Synthesis and Analysis of Glucuronic Acid‐Conjugated Metabolites of 4‐Bromo‐2,5‐Dimethoxyphenethylamine

In the study reported here, two glucuronic acid‐conjugated metabolites of 4‐bromo‐2,5‐dimethoxyphenethylamine (2C‐B)—a ring‐substituted psychoactive phenethylamine—were chemically synthesized for the first time and a method for analyzing them in urine was developed. β‐D‐Glucuronide of 4‐bromo‐2,5‐dimethoxyphenylethylalcohol was successfully synthesized using methyl 2,3,4‐tri‐Ο‐acetyl‐1‐O‐(trichloroacetimidoyl)‐α‐D‐glucuronate as a glucuronyl donor and boron trifluoride diethylether complex as a Lewis acid catalyst. β‐D‐Glucuronide of 4‐bromo‐2,5‐dimethoxyphenylacetic acid was synthesized by condensing 4‐bromo‐2,5‐dimethoxyphenylacetic acid and benzyl D‐glucuronate followed by benzyl group deprotection based on catalytic hydrogenation. Two glucuronic acid‐conjugated metabolites of 2C‐B in urine were qualitatively and semiquantitatively evaluated via direct liquid chromatography/mass spectrometry (LC/MS) analysis of a diluted urine sample. The simple method proposed is expected to be useful for studying the metabolic fate of 2C‐B.