Mechanism of the etherification of 2-alkylamino-1-phenylethanol derivatives

Derivatives of 2-alkylamino-1-(4-hydroxyphenyl)-1-ethanol have been converted to the β-methylethers in good yield. Etherification of 2-alkylamino-1-(4-methoxyphenyl)-1-ethanol could not be accomplished. Based on this unreactivity, a mechanism is proposed whereby the etherification proceeds via a quinoidal intermediate and not via a carbonium ion intermediate. It is concluded that the acid catalyzed racemization of catecholamines may occur via a quinoidal intermediate.