Synthesis of glucuronides of multidrug resistance reversing drug MS-209

We synthesized the glucuronides of MS-209 to identify the two main unknown metabolites in human urine. Reaction of MS-209 and glucuronyl trichloroacetimidate gave two β-isomers, which were each glucuronate of (R)- and (S)-MS-209. These spectrum data were identical with the metabolites.