反应详情

温度

25 °C

To a solution of 5-methoxy-2,3-dihydro-benzofuran-2-carboxylic acid methyl ester (0.44 g, 2.0 mmol) and HMPA (0.20 mL) in THF (15 mL) at −78° C. was added LiHMDS (1M in THF, 3.0 mL, 3.0 mmol). After 15 min, methyl iodide (0.42 g, 3.0 mmol) was added and the reaction was gradually warmed to 25° C. overnight. The reaction mixture was diluted with ethyl acetate and washed with a saturated aqueous solution of NH4Cl. The organic phase was dried and concentrated. The residue was chromatographed on silica gel eluting with 8:2 hexane:ethyl acetate to give 0.32 g 5-methoxy-2-methyl-2,3-dihydro-benzofuran-2-carboxylic acid methyl ester.

1. washwashed with a saturated aqueous solution of NH4Cl
2. customThe organic phase was dried
3. concentrationconcentrated
4. customThe residue was chromatographed on silica gel eluting with 8:2 hexane