Preparation of a 1-Unsubstituted 2,3-Dihydro-1-benzazepine Derivative

We developed a three-step method of producing a 1-unsubstituted-2,3-dihydro-1-benzazepine derivative (2) from 11. The alkylation of 9, obtained from 11, and the subsequent intramolecular condensation of 12 in dialkyl carbonate with a metal alcoholate were conducted in one pot to afford 1-benzazepine (13) in good yield. 13 was then hydrolyzed to give 2 in 48% overall yield from 11. Furthermore, we synthesized the orally active CCR5 antagonist intermediate 18 from 2.