Abstract
Irradiation of 4-azidoisoquinolines (1a-e) in the presence of sodium methoxide resulted in ring-expansion to give 5-methoxy-1H-2, 4-benzodiazepines (10) : the structures of the products were confirmed by the following chemical studies as well as spectral analyses. Treatment of the diazepines (10) with hydrochloric acid or acidic alumina in methanol resulted in ring-contraction to afford 1-aminoisoindolenines (14), and treatment with acetic anhydride gave the ring-opened products (16). The diazepines (10) were also converted to 1-methoxyisoindolenines (19) by further irradiation and to the diazepin-3-one (21) by treatment with either mesitylnitrile oxide or lead tetraacetate.
