Synonyms: Cyclobutenedione,dichloro- (7CI,8CI); 1,2-Dichloro-1-cyclobutene-3,4-dione;1,2-Dichloro-1-cyclobutenedione; 1,2-Dichlorocyclobutene-3,4-dione;3,4-Dichloro-1,2-cyclobutenedione; 3,4-Dichloro-3-cyclobuten-1,2-dione;3,4-Dichloro-3-cyclobutene-1,2-dione; 3,4-Dichlorocyclobutenedione;Dichlorocyclobutene-1,2-dione; Dichlorocyclobutenedione; Quadratic aciddichloride; Squaric acid dichloride; Squaryl dichloride