Improvements in or relating to the manufacture of halogen substituted aromatic nitriles

The invention comprises an improvement in the process described in the parent Specification for the preparation of o : o1-dihalo-nitriles, wherein the o : o1-dinitrocyano or o-halo-o-nitrocyano compound is passed in fluid state in countercurrent to a stream of chlorine or thionyl chloride. In an example molten 2-chloro-6-nitrobenzonitrile or 2 : 6-dinitrobenzonitrile was passed down a heated packed glass tube and chlorine was introduced at the base of the tube, the product 2 : 6-dichlorobenzonitrile being collected at the base of the column.