Patent GB-748127-A (GB)
Title: Improvements in or relating to organic halides prepared from ammonium halides and organic oxygen, sulphur and nitrogen bearing compounds
IPC: C07B39/00
Filed: 1952-11-28
Abstract: Halogen-substituted organic compounds are obtained by forming a slurry of a solid ammonium or organic substituted ammonium halide (but excluding iodides) containing at least one H atom attached to the N atom in a polychlorobenzene or tetraphenylsilicon, heating such slurry, and reacting the ammonium halide with an organic compound consisting of an alcohol, ether, aldehyde, ketone, ester, thioalcohol, thioether, thioester or amine at 250-500 DEG  C. in the presence of a dehydro chlorination catalyst of acidic to mildly alkaline character.  The catalyst may be suspended in the slurry along with the ammonium halide or the latter may be vaporized from the slurry and the resulting vapours separately reacted with the organic compound in the presence of the catalyst.  The latter procedure may be further modified by passing an inert gas such as carbon dioxide, steam, or nitrogen through the slurry to assist in the vaporization of the ammonium halide.  The process may be operated batchwise or continuously.  In the batchwise operation a vessel is charged with the organic liquid and internal or external heating means are provided.  Ammonium halide is charged to the heating vessel along with the organic liquid and the resulting slurry is then heated and the vaporized ammonium halide passed to a reaction zone where it is contacted with vapours of the organic compound in the presence of the catalyst.  When the catalyst is also in suspension in the organic liquid the organic compound is introduced as vapour or liquid until the proportion of ammonium halide is too low to maintain a satisfactory degree of conversion.  The operation may be made continuous by the addition continuously or intermittently of fresh ammonium halide to the slurry containing the catalyst and a portion of the slurry removed from the heating chamber, filtered, and returned to the heating chamber with addition of fresh catalyst.  The organic compound is injected continuously as vapour or liquid into the slurry and a long transfer line is provided for adequate reaction time.  The slurry then passes through a separating zone where the vaporized reaction products are separated.  If the reaction is incomplete it may be completed in a second reaction zone which may contain catalyst in the form of a fluidized bed, fixed bed, or a moving compact bed in pill form.  The organic halide is separated from the gaseous products in a fractionating column and by-products, and unreacted materials may be returned to the system.  The preferred catalyst is alumina which is preferably activated before use, e.g. by heating at about 200 DEG  C. for 15 hours.  The process is normally carried out at atmospheric pressure but may also be operated at reduced or elevated pressure.  Specified organic compounds which may be used as starting materials are methanol, ethanol, isopropanol, isoamyl alcohol, lauryl alcohol, cycloaliphatic alcohols, e.g. cyclohexanol and aromatic substituted alcohols, e.g. benzhydrol.  In examples a slurry of ammonium chloride and alumina in 1,2,3,4-tetrachlorobenzene or pentachlorobenzene is maintained at 250 DEG  C. in an externally-heated reaction chamber.  Ethanol is vaporized and passed through the slurry and the product passed to a condensing system for the recovery of ethyl chloride.