A neolignan-type impurity arising from the peracid oxidation reaction of anethole in the surreptitious synthesis of 4-methoxyamphetamine (PMA).

The neolignan-type substance 2,4-dimethyl-3,5-bis(4'-methoxyphenyl) tetrahydrofuran is presented as a new forensic marker compound for the peracid oxidation of anethole. It is hypothesized that the formation of a stable intermediary carbocation in the hydrolysis reaction of anethole epoxide is not only responsible for the presence of 1,2-diols (and its esters) and 4-methoxyphenyl-2-propanone (PMP2P) but can also be the cause for the creation of this neolignan impurity due to interaction with anethole itself. Moreover, the applicability of this new forensic marker is demonstrated by its retrieval in clandestinely manufactured 4-methoxyamphetamine (PMA) preparations.