A new protocol for the synthesis of 4,7,12,15-tetrachloro[2.2]paracyclophane

• Donghui Pan,
• Yanbin Wang and
• Guomin Xiao

Beilstein J. Org. Chem. 2016, 12, 2443–2449, doi:10.3762/bjoc.12.237

• sodium hydroxide solution instead of silver oxide for anion exchange, results in a significant improvement in product yield. Furthermore, four substituted [2.2]paracyclophanes were also prepared in this convenient way. Keywords: bromination; dimerization; H2O2–HBr system; paracyclophane; polymerization

• drawbacks such as low atom efficiency and the requirement of reagent residue elimination [14]. In contrast to traditional brominating reagents, the H2O2–HBr system, which generates active bromine in situ, is a convenient and green brominating agent [15]. Furthermore, the use of the H2O2–HBr couple improves

• . Results and Discussion We initially planned to optimize the reaction conditions for the bromination of the benzylic position of 2,5-dichloro-p-xylene (1) by using the H2O2–HBr system, and investigated various factors, including the activation mode, the reagent stoichiometry, the solvent, and the reaction