Method for preparing 4,4-dimethyl-1-(4-chlorphenyl)-3-pentanone

A dimethyl and chlorophenyl technology, applied in the field of organic compound synthesis, can solve the problems of poor product quality, high equipment requirements, low synthesis yield, etc., and achieves the advantages of reducing unit consumption, reducing equipment requirements and improving reaction yield Effect

Inactive Publication Date: 2012-02-15
苏州诚和医药化学有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] 4,4-Dimethyl-1-(4-chlorophenyl)-3-pentanone is an important intermediate of the triazole pesticide tebuconazole. At present, there are many domestic manufacturers, all of which use p-chlorobenzaldehyde Reaction with 3,3-dimethyl-2-butanone in the presence of potassium hydroxide and methanol as a solvent. The disadvantages of this process are that the synthesis yield is about 85%, the product quality is poor, the content is about 90%, and a large amount of water is produced. Methanol, methanol can be reused only after rectification, high equipment requirements and large loss

Method used

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  • Method for preparing 4,4-dimethyl-1-(4-chlorphenyl)-3-pentanone

Examples

Experimental program
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Effect test

Embodiment 1

[0011] Add 100g (0.71mol) of p-chlorobenzaldehyde, 76g (0.76mol) of 3,3-dimethyl-2-butanone, 200g of methanol, and 46g (0.86mol) of solid sodium methoxide into a 500ml reaction bottle, and heat up to reflux. The reflux temperature is 67-70°C, and it is kept at reflux for 6 hours. After the reflux is over, the recovery of methanol is started. When the recovery reaches 170g, the recovery of methanol is stopped. The product is cooled to 10-20°C, filtered, and dried at 60°C for 5 hours to obtain light Yellow crystalline solid 148g, content: 97.2% (HPLC), yield 95.1%. Recover 0.32% methanol water (mass content, the same below).

Embodiment 2

[0013] Add 100g (0.71mol) of p-chlorobenzaldehyde, 80g (0.8mol) of 3,3-dimethyl-2-butanone, 200g of methanol, and 50g (0.93mol) of solid sodium methoxide into a 500ml reaction bottle, and heat up to reflux. The reflux temperature is 67-70°C, and it is kept at reflux for 6 hours. After the reflux is over, the recovery of methanol is started. When the recovery reaches 170g, the recovery of methanol is stopped. The product is cooled to 10-20°C, filtered, and dried at 60°C for 5 hours to obtain light Yellow crystalline solid 151g, content: 96.8% (HPLC), yield 97.1%. Recover 0.25% methanol water.

Embodiment 3

[0015] Add 100g (0.71mol) of p-chlorobenzaldehyde and 83.6g (0.84mol) of 3,3-dimethyl-2-butanone into a 500ml reaction bottle, recover 200g of methanol and 54g (1mol) of solid sodium methoxide, and heat up to reflux , the reflux temperature is 67-70°C, and it is kept under reflux for 6 hours. After the reflux is over, the recovery of methanol is started. When the recovery reaches 170g, the recovery of methanol is stopped, the product is cooled to 10-20°C, filtered, and dried at 60°C for 5h to obtain 149 grams of light yellow crystalline solid, content: 96.4% (HPLC), yield 95.8%. Recover methanol water 0.33%.

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Abstract

The invention discloses a method for preparing 4,4-dimethyl-1-(4-chlorphenyl)-3-pentanone, which comprises the following steps: reacting 3,3-dimethyl-2-butanone and p-chlorobenzaldehyde under reflux for 5-10 hours by using methanol as a solvent and sodium methoxide as an alkalizer, recycling part of methanol, cooling to 10-20 DEG C, filtering to obtain the 4,4-dimethyl-1-(4-chlorphenyl)-3-pentanone, and drying, wherein the mol ratio of p-chlorobenzaldehyde:3,3-dimethyl-2-butanone:sodium methoxide is 1:(1.0-1.3):(1.2-1.5). Methanol is substituted for potassium hydroxide, so that water generated in reaction is decomposed by sodium methoxide, thereby effectively enhancing the reaction speed and reaction yield; and since the reaction system does not contain water, the solvent can be recycled by simple distillation, thereby greatly lowering the facility request and reducing the raw material unit consumption. The synthesis yield of the method is higher than 97%, the product content is higher than 96%, and the recovery rate of the solvent methanol is up to 85%; and thus, the invention can easily implement industrial production, has good practicality, and can generate high economic benefit and social benefit.

Description

technical field [0001] The invention belongs to the technical field of organic compound synthesis, and specifically relates to a method for preparing 4,4-dimethyl-1-(4-chlorophenyl)-3-pentanone. Background technique [0002] 4,4-Dimethyl-1-(4-chlorophenyl)-3-pentanone is an important intermediate of the triazole pesticide tebuconazole. At present, there are many domestic manufacturers, all of which use p-chlorobenzaldehyde Reaction with 3,3-dimethyl-2-butanone in the presence of potassium hydroxide and methanol as a solvent. The disadvantages of this process are that the synthesis yield is about 85%, the product quality is poor, the content is about 90%, and a large amount of water is produced. Methanol can be reused only after rectification, which requires high equipment and high loss. Contents of the invention [0003] Purpose of the invention: In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing 4,4-dim...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C49/235C07C45/74
Inventor 王利明夏秋景陈浩
Owner 苏州诚和医药化学有限公司
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