25786-99-6 NSC71921 Urea, 1,1'-p-phenylenebis[3-[m-(1,4,5,6-tetrahydro-2-pyrimidinyl)phenyl]-, dihydrochloride Urea, N',N''-1,4-phenylenebis[N'-[3-(1,4,5,6,-tetrahydro-2-pyrimidinyl)phenyl]-, dihydrochloride