A kind of preparation method of sunscreen agent octyl triazone

Abstract

The invention discloses a preparation method of sunscreen octyl triazone and the prepared octyl triazone and its application. The method comprises: step 1, carrying out esterification reaction between p-nitrobenzoic acid and isooctyl alcohol, Product I is obtained; step 2, product I undergoes hydrogenation reaction in the presence of a catalyst, after the reaction is completed, filter and distill under reduced pressure to obtain product II; step 3, add solvent to product II, and heat up to reflux, add solution A , to react, after post-treatment, to obtain octyl triazone. In the present invention, the sunscreen agent octyl triazone is efficiently prepared by using cheap and easily available p-nitrobenzoic acid as a raw material through esterification, hydrogenation, and coupling, and at the same time, isooctyl p-aminobenzoate is obtained, and the obtained octyl The triazone has high chromatographic purity and high yield, and has the advantages of less three wastes, low cost, environmental protection, simple operation, easy control, and easy realization of industrial production.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a preparation method of sunscreen agent octyl triazone. Background technique [0002] Sunscreen agent octyl triazone is a new type of ultraviolet absorber. It has a large molecular structure and high ultraviolet absorption efficiency, and has a broad-spectrum sunscreen effect. Used as an additive in sunscreen products, it is the oil-soluble absorbent with the strongest UVB absorption capacity on the market today. It has high photostability, prevents the immunosuppressive effect induced by UVB, has strong water resistance, and has a good effect on skin keratin. affinity. As a sunscreen agent, octyltriazone has the advantages of high absorption rate and low addition amount. Usually in sunscreen care products, it only needs a very small dose to achieve a high SPF value and has excellent sunscreen effect. [0003] BASF company patent WO2012 / 127425 discloses a method for synthesizin...

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Problems solved by technology

The method has the following defects: the reaction route is long, the yield of intermediate I is 92.5%, the yield of intermediate II is 93.2%, the yield of intermediate III is 93.2%, the yield of product octyl triazone ketone is 91.6%, and the total yield is only 73.6% %; The preparation of intermediate II adopts chemical reduction method, which will produce a large amount of iron sludge and seriously pollute the environment; when intermediate III is prepared, it is difficult to control the substitution quantity of cyanuric chloride, thus causing the low yield of intermediate III, and the intermediate III is very sensitive to water and is easy to hydrolyze to produce impurities that are difficult to remove; more solvents are introduced in the whole preparation process, which creates hidden dangers for the final product's dissolved residue

The problem that this method exists is: when melamine is coupled with p-chlorobenzoic acid, the chlorine activity on the benzene ring is low, and it is difficult to react with the amino group on the melamine, so that the yield of intermediate I is low; In the process of sodium bisulfate catalyzed esterification with isooctyl alcohol, it is difficult to completely esterify the three carboxyl groups on the intermediate I at the same time, so that the finished product contains unesterified impurities, which brings difficulties to separation and purification. It also ultimately affects the yield and quality of the product

The patent does not provide a preparation method for methyl p-aminobenzoate, and the outsourcing price is relatively expensive and difficult to obtain; the use of various solvents such as xylene, toluene, methanol, ethanol, isooctyl alcohol, etc., poses a hidden danger to the solvent residue of subsequent products ; Use 10% sodium methylate to catalyze the transesterification reaction between intermediate I and isooctyl alcohol, which will inevitably increase the cost of product manufacturing and cause three wastes to pollute the environment; The finished product contains impurities that have not been completely transesterified, which brings difficulties to separation and purification, and ultimately affects product quality

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