What is "benzocyclobutadiene"

Benzocyclobutadiene is the simplest polycyclic aromatic hydrocarbon, being composed of a benzene ring fused to a cyclobutadiene ring. It has chemical formula . Though the benzene ring is stabilized by aromaticity, the cyclobutadiene portion has a destabilizing effect. For this reason, benzocyclobutadiene will readily dimerize or polymerize and it reacts as a dienophile in Diels-Alder reactions.

One known use of Benzocyclobutadiene was in the production of naflocort.