1770-80-5 5-Norbornene-2,3-dicarboxylic acid, 1,4,5,6,7,7-hexachloro-, dibutyl ester Bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid, 1,4,5,6,7,7-hexachloro-, dibutyl ester Chlorendic acid dibutyl ester Dibutyl chlorendate NSC5261