NSC609970 Urea, 3-(3,4-dihydro-2-isopropylthio-4-oxo-6-pyrimidinyl)- 1-methyl-1-nitroso- Urea, N-[3,4-dihydro-2-[(1-methylethyl)thio]-4-oxo- 6-pyrimidinyl]-N'-methyl-N'-nitroso-