A method for synthesis of benzyl benzoate that manufactured at low temperature
Benzyl benzoate, is a colorless or yellowish oily liquid. Melting point 21℃, boiling point 324℃, flash point 146℃, insoluble in water, soluble in oil, ethanol, ether. A light almond-like aroma. Mainly used in the preparation of cherry, plum and other berry flavor; in the paint industry can be used as plasticizer; in medicine has vasodilator and spasmolysis, can also be used in the preparation of pertussis drugs, asthma drugs and so on; this product is also widely used as musk solvent, considered to be the best solvent for solid spices insoluble in flavor.
The synthesis of benzyl benzoate has several methods, one is the reaction of benzoic acid and benzyl alcohol to synthesize benzyl benzoate.However, the complex of HfCl4 and tetrahydrofuran is used as catalyst, which is expensive and complex. One is the synthesis of benzyl benzoate with benzoic acid and benzyl alcohol.
A method for direct synthesis of benzaldehyde benzyl benzoate by self-differentiation of benzaldehyde. Using Al (OPh)3 and ZnCl2 as catalysts, the catalyst cost is high, the post-treatment is complex, and the target product yield is low. A method of direct synthesis of benzyl benzoate by oxidation of benzyl alcohol by oxygen at high temperature and high pressure has high price, many by-products and only 31% yield of target product, which is difficult to realize industrialization.
A method for the direct synthesis of benzyl benzoate from toluene alone, Pd (oac)2 and o-phenanthroline as catalysts, in which benzyl benzoate was obtained as a by-product with Pd (oac)2 and o-phenanthroline as catalysts in extremely low yields. Benzyl benzoate is prepared by sodium benzoate and benzyl chloride under the action of triethylamine catalyst. Triethylamine is flammable, explosive, toxic, has strong irritation and is dangerous and unsafe to use. Therefore, it is urgent to study and solve the can improve the conversion rate is an urgent need to study and solve the problem of existing technology.
At present, there is an invention overcomes the shortcomings of existed technology and provides a kind of low temperature preparation with zinc oxide as catalyst to prepare benzyl benzoate.
Sodium benzoate and benzyl chloride as catalysts in zinc oxide, Benzyl benzoate was produced by esterification at ℃ temperature of 50-70. Remove salt by washing, Adjust the pH value 7-8 with soda solution. The low boiling and high boiling in the product are removed by distillation and distillation, The finished product is obtained. Benzyl chloride 1000 Kg, in reactor Turn on the stirring, Kg ,1150 sodium benzoate After mixing, Add zinc oxide 10-15 Kg start heating up, Heating for 10-15 minutes to 50-70℃, Reaction was 2-2.5 hours, The invention adopts zinc oxide as catalyst for reaction, High catalytic efficiency, Low reaction temperature, safe production, High purity and stability, Reduced energy consumption, Simple reprocessing, The target yield can reach 99-99.5% high.
