Abstract
To extend the use of unique polymer cellulose, it is necessary to develop and establish new synthesis paths for the preparation of tailored derivatives. Major stimulations for the synthesis of cellulose esters were the development of new solvents and the in situ activation for carboxylic acids [1,2]. These tools can overcome the major disadvantages of the heterogeneous esterification with acid chlorides and anhydrides (e.g., uncontrolled functionalization and side reactions, limited commercial availability or high costs, and time consuming purification of the products). p-Toluenesulfonyl chloride (tosyl chloride) [3,7] and N,N-dicyclohexylcarbodiimide (DCC) in combination with 4-pyrollidinopyridine (PP) [8,9] were investigated extensively for the in situ activation of carboxylic acids and the conversion of cellulose dissolved in N,N-dimethylacetamide (DMA)/LiCl. Tosyl chloride is a very efficient reagent.