Method for preparing linalyl acetate from dehydrolinalool

Abstract

The invention relates to a method for preparing linalyl acetate from dehydrolinalool. The method comprises esterification between dehydrolinalool and acetic anhydride is carried out in the presence of catalyst. The catalyst is macroporous sulfonic acidic cation exchange resin, dosage of which is 2-20wt percent of total amount of the raw material provided. Product of the esterification, after being removed of the catalyst, is washed till oil phase material is neutral, and the dehydrolinalyl acetate is obtained. The dehydrolinalyl acetate undertakes hydrogenation reaction with hydrogen in the presence of catalyst ; the catalyst adopts calcium carbonate as a carrier; active components loaded contain Pd, Pb and A ingredient, A is either Bi or Zn or mixture of Bi and Zn, total content of Pd and Pb is 0.1-4.0wt percent, mass ratio of Pd and Pb is (5-1):1, content of A is 0.5-3.0wt percent and dosage of the catalyst accounting for 0.01-5.0wt percent of reaction liquid. The catalyst is removed from the product of the hydrogenation reaction through solid and liquid separation, and linalyl acetate is obtained by rectifying and refining. The invention has the advantages that the catalyst of esterification and hydrogenation reaction has relatively high activity, and conversion and selectivity are higher.

Description

technical field [0001] The present invention relates to a preparation method of acid-containing linalyl ester, in particular to a method in which dehydrolinalyl alcohol is subjected to an esterification reaction in the presence of an acidic catalyst to generate dehydrolinalyl acetate, and then hydrogenated to prepare linalyl acetate . Background technique [0002] Dehydrolinalyl acetate is an important fine chemical intermediate for the preparation of fragrances, and can be used to produce fine chemical products such as citral and ionone. Linalyl acetate can also be obtained through hydrogenation reaction of dehydrolinalyl acetate. Linalyl acetate is one of the main components of lavender oil. It has an elegant fragrance, similar to bergamot oil and lavender oil. An important raw material for spices or essences. In the prior art, linalyl acetate is mostly prepared by esterification of linalool and acetic anhydride, because linalool can be obtained from isoprene, the separa...

AI Technical Summary

Problems solved by technology

The hydrogenation process of the method described in the above-mentioned U.S. Patent US 2,797,235 has adopted a hydrogenation catalyst similar to Lindlar catalyst. It not only needs to add quinoline as a catalyst accelerator, but also adds a large amount of cyclohexane as a solvent for the hydrogenation reaction, so In addition to the long time required for the esterification reaction, the method is also very difficult to refine the hydrogenation product, and it is difficult to meet the requirements for the manufacture of high-grade fragrances.

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