ETHYL VANILLIN PROPYLENE GLYCOL ACETAL synthesis

Yield:68527-76-4 98%

Reaction Conditions:

with mixture of acetic anhydride and phosphoric acid composite catalyst in toluene for 20 h;Reflux;Industrial scale;Time;

Steps:

1-9 Example 1
a. Into a three-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, 5.0 g of phosphoric acid and 45.0 g of acetic anhydride were placed, and the mixture was heated and kept at 35 ° C for 24 hours to obtain 50.0 g of a composite catalyst.b. In a three-necked flask equipped with a thermometer, a stirrer, a water-oil separator and a reflux condenser, 1.0 kg (6.0 mol) of ethyl vanillin, 0.92 kg (12.0 mol) of 1,2-propanediol, and 50.0 g of a composite catalyst were placed. And 2.0 kg of toluene, stirred and heated to reflux for dehydration, and the dehydration time was 20 hours.After the reaction, the system was lowered to room temperature.The reaction solution was washed with saturated brine, and then a small amount of 20% by mass of Na was added to the system.₂CO₃The solution was adjusted to pH = 8-9.Then, toluene and unreacted 1,2-propanediol are distilled off under normal pressure, and then distilled under reduced pressure to collect a fraction of 150-152 ° C / 0.2 kPa, which is the target product ethyl vanillin 1,2-propanediol acetal, and the product is obtained. 0.98 kg, as shown in Fig. 1, was found to have a content of 99.1% and a yield of 98%.

References:

Shenzhen Bo Dun Flavors Co., Ltd.;Ma Hongliang;Jiang Xingtao;Li Rui;Li Jianzheng;Wu Qilin;Li Qingting CN104370875, 2018, B Location in patent:Paragraph 0033-0065

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