This work examines the reaction kinetics of the syntheses of 1-phenoxyoctane from 1-bromooctane and sodium phenoxide in microemulsions with excess phases. It can be shown that an interfacial reaction model proposed in a previous paper [5] which describes the kinetics of the same reaction in a single-phased microemulsion can also be applied to two-phase systems. In this model the microemulsion is divided into an aqueous and an organic subvolume. The reaction takes place only at the interface between these subvolumes which is covered by a monolayer of surfactant molecules. This study shows that at constant temperatures the reaction rate is proportional to the fraction of surfactant in the microemulsion and therefore to size of the interfacial area. It does not depend on the presence and the size of excess phases.