Anisaldehyde, or anisic aldehyde, is an organic compound that consists of a benzene ring substituted with an aldehyde and a methoxy group. It is a clear colorless liquid with a strong aroma. It comes in 3 varieties, ortho, meta, and para in which the two functional groups (methoxy and aldehyde) are alpha, beta, and gamma, respectively to each other. The unmodified term anisaldehyde generally refers to the para isomer.
Anisaldehyde is used as an intermediate in the synthesis of other compounds important in pharmaceuticals and perfumery, particularly ortho-anisaldehyde, which has a scent of licorice.
A solution of para-anisaldehyde in acid and ethanol is frequently used to stain thin layer chromatography plates. It is a particularly useful stain because different spots on the plate can be stained different colors allowing easy distinction.