Heterocyclic rearrangements. Part VI. Rearrangements of 4-acyl- and 4-iminoalkyl-benzofuroxans: new syntheses of the anthranil and indazole ring systems

Abstract

4-Acyl- and 4-iminoalkyl-benzofuroxans, on preparation by nitrogen elimination from the corresponding 3-substituted 2-nitrophenyl azides, rearrange spontaneously to the anthranil and indazole ring systems. Attempts to prepare 4-alkenylbenzofuroxans failed. In 3-chloro-2-nitro- and 3-methoxy-2-nitro-benzaldehydes, the nitro-group is displaced by nucleophils in preference to the methoxy-group of chlorine atom.