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Nitrobenzy alcohol preparing method

A technology for p-nitrobenzyl alcohol and p-nitrotoluene is applied in the field of preparation of p-nitrobenzyl alcohol, and can solve the problems of large amount of water used as a solvent for hydrolysis reaction, difficulty in recovering halogenated aromatic hydrocarbon solvent, difficulty in recovering organic solvent, and the like, Achieve high bromine content, simplified operation and mild conditions

Inactive Publication Date: 2019-05-14
台州昌霖化工科技有限公司 +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

After the bromination of this method is completed, alkali hydrolysis is directly added, which greatly increases the amount of alkali used. After the hydrolysis is completed, the water layer is not recycled, which increases waste water discharge, and the recovery of the used halogenated aromatic solvent is difficult, and the organic phase obtained by the reaction The purity of p-nitrobenzyl alcohol in medium is only 55-60%, and the content of p-nitrobenzaldehyde reaches 15-20%, so the purification is difficult and the yield is low
[0005] At present p-nitrotoluene bromination method is a kind of method most suitable for p-nitrobenzyl alcohol industrialization, but because in the method of prior art report, the organic solvent recovery that bromination reaction uses is difficult, the use of hydrolysis reaction solvent water Large amount of waste water, so it is necessary to develop a green synthesis process with low investment, low cost and less waste

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0028] Put 400 kg of p-nitrotoluene and 400 kg of water into a 5000L reactor, raise the temperature to 58-60°C, add 8 kg of benzoyl peroxide, add 246 kg of bromine dropwise, and continue to add 30% hydrogen peroxide dropwise 175 kg, reacted until the color of the reaction solution faded, allowed to stand for stratification, and took out the supernatant water layer while it was hot (the water layer was inserted into the next batch of bromination reaction). Add 3200 kilograms of water and 155 kilograms of sodium carbonate, heat up and reflux, after the hydrolysis is over, let stand for stratification, take out the supernatant water layer while it is hot (the water layer is inserted into the next batch of hydrolysis reaction while it is hot), add 1200 kilograms of toluene to the organic layer while it is hot , heated up to 60-70°C to dissolve, lowered to 10-20°C to crystallize, filtered, and dried to obtain 357 kg of p-nitrobenzyl alcohol with a yield of 79.9% and a liquid phase p...

Embodiment 2

[0034] Put 400 kg of p-nitrotoluene and 400 kg of water into a 5000L reactor, raise the temperature to 51-55°C, add 8 kg of azobisisoheptylcyanide, add 235 kg of bromine dropwise, and continue to add 30% dropwise 200 kg of hydrogen peroxide, reacted until the color of the reaction solution faded, allowed to stand for stratification, and took out the supernatant water layer while it was hot (the water layer was applied mechanically to the next batch of bromination reaction). Add 2800 kilograms of water and 270 kilograms of sodium bicarbonate to the organic layer, heat up and reflux, after the hydrolysis is over, let it stand for stratification, take out the supernatant water layer while it is hot (the water layer is inserted into the next batch of hydrolysis reaction while it is hot), and add the organic layer while it is hot 1,200 kg of toluene was heated up to 60-70°C to dissolve, then crystallized at 10-20°C, filtered, and dried to obtain 335 kg of p-nitrobenzyl alcohol, with...

Embodiment 3

[0036] Put 400 kg of p-nitrotoluene and 800 kg of water into a 5000L reactor, raise the temperature to 56-58°C, add 6 kg of azobisisobutyronitrile, add 257 kg of bromine dropwise, and continue to add 30% dropwise 175 kg of hydrogen peroxide was reacted until the color of the reaction solution faded, and the layers were left to stand, and the supernatant water layer was taken out while it was hot (the water layer was applied mechanically to the next batch of bromination reactions). Add 2000 kilograms of water and 139 kilograms of sodium carbonate to the organic layer, heat up and reflux, after the hydrolysis ends, let stand to separate layers, take out the supernatant water layer while hot (the water layer is inserted into the next batch of hydrolysis reaction while hot), and add acetic acid to the organic layer while hot 1,600 kg of ethyl ester was heated to 60-70°C to dissolve, then crystallized at 0-10°C, filtered, and dried to obtain 331 kg of p-nitrobenzyl alcohol, with a y...

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Abstract

The invention relates to a nitrobenzy alcohol preparing method. Specifically, the nitrobenzy alcohol preparing method takes methyl nitrobenzene as the raw material to prepare nitrobenzy alcohol through processes of bromination, hydrolysis, refining and the like. During the processes, separation and purification of intermediates are saved, reaction solvent for both bromination and hydrolysis is water and can be repeatedly recycled and reused, and meanwhile, operation is simplified, the production cost can be saved, and emission of wastewater and waste gas can be reduced. The nitrobenzy alcoholpreparing method has the advantages of being simple in operation, low in investment, green, environmentally friendly and the like and is applicable to industrial production.

Description

technical field [0001] The invention belongs to the technical field of synthesis of fine chemicals, and in particular relates to a preparation method of p-nitrobenzyl alcohol. Background technique [0002] p-nitrobenzyl alcohol, also known as 4-nitrobenzyl alcohol or p-nitrobenzyl alcohol, is an important fine chemical. In the field of synthetic pharmaceuticals, multiple key intermediates of penem antibiotics, such as 2-heavy Nitrobenzyl alcohol p-nitrobenzyl alcohol, p-nitrobenzyl alcohol malonate monoester, meropenem side chain, etc. all need p-nitrobenzyl alcohol as the starting material. [0003] At present, there are mainly five methods for preparing p-nitrobenzyl alcohol: 1) Patent CN104370746 announces that p-nitrotoluene is used as a raw material, and p-nitrobenzyl chloride is obtained through chlorination, and then p-nitrobenzyl chloride is obtained through steps such as purification, alkaline hydrolysis, and distillation. Nitrobenzyl alcohol. In this method, the ...

Claims

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Application Information

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IPC IPC(8): C07C205/19C07C201/12C07C201/16C07C205/11
Inventor 汪祝胜钟智奎熊轶
Owner 台州昌霖化工科技有限公司
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