The invention discloses a preparation method for
dimethyl dicarbonate, and belongs to the technical field of
fine chemical industry. The method is characterized in that: in a
organic solvent which is insoluble in water,
quaternary ammonium salt is adopted as a catalyst,
methyl chloroformate and a alkaline solutionare are adopted as raw materials to be subjected to a reaction for 0.5-3 hours at a temperature of 0-25 DEG C; after completing the reaction, the resulting solution is stood for demixing; the resulting
organic layer is processed, and is subjected to reduced pressure
distillation to collect fractions under pressure of 200 Pa at the temperature of 30-35 DEG C to obtain the product of the
dimethyl dicarbonate. With the present invention, the
quaternary ammonium salt is adopted as the catalyst, such that complete performance of the reaction is prompted, and the
quaternary ammonium salt is easily removed after completing the reaction and is not remained in the product so as to do not influence on purity of the product;
tertiary amine used in the prior art is avoided, because the
tertiary amine can prompt the reaction, and can also inhibit the reaction when
reaction conditions can not be controlled well, and the
tertiary amine is difficult to be removed completely and can be remained in the product so as to enable the product to have disadvantages of
decomposition and deterioration; reaction yield of the
dimethyl dicarbonate is higher than 81%, purity of the dimethyl
dicarbonate is high, GC of the dimethyl
dicarbonate is more than equal to 99.8%, a solidification point of the dimethyl
dicarbonate is 17 DEG C, such that each index of the dimethyl dicarbonate meets requirements of food additives, and the dimethyl dicarbonate is applicable for industrial production.