture was stirred at room temperature night. The reaction solution was concentrated to give a brown oil which was adjusted to pH = 7 with HCl (1.0 M), precipitated with a pale yellow solid, filtered, The filtrate was extracted with EtOAc / MeOH (v / v) = 5/1, 20 mL x 2) and the organic phase was concentrated and the cake was combined and evaporated to dryness to give 4.0 g of yellow Color solid, yield: 99.0%.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, and friends who are interested can also refer to it.

Reference:
Patent; Guangdong East Sunshine Pharmaceutical Co., Ltd; Liu, Bing; Huang, Jiuzhong; Zhang, Yingjun; Xue, Yaping; Xing, Wei; Xu, Juan; Wu, Zuping; Yu, Tianxi; (106 pag.)CN106432246; (2017); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem