Preparation of tri‐O‐substituted cellulose ethers by the use of a nonaqueous cellulose solvent

The previously reported method for the preparation of tri‐O‐benzylcellulose was applied to the preparation of various tri‐O‐substituted cellulose ethers. By this method, in which a mixture consisting of SO2, diethylamine (DEA), and dimethylsulfoxide (DMSO) and powdered sodium hydroxide were used as a cellulose solvent and a base, respectively, many tri‐O‐arylmethylcelluloses could be prepared from the corresponding chlorides. Cellulose ethers containing double bonds such as tri‐O‐allyl, tri‐O‐methallyl‐, and tri‐O‐2‐butenylcellulose were also prepared from the corresponding chlorides under a milder condition than that used for the preparation of tri‐O‐arylmethylcelluloses. Reaction factors accelerating complete etherification were discussed.