Synthesis of sodium decyl sulfonate from 1-bromodecane and sodium sulfite was performed in microemulsions based on nonionic surfactant, in liquid crystals and in 2-phase systems with or without a phase transfer agent added. The reactions were fast in both bicontinuous and W/O microemulsion, slower in liquid crystal and very sluggish in 2-phase systems also in the presence of a Q salt or a crown ether. Addition of a small amount of anionic surfactant to the microemulsion systems decreased reaction rate. Addition of cationic surfactant either increased or decreased the reaction rate depending on the choice of counterion.