Piperic acid

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Piperic acid
IUPAC name
(2E,4E)-5-(3,4-methylenedioxyphenyl)-2,4-pentadienoic acid
3D model (Jmol)
EC Number 226-118-4
MeSH C017637
Molar mass 218.21 g·mol−1
Boiling point decomposes
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

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.[3] Piperic acid is an intermediate in the synthesis of other compounds such as piperonal, and as-such may be used to produce fragrances, perfumes flavorants and drugs as well as other useful compounds.


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.

Piperic acid from piperine


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.[4][5] Piperonal has many uses in industry and is itself a precursor to a good subsection of other chemicals. On reduction with sodium amalgam piperic acid forms α- and β-dihydropiperic acid, C12H12O4, and the latter can take up two further atoms of hydrogen to produce tetrahydropiperic acid.

See also[edit]


  1. ^ Paul M. Dewick. (2009). Medicinal natural products : a biosynthetic approach. Chichester: A John Wiley & Sons. p. 327. ISBN 978-0-470-74167-2. 
  2. ^ http://chestofbooks.com/health/aromatherapy/The-Volatile-Oils-Vol1/Heliotropin.html
  3. ^ http://www.erowid.org/archive/rhodium/chemistry/3base/piperonal.pepper/degradation.piperine/index.html
  4. ^ http://www.freepatentsonline.com/5095128.html, Preparation process for piperonal, US Patent No. 5095128
  5. ^ http://www.erowid.org/archive/rhodium/chemistry/3base/piperonal.pepper/cleavage.piperic_acid/index.html