Patent GB-365214-A (GB)
Title: Improvements in the manufacture and production of saturated amines
Filed: 1930-10-24
Abstract: The hydrogenation catalysts employed for the production of amines by treatment of carbonyl compounds with ammonia or amines in the presence of hydrogen, comprise finely-divided metals of the 8th periodic group which may be activated by the addition of metallic oxides or compounds furnishing the same, e.g. cobalt oxide, zinc carbonate and ammonium chromate, or substances having a weakly acid reaction, e.g. silica, or weakly alkaline reaction, e.g. lime, aluminium phosphate and calcium silicate.  According to examples, (1) nickel carbonate is soaked with chromic acid solution and reduced with hydrogen, (2) basic nickel carbonate is precipitated from a solution of nickel nitrate containing some kieselguhr and reduced with hydrogen; (3) nickel and cobalt hydrates are precipitated from a solution of nickel and cobalt nitrates containing kieselguhr and then reduced.ALSO:Saturated amines are prepared by condensing unsaturated carbonyl compounds containing at least five carbon atoms with primary amines and simultaneously or subsequently treating with hydrogen in the presence of a hydrogenation catalyst, the reaction being effected in the liquid phase using hydrogen under pressure. Instead of amines, ammonia may be employed when the hydrogenation is simultaneous, whilst the unsaturated carbonyl compounds may be replaced by aldols when elevated temperatures are employed.  The catalysts preferably comprise finely-divided metals of the 8th periodic group and may be activated by the addition of metallic oxides or compounds furnishing the same, e.g. cobalt oxide, zinc carbonate, and ammonium chromate, or substances having a weakly acid reaction, e.g. silica, or weakly alkaline reaction, e.g. lime, aluminium phosphate and calcium silicate.  The process may be effected intermittently in autoclaves or continuously in pressure tubes or towers, the liquid and gases then moving in countercurrent.  The ammonia and amines may be employed in equimolecular quantities with respect to the carbonyl compounds, but preferably in slight excess.  Liquid diluents, such as water or alcohol, may be present.  According to the examples, (1) the treatment of ethylpropylacrolein, prepared by condensing butyraldehyde with alkali and distilling the resulting butyraldol, with ammonia and hydrogen under pressure in the presence of a catalyst, prepared by soaking nickel carbonate with chromic acid solution and reducing, yields a -amino-b -ethylhexane; a -amino-b -methyl-n-pentane is obtained by similar treatment of methylethylacrolein using a catalyst prepared by precipitating basic nickel carbonate from a solution of nickel nitrate containing some kieselguhr and reducing; (2) ethylpropylacrolein is heated with ethylhexylamine and the Schiff's base formed is isolated and heated with hydrogen under pressure in the presence of nickel; a -amino-di [b -ethyl-n-hexane] is separated from the product; (3) b -isohexylamine is prepared by the hydrogenation of mesityl oxide in presence of ammonia and of a catalyst obtained by precipitating nickel and cobalt hydrates from a solution of nickel and cobalt nitrates containing kieselguhr and reducing; (4) a product consisting of n-butylamine, b -ethyl-hexylamine and b -ethyl-g -hydroxyhexylamine results when butyraldol is treated with hydrogen and ammonia in the presence of reduced nickel; (5) aniline is mixed with methylethylacrolein and a catalyst prepared by reducing nickel carbonate with hydrogen and heated with hydrogen under pressure; the product mainly consists of phenyl-(b -methyl-n-amyl)-amine; (6) a -methylcinnamic aldehyde, prepared according to Specification 284,458, [Class 2 (iii), Dyes &c.], is heated with hydrogen and ammonia to give b -methyl-g -phenyl-n-propylamine.  Specifications 304,640 and 328,381, [both in Class 2(iii), Dyes &c.], also are referred to.