Electrochemical Synthesis of Phthalimidine‐d2 with Heavy Water as Deuterium Source

Abstract Phthalimidine finds wide pharmaceutical applications and its deuterated derivative is supposed to exhibit enhanced stability towards metabolism. In this work, an electrochemically reductive deuteration strategy from phthalimide to phthalimidine‐ d 2 was achieved with D 2 O as a deuterium source at the reagent level in common solvents. This approach showed broad compatibility with a variety of functional groups. Mechanistic investigations assisted by electrochemical analysis revealed a 4‐electron reduction pathway, and the coupled anodic oxygen evolution collectively maintains a neutral to mild basic conditions for the ongoing electrochemical reaction.