Patent GB-401353-A (GB)
Title: Reaction products of ketones and amines
IPC: C08K11/00
Filed: 1932-05-12
Abstract: Ketone-amine reaction products are manufactured by reacting a ketone with an amine containing only secondary amino groups at a temperature not exceeding about 100 DEG  C. in the presence of hydriodic or hydrobromic acid, preferably the former, or mixtures thereof, alone or in conjunction with known catalysts, the amount of acid being such as to enable it only to function as a catalyst, i.e. an amount considerably less than the equivalent of the amine employed.  The reaction may be carried out by refluxing at atmospheric pressure, or by heating up to 100 DEG  C. under increased pressure.  The products may be employed as anti-oxidants for rubber.  In some cases their anti-oxidant properties are improved by heating the dried reaction product to a sufficiently high temperature to produce a further condensation within the material with elimination of water.  The products may be further improved by treatment with alkali solutions, e.g. ammonia or sodium or potassium hydroxide, if desired in the presence of organic solvents such as acetone or alcohol, and preferably removing excess alkali by washing with water.  With efficient agitation a certain improvement is obtained by washing with water alone.  In examples: (1) phenyl-b -naphthylamine and acetone are refluxed together in the presence of hydriodic acid, excess acetone and water then being distilled off; (2) the reaction of (1) is carried out at 100 DEG  C. under increased pressure; (3) as (2) using less hydriodic acid; (4) the reaction of (1) is carried out in two stages, acetone and water being intermediately distilled off or the aqueous layer decanted, and fresh acetone then added, together with a fresh quantity of catalyst when employing decantation; (5) diphenylamine and acetone are refluxed together in the presence of hydriodic acid, and acetone and water are then distilled off; the dried reaction product is heated to 250 DEG  C. to improve its antioxidant properties; the product of (1) may be similarly improved by heating to 150 DEG  C.  As additional starting materials are specified on the one hand diethyl ketone, ethyl methyl ketone, acetophenone, benzophenone, phorone, cyclopentanone, benzalacetone, furfuralacetone and mesityl oxide, and on the other hand a -a - or b -b - dinaphthylamine, N-N<1>-diphenylethylenediamine, monomethylaniline, monoethylaniline, phenyl-a -naphthylamine, N-N<1>-di-a -a - or b  b - naphthyl-p-phenylenediamine.  The process is applicable to the production of ketone-amine reaction products as such or as a first step in the preparation of their aldehyde or other derivatives.ALSO:As antioxidants for rubber may be employed the products obtained by reacting a ketone, e.g. acetone, diethyl ketone, ethyl methyl ketone, acetophenone, benzophenone, phorone, cyclopentanone, benzalacetone, furfuralacetone or mesityl oxide, with an amine containing only secondary amino groups, e.g. phenyla  - or b -naphthylamine, diphenylamine, a  - a  - or b -b -dinaphthylamine, N-N1-diphenylethylene-diamine, monomethylaniline, monoethylaniline, or N-N1-di-a -a - or b -b -naphthyl-p-phenylene diamine, at a temperature not exceeding about 100 DEG  C. in the presence of hydriodic or hydrobromic acid or a mixture thereof, alone or in conjunction with known catalysts. In some cases the antioxidant properties are improved by heating the dried reaction product to a sufficiently high temperature to produce a further condensation within the material with elimination of water.  The products may be further improved by treatment with alkali solutions, e.g. ammonia or sodium or potassium hydroxide, if desired, in the presence of organic solvents such as acetone or alcohol, and preferably removing excess alkali by washing with water.  With efficient agitation a certain improvement is obtained by washing with water alone.