反应详情

To a solution of n-BuLi (1.6 M, 1.7 mL) in 8 mL THF was added a solution of 3,4,5-trimethoxybromobenzene (2.47 mmol) in 3 mL THF under −78° C. The mixture was allowed to stir for 2 h and a solution of Weinreb amide 65a (1.24 mmol) in 3 mL THF was charged. The temperature was allowed to increase at RT and stirred overnight. The reaction mixture was quenched with satd. NH4Cl, extracted with ethyl ether, dried with MgSO4. The solvent was removed under reduced pressure to yield a crude product, which was refluxed in 1 N NaOH in 5 mL ethanol solution to obtain the deprotected compound 66a and purified by column chromatography to obtain pure compound as a light yellow solid (36.3%). 1H NMR (300M, CDCl3) δ 8.36 (br, s, 1H), 8.31 (s, 1H), 8.21 (s, 1H), 7.92, 7.89 (dd, 1H, J=1.8, 2.7 Hz), 7.46 (d, 1H) 7.62 (s, 2H, J=8.7 Hz), 7.29 (t, 1H, J=2.7 Hz), 6.64 (br, 1H), 3.97 (s, 6H), 3.97 (s, 3H); MS (ESI) m/z 417.1 (M+Na)+, 392.9 (M−H)−.

1. stirringstirred overnight
2. customThe reaction mixture was quenched with satd
3. extractionNH4Cl, extracted with ethyl ether
4. dry with materialdried with MgSO4
5. customThe solvent was removed under reduced pressure
6. customto yield a crude product, which