Isomer separation - from chlorination and nitration products of benzene and toluene

摘要

Dichloro-, trichloro-, dichloronitro- or trichloronitro-benzene or nitro-, chloro-, dichloro- or nitrochlorotoluene can be separated into their isomers, by modification of process disclosed in parent patent in which p-nitrochlorobenzene is continuously separated from an o-/p-/m- nitrochlorobenzene isomer mixt. by fractional crystallisation and filtering to form a crystal prod. enriched by 85 - 95% p-nitrochlorobenzene, which is purified by pressing.