Synonyms: Spiro[2H-1-benzopyran-2,2'-[2H]indole], 1',3'-dihydro-1',3',3'-trimethyl-8-nitro-, Spiro[2H-1-benzopyran-2,2'-indoline], 1',3',3'-trimethyl-8-nitro- (6CI,7CI,8CI); 1',3'-Dihydro-1',3',3'-trimethyl-8-nitrospiro[2H-1-benzopyran-2,2'-[2H]indole]; 8-Nitro-1',3',3'-trimethylspiro[2H-1-benzopyran-2,2'-indoline]