A process for the preparation of amines, comprising the steps:
- a) performing an O-alkylation of one or more compounds by reacting said compounds with an alkylating agent in a reaction mixture, wherein said alkylating agent is selected from the group consisting of:
- alkyl halides;
- esters of sulphonic acid;
- esters of fluorosulphonic acid;
- esters of trifluoromethanesulphonic acid;
- esters of chloroformic acid;
- oxonium salts;
- dialkyl sulphates;
- and diazomethane and said compounds are selected from the group consisting of:
- i) a carboxylic acid amide of the general formula (I):
- wherein:
- R is selected from the group consisting of:
- H, (C1-C24)-alkyl, (C3-C20)-cycloalkyl, (C2-C13)-heterocycloalkyl, (C6-C14)-aryl, (C3-C13)-heteroaryl and the acid radical of an amino acid selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine;
- and
- R1 and R2, independently of one another, are selected from the group consisting of:
- H, (C1-C24)-alkyl, (C3-C8)-cycloalkyl, (C2-C7)-heterocycloalkyl, (C6-C14)-aryl or (C3-C13)-heteroaryl, where both the radicals R with R1, R with R2 and also R1 with R2 may, independently of one another, form a saturated or mono- or polyunsaturated (C2-C18)-alkylene or (C2-C18)-heteroalkylene bridge, such that an aliphatic or aromatic ring having in total 3-20 ring atoms is formed;
- ii) a carboxylic acid diamide of the general formula (II):
- wherein:
- R′″ is selected from the group consisting of divalent (C1-C24)-alkyl radicals, (C3-C20)-cycloalkyl radicals, (C2-C13)-heterocycloalkyl radicals, (C6-C14)-aryl radicals, (C3-C13)-heteroaryl radicals;
- and
- R′ and R″, independently of one another, are selected from the group consisting of H, (C1-C24)-alkyl, (C1-C24)-heteroalkyl, (C3-C8)-cycloalkyl, (C2-C7)-heterocycloalkyl, (C6-C14)-aryl or (C3-C13)-heteroaryl, where the radicals R′ with R″ may together form a saturated or mono- or polyunsaturated (C2-C18)-alkylene or (C2-C18)-heteroalkylene bridge, such that an aliphatic or aromatic ring having in total 3-20 ring atoms is formed;
- iii) a di-, tri- or polypeptide, and
- iv) a peptide amide with a carboxy-terminal amide function;
- b) adding a hydrogenation catalyst to the reaction mixture, wherein the molar ratio of hydrogenation catalyst to carboxylic acid amide, or carboxylic acid diamide, or di-, tri- or polypeptide or peptide amide, is in a range of from 1:10 to 1:100 000;
- c) reacting the reaction mixture with hydrogen, at a hydrogen pressure of from 0.1 bar to 200 bar and at a temperature of from 0° C. to 250° C.