GB416631A - Manufacture of nitriles of unsaturated fatty acids - Google Patents

Abstract

Nitriles of unsaturated fatty acids of high molecular weight are manufactured by passing a saturated or unsaturated hydroxy-fatty acid containing more than ten carbon atoms or an ester thereof, alone or mixed with a solvent or diluent, together with ammonia at a raised temperature, preferably about 300--450 DEG C., over a catalyst capable of splitting off water, e.g. aluminium oxide, thorium oxide or silica gel. As solvents or diluents may be employed other fatty acids, also nitriles, hydrocarbons or alcohols. The products may be used for the preparation of assistants in the textile industry or as intermediate products for obtaining substances having long carbon chains, e.g. higher unsaturated amines. In examples: (1) commercial ricinoleic acid is passed with ammonia at 350--360 DEG C. over silica gel, yielding a p doubly unsaturated nitrile C18H13N (ricinenic nitrile), which may be reduced with sodium and alcohol to the corresponding amine; (2) vitreous alumina is employed as catalyst in (1); (3) the ricinoleic acid of (1) is replaced by castor oil; (4) ricinoleic acid methyl ester is passed with ammonia at 350--370 DEG C. over bauxite, producing ricinenic nitrile; (5) a solution of a -hydroxystearic acid in a fatty acid nitrile is passed with ammonia at 350--450 DEG C. over silica gel to produce an unsaturated nitrile C17H33CN; (6) an alcoholic solution of a -hydroxystearic acid ethyl ester is similarly treated, giving the same product; (7) a -hydroxylauric acid is treated as in (5) to yield an unsaturated nitrile C11H21CH; (8) a solution of 9 : 10 - dihydroxystearic acid in a fatty acid nitrile is passed with ammonia at 400--450 DEG C. over silica gel, producing a doubly unsaturated nitrile C17H31CN.