ISOSORBIDE DIMETHYL ETHER is acquired by methylation of isosorbide. The utilized methylating reagents are dimethyl sulfate (United States License US4659846 as well as US4322359), dimethyl carbonate (United States Patent US4700871), methyl chloride (United States Patent US4435586 and World Patent WO2007096511).
When synthesizing ISOSORBIDE DIMETHYL ETHER with dimethyl sulfate, the yield can reach more than 70%, and also the highest possible reported in the literature is 83.5%. As we all know, dimethyl sulfate is an extremely harmful chemical, a health hazard, and damaging to the health of operators. When using dimethyl carbonate to manufacture dimethyl isosorbide, the highest possible conversion price of isosorbide is only 89%, and the weight proportion of isosorbide dimethyl ether to monomethyl ether in the product is 59:41. For that reason, dimethyl carbonate is not a suitable beginning product for the synthesis of dimethyl isosorbide.
When manufacturing ISOSORBIDE DIMETHYL ETHER, the solvents used are tert-butanol, acetone, dimethyl sulfoxide, and so on. These solvents have the drawbacks of low boiling point, very easy volatility, problem in solvent healing, environmental pollution and high price of use. Fuertes, Patrick enhanced the solvent in TO2007096511, utilizing the methylated item isosorbide dimethyl ether as the solvent, as well as the return was raised to 95%. However, with ISOSORBIDE DIMETHYL ETHER as solvent, the manufacturing price is reasonably high.
A maximized and also enhanced process for manufacturing ISOSORBIDE DIMETHYL ETHER can not only decrease production expenses, yet also reduce environmental pollution. It is identified because,
Proceed as follows:
( 1) in response vessel, add solvent, isosorbide, alkali as well as phase transfer stimulant;
( 2) mixing, warming up, unwinding and also dehydrating;
( 3) feed right into methyl chloride, total etherification response under particular pressure and also temperature level;
( 4) Add acid to reduce the effects of;
( 5) filtering desalination;
( 6) underpressure purification, acquire item ISOSORBIDE DIMETHYL ETHER as well as recover solvent; The antacids used in reaction is selected from sodium hydroxide, potassium hydroxide or salt methylate; Explained stage transfer stimulant is the stage transfer driver of quaternary ammonium salts, or It is a quaternary phosphonium salt type phase transfer driver; The solvent adopts an alkyl-terminated low-molecular-weight polyether, as well as the architectural formula of the alkyl-terminated low-molecular-weight polyether is:
In the formula R1, R2 are to select the same or various straight-chain or branched alkyl teams; The alkyl group utilized includes 1 ～ 15 carbon atoms; R3, R4 are hydrogen atoms or methyl teams; m+n is an integer of 4 ～ 15.