Catalytic amounts of NaNO2 are able to successfully promote the reaction between 1,4-hydroquinone and methanol under
acidic conditions, affording selectively the corresponding mequinol in excellent isolated yields. According to the proposed reaction
mechanism, the semi-quinone intermediate, generated in situ from the corresponding hydroquinone by NO2 oxidation, is the real reactive
species, undergoing nucleophilic attack onto the alcoholic molecule. Experimental evidences emphasize the key role of NO2. After optimization
of the reaction conditions, the scope of the proposed protocol is extended to a wider range of alcohols, providing the corresponding
mono-ethers in good to excellent yields. Moreover, when substituted hydroquinones are selected as reactive substrates, monoetherification
occurs with complete regio-selectivity towards the less hindered phenolic –OH group.