Catalyst-Free, Facile and Green Synthesis of New Symmetric and Asymmetric Benzofurans through Hydroquinones Oxidation in the Presence of Meldrum’s Acid

Resumo

Electrochemical oxidation of hydroquinones (1a–1b) were studied in the presence of meldrum’s acid (3) as a nucleophile in an ethanol-phosphate buffer (pH 7, 0.20 M) mixture (as a green media), by means of voltammetric techniques. The obtained results indicated that the p-quinones (2a–2b) are derived from 1a–1b participation in a 1,4-Michael addition reaction, with the meldrum’s acid (3) to form the corresponding new symmetric and asymmetric benzofurans (8a and 6b). The electrochemical synthesis of these new compounds (8a and 6b) has been successfully performed in an undivided cell with high yield and good purity.