Crystallization-Induced Dynamic Resolution toward the Synthesis of (S)-7-Amino-5H,7H-dibenzo[b,d]-azepin-6-one: An Important Scaffold for γ-Secretase Inhibitors

An enantioselective synthesis of (S)-7-amino-5H,7H-dibenzo[b,d]azepin-6-one (S-1) is described. The key step in the sequence involved crystallization-induced dynamic resolution (CIDR) of compound 7 using Boc-d-phenylalanine as a chiral resolving agent and 3,5-dichlorosalicylaldehyde as a racemization catalyst to afford S-1 in 81% overall yield with 98.5% enantiomeric excess.