Reactions of O-methyl o-quinone monoximes with methyl-, methylene- and methine- substituted aromatic compounds. Synthesis of benzo[d]oxazole and 1,4-benzoxazine derivatives

O‐Methyl o‐quinone monoxime 1 reacts thermally with compounds 2a‐d or 6a,b or 7a,b to give mainly the corresponding 2‐substituted phenanthroxazoles 3a‐c and 8. The reaction of 1 with aromatic methylene compounds lOa‐c affords the ketones 13a‐c in moderate to high yields. Similar products are also obtained from the reaction of monoximes 15a,b with some of the above reactants. The unexpected products 5 and 20 are obtained from the reaction of 1 with 2‐methylimidazole (2d) and with phenyloxirane (19) respectively, while the 4H‐1,4‐oxazine derivative 23 is obtained from the reaction of 1 with indene (21).