These common heterocyclic compound, 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, 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. name: (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine
Step B – Syntheses of Intermediate Compound Int-31b (0407) (0408) To a -78 °C solution of (2R)-(-)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine (0.61 g, 4.36 mmol) in THF (8 mL) was added n-BuLi (2.5 M in hexane, 1.8 mL, 4.58 mmol). The resulting reaction was allowed to stir for 20 minutes, then Compound Int-31a (2.75 g, 6.98 mmol, in 2 mL of THF) was added and the reaction was allowed to stir at -78 °C for 4 hours. The reaction was quenched with saturated aqueous NH4Cl solution and the organic layers were extracted with EtOAc. The combined organic solution was washed with brine solution, dried (Na2SO4), filtered and concentrated in vacuo. The resulting residue was purified using an ISCO 40 g column (gradient from 0percent to 2.5percent ether in hexane) to provide Compound Int-31b, 783 mg (44percent). 1H NMR (CDCl3) delta 4.05 (m, 1H), 3.96 (t, J = 3.4 Hz, 1H), 3.72 (s, 3H), 3.71 (s, 3H), 3.49 (dd, J = 2,8, 0.4 Hz, 1H), 3.26 (dd, J = 6, 9.4 Hz, 1H), 2.30 (m, 1H), 1.96 (m, 1H), 1.60 (m, 2H), 1.37-1.17 (m, 3H), 1.08 (d, J = 6.9 Hz, 3H), 0.99-0.86 (m, 2H), 0.72 (d, J = 6.6 Hz, 3H), 0.49 (dd, J = 11.0, 14.4 Hz, 1H), 0.35 (dd, J = 11.0, 14.2 Hz, 1H), 0.16 (s, 6H).
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.; Nair, Anilkumar Gopinadhan; Keertikar, Kerry M.; Kim, Seong Heon; Kozlowski, Joseph A.; Rosenblum, Stuart; Selyutin, Oleg B.; Wong, Michael; Yu, Wensheng; Zeng, Qingbei; EP2545060; (2015); B1;,
Pyrazine – Wikipedia,
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