Processes for the Preparation of Enamines

A process to produce 1-(3-methylsulfanyl-but-1-enyl)-pyrrolidine said process comprising:

• (A) contacting, in a reaction zone, a first mixture with a second mixture
• (1) wherein said first mixture comprises a carbonyl wherein said carbonyl is 3-methylsulfanyl-butyraldehyde, and
• (2) wherein said second mixture comprises toluene and an amine wherein said amine is pyrrolidine;
• (B) reacting in said reaction zone said amine and said carbonyl to produce an enamine and H2O, wherein said enamine is 1-(3-methylsulfanyl-but-1-enyl)-pyrrolidine, and wherein reacting is conducted under azeotropic distillation conditions comprising
• (1) a pressure from about 100 Pascals (Pa) to about 120,000 Pa, and
• (2) a temperature below about the thermal decomposition temperature of said enamine during said reacting;
• and
• (C) removing a vapor phase comprising said toluene, amine, and H2O;
• and
• (D) condensing said vapor phase from step (C) to produce a condensate;
• and
• (E) contacting said condensate from step (D) with a recovery mixture comprising H2O, toluene, amine, and sodium hydroxide to produce a separate mixture comprising said amine and said toluene, and another mixture comprising H2O and sodium hydroxide;
• and
• (F) optionally, returning said mixture comprising amine and toluene from step (E) back to said reaction zone;
• wherein said process no desiccants are used to remove water and
• wherein said process the molar ratio of amine to carbonyl is greater than 1 but less than about 1.1.