METHOD FOR PREPARING DIALKYLOXYDIANHYDROHEXITOL BY ETHERIFICATION OF DIANHYDROHEXITOL USING A LIGHT ALCOHOL IN THE PRESENCE OF AN ACIDIC CATALYST

摘要

The present invention relates to a method of preparing a dialkyloxydianhydrohexitol (dimethylisosorbide) composition by etherification of dianhydrohexitol (isosorbide). It is an object of the present invention to obtain a methylating agent that produces a stoichiometric amount of salt, for example dimethyl sulfate or methyl chloride, or of expensive dialkyl-carbonates where only one of the two methyl groups participates in the preparation of mixed isosorbide ethers. It's to get a "clean" way to avoid use. The method involves the use of a catalyst comprising at least one O-alkylating agent and an acid or acid salt, preferably a catalyst having Lewis acid or Bronsted acid properties. The invention further relates to equipment for carrying out the method according to any of the preceding claims, characterized in that it comprises an evaporation oven and a reaction oven.