Preparation of highly chemoselective N-phthaloyl chitosan in aqueous media

Highly chemoselective N-phthaloylations of chitosan were achieved by reaction in aqueous acetic acid media in concentrations from 0 to 10.0%. The degree of substitution (DS) values of phthaloyl groups determined by elemental analysis and H-1 NMR were approximately 1. The H-1 and C-13 NMR spectra strongly support the structural uniformity of N-phthaloyl chitosan.