O-Alkyl (N-phenylanthranilo)hydroxamic acids 2, easily available by condensation of Nphenylanthranilic acid 1 with 1,1’-carbonyldiimidazole and the appropriate hydroxylamine in tetrahydrofuran, are cyclized by oxalyl chloride in the presence of imidazole to give 4-alkoxy-2,3,4,5- tetrahydro-1H-1,4-benzodiazepine-2,3,5-triones (3) in fair to good yields