Silica gel-catalysed transacylation of 2,2'-disubstituted benzophenones

Silica gel catalyses the transacylation of 2,2'-disubstituted benzophenones of type 1, to give their isomeric compounds 2, at reasonable temperatures and with a high degree of selectivity. The kinetics of the reaction has been studied by 1H NMR spectroscopy, taking into account the relative intensities of the signals due to the methoxy (or methyl) and acetyl groups of 1 and 2. On the basis of the obtained kinetic data, a plausible mechanism for the reaction is proposed.