ACYLATION WITH BIS(ACYLAMIDES) - N-METHYL-BIS(TRIFLUOROACETAMIDE) AND BIS(TRIFLUOROACETAMIDE), 2 NEW REAGENTS FOR TRIFLUOROACETYLATION

Trifluoroacetylation of amine, hydroxyl, and thiol groups has been achieved under mild, non-acidic conditions with either N-Methyl-bis(trifluoroacetamide) or bis(trifluoroacetamide). Products remaining after substituting a trifluoroacetyl residue for a reactive proton are neutral trifluoroacetamides. These volatile compounds are eluted at the beginning of the gas chromatogram as sharp peaks so that evaporation of excess reagent and by-products, which can lead to serious errors, especially in the case of very volatile substances, is not necessary. N-Methyl-bis(trifluoroacetamide) is a liquid at room temperature and can be used in many cases without additional solvents, which favours its application in trace analysis. An excess of reagent protects those functions which are sensitive to hydrolysis. Selective acylation of amine functions in the presence of hydroxyl or carboxyl groups is possible if these groups are protected by trimethylsilylation. © Elsevier Scientific Publishing Company, Amsterdam.