A kind of synthetic method of environment-friendly 2,3,5-trimethylhydroquinone

Abstract

The invention relates to the field of chemical pharmacy, and in particular relates to an environment-friendly synthesis method for 2,3,5-trimethyl hydroquinone. The environment-friendly synthesis method for 2,3,5-trimethyl hydroquinone comprises the following steps: dissolving 1,2,4-trimethylbenzene serving as a raw material by using an organic solvent; adding hydrogen peroxide oxidant to oxidize 1,2,4-trimethylbenzene into 2,3,5-trimethyl p-benzoquinone to obtain a synthetic product; extracting the synthetic product to obtain an extract liquid; adding a reducing agent into the extract liquid; heating to perform a reduction reaction to synthesize 2,3,5-trimethyl hydroquinone. 1,2,4-trimethylbenzene serving as the raw material used in the synthesis method is inexpensive and easy to get; the used reaction reagents, for example, hydrogen peroxide, the organic solvent, the extraction agent and the reducing agent, are all commonly used reagents; moreover, the raw materials are low in cost; the used reagents can be recycled; the synthesis method has the advantages of mild reaction conditions, easiness in operation, a short process flow, low causticity on reaction equipment and low pollution to the environment, and is a green and environment-friendly industrial production line.

Description

technical field [0001] The invention relates to the field of chemical industry and pharmacy, in particular to an environment-friendly synthesis method of 2,3,5-trimethylhydroquinone. Background technique [0002] 2,3,5-Trimethylhydroquinone, referred to as 2,3,5-trimethylhydroquinone (TMHQ), is an important intermediate for the synthesis of vitamin E in industry, and it undergoes a condensation reaction with isophytic alcohol to synthesize vitamins E, vitamin E is mainly used as an additive in medicine, feed, food and cosmetics, and the market demand is very large. Therefore, the synthesis technology of 2,3,5-trimethylhydroquinone has attracted much attention. [0003] The existing synthesis process uses phenol as a raw material to synthesize trimethylhydroquinone through three steps of methylation, oxidation and rearrangement. The reaction is carried out under high temperature and high pressure, and the equipment requirements for the reaction are relatively high, thereby l...

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Problems solved by technology

[0007] Chinese patent CN97104282 has reported a kind of synthetic method for preparing 2,3,5-trimethylhydroquinone, and concrete synthetic method is as follows: take 4-oxo-isophorone as raw material, condense isophorone with acetic anhydride Structuring reaction generates 2,3,5-trimethylhydroquinone diacetate, and then saponification hydrolysis reaction makes 2,3,5-trimethylhydroquinone, this method is easy to prepare, and the yield is higher High, but the synthesis cost of the raw material 4-oxo-isophorone required for synthesis is relatively high

Disclosed in the preparation method of 4-oxo-isophorone in US6297404 and US6300521, described a kind of in the presence of DMF and DMA and triethylamine, use ammonium acetate as catalyst, catalytic oxidation β-isophorone The method of ketone and then synthetic 4-oxo-isophorone, the shortcoming of this method is easy to produce 3,5,5-trimethyl-cyclohexyl-2-en-1-one and 2,2,6-tri By-products such as methylcyclohexyl-1,4-dione, because these by-products have a closer boiling point than the product, it is difficult to separate and prepare high-purity 4-oxo-isophorone

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