Dibenzoylmethane CAS# 120-46-7

The original industrial production process is: using solid sodium methanol as the catalyst, acetophenone, and methyl benzoate under xylene as the solvent for the Claisen condensation reaction to obtain dibenzoylmethane. Because the solid sodium methanol powder is flammable and explosive, it is easy to decompose when it meets water, so the solvent must be dehydrated before adding, and then the solid sodium methanol must be added under nitrogen protection after cooling down to 35°C. The reaction process must be protected by nitrogen, so there are great safety hazards and large power consumption. The molar ratio of industrial production is acetophenone: methyl benzoate: solid sodium methanol = 1:1.2:1.29. The average primary yield of the product is 80%, and the overall yield of the mother liquor is 85.5% after recovery.

The production process of Xinda is as follows: add 3000L of xylene solvent to the reactor, add 215Kg of solid sodium hydroxide, turn on the stirring, raise the temperature to 133℃, evaporate the low fraction water; then add 765Kg of methyl benzoate, continue to raise the temperature to 137℃, start to add 500Kg of acetophenone dropwise, four hours dropwise, keep the reaction temperature at 137-139℃, with the dropwise addition of acetophenone, the material solution gradually becomes thicker. The reaction process removes the by-product methanol, which makes the reaction proceed in the positive direction and evaporates the mixed solvent of methanol and xylene. After the titration is finished, hold the reaction for 2 hours. When there is basically no distillate, the reaction is finished.

Comparison between the new process and the original process: solvent dosage is reduced by 500L, solvent consumption is reduced by 5%; the process of solvent heating and negative pressure dehydration is eliminated, and the process of cooling and cooling is eliminated; sodium hydroxide is used instead of solid sodium methanol as a catalyst, and nitrogen protection is eliminated; the processing time for this step of condensation reaction is reduced by 3 hours per batch; the amount of mixed solvent is reduced by about 500L, and the amount of hydrochloric acid in acidification post is reduced by 300Kg per batch. methyl benzoate Each batch uses 85Kg more, and the extra methyl benzoate consumed can be recovered, with a recovery rate of 80% and a recovery cost of 500 RMB per ton. Use I】As co-stabilizer of calcium/zinc hydroxylate stabilization system, used to manufacture PVC mineral water bottles. Use II】Analytical reagent, check carbon disulfide and thallium, weight determination of uranium, photometric determination of U+4, extraction of silver, aluminum, barium, beryllium, calcium, cadmium, cobalt, copper, iron, gallium, mercury, captivity, lanthanum, magnesium, manganese, nickel, lead, palladium, scandium, thorium, titanium, zinc, zirconium, etc.