1-Bromobenzocyclobutene is a useful synthon. It has important applications in organometallic methodology. Reaction between cycloheptatriene, bromoform, potassium carbonate and 18-crown-6 at 140°C yields 1-bromobenzocyclobutene.1-Bromobenzocyclobutene may be used in the synthesis of following compounds: · five-membered zirconacycles · benzocyclobutenol and benzocyclobutenone · 2,3-dimethoxyprotoberberinium bromide, via reaction with 3,4-dihydro-6,7-dimethoxyisoquinoline 1-Bromobenzocyclobutene is a useful synthon. It has important applications in organometallic methodology. Reaction between cycloheptatriene, bromoform, potassium carbonate and 18-crown-6 at 140°C yields 1-bromobenzocyclobutene.