Improved synthesis of (S)-7-amino-5H,7H-dibenzo[b,d]azepin-6-one, a building block for γ-secretase inhibitors

An improved synthesis of (S)-7-amino-5H,7H-dibenzo[b,d]azepin-6-one (1), involving a selective crystallization of epimeric menthylcarbamates for the resolution step followed by simultaneous cleavage of the carbamate and the lactam protecting group is described. Epimerization conditions of the undesired epimer have also been determined.