The reaction of 4-nitrophenyl bis(chloromethyl)phosphinate with 2-dialkylaminomethylphenols in toluene solutions of polyethylene glycol 600 monolaurate was studied spectrophotometrically. The effect of structural features of the micellar system on the catalytic effect depends on the nucleophile hydrophobicity. Micellization of the nonionic surfactant was studied by dielectrometric titration and by the kinetic method. The aggregation numbers and the composition of detergent aggregates were determined.