l-Bromobenzocyclobutene (1). A 250-mL flask, equipped with condenser, drying tower, and efficient magnetic stirrer, wm charged with cycloheptatriene (freshly distilled, 27.6 g, 300 mmol), bromoform (freshly distilled, 25.3 g, 100 mmol), anhydrous K&03 (15.0 g, 109 mmol), and 18-crown-6 (0.75 8). The reaction vessel was immersed in an oil bath preheated to 145" C. Progress of the reaction was monitored by regular VPC analysis. After ca. 10 h the ...
