A new synthesis of oxcarbazepine using a Friedel–Crafts cyclization strategy

A novel, simple, and straightforward process for the large-scale synthesis of oxcarbazepine, the active ingredient of Trileptal®, a medicine for the treatment of epilepsy, has been developed. Starting from readily available 1,3-dihydro-1-phenyl-2H-indol-2-one, a Friedel–Crafts cyclization strategy provides a direct route to the tricyclic framework of the target molecule. Crucial to the success of the strategy was the choice of the proper nitrogen-protecting group.