Studies on the tosylation of cellulose in mixtures of ionic liquids and a co-solvent

► Tosyl celluloses can be prepared by homogeneous derivatization in mixtures of ionic liquids and a co-solvent. ► Reaction time, molar ratio, and type of base determine the properties of the products obtained. ► NMR- and FT-IR spectroscopy as well as SEC were used to characterize tosyl celluloses with DStosyl ≤ 1.14 and DSCl ≤ 0.16. ► Tosyl- and chloro-deoxy groups could be substituted completely by azide. ► Recycling of ionic liquids and co-solvents could is possible.