Method for synthesizing isooctyl salicylate with sodium salicylate

Abstract

The invention provides an industrial synthesis method of isooctyl salicylate. In the method, sodium salicylate and 3-(chloromethyl)heptane are utilized to form a solid-liquid phase reaction system, and the isooctyl salicylate is synthesized in the presence of a catalyst. According to the synthesis method, processes of sodium salicylate acidification and subsequent esterification are simplified, and use of sulfuric acid is greatly reduced, thereby reducing the generation of acidic wastewater. Sodium chloride produced during the process can be automatically precipitated in the reaction system, and the remaining solvent, the catalyst, and the residual small amount of raw materials can be recovered and reused. The post-processing step is simplified, the production of three wastes is reduced, the production cost is reduced, and the need of green clean production can be satisfied.

Description

technical field [0001] The invention belongs to the technical field of daily chemical industry, and in particular relates to a method for synthesizing isooctyl salicylate by solid-liquid phase reaction. Background technique [0002] Isooctyl salicylate, also known as 2-ethylhexyl salicylate, is an important daily chemical product, which can be used as a blending fragrance of soap, perfume, daily cosmetics, organic solvent and organic synthesis intermediate Wait. Isooctyl salicylate can absorb wavelengths near 300nm and has a slight aromatic smell. As one of the most commonly used and effective ultraviolet absorbers at present, it is widely used in sunscreens. The industrial synthesis of isooctyl salicylate mainly uses concentrated sulfuric acid as a catalyst for direct esterification. This method has the disadvantages of dark product color, serious equipment corrosion, and unfavorable clean production. [0003] The current industrialization route mainly utilizes salicylic ...

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Problems solved by technology

[0006] The second process route is to use methyl salicylate and isooctyl alcohol to carry out transesterification reaction to synthesize isooctyl salicylate, which will produce a large amount of methanol by-product

[0008] Both of these two processes use concentrated sulfuric acid as the traditional esterification catalyst. Although they have the advantages of low catalyst price, good catalytic effect, and mature technology, they also have the characteristics of corroding equipment, polluting the environment, dark product color, and many side reactions.

[0009] In recent years, a lot of research and development have been done on the synthesis process of isooctyl salicylate. Most of the research focuses on exploring new and efficient catalysts to replace the use of concentrated sulfuric acid. The developed catalysts mainly include solid acid, solid super acid, Phosphoric acid, sulfonic acids, HY molecular sieves, and rare earth solid superacids, etc., although higher conversion rates of salicylic acid can be obtained, and catalysts have their own strengths, there are still problems such as high catalyst cost, long reaction time or catalyst preparation. Problems such as complex process are not suitable for industrial production

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