Deoximation Reaction in Room Temperature Ionic Liquids under Mild Conditions

Deoximation in metal chloride ionic liquids based on 1‐alkyl‐3‐methylimidazolium and triethylene ammonium cations, such as AmimBr(Cl)‐MCl_x(A=ethyl, butyl, benzyl; M=Al, Fe, Cu, Sn and Zn; x=2, 3) and Et₃NHCl‐FeCl₃ were investigated under mild conditions. Ferrate chloride ionic liquid was proved to be an effective catalyst for deoximation of cyclohexanone oxime, exhibiting high conversion of oximes and selectivity to cyclohexanone. Good performance for the deoximation of other oximes such as salicylald oxime, acetone oxime, benzophenone oxime, 4‐nitrobenzald oxime, acetophenone oxime, 2‐chlorobenzaldehyde oxime, Acetald oxime, 2‐butanone oxime and (1R)‐camphor oxime was also achieved with bmimBr‐FeCl₃ as catalyst and solvent. The deoximation was determined to carry out via acid‐catalytic hydrolysis and the reaction mechanism was proposed.