A Simple and Facile Method for Triphenylmethylation of Cellulose in a Solution of Lithium Chloride in N,N-dimethylacetamide.

Triphenylmethylcellulose prepared in a solvent system containing lithium chloride and dimethylacetamide yielded products for which ds values of 1.00 were calculated even when the reaction temperature was only 60°C. The ds values calculated when the reaction temperature was 100°C were much greater than 1.00, indicating extensive substitution at positions other than C-6. Both ds and yield decreased with increasing reaction time, suggesting that both depolymerization and detritylation occured. Methylation analysis revealed that substitution proceeded mainly at C-6 but also proceeded at C-3. With this technique, tritylation can be undertaken without pretreating the starting materials.