Conversion of Benzal Halides to Benzaldehydes in the Presence of Aqueous Dimethylamine

ABSTRACT Aqueous dimethylamine is an efficient reagent for the conversion of a variety of benzal halides to their corresponding benz­aldehydes. Studies indicate that aqueous dimethylamine significantly accelerates aldehyde formation from benzal halide precursors, as compared to the use of water alone. Indeed, these reactions are routinely completed in one hour or less, depending upon substrate substitution. Desired products can be isolated in pure form, and in high yield, but silica gel filtration is often necessary to remove baseline contaminants. The method represents a novel, economical approach to acquire pure, substituted benzaldehydes from commercially available, or easily prepared starting materials.