T. Horaguchi, S. Matsuda, K. Tanemura
Jul 1, 1987
Citations
0
Influential Citations
9
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
3-Methyl-5-nitrobenzofuran (2) and 3-methyl-5-nitrobenzofuran-2-carboxylic acid (3) were obtained by heating 2-acetyl-4-nitrophenoxyacetic acid (1) with various bases in acetic anhydride. It appeared that 3-hydroxy-3-methyl-5-nitro-2,3-dihydrobenzofuran-2-carboxylic acid (4) was the intermediate in the benzofuran synthesis. The properties of 4 were examined under various conditions. Using strong bases such as triethyl-amine in place of sodium acetate, 3-methyl-5-nitrobenzofuran-2-carboxylic acid (3) was obtained exclusively. However, in the presence of acetic acid in the reaction mixture 3-methyl-5-nitrobenzofuran (2) was obtained in good yield. The reaction pathways for the formation of 2 and 3 are discussed.