| 摘要 |
PURPOSE:In the gas-phase oxidative bromination of benzene or brombenzene using bromine or a combination of hydrogen bromide and oxygen, a Y-type zeolite bearing metallic copper and/or copper compounds is used as a catalyst to obtain the title compound in high selectivity. CONSTITUTION:A Y-type zeolite supporting more than 5wt%, preferably 5-200wt%, particularly 15-100wt% of metallic copper and/or copper compounds, calculated as copper element, is used as a catalyst to effect gas- phase oxidative bromination of benzene and/or brombenzene at a molar ratio of 0.5-5.0, preferably 0.8-3.0 (a) bromine and/or hydrogen bromide to (b) oxygen whereby p-dibromobenzene which is used as an intermediate of p- penylenediamine (a starting material for aramide fibers) or other material for various heat-resistant resin. The process can high reaction selectivity and the content of the p-isomer exceeds 80% with industrial advantage. |
