反应详情

To a stirred solution of 2-(4-bromo-2-methylphenyl)-2-methylpropanenitrile (3.1 g, 13.0 mmol) in anhydrous THF (75 mL) at −78° C. is added n-butyllithium (2 M in c-hexane) (7.16 mL, 14.3 mmol). This reaction mixture is stirred at that temperature 10 min., then N-methoxy-N-methyl-acetamide (2.77 mL, 26.0 mmol) is added and the solution is then warmed up to room temperature over 1 h. Acidic brine (30 mL of brine, 15 mL of 3% HCl aq) is then slowly added and the solution extracted with EtOAc (3×100 mL). The organic layer is dried with MgSO4, filtered and concentrated under reduced pressure. The crude product is purified by flash-chromatography using a 5 to 20% EtOAc in hexane gradient to provide the expected product 2-(4-acetyl-2-methylphenyl)-2-methylpropanenitrile (1.77 g, 68%) as a yellowish oil. 1H NMR (300 MHz, CHLOROFORM-D): δ 7.84-7.74 (2H, m), 7.43-7.40 (1H, m), 2.70 (3H, s), 2.60 (3H, s), 1.81 (6H, s).

1. extractionthe solution extracted with EtOAc (3×100 mL)
2. dry with materialThe organic layer is dried with MgSO4
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. customThe crude product is purified by flash-chromatography