1,6-Diisopropyltetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dione - 1,4-diisopropyltetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dione (1:1) AIDS-017035 AIDS017035 NSC370928