1,4,5,6,7,7-Hexachloro-5-norbornene-2,3-dicarboxylic anhydride 115-27-5 4,7-Methanoisobenzofuran-1,3-dione, 4,5,6,7,8,8-hexachloro-3a,4,7,7a-tetrahydro- 5-Norbornene-2,3-dicarboxylic anhydride, 1,4,5,6,7,7-hexachloro- Chloran 542 Chlorendic anhydride HET Anhydride Hexachloro-5-norbornene-2,3-dicarboxylic anhydride Hexachloroendomethylene tetrahydrophthalic anhydride NSC22229