Dimethylformamide → 2-(3,4-Dichlorophenoxy)-3-(dimethylamino)prop-2-enal

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Reaction Conditions

Reaction Steps

Phosphorus oxychloride (18.4 g, 120 mmol) was added to dimethylformamide (8.8 g, 120 mmol), maintaining the temperature below 25° C. by an external ice-bath. Upon completion of the addition the reaction mixture was heated to 50° C. for 45 minutes and then cooled to room temperature. Chloroform (35 ml) was added and the resulting solution was brought to reflux. 3,4-Dichlorophenoxyacetaldehyde diethylacetal (9.61 g, 40.0 mmol) was added in portions. After heating for 3 hours at reflux the solution was cooled to room temperature and poured carefully onto a solution of potassium carbonate (115 g) in water (100 ml). The mixture was cooled in an ice-bath to around room temperature and extracted twice with dichloromethane. The combined organic layers were dried over sodium sulphate, filtered and evaporated in vacuo yielding a brown oil, which was purified by flash column chromatography (SiO2, ethyl acetate) yielding the title compound (5.38 g, 52% yield) as a brown solid.

Provenance & Evidence