5-(4-(4-(4,6-Dioxo-2,3-diphenylhexahydro-5H-pyrrolo[3,4-d]isoxazol-5-yl)benzyl)phenyl)-2,3-diphenyldihydro-2H-pyrrolo[3,4-d]isoxazole-4,6(3H,5H)-dione AIDS-136951 AIDS136951 NSC640248