It has been reported in few literature that glycoluril is soluble in hydrochloric acid/ammonium hydroxide/diethylether. We have purchased glycoluril from Sigma-Aldrich and tried to dissolve it in all of the above mentioned solvents at 25 to 50 degree Celsius. It seems that glycoluril is not soluble in either of the solvents. Is there any particular technique to make it soluble or are there any other solvents in which it shows better solubility ?