reaction of trifluoromethyl diazomethane (2,2,2-trifluorodiazoethane, CF3CHN2) with drug-likemolecules. We found our previous copper-catalyzed transformation of carboxylic acids to the corresponding N-trifluoroethylimides with CF3CHN2 and acetonitrile is well-suited for the late-stagemodification of drug and drug-like acids. A procedure that enables the use of solid nitriles and nitriles with high