Process for the preparation of tetrachlorophthalodinitrile by catalytic vapor-phasechlorination of o-phthalodinitrile

摘要

Tetrachlorophthalodinitriles, are produced by mixing o-phthalodinitrile in a vapour state and chlorine gas and passing the mixture continuously in a vapour state over an active carbon catalyst maintained at a temperature between 200-450 DEG C. so as to produce a catalytic chlorination of the o-phthalodinitrile. The active carbon catalyst may contain an additional substance e.g. potassium chloride, calcium chloride, barium chloride or acidic clay, in an amount from 0.1 to 50 times the weight of the active carbon. A diluent may be added to the o-phthalodinitrile and chlorine mixture, e.g. nitrogen, hydrochloric acid gas or carbon tetrachloride in a volume amount above 0.2 times the volume of the chlorine gas. The tetrachloride phthalodinitrile may be selectively separated from the reaction products by treating it with aliphatic alcohols, e.g. methyl, ethyl, isopropyl, butyl and amyl-alcohols at a temperature from room temperature to 150 DEG C. or by treating with aliphatic hydrocarbon chlorides, e.g. trichloroethylene and carbon tetrachloride or by using aromatic hydrocarbons such as benzene and xylene.