Automated Optimization of the Synthesis of Alkyl Arenesulfonates in an Undivided Electrochemical Flow Cell

The necessary separation of anodic and cathodic compartments in the electrochemical multicomponent synthesis of alkyl arenesulfonates in batch was overcome by the transfer of this reaction in an undivided electrochemical flow cell. The yield was increased from an initial 23 % to 67 % by optimization using Design of Experiments (DoE). The experiments were carried out using an automated experimental flow electrolysis setup controlled by the automation software LABS (Laboratory Automation and Batch Scheduling), an open‐source software that allows to plan and conduct experiments with an arbitrary, freely selectable experimental setup. The automated experimental setup turned out to be stable and provides reproducible results. In total, 6 examples are demonstrated with isolated yields up to 81 %. In addition, the robust scalability of the electrochemical reaction was demonstrated in a 10‐fold scale‐up. The combination of DoE with reaction automation using LABS was the key to the efficient optimization of the direct undivided multicomponent synthesis of alkyl arenesulfonates in flow. The transfer from the previously divided batch electrolysis protocol to undivided flow resulted in an increase in yield and productivity in scale‐up.