Piperonal

Structural formula
General
Surname	Piperonal
other names	Piperonyl aldehyde Heliotropin 3,4- (methylenedioxy) benzaldehyde Methylene protocatechualdehyde
Molecular formula	C 8 H 6 O 3
Brief description	colorless solid with a floral odor
External identifiers / databases
CAS number 120-57-0 EC number 204-409-7 ECHA InfoCard 100.004.009 PubChem 8438 Wikidata Q418985
properties
Molar mass	150.14 g mol −1
Physical state	firmly
density	1.337 ± 0.06 g cm −3
Melting point	37 ° C
boiling point	263 ° C
Vapor pressure	1.3 h Pa (87 ° C)
solubility	easily soluble in ethanol poor in water (3.5 g l −1 at 20 ° C) moderate in methanol (100 g l −1 at 20 ° C)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 317 P: 261-280-302 + 352-363
Toxicological data	2700 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Piperonal is a flavoring substance with a vanilla and almond scent . Piperonal is also known as heliotropin because of its heliotrope- like odor .

The name piperonal comes from the first synthesis, which originated from the pepper ingredient piperine ("piperyl-piperidine"). The piperic acid formed by the decomposition of piperine gave piperonal after a reaction with potassium permanganate in an alkaline solution.

Occurrence

Piperonal occurs in small quantities in the flower oils of real meadowsweet ( Filipendula ulmaria ) and the common locust tree ( Robinia pseudoacacia ).

Extraction and presentation

The first research work goes back to Carl Liebermann at the Berlin industrial institute . There are several ways to represent piperonal. The usual production is the isomerization of the natural substance safrole to isosafrole and subsequent oxidation to piperonal with potassium permanganate , potassium dichromate or ozone . An older method is the reaction of protocatechualdehyde and methylene iodide with potassium hydroxide .

The question of whether it is actually possible to obtain piperonal on a larger scale from natural substances, or whether it is a synthesis, was publicly discussed in a legal dispute between the chocolate manufacturer Ritter Sport and the Stiftung Warentest . In January 2014, the Munich district court confirmed an injunction against the Stiftung Warentest that they can no longer claim that the Piperonal used by Ritter Sport was wrongly declared as a " natural flavor ". How the Piperonal supplied by the Symrise company was actually produced is not clear from the judgment that the Stiftung Warentest challenged. According to a later presentation, the company uses the safrole extracted and enriched from the sassafras tree ( Sassafras albidum ) as a preliminary stage of a biochemical conversion for the production of piperonal, from which Ritter Sport receives six kilograms per year. In September 2014, the Munich Higher Regional Court confirmed the judgment and finally dismissed Stiftung Warentest's objection.

properties

Piperonal usually forms colorless, well-developed crystals, which under the influence of light, great heat or in contact with iron, e.g. B. Tin cans, color brown. The substance is easily soluble in ethanol and diethyl ether , very difficult in water (about 0.5%), and in glycerine hardly at all.

proof

The reliable detection and quantification of piperonal is made possible after adequate sample preparation by coupling gas chromatography with mass spectrometry . RP- HPLC is also used to detect the piperonal in vanilla pod extracts .

use

Due to its pleasant heliotrope smell, piperonal is used as a perfume and cosmetics component and for flavoring soaps and detergents. It is used as a flavoring in the food industry. It is also a starting material in the synthesis of Tadalafil . It is also added to some tobacco products . It is fungicidal and harmful to aquatic organisms.

Piperonal is listed in Appendix I to the United Nations Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances of 1988 as a precursor . It is used in illegal drug production for the manufacture of MDA and MDMA .

Special information for certain groups of chemicals

In the European Union, manufacturing, trading, importing, exporting, selling, selling, placing on the market and purchasing Piperonal without a special permit from the Federal Institute for Drugs and Medical Devices (BfArM) are prohibited and punishable. The same applies u. a. for the substances safrole and isosafrole. Pharmacies do not need this permit for their normal business operations. The national legal basis is the Basic Materials Monitoring Act of October 7, 1994.

Individual evidence

1. ↑ ^{a b c} Entry on piperonal in the GESTIS substance database of the IFA , accessed on January 8, 2018(JavaScript required) .
2. ↑ entry heliotropin at thegoodscentscompany, accessed on 27 January 2018th
3. ↑ ^{a b c d} Entry Piperonal in the SRC PhysProp Database, accessed on January 27, 2018.
4. ↑ ^{a b c} data sheet Piperonal purum from Sigma-Aldrich , accessed on October 20, 2016 ( PDF ).
5. ^ Süddeutsche Zeitung: Schokolade, bittersweet , December 20, 2013, accessed: January 14, 2014.
6. ↑ Spiegel Online: Chocolate dispute: Ritter Sport wins against Stiftung Warentest , January 13, 2014, accessed: January 13, 2014.
7. ↑ taz Online: Stiftung Warentest vs. Ritter Sport; Square, Practical, Successful , January 13, 2014, accessed January 13, 2014.
8. ↑ Aroma production: square, practical, unnatural? In: transkript 1-2 2014; P. 10.
9. ↑ ZEIT Online: Stiftung Warentest finally loses against Ritter Sport , September 9, 2014, accessed: September 9, 2014.
10. ^ Stanfill SB, Ashley DL: Quantitation of flavor-related alkenylbenzenes in tobacco smoke particulate by selected ion monitoring gas chromatography-mass spectrometry. , J Agric Food Chem. 2000 Apr; 48 (4): 1298-306, PMID 10775389 .
11. ↑ Sinha AK, Verma SC, Sharma UK: Development and validation of an RP-HPLC method for quantitative determination of vanillin and related phenolic compounds in Vanilla planifolia. , In: J Sep Sci . 2007 Jan; 30 (1): 15-20, PMID 17313136 .
12. ↑ Chocolate: Testers stick to the verdict for Ritter Sport. Stiftung Warentest, November 25, 2013, accessed on November 26, 2013 . 
13. ↑ Hazardous substance database. University of Hamburg Department of Chemistry, April 20, 2009, accessed on November 26, 2013 . 
14. ↑ Gilla, G .; Anumula, RR; Aalla, S .; Vurimidi, H .; Ghanta, MR: Synthesis and characterization of related substances and metabolites of tadalafil, a PDE-5 inhibitor. Org Commun 2013; 6 (1): 12-22
15. ↑ BMEL: Tobacco Additives Database , accessed on January 27, 2018.
16. ^ Entry on Piperonal at ChemicalBook , accessed on January 20, 2014.
17. ^ European commission: Control of drug precursors .