2,3,5,6-Tetradeuterio-4-methoxyaniline is a useful research chemical. It is the labelled form of p-Anisidine, a grey-brown solid, is the most toxic of the three isomers of anisidine. It can be used for the detection of fats and oils, since p-Anisidine reacts with aldehydes and ketones in fats and oils to form products that absorb at 350 nm wavelength of light.
