Carbamic acid, [6-oxo-6-(tetrahydro-2-oxo-1(2H)-pyrimidinyl)hexyl]-,2-methyl-2-[[[[[6-oxo-6-(tetrahydro-2-oxo-1(2H)-pyrimidinyl)hexyl]amino]carbonyl]oxy]methyl]-1,3-propanediyl ester