The synthesis of some thioxanthene derivatives as possible metabolites of Methixerc (VI-hydrochloride) is described. The VON BRAUN degradation of VI with cyanogen bromide leads to the demethyl derivative 9- [(3-piperidyl)-methyl]-thioxanthene (VIII). Oxidation of Methixen with hydrogen peroxide at 20° gives a mixture of the two steroisomerie sulfoxides IX and X; they were separated by preparative