Preparation method of m-phenoxy benzaldehyde

Abstract

The invention discloses a preparation method of m-phenoxy benzaldehyde, which comprises the following steps: by using water as a reaction solvent, introducing oxygen to perform oxidation reaction at 20-70 DEG C under the catalytic conditions of hydrogen peroxide, transition metal salt and activated carbon, filtering the reaction solution, regulating the pH value, layering the mixture, and performing simple distillation to obtain the refined m-phenoxy benzaldehyde. According to the method disclosed by the invention, the content of m-phenoxybenzaldehyde in the product is greater than 99%, and the yield of raw materials is greater than 98%; the obtained m-phenoxy benzaldehyde can be directly used as a raw material for synthesizing related pyrethroid. The method has the advantages of simple operation, high reaction yield, good environmental protection benefit, easy industrialization, and good application value.

Description

technical field

[0001] The invention relates to a method for preparing m-phenoxybenzaldehyde, in particular to a method for preparing m-phenoxybenzaldehyde by oxidation of a mixture of m-phenylbenzaldehyde and m-phenoxybenzyl alcohol. Background technique

[0002] m-phenoxybenzaldehyde, referred to as ether aldehyde, is the main intermediate for the synthesis of pyrethroids such as cypermethrin, kung futhrin, fenvalerate (quick kill), fenpropathrin, etc., and is widely used. There are many synthetic methods reported in the literature, but most of the production methods that have industrial production value and are widely used at home and abroad use m-phenoxytoluene as a raw material, obtain a mixture of monochlorobenzyl and dichlorobenzyl through chlorination, and hydrolyze A mixture of m-phenoxybenzaldehyde (referred to as ether aldehyde) and m-phenoxybenzyl alcohol (referred to as ether alcohol) is obtained, and then oxidized to obtain ether aldehyde. The process is matur...

Examples

Embodiment 1

[0033] In the 1500L reactor, drop into 1000Kg of the mixture of ether aldehyde and ether alcohol (containing ether alcohol 35%), add 20Kg water, 5kg hydrogen peroxide, 0.5Kg ferrous sulfate, 0.4Kg gac (specific surface area is 800m 2 / g), stir and heat up to 45-55 degrees, feed oxygen (content 99%) for 2hr, the content of ether alcohol in the central control reactant is 0.11%, stop oxygen feeding, filter the reaction solution through a pressure filter tank, and let the filtrate stand Add 0.1Kg hydrochloric acid (mass fraction 30%) to adjust pH=6, let stand for 1hr to separate layers, the oil layer is 999.5Kg of crude ether aldehyde, the content is 98.32% (containing ether alcohol 0.08%, containing m-phenoxybenzoic acid 0.09%) , the oxidation yield was 98.6%. The oil layer is simply evaporated to obtain refined ether aldehyde with a content of 99.2%.

Embodiment 2

[0035] In the 1500L reactor, drop into 1000Kg of the mixture of ether aldehyde and ether alcohol (containing ether alcohol 65%), add 20Kg water, 5kg hydrogen peroxide, 0.5Kg ferrous sulfate, 0.4Kg gac (specific surface area is 800m 2 / g), stir and heat up to 45-55 degrees, feed oxygen (content 99%) for 2.5hr, the content of ether alcohol in the central control reactant is 0.20%, stop oxygen feeding, the reaction solution is filtered through the pressure filter tank, and the filtrate is static Add 0.12Kg hydrochloric acid (mass fraction 30%) to adjust pH=6, let stand for 1hr to separate layers, and the oil layer is 996Kg of crude ether aldehyde, with a content of 98.9% (containing 0.05% ether alcohol and 0.05% m-phenoxybenzoic acid) , the oxidation yield was 99.15%. The oil layer is simply evaporated to obtain refined ether aldehyde with a content of 99.35%.

