3,6-cyclohexadiene-1,3-dicarbonitrile, 4,6-dichloro-2,5-dioxo- 4,6-dichloro-2,5-dioxocyclohexa-3,6-diene-1,3-dicarbonitrile InChI=1/C8Cl2N2O2/c9-5-3(1-11)7(13)4(2-12)6(10)8(5)1