Glycoluril
Glycoluril is an organic compound with the formula. It is classified as diurea, consistinng of two cyclic urea groups sharing a two-carbon linker. It is a white powder that has been extensively examined as a precursor to macrocyclic compounds and as a precursor to amino resins used in paints and coatings. Many other applications have been considered.
Production
Glycoluril can be synthesized by the reaction two equivalents of urea with glyoxal. The reaction is catalyzed by sulfuric acid:Likewise, using other vicinal carbonyl reactants give derivatives having various functional groups in place of the hydrogen atoms on the carbon chain.
Reactions
The four amide-like hydrogen atoms of glycoluril undergo a variety of reactions. Substitution with halogen atoms gives the tetrachloride and tetrabromide:Tetrachloromoglycoluril and tetrabromoglycoluril are halogenating agents and potential disinfectants.
Condensation reactions with aldehydes results initially in hydroxyalkylation, but is often pushed to give macrocycles or polymers. One large family of rings are formed from formaldehyde:
This tetramethylol glycoluril has use as a [biocide in water-based paints, in liquid detergents and in care and cleaning agents. It also finds utility as a crosslinker for hydroxyl-containing polymers, as an industrial fungicide and as an accelerator in cements.
These cucurbituril-like chains, rings, and polymers serve as hosts to bind to various neutral and cationic species.
Use
Glycoluril has been assessed as a controlled-release fertilizer, but the economic factors are not favorable.Tetraacetylglycoluril can be prepared from glycoluril by reaction with acetic anhydride. Tetraacetylglycoluril can be used, but it not very common as a bleach activator for sodium percarbonate in solid detergent formulations because of its slow biodegradability.
The reaction with nitrating acid leads to the explosives dinitroglycoluril and tetranitroglycoluril.