Method for preparing 2-hydroxy-benzonitril by adopting micro-flow field technology

A salicylonitrile and microfluidic field technology, applied in the field of organic compound preparation, can solve the problems of increased salicylaldehyde by-products, difficult to proceed in a forward direction, low reaction conversion rate, etc., and achieves less reaction impurities, shortened reaction time, Simple to use effects

Active Publication Date: 2021-08-13
NANJING ADVANCED BIOLOGICAL MATERIALS & PROCESS EQUIP INST CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The method is cumbersome to operate, and salicylaldehyde is unstable in an alkaline environment, resulting in increased by-products, low reaction yield and difficult purification
[0007] In the third type of traditional tank reaction, the amount of water taken off continues to accumulate, making it more difficult for the reaction to proceed forward, resulting in a low reaction conversion rate, and dehydrating agents such as concentrated sulfuric acid and acetic anhydride are needed to promote the forward reaction.

Method used

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  • Method for preparing 2-hydroxy-benzonitril by adopting micro-flow field technology
  • Method for preparing 2-hydroxy-benzonitril by adopting micro-flow field technology
  • Method for preparing 2-hydroxy-benzonitril by adopting micro-flow field technology

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Experimental program
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Effect test

Embodiment 1

[0034] The preparation method of salicylonitrile comprises the steps:

[0035] Use 100mL dimethyl sulfoxide (DMSO) to ultrasonically dissolve 20.0g (1.05eq) of hydroxylamine hydrochloride, add 33.47g (1.0eq) of salicylaldehyde after complete dissolution, and stir evenly. Single feed: pump the raw materials into the microchannel reactor, place the reactor in a constant temperature oil bath at 100°C, control the pumping speed so that the residence time is 10min, and adjust the pressure backup valve to make the system pressure 0.85MPa to make the system The fluid is kept flowing, the reactor outlet is sampled, washed with water, and extracted to obtain the crude salicylonitrile. Then recrystallized with xylene to obtain 31.14 g of white solid, with a yield of 95.38% and a purity of 99.79%.

Embodiment 2

[0037] The preparation method of salicylonitrile comprises the steps:

[0038] Use 250mL dimethyl sulfoxide (DMSO) to ultrasonically dissolve 50.0g (1.05eq) of hydroxylamine hydrochloride, add 83.68g (1.0eq) of salicylaldehyde after complete dissolution, and stir evenly. Single feed: pump the raw materials into the microchannel reactor, place the reactor in a constant temperature oil bath at 100°C, control the pumping speed so that the residence time is 10min, and adjust the pressure backup valve to make the system pressure 0.85MPa to make the system The fluid is kept flowing, the reactor outlet is sampled, washed with water, and extracted to obtain the crude salicylonitrile. Then recrystallized from xylene to obtain 77.45 g of white solid with a yield of 94.89% and a purity of 99.56%.

Embodiment 3

[0040] The preparation method of salicylonitrile comprises the steps:

[0041] Use 100mL dimethyl sulfoxide (DMSO) to ultrasonically dissolve 20.0g (1.05eq) of hydroxylamine hydrochloride, add 33.47g (1.0eq) of salicylaldehyde after complete dissolution, and stir evenly. Single-feed feed: pump the raw materials into the microchannel reactor, place the reactor in a 90°C constant temperature oil bath, control the pumping speed so that the residence time is 20min, and adjust the pressure backup valve to make the system pressure 0.65MPa to make the system The fluid is kept flowing, the reactor outlet is sampled, washed with water, and extracted to obtain the crude salicylonitrile. Then recrystallized from xylene to obtain 30.85 g of white solid, with a yield of 94.49% and a purity of 99.32%.

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Abstract

The invention discloses a method for preparing 2-hydroxy benzonitrile (o-hydroxy benzonitrile) by adopting a micro-flow field technology, which comprises the following steps: (1) dissolving hydroxylamine hydrochloride in a solvent, adding salicylaldehyde, and fully stirring and uniformly mixing to obtain a reaction solution; and (2) pumping the uniformly mixed reaction liquid into the micro-channel reactor by adopting single-strand feeding, and carrying out one-step reaction to obtain a 2-hydroxy-benzonitrile crude product. Compared with a traditional preparation method of the 2-hydroxy-benzonitrile, the method has the advantages that the use of a dehydrating agent is avoided, the reaction time is short, the conversion rate of the 2-hydroxy-benzonitrile is high, the operation is simple, the safety is high, and the method is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of organic compound preparation, in particular to a method for preparing salicylonitrile through a microchannel. Background technique [0002] Salicylonitrile, or o-hydroxybenzonitrile, is a kind of off-white to light brown powder, which is an important chemical intermediate for the synthesis of liquid crystal materials, spices, pesticides, etc. Therefore, salicylonitrile has a wide range of application value in various industrial fields. [0003] At present, the industrial synthesis of salicylonitrile mainly contains the following methods: [0004] (1) Taking salicylamide as a raw material, adopting phosphorus oxychloride as a dehydrating agent to reflux in toluene to prepare salicylonitrile. This method produces a large amount of phosphorus-containing wastewater, and the post-treatment cost is high, and it does not meet the increasingly stringent environmental protection requirements. [0005] (2) Use s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C253/00C07C255/53C07C249/08C07C251/48B01J19/00
CPCC07C253/00C07C249/08B01J19/0093C07C251/48C07C255/53
Inventor 赵云郭凯李玉光乔凯黄达杜金珺
Owner NANJING ADVANCED BIOLOGICAL MATERIALS & PROCESS EQUIP INST CO LTD
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