| 摘要 |
A process for the chlorination of a hydrocarbon or a partially halogenated derivative thereof comprises allowing chlorine to act on a hydrocarbon or a partly halogenated derivative thereof in the gas phase at a temperature at or above its boiling point up to about 400 DEG C. in the presence of a catalyst which contains a halide of a platinum metal. The catalysts specified comprise platinum, palladium, iridium and rhodium as halides, e.g. chlorides, bromides and iodides. Carriers specified include aluminium oxide, silica gel, pumice, fuller's earth and active carbon and such carriers may be impregnated with aqueous solutions of compounds of the platinum metals and heated. Catalysts so prepared may be treated with chlorine before use. The catalysts may optionally be employed in fluidized form. The starting materials may be vapourized before feeding to the reaction vessel or may be vaporized therein. Preferably an inert organic solvent, e.g. a chlorinated hydrocarbon may be led into the reaction at the same time as the starting material. The chlorine may be mixed with nitrogen or other inert gas. Included among the starting materials mentioned are alkanes from methane to octane including the normal and branched chain forms and partially halogenated derivatives thereof, cyclopentane, cyclohexane, methyl cyclohexane, benzene, toluene xylene, indene, diphenyl and naphthalene and their partially halogenated derivatives of trichlorobenzene. Mixtures of hydrocarbons may be chlorinated, e.g. a mixture of cyclohexane and naphthalene. In examples: Para-dichlorobenzene, together with some ortho,-di-and1, 2, 4-trichlorobenzenes is obtained by continuous chlorination of benzene in the presence of a palladium chloride catalyst supported on aluminium oxide whilst similar results are obtained with iridium, rhodium and platinic chlorides on aluminium oxide or palladium chloride on silica (1); normal hexyl chloride is obtained by chlorinating normal hexane in the presence of carbon tetrachloride under similar conditions (2); cyclohexyl chloride is obtained by chlorination of cyclohexane in the presence of carbon tetrachloride and nitrogen with a fluidized palladium chloride or aluminium oxide catalyst-(3); and toluene is chlorinated to obtain mono- and dichlorotoluene in the presence of nitrogen and a palladium chloride catalyst supported on alumina. Specification 738,992 is referred to. |
