Patent GB-950151-A (GB)
Title: Production of n,n-secondary dialkyl aryldiamines
Inventor: SUTER HUBERT
IPC: C07C209/18
Filed: 1962-05-17
Abstract: N-N1-secondary dialkylaryl diamines are prepared in a continuous process by treating aryl diamines with secondary alkanols at above 150 DEG C. in the liquid phase and at a raised pressure in the presence of a catalyst containing nickel and (or) cobalt and in the presence or absence of hydrogen or other inert gas. Specified aryl diamines are o, m- and p-phenylene diamine and 1, 4- and 1,5-diaminonaphthalene. Specified secondary alcohols are isopropanol, 2-octanol and secondary butyl and amyl alcohols. The process may be combined directly with the preparation of the diamino aryl compound by hydrogenation of the corresponding dinitro or nitroamino compound, the alcohol required for the alkylation process being used as a solvent in the reduction process. The catalyst may be Raney nickel or Raney cobalt and may be used as such or in association with copper and (or) manganese as promoters. Addition to the catalyst of up to 4% of alkali compounds (calculated as oxides), e.g. alkali hydroxides, carbonates or silicates, is advantageous. The catalyst may be used in granulated, tableted or pelleted form and may be deposited on inert carriers. A number of carriers are specified. In the examples, (1) a solution of p-phenylene diamine in secondary butyl alcohol is passed at 160-180 DEG C. under 14 atm. pressure through a column charged with a granulated catalyst consisting of nickel 15, copper 5 and manganese 1% supported on pumice; N, N1-di-sec.-butyl-p-phenylene diamine is obtained; (2) a solution of p-nitraniline in secondary butyl alcohol is fed to a first reaction vessel together with hydrogen at 160-180 DEG C. and 14 atm. pressure, the vessel containing a catalyst comprising 20% of copper on silica pellets; the product, after release of gas, is passed to a second reaction vessel under the same temperature and pressure, the second vessel containing a nickel catalyst, as described in example 1; N,N1-di-sec.-butyl-p-phenylene is again obtained with some N-mono-sec.-butyl-p-phenylene diamine; (3) a solution of p-nitraniline in secondary butyl alcohol is fed with hydrogen under 14 atm. pressure to a column charged with a catalyst as described in example 1; reduction of p-nitraniline to p-phenylene diamine takes place at 160 DEG C. in the upper part of the column and alkylation of the p-phenylene diamine at 170-180 DEG C. proceeds in the lower part.ALSO:Catalysts for use in the continuous production of diamines comprise nickel and/or cobalt which may be Raney nickel or Raney cobalt and may be used as such or in association with copper and/or manganese as promoters.  Addition to the catalyst of up to 4% of alkali compounds (calculated as oxides), e.g. alkali hydroxides, carbonates or silicates, is advantageous.  The catalyst may be used in granulated, tableted or pelleted form and may be deposited on inert carriers.  Specified carriers are diatomaceous earth, clay, kaolin, bleaching earths, pumice, bauxites, silica gel, aluminium oxide, zinc oxide, thorium oxide, mixtures of these oxides, and "Bayer mass", a product obtained in the production of aluminium oxide and having the approximate composition ferric oxide 40-50, aluminium oxide 17-25, silica 2-10, titanium dioxide 3-8, alkaline-earth oxides 0,2-4 and alkali-metal oxides 2-5% by weight, the balance being water.  In the examples, (1) a solution of p-phenylene diamine in secondary butyl alcohol is passed at 160-180  DEG C. under 14 atm. pressure through a column charged with a granulated catalyst consisting of nickel 15, copper 5 and manganese 1% supported on pumice; N,N1-di-sec.-butyl-p-phenylene diamine is obtained; (2) a solution of p-nitraniline in secondary butyl alcohol is fed to a first reaction vessel together with hydogen at 160-180  DEG C. and 14 atm. pressure, the vessel containing a catalyst comprising 20% of copper on silica pellets; the product, after release of gas, is passed to a second reaction vessel under the same temperature and pressure, the second vessel containing a nickel catalyst, as described in example 1; N,N1-di-sec.-butyl-p-phenylene diamine is again obtained, with some N-mono-sec.-butyl-p-phenylene diamine; (3) a solution of p-nitraniline in secondary butyl alcohol is fed with hydrogen under 14 atm. pressure to a column charged with a catalyst as described in example 1; reduction of p-nitraniline to p-phenylene diamine takes place at 160  DEG C. in the upper part of the column and alkylation of the p-phenylene diamine at 170-180  DEG C. proceeds in the lower part.