Hexafluorocyclobutene is the organofluorine compound with the formula (CF2)2(CF)2.

A colorless gas, it is a precursor to a variety of compounds, including squaric acid.

[1] Hexafluorocyclobutene is prepared in two steps from chlorotrifluoroethylene.

The thermal dimerization gives 1,2-dichloro-1,2,3,3,4,4-hexafluorocyclobutane.

[2] Dechlorination of the latter gives hexafluorocyclobutene:[3] Reminiscent of perfluoroisobutene, hexafluorocyclobutene is quite toxic with an LD = 6000 mg/min/m−3 (mice).