反应详情

At room temperature, first 14.0 g (125 mmol) of potassium t-butoxide and then, after 30 minutes, 23.3 g (100 mmol) of methyl 2,4-dichloro-3-formylbenzoate in 200 ml of tetrahydrofuran were added to 53.2 g (150 mmol) of (2-oxopropyl)triphenylphosphonium chloride in 300 ml of tetrahydrofuran. The mixture was stirred at room temperature for 4.5 hours and 400 ml of water were then added, the organic phase was separated off and the aqueous phase was extracted with methyl t-butyl ether. The combined organic phases were dried and concentrated and the resulting residue was chromatographed over silica gel (eluent: cyclohexane:ethyl acetate=9:1). 24.0 g (88% of theory) of methyl 2,4-dichloro-3-(2-oxobut-3-en-4-yl)benzoate were obtained.

1. customthe organic phase was separated off
2. extractionthe aqueous phase was extracted with methyl t-butyl ether
3. customThe combined organic phases were dried
4. concentrationconcentrated
5. customthe resulting residue was chromatographed over silica gel (eluent: cyclohexane:ethyl acetate=9:1)