Method for preparing vanitrope from sassafras oil

Abstract

The invention discloses a method for preparing vanitrope from sassafras oil, which comprises the following steps: by using safrole oil as a raw material, adjusting the amounts of KOH and methanol during ring-opening isomerization of safrole, and carrying out ring-opening by using a method of distilling methanol with water, so that the reaction is milder and more controllable, the ring-opening product is not acidified, and diethyl sulfate is directly used for ethylation. The reaction temperature is greatly reduced, the process is simple and the yield is high; meanwhile, the ethyl vanillin is synthesized from the by-product isoeugenol generated in the production process through an oxidation reaction, so that the treatment process and cost of the by-product are reduced, the selling cost of the by-product ethyl vanillin can be further reduced, and the method is an ideal route for industrially preparing vanitrope.

Description

technical field [0001] The invention relates to the technical field of organic chemical synthesis, in particular to a method for preparing strong vanillin from sassafras oil. Background technique [0002] Concentrated vanillin, chemical name 2-ethoxy-5-(1-propenyl)phenol, appearance is white flaky crystal, melting point 85-87 ℃, slightly soluble in water, 10% soluble in ethanol, in benzyl Dissolve 20% in alcohol. It has a strong and long-lasting clove and vanilla aroma, and its aroma intensity is 16-25 times that of vanillin. It can be used in food flavor formulations such as ice cream, candy, and chocolate, and can also be used in soaps and cosmetics. At the same time, it can be used as an antioxidant and synergists used. [0003] Nongfu vanillin was successfully developed as early as the 1920s. The initial synthetic route was to use safrole as a raw material, which was subjected to a hot-pressing reaction with an alcoholic solution of potassium hydroxide to open the ring...

AI Technical Summary

Problems solved by technology

However, because the aroma purity of the product obtained by this method is not enough, it is rarely used in practical applications.

In the 1950s, a synthetic route for producing strong vanillin from eugenol was developed, and industrial production was realized. The commonly used preparation method is to use eugenol as a raw material, and then use diethyl carbonate as an ethylating reagent. Potassium carbonate catalyzes the synthesis of eugenol ether; then uses KOH and phase transfer catalyst (PTC) polyethylene glycol to isomerize eugenol ether into isoeugenol ether; finally uses aluminum chloride as a catalyst to catalyze the demethylation of isoeugenol ether Methylation generates strong vanillin, but the yield of the demethylation reaction in the last step of the process route is too low, only about 38%

In the 1960s, spice chemists in the former Soviet Union successfully developed a synthetic route using catechol as a raw material that is cheaper and easier to obtain. First, monoalkylate catechol with allyl chloride, and the yield It is 75%; followed by rearrangement reaction, the yield is 35-38%; then monoethylated with sodium ethyl sulfate, the yield is 82%; finally isomerized with potassium hydroxide to obtain vanillin, producing The yield is 84%, and the melting point of the crude product after recrystallization is 85.5-86°C. Although the raw material is cheap and easy to obtain in this route, the process route is long and the yield is very low

[0004] In the above synthesis route of strong vanillin, the synthesis of strong vanillin through the eugenol route has problems such as low yield, few and expensive raw material sources, and high manufacturing cost.

Take pyrocatechol as the synthetic technique of raw material to have route long, the shortcoming that yield is too low (only 20%)

The original process of synthesizing strong vanillin from safrole, when safrole is ring-opened, or reacts with alcohol-alkali solution under hot pressure, or reacts with metal sodium under normal pressure, there are potential safety hazards in the reaction, and at the same time, in the ethylation reaction When using sodium ethyl sulfate, the reaction temperature is about 150 ° C, the temperature is too high

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