|Jmol-3D images||Image 1
|Molar mass||150.13 g mol−1|
|Melting point||37 °C; 99 °F; 310 K ()|
|Boiling point||263 °C; 505 °F; 536 K ()|
|Solubility in water||Soluble in 500 parts|
|LD50||2700 mg/kg (orally in rats)|
| (what is: / ?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Piperonal, also known as heliotropin, is an organic compound that is commonly found in fragrances and flavors. The molecule is structurally related to benzaldehyde and vanillin. It exists as a white or colorless solid. It has a floral odor commonly described as being similar to that of vanillin and cherry. It is used as flavoring, e.g. in perfumes or chocolate.
Preparation and reactions
Piperonal is prepared by oxidation of isosafrole, which occurs naturally. It is also prepared in a multistep sequence from catechol or 1,2-methylenedioxybenzene by condensation with glyoxylic acid.
Reduction gives piperonyl alcohol and oxidation gives piperonylic acid. Piperonal may be used in the synthesis of 3,4-methylenedioxyamphetamine (MDA) via the substituted nitrostyrene via Knoevenagel condensation. This intermediate can then be reduced by a strong reducing agent such as lithium aluminium hydride (LiAlH4) to yield MDA.
Heliotropine was discovered in 1869 by Fittig and Mielk who synthesised it and thus made the 'cherry pie' note of the heliotrope flower, for which it is named, available to perfumers for the first time - it was already in use in fragrances by the early 1880s.
It is used for vanilla or almond accords to bring a balsamic character and also has powdery, floral aspects. Despite having acquired the name heliotropine for its similar scent to that of the heliotrope flower this chemical does not itself appear in the flower scent and so cannot be extracted from those flowers.
- Budavari, Susan, ed. (1996), The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (12th ed.), Merck, ISBN 0911910123
- Karl-Georg Fahlbusch, Franz-Josef Hammerschmidt, Johannes Panten, Wilhelm Pickenhagen, Dietmar Schatkowski, Kurt Bauer, Dorothea Garbe and Horst Surburg "Flavors and Fragrances" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2003. doi:10.1002/14356007.a11_141
-  Ritter Sport plant rechtliche Schritte gegen Warentest, Spiegel Online, 25 Nov 2013
- Furniss, Brian; Hannaford, Antony; Smith, Peter; and Tatchell, Austin (1996). Vogel's Textbook of Practical Organic Chemistry 5th Ed.. London: Longman Science & Technical. p. 1035-1036. ISBN 9780582462366.
- The Force of Fashion in Politics and Society: Global Perspectives from Early Modern to Contemporary Times By Beverly Lemire ISBN 13: 9781409404927 ISBN 10: 1409404927
- The Good Scents Company database entry for Heliotropin
|Wikisource has the text of the 1911 Encyclopædia Britannica article Piperonal.|