[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]([CH3:16])([CH3:15])[C:9](N(OC)C)=[O:10])=[CH:4][C:3]=1[O:17][CH3:18].[Li][CH3:20]>C1COCC1>[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]([CH3:15])([CH3:16])[C:9](=[O:10])[CH3:20])=[CH:4][C:3]=1[O:17][CH3:18]To a solution of 2-(4-fluoro-3-methoxyphenyl)-N-methoxy-N,2-dimethylpropanamide (123 g, 0.48 mol) in THF (1 L)-78° C. was added 3M ethereal solution of MeLi (210 mL, 0.627 mol). The resulting solution was warmed to ambient temperature and stirred 16 h. The reaction mixture was quenched with 3N HCl (400 mL) and extracted with EtOAc (600 mL×2). The combined extracts were washed with satd NaHCO3 (1.0 L) and brine (1.0 L), then dried over MgSO4 and concentrated at reduced pressure to give 3-(4-fluoro-3-methoxyphenyl)-3-methylbutan-2-one as yellow color oil (92.5 g, 91%). 1H NMR (400 MHz, CDCl3): δ 7.05 (m, 1H), 6.83-6.78 (m, 2H), 3.88 (s, 3H), 1.95 (s, 3H), 1.47 (s, 6H).
読み込み中…