The Polymer Effect. I. The Acceleration Effect of Poly(vinylpyrrolidone) on a Williamson’s Reaction

The additive effect of poly(vinylpyrrolidone) (PVPD) to a Williamson’s reaction, ether synthesis from sodium phenoxide and n-butyl bromide, in dioxane—ethanol mixed solution at 45°C has been investigated, and compared with that of N-methylpyrrolidone (NMPD), which is a monomeric analogue of PVPD.A marked acceleration effect of PVPD on the rate of the reaction was observed in dioxane, which was about 100 times greater than that of NMPD at a concentration of 0.135 mol/l. Evidence is presented to show that the remarkable rate acceleration by PVPD is produced owing not only to the enrichment of the phenoxide in the polymer domain due to the complexation of sodium cation with pyrrolidone unit of the polymer, but also to the dissociation of sodium phenoxide based on the tight solvation of sodium cation with a pyrrolidone unit in the contracted polymer coil.