The Chemistry of Indoles. XII. A Facile Route to 5-Nitroisocoumarins and Methyl Indole-4-carboxylate

摘要

A convenient synthesis of 5-substituted isocoumarin derivatives, such as 5-nitroisocoumarin (2), 5-aminoisocoumarin (8), 3, 4-dihydro-3-methoxy-5-nitroisocoumarin (3), and 5-amino-3, 4-dihydro-3-methoxyisocoumarin (10), from 2-methyl-3-nitrobenzoic acid (1) is reported. Several synthetic routes to methyl indole-4-carboxylate (9) from methyl 2-methyl-3-nitrobenzoate (4) directly or via these isocoumarins (8 and 10) are also presented.