反应详情

温度

0 °C

(2,5-Dirnethoxy-phenyl)-acetic acid (3.00 g, 15.29 mmol) was dissolved in 30 ml of acetic acid and cooled to 0° C. To this solution was added bromine (2.44 g, 15.33 mmol), the reaction mixture was stirred overnight at room temperature and concentrated under reduced pressure, the solid residue was washed with cold hexane and dried overnight. The residue was dissolved in THF and cooled to 0° C. LAH (20 ml of 1.0 M in THF) was added slowly and then the reaction mixture was stirred at 0° C. for 2 h. Excess LAH was destroyed by careful addition of ethyl acetate and an aqueous solution of 0.10 M hydrogen chloride. The organic layer was separated, dried (MgSO4) and concentrated under reduced pressure to give an oil (3.1 g), which solidifies slowly. MS (m/z) 278 (M+NH4)+. 1HNMR(CDCl3): δ ppm 2.86 (m, 2H), 378-3.84 (2s+m, 8H), 6.77 (s, 1H), 7.04 (s, 1H).

1. concentrationconcentrated under reduced pressure
2. washthe solid residue was washed with cold hexane
3. customdried overnight
4. dissolutionThe residue was dissolved in THF
5. temperaturecooled to 0° C
6. additionLAH (20 ml of 1.0 M in THF) was added slowly
7. stirringthe reaction mixture was stirred at 0° C. for 2 h
8. customExcess LAH was destroyed by careful addition of ethyl acetate
9. customThe organic layer was separated
10. dry with materialdried (MgSO4)
11. concentrationconcentrated under reduced pressure