The operating conditions for scaling up the synthesis in semibatch-type reactors of an ionic-esterified amino acid salt, namely, 2-(tetradecyloxy)-2-oxoethanaminium methanesulfonate, a demulsifier for breaking crude oil-in-water emulsions, were established. The conversion and reaction time were studied at different temperatures on a laboratory scale, and the best conditions for the reaction were found at 90 degrees C. At different reaction scales up to an industrial reactor, the influence of reaction variables such as temperature, order and rate of reagent addition, and reaction time were studied. This progressive scaling study found the most suitable and safest conditions to carry out the industrial-level scaling of a high-performance product for oilfield application.