Related Experiment Video
Updated: May 14, 2026

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores
Published on: August 19, 2013
Identification of (2-aminopropyl)benzofuran (APB) phenyl ring positional isomers in internet purchased products
Andrzej Stanczuk1, Noreen Morris, Elizabeth A Gardner
1Department of Life and Physical Science, Athlone Institute of Technology, Athlone, Co. Westmeath, Ireland.
Abstract:
5-(2-Aminopropyl)benzofuran (5-APB), a 'research chemical' that was first reported by UK authorities to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) in 2010, is anecdotally reported to produce a combination of stimulant and entactogenic effects. More recently, in 2011, 6-(2-aminopropyl)benzofuran (6-APB) was identified by Hungarian authorities. To confirm positional isomer identity in Internet purchased products, 4- 5- 6- and 7-APBs were synthesized and found to be separable by gas chromatography (as heptafluorobutyramide derivatives) and liquid chromatography. The analyses of products purchased from online vendors of 'research chemicals' identified the presence of 5- or 6-APBs. These findings were further confirmed by liquid chromatography-mass spectrometry and (1) H nuclear magnetic resonance spectroscopy. In products containing 6-APB, the 4- positional isomer was also identified and this may have arisen during the manufacturing process.
Related Concept Videos
NMR Spectroscopy of Benzene Derivatives
Nomenclature of Aromatic Compounds with Multiple Substituents
For disubstituted benzene derivatives, with two groups attached to the benzene ring, three constitutional isomers are possible. For example, consider dimethyl benzene, often called xylene, where the second methyl group can be substituted at the second, third, or fourth carbon. The relative position of the substituents is represented by prefixes ortho, meta, or...
Prochirality
Nomenclature of Aromatic Compounds with a Single Substituent
Nomenclature of Aryl and Heterocyclic Amines
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene

