Preparation method of pyrocatechol monoisopropyl ether

Abstract

The invention discloses a preparation method of pyrocatechol monoisopropyl ether. The method comprises the following steps: by using pyrocatechin and 2-chloropropane as raw materials, and using a compound in a formula (1) as a solvent, carrying out reaction in a high pressure kettle under an effect of an acid acceptor to prepare pyrocatechol monoisopropyl ether. Side reaction between the solvent adopted in the preparation method of the invention and the raw materials is avoided, so that the raw materials are not consumed, and by-products are not produced; therefore, the using amount of the raw materials can be reduced, the production cost is reduced, the purity and the yield of the product also can be improved, and the problems of high production cost, and low purity and yield of the product caused by reaction between the raw materials and the solvent commonly in the prior art are solved; the preparation method has the advantages of simple process, low production cost, and high purity and yield of the product, and is suitable for industrial production; the purity of the product reaches 99% or above, and the yield reaches 90% or above.

Description

Technical field [0001] The invention belongs to the field of pesticides and relates to a preparation method of o-isopropoxyphenol. Background technique [0002] O-isopropoxyphenol is a key intermediate for the preparation of propoxur, a compound with the following structural formula: [0003] [0004] At present, the preparation methods of o-isopropoxyphenol reported in domestic and foreign literature include the following: (1) o-nitrochlorobenzene method; (2) halogenated phenol method; (3) cyclohexanone method; (4) Cyclohexanol method; (5) Catechol method. Among them, the catechol method is widely used by domestic and foreign companies producing Proxacarb because of its easy availability of raw materials, simple process flow and high synthesis yield. The method is prepared by reacting catechol, 2-chloropropane or 2-bromopropane as raw materials, and its synthesis method is as follows: [0005] [0006] In the existing catechol process, when 2-bromopropane is used as the raw mater...

AI Technical Summary

Problems solved by technology

[0006] In the existing catechol method, when 2-bromopropane is used as a raw material, normal pressure is usually used, but due to the high price of 2-bromopropane, the production cost is too high, and due to the need for subsequent processing of 2-bromopropane The use of sulfuric acid for neutralization and water washing has problems such as high treatment cost, complicated treatment process, and easy pollution. Therefore, 2-bromopropane is usually not used as raw material in actual industrial production.

In the method for the existing industrialized production of o-isopropoxyphenol, 2-chloropropane is usually used as a raw material instead of 2-bromopropane. However, since 2-chloropropane easily reacts with solvents, the amount of 2-chloropropane increases. And when solvent is consumed, by-product is introduced, which will not only increase production cost, but also reduce the purity and yield of product, such as, when using ethylene glycol monomethyl ether as solvent, the side reaction is as follows: The generation of this side reaction makes the consumption of 2-chloropropane increase, and consumes solvent ethylene glycol monomethyl ether, generates by-product 1-methoxyl group-2-isopropoxyl ethane, and this is for the production cost reduction, product purity and yield increase are very unfavorable

It can be seen that the large amount of raw materials, solvent consumption, and many by-products are important factors causing high production costs, low product purity and yield, which are common problems in the existing catechol method, and are also urgently needed by those of ordinary skill in the art. technical issues to be resolved

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