Chemical synthesis and analgesic effect of morphine ethereal sulfates

Abstract Chemical synthesis of morphine-3- and -6-ethereal sulfate was accomplished, utilizing chlorosulfonic acid as sulfonating reagent. The analgesic effect of morphine-6-sulfate in mice was about same order of magnitude as that of morphine-6-glucuronide, being much higher in potency and longer in duration than that of morphine. On the other hand, no effect was observed with morphine-3-sulfate (20 mg/kg, s. c.). Morphine-6-sulfate, an active conjugate, could not be detected in the urine of cats injected with morphine by careful examination with thin-layer chromatography.