Benz oxadiazepines

Quinoxaline /V-oxides undergo rearrangements when UV-irradiated. 2,3-Diphenylquinoxaline 1-oxide (224) was originally thought to rearrange to the oxazirino[2,3-a]quinoxaline (225).225 However, subsequently the product was found to be 2,4-diphenyl-3,l,5-benz-oxadiazepine (226).226 This reassignment was supported by NMR spectroscopy, and oxadiazepine formation on irradiation of 2,3-bis(4-bromophenyl)quinoxaline 1-oxide was confirmed by X-ray crystallography.227... 

Ring expansion has also been observed in the transformation of certain 1-cyano- and 1-phenylisoquinoline 2-oxides to the corresponding benz[/]-l,3-oxazepines,163 of phenyl-substituted quinoxaline 1-oxides to the substituted benz[d]-l,3,6-oxadiazepines,161 164 and of 4-phenylquinazoline 3-oxide (190) to 2-phenylbenz[/]-l,3,5-oxadiazepine (191).165... 

Ci9H2 6N Ob, (2,3 11,12)-rDibenzo-1,13-dioxa-5,9-diazonia-2,11-cyclo-pentadecadiene dinitrate, 456, 413 Cl9H35CIN2O9, 3,6,9,12,15-Pentaoxa-21-azabicyclo[15.3.1]heneicosa-1(20),17,l9-triene t-butylammonium perchlorate, 456, 413 C2oHi2Br2N20, 2,4-6is-(4-bromophenyl)benz[d](1,3,6)oxadiazepine,... 

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