Preparation method of electronic-grade p-nitrobenzyl alcohol

A technology of p-nitrobenzyl alcohol and electronic grade, which is applied in the field of preparation of electronic grade p-nitrobenzyl alcohol, can solve the problems of not reaching electronic grade products, endangering the health of operators, and high content of sulfate ions, so as to improve the Yield and Purity Effects

Inactive Publication Date: 2018-06-15
GUANNAN YISITE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are following defects in the process of above-mentioned freeze crystallization: 1, need to use dichloroethane as organic solvent, dichloroethane has pungent smell, seriously endangers the health of operator; 2, due to the addition of dichloroethane Make in p-nitrobenzyl alcohol product introduce the chloride ion of higher content, and for the p-nitrobenzyl alcohol product of electronic grade, the chloride ion content in the product will be lower than 5PPM, and above-mentioned method can't reach; 3, The content of bromide in the p-nitrobenzyl alcohol product that above-mentioned method generates is higher, and the bromide content in the p-nitrobenzyl alcohol product of electronic grade will be lower than 5PPM; 4, in the p-nitrobenzyl alcohol product of electronic grade Sulfate ions in the solution will be lower than 10PPM. The above method has a higher content of sulfate ions due to the higher sulfate content of soda ash, which cannot meet the requirements of electronic grade products.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0017] Bromination: put 400kg of p-nitrotoluene, 1200kg of tap water and 240kg of bromine into the reaction pot, seal the lid of the pot, heat up the jacket with steam, raise the temperature to 50°C, turn off the steam, add 10kg of initiator, and initiate the reaction , the temperature is controlled at 80~85°C, when the red color in the pot fades, start to add 230 kg of hydrogen peroxide dropwise, control the dropwise addition within 4 hours, add the initiator according to the reaction situation, keep the temperature for 3 hours after the hydrogen peroxide drops, finish the reaction, and get the bromide;

[0018] Hydrolysis: Pump the bromide into the hydrolysis pot, add 380kg of liquid caustic soda with a mass fraction of 30%, add 1500kg of tap water, close the pot cover, heat the jacket to 75~80°C with steam, keep it warm for 6~8h, and get the hydrolyzate ;

[0019] Separation and purification of alcohol and water: after the heat preservation, pump the hydrolyzate into the al...

Embodiment approach 2

[0022] Bromination: Put 400kg of p-nitrotoluene, 1200kg of tap water and 260kg of bromine into the reaction pot, seal the lid of the pot, heat up the jacket with steam, raise the temperature to 50°C, turn off the steam, add 10kg of initiator, and initiate the reaction , the temperature is controlled at 80~85°C, when the red color in the pot fades, start to add 250 kg of hydrogen peroxide dropwise, control the dropwise addition within 4 hours, add the initiator according to the reaction situation, keep the temperature for 3 hours after the hydrogen peroxide drops, finish the reaction, and get the bromide;

[0023] Hydrolysis: pump the bromide into the hydrolysis pot, add 410kg of liquid caustic soda with a mass fraction of 30%, add 1500kg of tap water, close the pot cover, heat the jacket to 75~80℃ with steam, keep it warm for 6~8h, and get the hydrolyzate ;

[0024] Separation and purification of alcohol and water: after the heat preservation, pump the hydrolyzate into the alc...

Embodiment approach 3

[0027] Bromination: Put 400kg of p-nitrotoluene, 1200kg of tap water and 230kg of bromine into the reaction pot, seal the lid of the pot, heat up the jacket with steam, raise the temperature to 50°C, turn off the steam, add 10kg of initiator, and initiate the reaction , the temperature is controlled at 80~85°C, when the red color in the pot fades, start to add 220kg of hydrogen peroxide dropwise, control the dropwise addition within 4 hours, add the initiator according to the reaction situation, keep the temperature for 3 hours after the hydrogen peroxide drops, finish the reaction, and get the bromide;

[0028] Hydrolysis: pump the bromide into the hydrolysis pot, add 360kg of liquid caustic soda with a mass fraction of 30%, add 1500kg of tap water, close the lid of the pot, heat the jacket to 75~80°C with steam, keep it warm for 6~8h, and get the hydrolyzate ;

[0029] Separation and purification of alcohol and water: after the heat preservation, pump the hydrolyzate into th...

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PUM

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Abstract

The invention relates to the field of medical intermediate and discloses a preparation method of electronic-grade p-nitrobenzyl alcohol. The preparation method comprises the steps: dissolving p-nitrotoluene and bromine into water, adding the mixed solution into a reaction kettle, and adding an initiator for an initiation reaction at 45-55 DEG C until red is faded; dropwise adding hydrogen peroxide, adding the initiator according to a reaction condition, and carrying out a reaction at 80-85 DEG C after the dropwise adding operation is ended until the red is faded to obtain a bromide; adding liquid caustic soda and water, and keeping the temperature of 75-80 DEG C for 6-8h to obtain a hydrolysate; adding water and methyl alcohol, keeping the temprature of 60-65 DEG C for 1h, separating out an oil layer, carrying out cooling for crystallization, and when the temperature is reduced to 0 DEG C, carrying out centrifugation to obtain a crude product of p-nitrobenzyl alcohol; and adding methylbenzene, keeping the temperature of 70-75 DEG C for 30min, and carrying out pressure filtration, cooling and crystallization to obtain an electronic-grade p-nitrobenzyl alcohol product. A dichloroethane organic solvent is not needed, no hazards to operating personnel are caused, and the product conforms to the standard of an electronic-grade product.

Description

technical field [0001] The invention relates to the field of pharmaceutical intermediates, in particular to a method for preparing electronic-grade p-nitrobenzyl alcohol. Background technique [0002] p-Nitrobenzyl alcohol is a very important intermediate in the pharmaceutical industry. The current preparation method is to first mix p-nitrotoluene and bromine for bromination reaction to generate p-nitrobenzyl bromide and p-nitrobenzyl bromide. Then hydrolyze after freeze crystallization and centrifugation, wherein p-nitro-benzyl bromide is hydrolyzed into p-nitrobenzyl alcohol. There are following defects in the process of above-mentioned freeze crystallization: 1, need to use dichloroethane as organic solvent, dichloroethane has pungent smell, seriously endangers the health of operator; 2, due to the addition of dichloroethane Make in p-nitrobenzyl alcohol product introduce the chloride ion of higher content, and for the p-nitrobenzyl alcohol product of electronic grade, t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C201/12C07C201/16C07C205/19
CPCC07C201/12C07C201/16C07C205/19C07C205/11
Inventor 张守平陈卫东
Owner GUANNAN YISITE CHEM
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