Method for removing benzaldehyde impurities in benzyl alcohol

A technology for benzyl alcohol and benzaldehyde, which is applied in the field of removing benzaldehyde impurities in benzyl alcohol, can solve problems such as being difficult to achieve higher-purity product quality standards, and achieve the effects of easy control, content reduction and product quality improvement.

Pending Publication Date: 2021-02-02
JIANGSU UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The method of removing benzaldehyde mostly adopts the method of multiple rectification, and it is difficult to meet the requirements of higher purity product quality standards (benzaldehyde content is less than 0.001%)

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Example 1: Nitrogen is used to replace the air in the vacuum rectification system with decompression (-0.06MPa) to the clean and dry vacuum rectification system with nitrogen gas with a purity of more than 99.9% for oil removal and water removal. Under certain conditions, the benzyl alcohol to be refined is added to the rectification system, and the rectification process is protected by nitrogen, and stirring and heating are started to control the temperature at 170°C for 30 minutes; a certain amount of sodium ethylate (to-be-refined 0.1% of the mass of benzyl alcohol), the temperature was controlled at 180°C for rectification, and the cuts were collected after 10 minutes, and the amount of the cuts was controlled at 15kg / hour. The content of benzyl alcohol in the product detection reaches more than 99.8%, the content of benzaldehyde ≤0.001%, cyclohexylmethanol ≤0.001%, benzyl chloride ≤0.0001%, dibenzyl ether ≤0.002%, benzene ≤0.00005%, peroxide ≤0.1 %, single unknown ...

Embodiment 2

[0029] Example 2: Nitrogen is used to replace the air in the clean and dry vacuum rectification system with nitrogen with a purity of more than 99.9% for oil removal and water removal; under reduced pressure (-0.10MPa), the Refined benzyl alcohol is added to the above-mentioned rectification system, and the rectification process is protected by nitrogen, and stirring and heating are started to control the temperature at 180°C for 50 minutes; a certain amount of sodium bisulfite (benzyl alcohol to be refined 0.5% of the mass), the temperature was controlled at 200°C for rectification, and the cut was collected after 30 minutes, and the amount of the cut was controlled at 20kg / hour. The content of benzyl alcohol in the product detection reaches more than 99.7%, the content of benzaldehyde ≤0.001%, cyclohexylmethanol ≤0.001%, benzyl chloride ≤0.0001%, dibenzyl ether ≤0.001%, benzene ≤0.00005%, peroxide ≤0.05 %, single unknown impurity ≤0.005%, total impurity ≤0.004%, moisture ≤0....

Embodiment 3

[0030] Example 3: Nitrogen is used to replace the air in the clean and dry vacuum rectification system with nitrogen with a purity of more than 99.9% for oil removal and water removal; under reduced pressure (-0.06MPa), the Refined benzyl alcohol was added to the above-mentioned rectification system, and the rectification process was protected by nitrogen, and stirring and heating were started to control the temperature at 200°C for 1 hour; a certain amount of 2,6-di-tert-butyl-4 - Cresol (0.1% of the mass of benzyl alcohol to be refined), its temperature is controlled at 210 ° C for rectification, and the cuts are collected after 1 hour and minutes, and the amount of the cuts is controlled at 30kg / hour. The content of benzyl alcohol is more than 99.9%, the content of benzaldehyde ≤0.001%, cyclohexylmethanol ≤0.001%, benzyl chloride ≤0.0001%, dibenzyl ether ≤0.001%, benzene ≤0.00005%, peroxide ≤0.03 %, single unknown impurity ≤0.002%, total impurity ≤0.005%, moisture ≤0.05%. ...

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PUM

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Abstract

The invention discloses a method for removing benzaldehyde impurities in benzyl alcohol, which comprises the following steps: opening a steam control valve to heat and dry a cleaned rectification system, introducing nitrogen into the rectification system through an atomizer for 15-30 minutes, and replacing air in the rectification system; under a reduced pressure condition, adding benzyl alcohol to be refined into a rectification system, starting stirring, slowly heating to raise the temperature, controlling the temperature to be 170-220 DEG C and the time to be 30-60 minutes, and discarding collected fractions; and under the condition of stirring, slowly adding a reducing agent into benzyl alcohol in a rectification system, and controlling the quantity of fractions to be 15-30kg/h. The method has the beneficial effects of simple process, high efficiency, environmental protection and large-scale industrial production; impurities and peroxides such as benzaldehyde, cyclohexyl methanol,benzyl chloride, dibenzyl ether and benzene remaining in benzyl alcohol can be efficiently removed, the quality of benzyl alcohol refined by improving the content of benzyl alcohol meets and exceeds related standard requirements of crude drugs and pharmaceutic adjuvants, and the content of benzaldehyde is smaller than 0.001%.

Description

technical field [0001] The invention relates to the fields of medicine and fine chemical industry, in particular to a method for removing benzaldehyde impurities in benzyl alcohol. Background technique [0002] Benzyl alcohol as a raw material (or API) and a pharmaceutical excipient has been included in Ch.P 2020 Edition (Pharmacopoeia of the People's Republic of China), USP (United States Pharmacopoeia), EP (European Pharmacopoeia), BP (British Pharmacopoeia) and JP (Japanese Pharmacopoeia) ) and other pharmacopoeias, in which the content of benzyl alcohol in key quality characteristic indicators is not less than 98.0%, and the content of impurities such as benzaldehyde, cyclohexylmethanol, benzyl chloride, dibenzyl ether and peroxides have been specified in detail; Among them, the content of benzaldehyde≤0.05%, cyclohexylmethanol≤0.1%, benzyl chloride≤0.005%, dibenzyl ether≤0.2%, benzene≤0.0001%, peroxide≤5%, single unknown impurity≤0.01% , total impurity ≤ 0.05%, moistur...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C29/80C07C29/88C07C33/22
CPCC07C29/80C07C29/88C07C33/22
Inventor 徐晨郑依依李红梅马千里王浩周虎马腾
Owner JIANGSU UNIV OF SCI & TECH
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