Reference of 109838-85-9, 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. 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.
Step A – Preparation of Compound Int- 13cA 5 L- 3 necked round bottomed flask, equipped with a mechanical stirrer, temperature probe, addition funnel and N2 inlet, was charged with the Schollkopf chiral auxiliary-(Int-13a, 200 g, 1.09 mol, 1.0 eq), bis(chloromethyl) dimethylsilane (Int-13b, 256 g, 1.63 mol, 1.5 eq), and THF (2 L, Aldrich anhydrous). The flask was cooled in a dry ice/ 2- propanol bath until the internal temperature reached -75 °C. n-Butyllithium (Aldrich 2.5 M in hexanes , 478 mL, 1.19 mol, 1.09 eq) was added via a dropping funnel over 1 hour while maintaining the internal reaction temperature between -67 °C and -76 °C. The resulting orange-red solution was allowed to gradually warm to room temperature for about 15 hours. The reaction mixture was then re-cooled to 0 °C and quenched with 500 mL of water.Diethyl ether (2L) was added and the layers were separated. The aqueous layer was extracted with 1 L of diethyl ether. The combined organic layers was washed with water and brine, dried with MgS04, filtered, and concentrated in vacuo to dryness, giving 480 g of orange oil. This material was left in vacuo for about 15 hours to provide 420 g of oil. The crude product was split into two batches and purified via silica gel chromatography on a 1.6 kg flash column. The column was eluted with gradient of 0-4percent Et20 in hexanes. The product fractions were concentrated in vacuo at a bath temperature at or below 40 °C giving 190 grams of Int-13c-(60percentyield).
The synthetic route of (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine has been constantly updated, and we look forward to future research findings.
Reference:
Patent; MERCK SHARP & DOHME CORP.; DWYER, Michael P; KEERTIKAR, Kartik M; COBURN, Craig A; WU, Hao; HU, Bin; ZHONG, Bin; ZHANG, Chengren; DAN, Zhigang; TONG, Ling; YU, Wensheng; WO2012/41227; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem