Patent GB-304640-A (GB)
Title: Catalytic reduction and hydrogenation of organic nitrogen compounds
Filed: 1928-03-19
Abstract: 304,640. Selden Co., (Assignees of Jaeger, A. 0.). Jan. 23, 1928, [Convention date]. Organic nitrogen compounds.-Reduction and hydrogenation of organic nitrogen compounds are effected in presence of catalysts formed of zeolites, which may be the multi-component zeolites described in Specification 279,466, or non-siliceous base-exchange bodies of the kind described in Specification 286,212, with which catalytically active components are associated either combined in an exchangeable or non-exchangeable form, or in physical admixture or associated with diluents, or in the form of anions forming salt-like bodies. The base-exchange bodies are formed by reaction of a silicate with metal salts or metallates or with both metal salts and metallates or by reaction of metal salts and metallates either in presence of water or by fusion in presence of fluxes. Natural base-exchange bodies such as nepheline, felspar, leucite, &c. may be used. The base-exchange bodies may be formed on or in admixture with diluents or massive carriers such as kieselguhr, celite, siliceous bodies, other base-exchange bodies, powdered rocks, stones, tuff, trass, or lava, greensand, glauconite, which may be leached with acid, slag wool, cement, sand, silica gel, pulverized earthenware, fullers earth, talc, glass powder, pumice, asbestos, graphite, activated carbon, quartz, metal powders, salts, particularly copper salts of oxymetal acids such as tungstates, vanadates, chromates, uranates, manganates, cerates or molybdates, silicates of copper; iron, nickel, cobalt, aluminium, or titanium, .or minerals or ores rich in copper. Stabilizers consisting of compounds of alkali, alkaline earth, or strongly basic earth metals, and stabilizer promoters consisting of substances which are not specific catalyst for the reaction, such as compounds of the metals of the fifth and sixth groups may be added, and salts-like bodies, may be formed by treatment with compounds containing simple or complex acid radicals of the elements, chromium, vanadium, tungsten, uranium, molybdenum, manganese, tantalum, niobium, antimony, selenium, tellurium, phosphorus, bismuth, tin, chlorine, platinum, or boron. The base-exchange bodies may be leached with sulphuric, hydrochloric or nitric acid to remove some or all of the exchangeable bases, and of the basic portion of the nucleus. Metal compounds which may be used to form the basic portion of the baseexchange bodies are those of copper, silver, gold, bismuth, beryllium, zinc, cadmium, boron, aluminium, rare earths, titanium, zirconium, tin, lead, thorium, niobium, antimony, tantalum, chromium, molybdenum, tungsten, uranium, - vanadium, manganese, iron, nickel, cobalt, platinum or palladium, and these metals may be in the form of complex ions associated with ammonia, hydrocyanic, oxalic, formic, tartaric or citric acid, glycerine, &c. These compounds may be reacted with alkali metals, salts of amphoteric metals, or of acids of boron, phosphorus, nitrogen, tin, titanium, vanadium, tungsten, chromium, niobium, tantalum, uranium, antimony or manganese. The reactions are carried out in the liquid or vapour phase, and with excess of hydrogen or gases containing hydrogen, such as water gas. The apparatus is preferably formed of copper. If iron is used, the surfaces are rendered inactive either by coating them with the contact substances or treating them with alkali salts of acids or metals of the fifth and sixth groups. The reactions which may be carried out -are the reduction of aromatic nitro compounds or 'halogen derivatives thereof to the corresponding amino or intermediate bodies, such as reduction of nitrobenzene to aniline or to azoxy-, azo-, or hydrazo-benzene, of alpha-nitronaphthalene to alpha-naphthylamine, of nitrophenols to aminophenols, of 3- nitropyridine to 3-aminopyridine, of nitroanisole to the corresponding amine, of aliphatic nitro bodies such as alkyl nitrites or nitromethane to amines and of oximes. Schiff's bases and nitrites to amines. Hydrogenation may take place simultaneously with the formation of hydrogenated -amines, for example, cyclohexylamine, dicyclo- 'hexylamine and cyclohexylaniline from nitrobenbene. Or hydrogenation only may take place, for example, of pyridine to piperidine or to amylamine, pyrrol to pyrrolidine, and quinoline to tetrahydroquinoline. Specifications 8462/14, 13149/14, 1358/15, and 153,290, [all in Class 1 (i), Chemical processes &c.], also are referred to.