Studies on Quinones. Part 30. Synthesis of Benzo[<i>b</i>]thiophene-4, 7-Quinones

Abstract

Abstract The synthesis of a variety of benzo[b]thiophene-4, 7-quinones (4a-f), by oxidative demethylation of the corresponding 4, 7-dimethoxybenzo[b]thiophenes (3a-f), with cerium (IV) ammonium nitrate is reported. Heterocycles (3a, b), were prepared by cyclization of the corresponding 2, 5-dimethoxy-6-nitrobenzaldehyde (1a), and 2, 5-dimethoxy-6-nitroacetophenone (1b), with methyl thioglycolate.