Embodiment 3

[0037] Put 1000Kg of the mixture of ether aldehyde and ether alcohol into the 1500L reactor (containing ether alcohol 65%), add 10Kg water, 2kg hydrogen peroxide, 0.35Kg ferrous sulfate, 0.2Kg activated carbon (the specific surface area is 800m 2 / g), stir and heat up to 45~50 degrees, pass into oxygen (content 99%) 3.0hr, the ether alcohol content in the control reactant is 0.15%, stop the oxygen flow, the reaction solution is filtered through the pressure filter cylinder, the filtrate is static Add 0.12Kg hydrochloric acid (mass fraction 30%) to adjust pH=6, let stand for 1hr to separate layers, the oil layer is 994Kg of crude ether aldehyde, the content is 98.5% (containing ether alcohol 0.07%, containing m-phenoxybenzoic acid 0.08%) , the oxidation yield was 98.55%. The oil layer is simply evaporated to obtain refined ether aldehyde with a content of 99.22%.

technical field

[0001] The invention relates to a method for preparing m-phenoxybenzaldehyde, in particular to a method for preparing m-phenoxybenzaldehyde by oxidation of a mixture of m-phenylbenzaldehyde and m-phenoxybenzyl alcohol. Background technique

[0002] m-phenoxybenzaldehyde, referred to as ether aldehyde, is the main intermediate for the synthesis of pyrethroids such as cypermethrin, kung futhrin, fenvalerate (quick kill), fenpropathrin, etc., and is widely used. There are many synthetic methods reported in the literature, but most of the production methods that have industrial production value and are widely used at home and abroad use m-phenoxytoluene as a raw material, obtain a mixture of monochlorobenzyl and dichlorobenzyl through chlorination, and hydrolyze A mixture of m-phenoxybenzaldehyde (referred to as ether aldehyde) and m-phenoxybenzyl alcohol (referred to as ether alcohol) is obtained, and then oxidized to obtain ether aldehyde. The process is matur...

Examples

Embodiment 1

[0033] In the 1500L reactor, drop into 1000Kg of the mixture of ether aldehyde and ether alcohol (containing ether alcohol 35%), add 20Kg water, 5kg hydrogen peroxide, 0.5Kg ferrous sulfate, 0.4Kg gac (specific surface area is 800m 2 / g), stir and heat up to 45-55 degrees, feed oxygen (content 99%) for 2hr, the content of ether alcohol in the central control reactant is 0.11%, stop oxygen feeding, filter the reaction solution through a pressure filter tank, and let the filtrate stand Add 0.1Kg hydrochloric acid (mass fraction 30%) to adjust pH=6, let stand for 1hr to separate layers, the oil layer is 999.5Kg of crude ether aldehyde, the content is 98.32% (containing ether alcohol 0.08%, containing m-phenoxybenzoic acid 0.09%) , the oxidation yield was 98.6%. The oil layer is simply evaporated to obtain refined ether aldehyde with a content of 99.2%.

Embodiment 2

[0035] In the 1500L reactor, drop into 1000Kg of the mixture of ether aldehyde and ether alcohol (containing ether alcohol 65%), add 20Kg water, 5kg hydrogen peroxide, 0.5Kg ferrous sulfate, 0.4Kg gac (specific surface area is 800m 2 / g), stir and heat up to 45-55 degrees, feed oxygen (content 99%) for 2.5hr, the content of ether alcohol in the central control reactant is 0.20%, stop oxygen feeding, the reaction solution is filtered through the pressure filter tank, and the filtrate is static Add 0.12Kg hydrochloric acid (mass fraction 30%) to adjust pH=6, let stand for 1hr to separate layers, and the oil layer is 996Kg of crude ether aldehyde, with a content of 98.9% (containing 0.05% ether alcohol and 0.05% m-phenoxybenzoic acid) , the oxidation yield was 99.15%. The oil layer is simply evaporated to obtain refined ether aldehyde with a content of 99.35%.

Embodiment 3

[0037] Put 1000Kg of the mixture of ether aldehyde and ether alcohol into the 1500L reactor (containing ether alcohol 65%), add 10Kg water, 2kg hydrogen peroxide, 0.35Kg ferrous sulfate, 0.2Kg activated carbon (the specific surface area is 800m 2 / g), stir and heat up to 45~50 degrees, pass into oxygen (content 99%) 3.0hr, the ether alcohol content in the control reactant is 0.15%, stop the oxygen flow, the reaction solution is filtered through the pressure filter cylinder, the filtrate is static Add 0.12Kg hydrochloric acid (mass fraction 30%) to adjust pH=6, let stand for 1hr to separate layers, the oil layer is 994Kg of crude ether aldehyde, the content is 98.5% (containing ether alcohol 0.07%, containing m-phenoxybenzoic acid 0.08%) , the oxidation yield was 98.55%. The oil layer is simply evaporated to obtain refined ether aldehyde with a content of 99.22%.

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