2,4,6(1H,3H,5H)-Pyrimidinetrione, 1,3-bis(2-((aminocarbonyl)oxy)-3-(1-methylethoxy)propyl)-5-ethyl-5-phenyl-, mixt. with 1-(2-((aminocarbonyl)oxy)-3-(1-methylethoxy)propyl)-5-ethyl-5-phenyl-2,4,6(1H,3H,5H)-pyrimidinetrione and 5-ethyl-5-phenyl-2,4,6(1H,3H,5H)-pyrimidinetrione