Abstract
Abstract The effect of phosphorus-containing catalysts, namely phosphorous acid, phosphoric acid, diethyl hydrogen phosphite, and 1-hydroxyethane-1,1-diyldiphosphonic acid (HEDP), in the synthesis of tetraacetylglycoluril by acylation of glycoluril with acetic anhydride at 140°C has been studied. The use of 4 equiv of phosphorous or phosphoric acid with respect to glycoluril has been found to be the most appropriate for achieving the maximum yield (95–98%), and specific effect of HEDP leads to N-acetylation–deacetylation of substrates. The positive effect of phosphorus acids on the formation of tetraacetylglycoluril may be related to not only their catalytic action but also the ability to solubilize the substrate.