Scheme 4.

The lipase‐catalyzed BASF process for the kinetic resolution of amines. Enantioselectivity is often essentially perfect and conversions quantitative, the amide and amine can be separated by distillation, the amide is readily hydrolyzed (giving access to both enantiomers), and the undesired enantiomer can be racemized and recycled. The process can also be run neat (e. g. in the case of 1‐methoxy‐2‐aminopropane). ^[108b] Other esters than the ethyl may be used; however, the methoxy‐group is critical for an efficient reaction.