The pyrethroid-class compound has been produced in multiphase reactor which contains immiscible liquid phases. The reactants, products, and catalysts are partitioned within. These conditions allow novel synthesis paths, higher yields, and faster reactions, as well as facilitate production separation. A systematic modelling framework of three modules has been developed to describe phase equilibria, reactions, mass transfer, and material balances of such processes. The resulting mathematical model contains a few rate parameters to be regressed to a minimum of time-dependent data. In addition to describing the behaviour of such systems, predictions can be made of the effectiveness in rates and ultimate amounts of product formation with different feed scheme for further optimizing of this complex system operation.