5,6,12,13-Tetrachloroanthra[2,1,9-def:6,5,10-d'e'f']diisochromene-1,3,8,10-tetraone 5g

5,6,12,13-Tetrachloroanthra[2,1,9-def:6,5,10-d'e'f']diisochromene-1,3,8,10-tetraone 5g