Synthesis of 1-benzazepines as precursors of 1-benzazepinediones

Abstract

The synthesis of 6-hydroxy-7-nitro-1-benzazepine-2-one 7 from 5-hydroxy-1 -tetralone 1 and 6-hydroxy-1 -benzazepine-2-one 2 is described. Bromination of 6-hydroxy- 1-benzazepine-2-one 2 with NBS in ethyl acetate afforded 7-bromo-6-hydroxy-1 -benzazepine-2-one 13 and 7,9-dibromo-6-hydroxy-1-benzazepine-2-one 14. Oxidation of benzazepinone 13 with (diacetoxyiodo)benzene provided 7-bromo-1-benzazepine-2,6,9-trione 5.