Synthese einiger Thioxanthen‐Derivate

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 paper‐chromatography. The same oxidant at 100° oxidizes Methixelz to the sulfone IV. This was also obtained by alkylation of thioxanthene‐10, 10‐dioxide (11). On oxidation with hydrogen peroxide the demethyl derivative VIII affords at 20° the sulfoxide XI (isolated in non‐uniform steric state), and at 100° the sulfone V. Alkylation of thio‐xanthene with N‐methyl‐3‐chloromethyl‐piperidine‐N‐oxide (I) leads to ‐[(N‐ methyl‐3‐piperidyl)‐methyl]‐thioxanthene‐N‐oxide (111), the constitution of which was proved by conversion to VI.