Silica gel-promoted convenient synthesis of 2-bromo-3-hydroxybenzoate derivatives

A convenient silica gel-promoted synthesis of 2-bromo-3-hydroxybenzoate derivatives has been developed via the Diels–Alder reaction of furans with methyl 3-bromopropiolate, followed by a ring-opening aromatization. In addition, 2-bromo-3-methoxybenzoate, derived from 2-bromo-3-hydroxybenzoate with iodomethane, was found to be a good substrate for Pd-catalyzed cross-coupling reactions, despite its sterically hindered structure.