Processes for the preparation of enamines

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

• (A) reacting, in a reaction zone that comprises solvents, pyrrolidine and 3-methylsulfanyl-butyraldehyde to produce 1-(3-methylsulfanyl-but-1-enyl)-pyrrolidine and H2O, wherein said reacting, in said reaction zone, is conducted under azeotropic distillation conditions comprising
• (1) a pressure from about 5000 Pascals (Pa) to about 15,000 Pa, and
• (2) a temperature from about 25° C. to about 65° C.;
• and
• wherein said solvents are initially toluene and acetonitrile, and then H2O, where said H2O is produced from the condensation of said pyrrolidine and said 3-methylsulfanyl-butyraldehyde to produce said 1-(3-methylsulfanyl-but-1-enyl)-pyrrolidine, thereby forming a ternary azeotrope of toluene, acetonitrile, and H2O;
• and
• (B) removing a vapor phase from said reaction zone wherein said vapor phase comprises H2O;
• wherein said process no desiccants are used to remove H2O;
• wherein said process said molar ratio of pyrrolidine to 3-methylsulfanyl-butyraldehyde is greater than 1 but less than about 1.1.