反应详情

Carbethoxymethylene triphenylphosphorane (150 g, 0.3 mol) was added to a solution of 3,4-dimethoxybenzaldehyde (50 g, 0.3 mol) in dry dichloromethane (150 ml), and the mixture was stirred at room temperature overnight. The solution was concentrated to about 50 ml, and the precipitate was filtered off and washed with hexane-dichloromethane (4:1, v/v). The combined filtrates were evaporated to a residue, which was purified by silica gel chromatography using hexane-ethyl acetate (9:1, v/v) as the eluant. The title compound was isolated as a crystalline mass (65 g, 91%), m.p. 52°-53° C.

1. concentrationThe solution was concentrated to about 50 ml
2. filtrationthe precipitate was filtered off
3. washwashed with hexane-dichloromethane (4:1
4. customThe combined filtrates were evaporated to a residue, which
5. customwas purified by silica gel chromatography