Activated dimethyl sulfoxide dehydration of amide and its application to one-pot preparation of benzyl-type perfluoroimidates

Various types of primary amides were treated under an activated dimethyl sulfoxide (DMSO) species, (COCl)2–DMSO and Et3N, as a dehydrating agent to obtain nitriles in excellent yield. This dehydration system was extended to a one-pot preparation of perfluoroimidates via volatile perfluoronitriles from perfluoroamides. Fifteen benzyl-type perfluoroimidates can be prepared in 70–90% yield as more stable imidates than the trichloro analogue. MPM- and DMPM-perfluoroimidates can be used to protect alcohols in place of the trichloroacetimidate with excellent chemical properties and in comparable yields.