Efficient synthesis of methyl carbamate via Hofmann rearrangement in the presence of TsNBr2

An efficient method has been developed for the synthesis of carbamates from the corresponding amides via the Hofmann rearrangement using N,N-dibromo-p-toluenesulfonamide (TsNBr2) in the presence of DBU in methanol. The reaction goes into completion in 10-20 min at 65 degrees C to produce the corresponding carbamate in excellent yield. (C) 2012 Elsevier Ltd. All rights reserved.