9-Methoxynaphtho[1,2-<i>b</i>]benzofuran

Abstract

A highly selective one-pot microwave-assisted synthesis of 9-methoxynaphtho[1,2-b]benzofuran was obtained by treating 1-naphthol with 1-bromo-4-methoxy-2-nitrobenzene and two molar equivalents of potassium tert-butoxide in dimethyl sulfoxide. The selectivity in the production of the title compound was addressed by the suitable position of the bromine and nitro group on the aryl reagent. Moreover, we highlight how the nitro group plays a dual role, as activator in the first nucleophilic substitution with the release of bromide ion and then as the leaving group in the furan cyclization. Eventually, the product was structurally characterized by MS and extensive NMR analyses.

Keywords

• naphthobenzofuran
• α-brasan
• nucleophilic aromatic substitution
• nitro group replacement
• microwave-assisted reaction
• chemoselectivity