2-CYCLOBUTEN-1-ONE, 2,3,4,4-TETRACHLORO- 3200-96-2 BRN 1864941 EINECS 221-704-6 NSC 125696 Perchloro-2-cyclobuten-1-one Perchloro-2-cyclobutene-1-one Perchlorocyclobut-2-enone Perchlorocyclobutenone Tetrachloro-2-cyclobutene-1-one Tetrachlorocyclobut-2-enone Tetrachlorocyclobutenone