We propose a model to express the kinetic and dynamic behavior of synthesis of dialkoxymethane from alcohols and dibromomethane in an alkaline solution of KOH/organic solvent by phase-transfer catalysis. The presence of measured constant concentration of tetrabutylammonium alkoxide during the reaction allows application of the pseudo-steady-state hypothesis in conjunction with the system parameters to construct the model. The mass-transfer resistance of tetrabutylammonium alkoxide from aqueous to organic phase is negligible. The ionic reaction in the aqueous phase is very rapid indicates that the step of the reaction in the organic phase determines the rate of the entire reaction. According to the derived model, the concentration of tetrabutylammonium alkoxide in the organic phase is determined from its distribution coefficient between two phases, the volume ratio of the organic phase to the aqueous phase, and the initial amount of catalyst added to the system. The results according to the model’s predictions are consistent with experimental data obtained from the two-phase phase-transfer-catalyzed reaction.