One-step continuous synthesis of anisole in microreactor

As an important chemical intermediate, anisole is mainly made by batch process using dimethyl sulfate and sodium phenol as raw materials in industry. However, neither the utilization rate of raw materials nor the production efficiency of anisole is satisfactory. Meanwhile, there are potential risks of dimethyl sulfate leakage during the production. In this paper, a microreactor system based on a microdispersion mixer and a static mixer was proposed, which employed phenol, sodium hydroxide, and dimethyl sulfate as the reactants, to implement the coupling of the formation of sodium phenate and the phenol methylation reaction and to realize the continuation and process intensification of the reaction process. The key influence factors such as feeding flow rate, molar ratio of phenol/dimethyl sulfate and concentration of sodium hydroxide were investigated, which demonstrated a transfer-controlled reaction mechanism within microreactor. Based on the mass transfer enhancement of micromixer and static mixer elements, up to 98.5% anisole yield was obtained in a reaction time less than 2min, and the consumption of dimethyl sulfate was reduced by 10% compared with the traditional reaction process, which provided the fundamental research for the upgrading of industrial production process. © 2022 Chemical Industry Press. All rights reserved.