Synthesis method of UV absorbent ethylhexyl triazone

Abstract

The invention discloses a synthesis method of a UV absorbent ethylhexyl triazone. The synthesis method comprises that melamine and 4-chlorobenzoic acid as initial raw materials undergo a trisubstitution reaction to produce 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine (H3TATAB), 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine (H3TATAB) and isooctanol undergo an esterification reaction to produce an ethylhexyl triazone crude product, the ethylhexyl triazone crude product is subjected to distillation desolvation and crystallization and the crystals are dried to form an ethylhexyl triazone finished product. The synthesis method has the characteristics of simple production route, easily available raw materials, mild reaction conditions, unique crystallization method, less three wastes and high product purity and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of preparation of ultraviolet absorbers, in particular to a method for synthesizing the ultraviolet absorber ethylhexyl triazone. Background technique [0002] Triazine UV absorbers are a new type of high-efficiency broad-spectrum UV absorbers developed in recent years. It has a large hair structure, high ultraviolet absorption efficiency and anti-oxidation function, and is the development direction of ultraviolet absorbers. In practical applications, triazine UV absorbers and hindered amine light stabilizers have a good synergistic effect, and when they are used together, they have a better effect than when they are used alone. At the same time, triazine compounds are a class of heterocyclic compounds with good activity, and new, efficient, safe and unique triazine compounds will appear in the future pharmaceutical field. As a new type of triazine UV absorber, ethylhexyl triazone has a large molecular structure and...

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Problems solved by technology

Patent application CN10525317A discloses a preparation process of octyl triazone and its tautomers, which uses a mixture of methanol or ethanol and water to solidify; this method can obtain solidified block products, and the operation is simple. The yield is high, but no crystalline product can be formed;

[0003] Patent application CN1639134 discloses the tautomeric form of 2,4,6-triphenylamino-p-((carbonyl-2'-ethylhexyl-1'-oxyl)-1,3,5-triazine ( Ⅰ) The preparation method, the key point of this method is the solvent used for recrystallization; with isooctyl p-aminobenzoate and cyanuric chloride as starting raw materials, react in xylene solvent to obtain 2,4,6-triphenylamine base-p-(carbonyl-2'-ethylhexyl-1'-oxyl)-1,3,5-triazine tautomeric mixture; then in one or more solvents selected from Crystallization in the presence of: aliphatic alcohols having 2-8 carbon atoms, aliphatic alkyl carboxylates having a total of 3-10 carbon atoms, aromatic alkyl carboxylates having a total of 8-12 carbon atoms , aliphatic carbonates having a total of 3 to 9 carbon atoms, nitriles having a total of 2 to 8 carbon atoms, dialkyl ketones having a total of 3 to 6 carbon atoms, and dialkyl ketones having a total of 3 to 6 carbon atoms Aliphatic sulfones, wherein the solvent or mixture may additionally contain up to 30% by weight of hydrocarbons; this method enables crystallized products to be obtained, but the crystallization operation is complicated, takes a long time, and the product yield is low;

[0004] Above two kinds of technical schemes, all do not relate to the preparation method of target product octyl triazone, the method for its crystallization (solidification) has defect respectively

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