Vapor-phase reactions of catechol with dimethyl carbonate. Part II. Selective synthesis of guaiacol over alumina loaded with alkali hydroxide Original Research Article

The methylation of catechcol (pyrocatechol) with dimethyl carbonate over alumina loaded with alkali hydroxide was studied. The main product was guaiacol (o-methoxyphenol), the selectivity being dependent upon the kind of hydroxides. Alumina loaded with LiOH (5 mmol g−1) gave the highest selectivity for guaiacol, the guaiacol selectivity being 84% at 100% conversion of catechol at 583 K. It is also demonstrated that dimethyl carbonate is a much more efficient methylating agent than methanol for the O-methylation over LiOH/alumina.