glycoluril

Glycoluril is an organic chemical composed of two cyclic urea groups joined across the same two-carbon chain. It is a white powder that has been used in water treatment, in paints and coatings, and occasionally as a slow-release fertilizer, and also occurs as the most prevalent impurity in commercial allantoin supplies. Glycouril itself and derivatives of it are used as monomers for producing the macrocyclic cucurbiturils polymers, which serve as hosts to bind to various neutral and anionic species. They are also used in several classes of non-cyclic structures that also bind a variety of structures.
Glycoluril can be synthesized by reacting two equivalents of urea with glyoxal. Likewise, using other vicinal carbonyl (or carbonyl hydrate) reactants give derivatives having various functional groups in place of the hydrogen atoms on the carbon chain.