New opinions on the amidoalkylation of hydrophosphorylic compounds

A new and milder version of the procedure for the synthesis of N-protected alpha-aminoalkylphosphorylic compounds by reaction of alkyl carbamates, aldehydes and hydrophosphorylic compounds in acetic anhydride/acetyl chloride and a new mechanism for this type of reaction are described. The isolation, for the first time, of N.N'-benzylidene- and N,N'-alkylidenebiscarbamates as intermediates from the reaction medium and studies of the direct reaction of pre-obtained biscarbamates and hydrophosphorylic compounds in acetic anhydride are reported. A new version of the mechanism for this reaction which includes an Arbuzov-type reaction is proposed. (C) 2010 Elsevier Ltd. All rights reserved.