Base catalysed aminolysis of oxime ethers by dimethyl amine and piperidine

Abstract

Aminolysis of four oxime ethers (<em>o</em>-aryl ethers) having structural variation in oxime moiety with two secondary amines, viz. dimethylamine and piperidine in 1:1 water acetonitrile has been reported. Reactions proceed to give the expected aminolysis product without accumulation of any substantial concentration of stable intermediate during the reaction. Secondary amine seems to promote base catalysis, which is explained on the basis of intramolecular H-bonding between the ammonium proton of the zwitterionic intermediate and the <em>ortho-</em>nitro group. Thermodynamic parameters for uncatalysed and catalysed route have been calculated for the reaction of two oxime ethers.