Dimethylformamide → 2-(p-Methoxyphenoxy)-3-(dimethylamino)acrolein

Participants

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. 4-Methoxyphenoxyacetaldehyde 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. The residue was heated with ethyl acetate:heptane and decanted, leaving a brown oil. The solvent was removed in vacuo to give a brown oil, which was purified by flash column chromatography (SiO2, ethyl acetate) yielding the title compound (3.87 g, 44% yield) as a white solid.

Provenance & Evidence