Abstract
The ring‐^14^C‐labelled p‐nonylphenol (NP) isomers 4(3′,5′‐dimethyl‐3′‐heptyl)‐phenol (__p__353NP), 4(3′,6′‐dimethyl‐3′‐heptyl)‐phenol (__p__363NP) and 4(2′,6′‐dimethyl‐2′‐heptyl)‐phenol (__p__262NP) were synthesized for application in metabolism and sorption studies. Friedel–Crafts alkylation of ^14^C‐labelled phenol and the corresponding tertiary nonylalcohol with BF~3~ as catalyst was used. After clean‐up of __p__262NP and __p__363NP by preparative thin‐layer chromatography radiochemical yields amounted to 62.8 and 64.6%, specific radioactivities were 332 and 88.2 MBq/mmol, and radiochemical purities 97.6 and 99.0%. For both isomers, a large‐scale synthesis with non‐labelled phenol was additionally developed, which led to pure products (96 and 99%, respectively) without further purification steps. In the case of __p__353NP, which was formed as a diastereomeric mixture, the crude synthetic product had a radiochemical purity of 96.9% (radiochemical yield: 76.0%; specific activity: 298 MBq/mmol); thus, purification was not necessary. All products were characterized by means of gas chromatography‐mass spectroscopy, ^1^H‐ and ^13^C‐NMR, as well as IR. Copyright © 2002 John Wiley & Sons, Ltd.