Preparation method of sun-screening agent iso-octyl p-methoxycinnamate

Abstract

The invention relates to a preparation method of a sun-screening agent OMC (iso-octyl P-Methoxycinnamate). The preparation method comprises the following steps of: 1, adding p-anisaldehyde, malonic acid, a catalyst I organic secondary amine substance, a catalyst II organic acid substance and a water-insoluble organic aromatic hydrocarbon solvent to a condensation reaction kettle, and carrying out reflux water diversion reaction for 4-5 hours; 2, after condensation reaction is finished, cooling to 5-15 DEG C, filtering to obtain a p-methoxycinnamic acid crude product, directly applying filter liquor to next reaction, and optionally supplementing a small quantity of catalysts and solvents to the filter liquor; 3, adding catalyst III macroporous type storng acid cation exchange resin, isooctyl alcohol, the p-methoxycinnamic acid crude product and an aromatic hydrocarbon or aliphatic hydrocarbon solvent to an esterifying reaction kettle, and carrying out reflux water diversion reaction for 2-3 hours; and 4, after esterifying reaction is finished, cooling to 65 DEG C, filtering and recovering the catalysts for mechanical application, washing the filter liquor to neutrality through a 5% sodium carbonate water solution, desolventizing, and rectifying to obtain the final product isooctyl p-methoxycinnamate. The method disclosed by the invention has the characteristics of easiness, convenience, easiness in control, industrial production, low environment pollution, low energy consumption, material recycling, high product purity, and the like.

Description

technical field [0001] The invention relates to a preparation method of sunscreen agent isooctyl p-methoxycinnamate, which belongs to the technical field of daily chemical industry. Background technique [0002] Isooctyl p-methoxycinnamate (OMC) is also known as isooctyl 4-methoxycinnamate, trans isooctyl p-methoxycinnamate, isooctyl p-methoxycinnamate; English name Isooctyl p-methoxycinnamate; CAS number: 83834-59-7; Molecular formula: C 18 h 26 o 3 ; Molecular weight: 290.4. [0003] Isooctyl p-methoxycinnamate is a good absorber of ultraviolet rays in the UVB region, and can effectively prevent ultraviolet rays of 280-330nm. It has a high absorption rate, no irritation to the skin, and good safety. It is almost an ideal sunscreen. [0004] The synthetic technique of isooctyl p-methoxycinnamate mainly contains following several. [0005] Perkin reaction preparation, such as in CN102060832; Asian J.Chem.2007,19 (6): 4945-4947; Rev.Roum.Chim.2005,50 (7-8): 627-631 is d...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: the reaction temperature is high, and more energy is consumed, and at such a high temperature, the material and safety requirements of the equipment are relatively high.

However, the above-mentioned process has the following disadvantages from the actual production: the utilization rate of the reaction raw material methyl acetate or isooctyl ester is not high, the decomposition of acetates under alkaline conditions causes raw material loss, and the condensation reaction produces more side reactions. The composition of the crude product is complex, which makes it difficult to separate the product. After the condensation reaction is completed, a large amount of water is required to wash the material. The high-salt and high-COD wastewater produced in this way brings pressure to environmental protection and pollutes the surrounding environment.

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