Abstract: A process for catalytic recovery in a phase transfer process wherein heterogeneous reactions in a liquid-liquid two phase reaction systems using a phase transfer catalyst is improved by separating the two liquid phases with a membrane which retains the catalyst while passing the aqueous polar liquid thereby allowing easy recovery of the phase transfer catalyst. The reaction is carried out between reactants selectively soluble in the different phases, one of the reactants being transferred into the other phase by means of a phase transfer catalyst which is soluble in said polar liquid phase with the one reactant. The phases are separated after completion of the reactions by adding water to the two-phase reaction system to dissolve out the polar liquid phase containing the phase transfer catalyst into an aqueous phase.