Method for decarboxylation of amino acids via imine formation

A method for decarboxylation of amino acids to produce an amine via an imine intermediate, the method comprising:

• (a) combining, in a pressurized reaction vessel, a mixture of an amino acid, a solvent, and a catalyst, the catalyst comprising a ketone, enone, enal, aldehyde, or combination thereof;
• (b) heating the mixture at about 180° C., or more, for about 5 minutes, or more, wherein the amino acid is converted to its imine;
• (c) cooling the reaction mixture from step (b) in the reaction vessel to a temperature below the boiling point of the solvent;
• (d) adding an acid to the cooled reaction mixture from step (c) in the vessel;
• and
• (e) heating the acid reaction mixture from step (d) to about 50° C., or more, to hydrolyze the imine to form an amine.