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.