反应详情

To a solution of lithium diisopropylamide (2 mol/L, 22 mL, 44 mmol) in tetrahydrofuran (80 mL) was dropwise a solution of methyl 2-(4-bromophenyl)acetate (10 g, 44 mmol) in tetrahydrofuran (20 mL) at −78° C. The mixture solution was stirred for 0.5 hour at that temperature, then iodomethane (8 g, 56 mmol) was added. The mixture was stirred for 10 minutes at −78° C., then was removed from the cooling bath and stirred for 0.5 hour. The reaction was quenched with sat. ammonium chloride, then diluted with ethyl acetate, washed with water, The organic layer concentrated to dry, purified by column chromatography (silica-gel, petroleum:ethyl acetate=20:1) to give methyl 2-(4-bromophenyl)propanoate as a colorless oil (10 g, 91%). 1H NMR (300 MHz, CDCl3): δ 7.44 (d, J=9 Hz, 2H), 7.17 (d, J=9 Hz, 2H), 3.65-3.70 (m, 4H), 1.48 (d, J=6 Hz, 3H).

1. customat −78° C
2. stirringThe mixture was stirred for 10 minutes at −78° C.
3. customwas removed from the cooling bath
4. stirringstirred for 0.5 hour
5. customThe reaction was quenched with sat. ammonium chloride
6. additiondiluted with ethyl acetate
7. washwashed with water
8. concentrationThe organic layer concentrated
9. customto dry
10. custompurified by column chromatography (silica-gel, petroleum:ethyl acetate=20:1)