60990-38-7 63998-89-0 Spiro(2H-1-benzopyran-2,2'-(2H)indole)-1'(3'H)-propanoic acid, 3',3'-dimethyl-6-nitro-, anhydride beta-1-(3,3-Dimethyl-6'-nitrospiro(indoline-2,2'-2H-benzopyrene))propionic anhydride