Process for the preparation of saturated or unsaturated primary fatty amines
Process for the preparation of unsaturated and saturated primary fatty amines comprising the steps of chlorination, treatment by ammonia, reduction and purification.
1. A process for the preparation of unsaturated and saturated primary fatty amines comprising the steps of:
(a) chlorination of the corresponding acid by treatment with neat thionyl chloride in dichloromethane at reflux temperature, to obtain a solution of the corresponding chloride in dichloromethane,
(b) addition of the chloride solution of step a) to a solution of liquid ammonia in dichloromethane at a temperature comprised between 0 and 10° C. to yield the corresponding amide,
(c) reduction of the amide to amine by treatment with lithium aluminium hydride in tetrahydrofuran, followed by extraction of amine by t-butyl methyl ether,
(d) purification of amine of step c) by treatment in solution in t-butyl methyl ether by hydrochloric acid followed by treatment by acetonitrile to yield amine hydrochloride, and optionally
(e) treatment of amine hydrochloride of step d) by t-butyl methyl ether and a base to yield amine as a free base.
2. The process according to claim 1 , wherein the primary saturated and unsaturated fatty amines are selected from the group consisting of amines comprising 4 to 30 carbon atoms, unsaturated amines being allowed to comprise one or more double bonds, isomers and salts thereof.
3. The process according to claim 1 , wherein the amines are selected from the group consisting of oleylamine, stearylamine and their respective isomers and salts.
4. The process according to claim 1 , wherein the acid used in step a) is oleic acid.
5. The process according to claim 2 , wherein the amines are selected from the group consisting of oleylamine, stearylamine and their respective isomers and salts.
6. The process according to claim 2 , wherein the amines comprise 15 to 24 carbon atoms.
7. The process according to claim 4 , wherein the acid is oleic acid with more than 99% purity.