Figure 1From: Pemoline and tetramisole 'positives' in English racehorses following levamisole administrationProposed conversion of Levamisole to Aminorex to Pemoline. Levamisole (1) can protonate to form intermediate 2, which can undergo alkylation of the double bond to form 3, with loss of thiirane, 3.1, to yield Aminorex 4. Aminorex can then undergo biological oxidation [O] to form Pemoline 5 (Eisenberg 2008; Ho [2]).Back to article page