Month: June 2021

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. 6905-47-1, name is 2-Amino-6-methoxypyrazine, A new synthetic method of this compound is introduced below., Safety of 2-Amino-6-methoxypyrazine

(6-Methoxy-pyrazin-2-yl)-thiourea 6-Methoxy-pyrazin-2-ylamine (0.85 g, 6.8 mmol) is dissolved in ethanol (7 ml) and benzoylisothiocyanate (0.91 ml) is added dropwise. The mixture is heated to 80 C. with stirring for 10 minutes then allowed to cool to room temperature. The solvent is removed in vacuo and the resulting solid dissolved in 1M sodium hydroxide (15 ml) and heated under reflux for 1 hour. The resultant suspension is filtered and the solid washed with water and a little cold ethanol. The solid is dried in vacuo to yield the title compound.

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; Press, Neil John; Taylor, Roger John; US2004/53982; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 1458-01-1,Some common heterocyclic compound, 1458-01-1, name is Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, molecular formula is C6H7ClN4O2, 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.

Method D To a suspension of 3,5-diamino-6-chloro-pyrazine-2-carboxylic acid methyl ester (10.9 g, 53.7 mmol) in 220 ml 1,4-dioxane and water (40 ml) was added 2-chloro-5-methoxybenzene boronic acid (20 g, 107 mmol), cesium carbonate (17.5 g, 53.7 mmol) and palladium tetrakis(triphenylphosphine) (620 mg, 0.54 mmol). The reaction was heated in an oil bath at 70-75° C. for 2 hours. The reaction was then cooled and poured into 500 ml water. The resulting slurry was stirred for 10 minutes before filtering under vacuum. The beige solid collected was then slurried in 100 ml methanol, stirred for 15 minutes, then filtered, washing the filter cake with methanol and vacuum drying to afford 17.4 g of the title product. 1H-NMR (d6-DMSO): NMR (DMSO): 3.65 (s, 3H), 3.75 (s, 3H), 6.4 (br s 2H), 6.9 (d, 1H), 7.0 (dd, 1H), 7.05 (br, s, 2H), 7.4 (d, 2H). LCMS Rt=3.74 min MS m/z 309 [MH]+

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate, its application will become more common.

Reference:
Patent; Pfizer Limited; US2007/105872; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 767340-03-4, A common heterocyclic compound, 767340-03-4, name is (2Z)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-yl]-1-(2,4,5-trifluorophenyl)but-2-en-2-amine, molecular formula is C16H13F6N5O, 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.

Into a 500 ml flask were charged chloro(l,5-cyclooctadiene)rhodium(l) dimer {[Rh(cod)CI]2} (292 mg, 1.18 mmol) and (R,S) t-butyl Josiphos (708 mg, 1.3 mmal) under a nitrogen atmosphere. Degassed MeOH was then added (200 ml_) and the mixture was stirred at room temperature for 1 h. Into a 4L hydrogenator was charged the enamine amide (VII) (118 g, 0.29 mal), MeOH (1 L). The catalyst solution was then transferred to the hydrogenator. After degassing three times, the enamine amide was hydrogenated under 200 psi hydrogen at 50 C for 13 h. The obtained methanol solution was concentrated and switched to methyl t-butyl ether (MTBE) (45 ml_). Into this solution was added aqueous H3P04 solution (0.5 M, 95 ml_). After separation of the layers, 3N NaOH (35 ml_) was added to the water layer, which was then extracted with MTBE (180 ml_ + 100 ml_). The MTBE solution was concentrated and solvent switched to hot toluene (180 ml_, about 75 C). The toluene solution was then cooled to O C. The crystals were isolated by filtration to obtained Sitagliptin (I) (13 g, yield 72%, 98-99% ee);

The synthetic route of 767340-03-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; F.I.S. – FABBRICA ITALIANA SINTETICI S.P.A.; SHI, Terry; LOU, Sam; DE LUCCHI, Ottorino; PADOVAN, Pierluigi; (45 pag.)WO2019/158285; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

957230-70-5, name is 3,6-Dibromopyrazin-2-amine, 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. name: 3,6-Dibromopyrazin-2-amine

Step 1: N’-(3,6-Dibromo-pyrazin-2-yl)-N,N-dimethylformamidine(D) A mixture of 3,6-dibromo-pyrazin-2-ylamine (15.37 g, 60.80 mmol) and N,N-dimethylformamide dimethyl acetal (10.1 mL, 76.00 mmol), suspended in ethanol (150 mL), is refluxed for 2 hours. The reaction mixture is evaporated in vacuo affording the title compound. 1H-NMR (400 MHz, CDCl3) delta (ppm) 3.20 (s, 3H), 3.21 (s, 3H), 7.93 (s, 1H), 8.48 (s, 1H). LCMS: Rt 3.81 min (99.1%), m/z (APCI) 307 (M+H)+.

