of a new heterocyclic compound, 1H-2,3-benzoaxazine-4(3H)-one (I), by cyclization of α-aminoxy-o-toluic acid (VIII) is reported. Some 3-acyl, 3-alkyl- and 3-aminoalkyl-derivatives of I as well as 6-nitro-, 6-amino and 6-sulfonamido-derivatives were prepared. The physico-chemical behaviour of the compounds is reported.