Effect of substituents in the formation of diacetanilides

Abstract

A number of diacetanilides, including some which have not been reported so far, have been synthesized from the corresponding monoacetyl derivatives and characterized by spectral and elemental analyses. A tlc/fid method for the quantitative estimation of the relative amounts of mono- and diacetyl derivatives has been standardized. Linear correlation of the extent of diacetylation with Hammett σ-values of substituents and basicity constants of monoacetyl derivatives has been established. A plausible mechanism for the diacetylation reaction based on experimental observations has been suggested. An explanation for the anomalous behaviour of acetanilides containing electron-withdrawing substituents in the ortho position has been put forth.