Guanidine derived ionic liquids: Catalyst free medium for N-formylation of amines

Abstract

A remarkable improvement of both the chemical yield and the reaction condition, of N-formylation of amines with formic acid was found, when tetra-substituted guanidinium salts were added as ionic liquids. Effects of amount and the type of guanidinium salts on the outcome of the reaction were investigated. This procedure works well for sterically hindered primary amine as well as electron-deficient primary arylamines, primary and secondary amino alcohols, α-amino acid esters, hydroxylamines and N, N-dimethylhydrazine. The recovered ionic liquid can be recycled for four runs without loss of activity.