Piperic acid is a chemical often obtained by the base-hydrolysis of the alkaloid piperine[1] from black pepper,[2] followed by acidification of the corresponding salt.

Piperic acid can be prepared from the commercially-available alkaloid piperine, a cyclic amide containing a piperidine group, by reacting it with a hydroxide such as potassium hydroxide, then acidifying the formed piperate salt with hydrochloric acid or another acid.

The toxic compound piperidine is given off during the base-hydrolysis of piperine and as-such, safety precautions should be taken.

Reaction of piperic acid with strong oxidizers such as potassium permanganate or ozone, or a halogen such as bromine followed by sodium hydroxide causes oxidative cleavage of the double-bonds, yielding piperonal and piperonylic acid.

[3] Piperonal has many uses in industry and is itself a precursor to a good subsection of other chemicals.