4-[1,1'-Biphenyl]-2-yl-N-(6-methoxy-3H-1.lambda.~4~,3-benzothiazol-2-yl)-2,4-dioxo-3-(3-oxo-1,3-dihydro-2-benzofuran-1-yl)butanamide AIDS-137554 AIDS137554 NSC642022