GB568230A - Improvements in or relating to the production of n.n -disecondary alkyl p-phenylene diamines - Google Patents

Abstract

N : N1 - di - secondary alkyl - p - phenylene diamines are prepared by heating p-phenylene-diamine with a dialkyl ketone in the presence of hydrogen and a hydrogenation catalyst at a temperature of 100-200 DEG C. and at elevated pressure. The reaction may be conducted in the presence of a solvent such as an alcohol, an ether, a hydrocarbon or in the presence of an excess of the particular ketone used. In examples: (1) para - phenylene - diamine is reacted with acetone in the presence of a copper chromite catalyst in a high-pressure autoclave at 140-170 DEG C., at 1200-1600 lbs./sq. in. hydrogen pressure. Instead of acetone methyl ethyl ketone or methyl-n-propyl ketone may be used; (2) p-phenylene-diamine and acetone are reacted as in example (1), but using isopropyl alcohol as a solvent; (3) p-phenylene-diamine is reacted with methyl n-propyl ketone at 134-139 DEG C., under 1020-1940 lbs./sq. in. hydrogen pressure in the presence of a copper-chromium - barium oxide catalyst; (4) p-phenylene-diamine and acetone are reacted in the presence of isopropyl alcohol and a Raney nickel catalyst at 125 DEG C., under 1200-2140 lbs./sq. in. hydrogen pressure; (5) as in example (4), using varying proportions of ingredients.