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 1H NMR were approximately 1. The 1H and 13C NMR spectra strongly support the structural uniformity of N-phthaloyl chitosan.