反应详情

To a solution of ethyl 3,5-dihydroxybenzoate (15.0 g) in N,N-dimethylformamide (180 ml) was gradually added sodium hydride (60% in oil, 3.30 g) at 0° C. and the mixture was stirred for 30 min. Iodoethane (12.9 g) was added and the mixture was further stirred for 2 hrs. The reaction mixture was poured into water, acidified with 2N hydrochloric acid and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4) and concentrated. The obtained residue was subjected to silica gel column chromatography, and ethyl 3-ethoxy-5-hydroxybenzoate (6.75 g, yield 39%) was obtained as crystals from a fraction eluted with ethyl acetate-hexane (1:3, volume ratio). Recrystallization from diethyl ether-hexane gave colorless needle-shaped crystals. melting point: 62–63° C.

1. customat 0° C.
2. stirringthe mixture was further stirred for 2 hrs
3. extractionthe mixture was extracted with ethyl acetate
4. washThe ethyl acetate layer was washed with water
5. dry with materialdried (MgSO4)
6. concentrationconcentrated