A reactivity and computational study of the basic-catalyzed methylation of phenol with methanol

The C-methylation of phenol aimed at the production of o-cresol and 2,6-xylenol is industrially carried out with methanol as alkylating agent and catalysts possessing basic characteristics. The reaction mechanism is still unclear. With the aim of investigating on the mechanism we studied (a) the transformations occurring on methanol in the presence and in the absence of phenol with basic catalysts, i.e., MgO and Mg/Fe/O; (b) the reaction of phenol with the intermediates formed by methanol transformation (i.e., formaldehyde and methylformate), (c) the adsorption of phenolic reactants and intermediates on MgO by means of FT-IR spectroscopy, and (d) the simulation of multi-step reaction between phenol and methanol by means of a computational approach. This approach allowed us to derive the mechanism of the entire process leading to the formation of o-cresol.