A search for synthetic routes to tetrabenzylglycoluril

In this study, a search for synthetic routes to never-before-seen tetrabenzylglycoluril was made and two synthetic strategies were examined: condensation of 1,3-dibenzylurea with glyoxal, and N-alkylation of glycoluril and its disubstituted derivative. The first synthetic approach furnished only a condensation product, 3,3′-bi(6,8-dibenzyl-2,4-dioxa-9,8-diazabicyclo[3.3.0]octan-7-one, bearing the dioxolane moiety, in 24% yield. The second method in which 2,6-dibenzylglycoluril was reacted with BnCl in acetonitrile in the presence of KOH for 3 h afforded the target product tetrabenzylglycoluril in over 60% yield.