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 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
Names
Preferred IUPAC name
(2E,4E)-5-(2H-1,3-Benzodioxol-5-yl)penta-2,4-dienoic acid
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
EC Number
  • 226-118-4
MeSH C017637
UNII
  • InChI=1S/C12H10O4/c13-12(14)4-2-1-3-9-5-6-10-11(7-9)16-8-15-10/h1-7H,8H2,(H,13,14)/b3-1+,4-2+ ☒N
    Key: RHBGITBPARBDPH-ZPUQHVIOSA-N ☒N
  • InChI=1/C12H10O4/c13-12(14)4-2-1-3-9-5-6-10-11(7-9)16-8-15-10/h1-7H,8H2,(H,13,14)/b3-1+,4-2+
    Key: RHBGITBPARBDPH-ZPUQHVIOBF
  • C1OC2=C(O1)C=C(C=C2)/C=C/C=C/C(=O)O
Properties
C12H10O4
Molar mass 218.208 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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Preparation

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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.

 

Reactions

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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. 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

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References

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  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. ^ E. Gildemeister. The Volatile Oils. Vol. 1.
  3. ^ US 5095128, "Preparation process for piperonal"