Efficient Synthesis of Functionalized Benzazepine Derivatives Utilizing Intramolecular Mitsunobu Reaction

The 5-hydroxy-2,3,4,5-tetrahydro-1H-benzazepine derivative (2), which is a typical metabolite of mozavaptan (1) having the 2,3,4,5-tetrahydro-1H-benzazepine skeleton, was synthesized by utilizing the intramolecular Mitsunobu reaction of the corresponding 2-(4-hydroxybutyl)aniline derivative. In the intramolecular Mitsunobu reaction, effect of the substituent group on nitrogen atom, influence of the functional group applying to synthesis of the other metabolites (3, 4 and 5) and utilization of synthesis of 2-substituent benzazepine derivatives were investigated.