A rate enhancement of tert-butoxycarbonylation of aromatic amines with Boc2O in alcoholic solvents

A rate enhancement of tert-butoxycarbonylation of aromatic amines by Boc2O in alcohols compared to aprotic solvents was demonstrated. Kinetic analysis by NMR suggested that the reaction in CD3OD was faster than in CDCl3 by a factor of 70. Reactions between Boc2O and various aliphatic and aromatic amines in ethanol provided the N-Boc derivatives in good to excellent yields in short reaction times.