Synthesis of cellulose tricarbonates in 1-butyl-3-methylimidazolium chloride/pyridine.

Cellulose phenyl tricarbonates could be synthesized by a novel and fast procedure applying 1-butyl-3-methylimidazolium chloride/pyridine as reaction medium. Even cellulose phenyl carbonates with high degree of substitution are accessible at low molar ratio very efficiently. The reagent phenyl chloroformate is inert in the mixture, which is different from the solvent N,N-dimethylacetamide/LiCl that is usually applied. The products were characterized in detail by two-dimensional NMR- and FTIR-spectroscopy, elemental analysis, and size-exclusion chromatography. This class of cellulose derivatives is a very important intermediate for the design of structures based on cellulose by nucleophilc attack on the carbonyl group.