Synthetic method of 3, 5-dichloro-2-pentanone

A synthesis method and technology of pentanone, which is applied in the field of synthesis of 3,5-dichloro-2-pentanone, can solve the problems of poor economy, poor selectivity, and low reaction yield, and achieve cost reduction, yield improvement, The effect of high product purity

Active Publication Date: 2016-04-06
大连科铎环境科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that glacial acetic acid is difficult to recover, the reaction yield is low, the selectivity is poor, the product must be rectified and purified, and the economy is poor

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Add 243g (2mol) of 30% concentrated hydrochloric acid and 23.4g sodium chloride (0.4mol) into a 1000ml four-necked bottle. Stir and heat up to reflux at 105°C, start to add dropwise a solution of 1.7g tetrabutylammonium bromide dissolved in 162.6g (1mol) α-chloro-α'-acetyl-γ-butyrolactone, and collect in the water separator lower layer of oil. After about 7 hours of dropping, the reaction was continued to reflux for 1 hour, a total of 166 g of oil was collected, washed once with 100 g of water, and 157 g of the oil layer product was obtained. The normalized purity detected by GC was 97%, and the calculated yield was 96.5%.

Embodiment 2

[0022] Add 243g (2mol) of 30% concentrated hydrochloric acid and 38g magnesium chloride (0.4mol) into a 1000ml four-necked bottle. Stir and heat up to reflux at 108°C, start to add dropwise a solution of 1.7g tetrabutylammonium bromide dissolved in 162.6g (1mol) α-chloro-α′-acetyl-γ-butyrolactone, and collect in the water separator lower layer of oil. After about 7 hours of dropwise addition, continue to reflux for 1 hour, collect a total of 160 g of oil, wash once with 100 g of water, and obtain 154 g of the oil layer product. The normalized purity detected by GC was 97%, and the calculated yield was 94.8%.

Embodiment 3

[0024] Add 243g (2mol) of 30% concentrated hydrochloric acid and 23.4g sodium chloride (0.4mol) into a 1000ml four-necked bottle. Stir and heat up to reflux at 105°C, start adding dropwise a solution of 4.8g tetrabutylammonium chloride dissolved in 162.6g (1mol) α-chloro-α'-acetyl-γ-butyrolactone, and collect in the water separator lower layer of oil. About 7 hours after the dropwise addition, continue to reflux for 1 hour, collect a total of 162 g of oil, wash once with 100 g of water, and obtain 150 g of the oil layer product. The normalized purity detected by GC was 97%, and the calculated yield was 93.4%.

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PUM

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Abstract

The invention discloses a synthetic method of 3, 5-dichloro-2-pentanone. Under the action of salt and a phase transfer catalyst, alpha-chloro-alpha'-acetyl-gamma-butyrolactone, which is used as a raw material, reacts with hydrochloric acid; and then, 3, 5-dichloro-2-pentanone is synthesized through a continuous steam distillation method. According to the characteristic of great boiling point difference between the raw material and the product, the technical scheme of reacting while separating is adopted. Therefore, purity of the product is raised, yield is greatly increased, and the hydrochloric acid solution in the reaction can be recycled. By adding the phase transfer catalyst, reaction speed of the raw material can be raised, and accumulation of the raw material in the reaction system is reduced. By adding salt, reaction distillation temperature can be increased, product separation speed is accelerated, and retention time of the raw material and the product in the reaction system is shortened. Thus, side reaction is minimized, and selectivity is enhanced.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, and in particular relates to a synthesis method of 3,5-dichloro-2-pentanone. Background technique [0002] 3,5-Dichloro-2-pentanone is an important intermediate in the synthesis of pharmaceuticals and pesticides. At present, its usual synthesis method is to react the raw material α-chloro-α′-acetyl-γ-butyrolactone with hydrochloric acid in the presence of glacial acetic acid, and then separate and purify it by extractive distillation. The disadvantage of this method is that glacial acetic acid is difficult to recover, the reaction yield is low, the selectivity is poor, the product must be rectified and purified, and the economy is relatively poor. Contents of the invention [0003] In view of the above problems, the present invention provides a method for synthesizing 3,5-dichloro-2-pentanone with low cost and high product yield. [0004] According to the characteristic that the boiling poin...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C49/16C07C45/59C07C45/84
CPCC07C45/59C07C45/84C07C49/16
Inventor 张宇潘作志李猛曹丽贤王善强杨宪斌王乃伟
Owner 大连科铎环境科技有限公司
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