| 摘要 |
PURPOSE:To provide paradichlorobenzene in an improved chlorination rate in an improved selectivity, while the by-production rate of chlorine adducts such as BHC and pentachlorocyclohexene is remarkably reduced. CONSTITUTION:Benzene is chlorinated in the presence of zeolite as a catalyst and in the coexistence of 1,2-dichloroethane, bromochloromethane or molecular oxygen in a liquid phase to directly produce para-dichlorobenzene in a high selectivity. The chlorination reaction of the benzene is performed at 50 deg.C to a temperature below the boiling point of the reaction solution under the ordinary pressure or an elevated pressure and subsequently finished at the time when the number of chlorine atoms substituted on the benzene reaches 1.4-2.0. |
