2,5-Dimethoxybenzaldehyde is used in the preparation of 2,5-dimethoxyphenethylamine, which is utilized to prepare psychoactive drugs such as 2,5-dimethoxy-4-bromophenethylamine, 2,5-dimethoxy-4-iodophenethylamine and 4-Chloro-2,5-dimethoxy-phenethylamine. It acts as an intermediate in organic synthesis.