A method and device for continuous hydrolysis and neutralization of vitamin A intermediate double Grignard condensate

Abstract

The invention discloses a method and a device for continuous hydrolysis and neutralization of a vitamin A intermediate double Grignard condensate. Steps are as follows: an ether solution and acid water containing the vitamin A intermediate double Grignard condensate are respectively pumped into a tubular reactor, and fully mixed by the tubular reactor for continuous hydrolysis to obtain a hydrolysis liquid; alkaline water is pumped into the tubular reactor by another feeding port of the tubular reactor for continuous neutralization with the hydrolysis liquid in the tubular reactor to obtain a neutralization solution; the neutralization solution is discharged from a product discharging port of the tubular reactor, and is layered into a water phase and an organic phase, the water phase is removed, the organic phase is washed with water to neutral, then an organic solvent is recovered by evaporation, and the vitamin A intermediate double Grignard condensate is obtained. The method has the advantages of high mixing efficiency and short time, the product has high purity and yield, high content and high pure-converting yield. At the same time, continuous operation can be realized, the device is safe and reliable, working environment of production workers is improved, and production efficiency and equipment utilization are improved.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a method and a device for continuous hydrolysis and neutralization of a vitamin A intermediate double Grignard condensate. Background technique [0002] The vitamin A intermediate double Grignard condensate is the hydrolysis precursor of the vitamin A intermediate condensate. The molecular formula is as follows: [0003] [0004] The preparation process of the double Grignard condensate is as follows: Magnesium and halogenated alkanes are prepared under the condition of ether solvent to obtain the Grignard reagent, and the six-carbon acetylenic alcohol is added dropwise to obtain the double Grignard six-carbon alcohol, and then tetradecanal is added dropwise, The reaction prepared double Grignard condensate. [0005] After the double Grignard condensate is hydrolyzed with acid water and neutralized with alkaline water, the product vitamin A intermediate condensate is obtaine...

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Problems solved by technology

[0008] 1) The traditional batch hydrolysis process uses a tank reactor for the hydrolysis reaction, and the organic solution of the double Grignard condensate is usually immiscible with the acidic water. Since the hydrolysis reaction usually mainly occurs at the liquid phase interface, in order to obtain an industrially acceptable The reaction rate is very fast, and the liquid phase needs to be mixed vigorously. However, the reaction effect is still not satisfactory, and back-mixing often occurs, leading to the formation of undesirable by-products, and even the occurrence of excessive reaction of raw materials;

[0009] 2) The hydrolysis time of the intermittent hydrolysis neutralization process is long, and the concentration of acid water is high, and the acidity of the whole system is unbalanced, so that the contact time between the condensate and the acid is too long, because the condensate is extremely unstable and easily destroyed in the acid, Therefore, the purity and yield of the condensate are low, and it brings difficulty to subsequent purification;

[0010] 3) In the traditional batch process, before neutralization in alkaline water, the hydrolyzate needs to be allowed to stand for stratification. If the standing time is too long, by-products are likely to be produced; if the standing time is too short, the condensate is easily brought into the waste acid water layer Medium, so the operation is more difficult, and it is not easy to control precisely

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