合成路线1

The hydrolysis of the known thioacetate (I) with NaOH in THF gives the thiol (II), which is condensed with 14C-labelled bromoacetic acid (III) by means of NaOH in water to yield the sulfanyl-acetic acid (IV). The reduction of (IV) with LiAlH4 in THF affords the sulfanylethanol derivative (V); which is condensed with 3-(4-hydroxyphenyl)propionic acid methyl ester (VI) by means of DEAD and PPh3 in toluene to provide the labelled aryl ether (VII).The hydrolysis of the ester group of (VII) by means of KOH in ethanol/water gives the propionic acid (VIII), which is converted into the trifluoromethyl ketone (IX) by reaction with oxalyl chloride, trifluoroacetic anhydride and pyridine in toluene/dichloromethane. Finally, the oxidation of the sulfanyl group of (IX) with MCPBA in dichloromethane affords the target labelled sulfone.