Synthetic routes to 1,5-dihydro-5-oxo-4,1-benzoxazepines and to 5-oxooxazolo[3,2-a]quinolines

Abstract The literature concerning phenacyl anthranilate, N - phenacylanthranilic acid and phenacyl N -phenacylanthranilate is clarified. Phenacyl anthranilate is dehydrated to 1,5-dihydro-5-oxo-2-pheny 1-4,1-benzoxazepine by treatment with phosphoryl chloride; other examples of this reaction are described. A preparation of 4-methyl-5-oxo-2-phenyloxazolo [3,2-a] quinoline from N -phenacylanthranilic acid and propionic anhydride is reported.