The synthetic route of 957230-70-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Andrews, Martin James Inglis; Chambers, Mark Stuart; Van De Poel, Herve; Bar, Gregory Louis Joseph; US2009/286798; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 69214-33-1,Some common heterocyclic compound, 69214-33-1, name is 8-Chloroimidazo[1,2-a]pyrazine, molecular formula is C6H4ClN3, 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 mixture of 8.-chIoroirnidazo[12.-a]pyrazinc (500 mg, 3.3 rnrnol) in AcOH (5 mL) was added Br2 (800 mg, 5.0 mmol) at RT. The resulting mixture was stirred at RT for 2 days, then poured into water (20 mL) and extracted with EtOAc (15 mL x 3). The combined organic layer was washed with aqueous sodium bicarbonate solution and brine, dried over MgSO,filtered and concentrated in vacuo. The residue was purified by chromatography on silica (9.?16% EtOAc in petroleum ether) to give the title compound (30() mg) as a yellow solid. LRMSm/z (M+H) 232.2, 234.1 found, 231.2, 234.1 required.

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

Reference:
Patent; MERCK SHARP & DOHME CORP.; LIVERTON, Nigel; KUDUK, Scott D.; BESHORE, Doug C.; MENG, Na; LUO, Yunfu; (127 pag.)WO2016/101119; (2016); 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. 19745-07-4, name is 2,5-Dichloropyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. Recommanded Product: 2,5-Dichloropyrazine

Step 3: 1,1-Dimethylethyl 7-[(5-chloro-2-pyrazinyl)oxy]-1,2,4,5-tetrahydro-3H-3- benzazepine-3-carboxylate 1,1-Dimethylethyl 7-hydroxy-1, 2, 4, 5-tetrahydro-3H-3-benzazepine-3-carboxylate (Description 3 of WO 02/40471) (182mg, 0.69mmole) was dissolved in dry dimethylformamide (3ml), cooled to 0°C and treated with sodium hydride (60percent in mineral oil, 29mg, 0.72mmole). The mixture was allowed to warm to room temperature over 60 minutes. A solution of 2,5-dichloropyrazine (product of E1, step 2) (112mg, 0.76mmole) in dry dimethylformamide (1 ml) was added and the mixture stirred at room temperature for 2 hours. The mixture was diluted with water (10ml) and extracted with ethyl acetate (x 2). The ethyl acetate layers were combined, dried under magnesium sulfate and evaporated in vacuo. The residue was purified by column chromatography eluting with ethyl acetate/pentane (1: 4) to afford the title compound (208mg). MS (ES+) m/e 376 [M+H]+.

The synthetic route of 19745-07-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; GLAXO GROUP LIMITED; WO2005/97778; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 4774-14-5, name is 2,6-Dichloropyrazine, 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 4774-14-5, Application In Synthesis of 2,6-Dichloropyrazine

To a solution of lithium diisopropylamide (2.0 M heptane/tetrahydrofuran/ethylbenzene, 11.10 mL, 22.20 mmol) in THF (75 mL) at -78 C was added a solution of 2,6-dichloropyrazine (1.44 g, 9.67 mmol) in THF (20 mL) at room temperature over 20 min. The reaction mixture was stirred at -78 C for 1.5 h and added via cannula to a 3 -neck flask containing dry ice at -78 C. The reaction mixture was warmed from -78 C to room temperature over 21 h and quenched with 5 M HC1. The mixture was partitioned between brine and EtOAc. The aqueous phase was acidified to pH 3.5 with 5 M HC1. The aqueous phase was extracted with EtOAc (6 x) and the combined organic extracts were washed with brine (1 x), dried over MgS04, filtered, and concentrated. Purification by flash column chromatography on silica gel (5% to 10% MeOH in DCM) gave 3,5-dichloropyrazine-2-carboxylic acid (0.408 g, 2.11 mmol, 22% yield) as a light brown solid. LC/MS (ESf ) m/z = 193.0 (M+H) +

