title: A new protocol for the synthesis of 4,7,12,15-tetrachloro[2.2]paracyclophane.
abstract: We report a green and convenient protocol to prepare 4,7,12,15-tetrachloro[2.2]paracyclophane, the precursor of parylene D, from 2,5-dichloro-p-xylene. In the first bromination step, with H2O2-HBr as a bromide source, this procedure becomes organic-waste-free and organic-solvent-free and can appropriately replace the existing bromination methods. The Winberg elimination-dimerization step, using aqueous 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.
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, 2 Dongnan Daxue Road, Nanjing, Jiangsu, 211189, P. R. China.
authors.forename: Donghui
authors.initials: D
authors.lastname: Pan
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, 2 Dongnan Daxue Road, Nanjing, Jiangsu, 211189, P. R. China.
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, 2 Dongnan Daxue Road, Nanjing, Jiangsu, 211189, P. R. China.
authors.forename: Guomin
authors.initials: G
authors.lastname: Xiao
keywords: H2O2–HBr system; bromination; dimerization; paracyclophane; polymerization inhibitor