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; AMGEN INC.; MINATTI, Ana Elena; LOW, Jonathan, D.; ALLEN, Jennifer, R.; AMEGADZIE, Albert; BROWN, James; FROHN, Michael, J.; GUZMAN-PEREZ, Angel; HARRINGTON, Paul, E.; LOPEZ, Patricia; MA, Vu Van; NISHIMURA, Nobuko; QIAN, Wenyuan; RUMFELT, Shannon; RZASA, Robert, M.; SHAM, Kelvin; SMITH, Adrian, L.; WHITE, Ryan; XUE, Qiufen; WO2014/138484; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 54608-52-5, These common heterocyclic compound, 54608-52-5, name is 2-Hydrazinopyrazine, 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.

(00646] Step A: 5-amino-4-methyl- 1 -(pyrazin-2-yl)- 1 H-pyrazol-3 (2H)-one: To a mixture of 2-hydrazinylpyrazine (0.551 g, 5.00 mmol) and ethyl 2-cyanopropanoate (0.669 g, 5.00 mmol) in abs. EtOH (10 mL) was added 3M NaOEt in EtOH (0.167 mL, 0.501 mmol) and the mixture was heated at reflux for 64 hours. The mixture was concentrated and the residual yellow-brown solid was treated with EtOAc (30 mL) and sonicated. The resulting tan suspension was stirred vigorously for 8 hours. The solid was collected via vacuum filtration, washed with EtOAc and dried in vacuum to afford the title compound as a light tan powder (682 mg, 7 1%). ?H NMR (DMSO d6) oe 10.3 (br s, 1H), 8.82 (s, 111), 8.30 (d, 211), 6.55 (s, 2H), 1.71 (s, 3H).

The synthetic route of 54608-52-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ARRAY BIOPHARMA INC.; ANDREWS, Steven Wade; BLAKE, James F.; BRANDHUBER, Barbara J.; KERCHER, Timothy; WINSKI, Shannon L.; WO2014/78325; (2014); A1;,
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 4430-75-5 as follows. Product Details of 4430-75-5

8. Synthesis of 2-(1-(triisopropylsityl)-1H-indol-6-yl)-octahydro-1H-pyrido[1,2-a]pyrazine Into a 100 mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed 6-bromo-1-(triisopropylsilyl)-1H-indole (2 g, 5.40 mmol). To this was added octahydro-1H-pyrido[1,2-a]pyrazine (2.1 g, 14.25 mmol). Addition of t-BuONa (2 g, 20.83 mmol) was next. This was followed by the addition of (t-Bu)3P (200 mg, 0.99 mmol). This was followed by the addition of Pd(OAc)2 (50 mg, 0.22 mmol). To the mixture was added xylene (30 mL). The resulting solution was allowed to react, with stirring, for 2 hours while the temperature was maintained at 110 C. in a bath of oil. The reaction progress was monitored by TLC (CH2Cl2MeOH=10:1). The resulting mixture was washed 1 time with 30 mL of H2O. The resulting solution was extracted three times with 100 mL of ethyl acetate and the organic layers combined. The resulting mixture was washed 1 time with 10 mL of NaCl(sat.). The mixture was dried over Na2SO4 and concentrated by evaporation under vacuum using a rotary evaporator. This resulted in 2.15 g (80%) of 2-(1-(triisopropylsilyl)-1H-indol-6-yl)-octahydro-1H-pyrido[1,2-a]pyrazine as red oil.

According to the analysis of related databases, 4430-75-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; MEMORY PHARMACEUTICALS CORPORATION; US2008/200471; (2008); 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. 23611-75-8, name is Methyl 6-chloropyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., Quality Control of Methyl 6-chloropyrazine-2-carboxylate

A mixture of 17 mmol methyl-5-chloropyrazine-2-carboxylate, 18 mmol of N-BOC-piperazine and 20 mmol of K2CO3 in 20 ml of acetonitrile was heated under reflux for 3 hours. The reaction mixture was concentrated, diluted with water and extracted with ethyl acetate. The title compound was recrystallized from ethyl acetate to yield a colorless solid. MS (m/e): 323.4 (MH+, 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; Jolidon, Synese J.; Narquizian, Robert; Nettekoven, Matthias Heinrich; Norcross, Roger David; Pinard, Emmanuel; Stalder, Henri; US2005/209241; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem