2-cyanophenol preparing method

A technology of o-hydroxybenzonitrile and o-hydroxybenzamide, which is applied in the field of preparation of o-hydroxybenzonitrile, can solve problems such as punching and clogging, and achieve the effects of promoting continued reaction, increasing contact area, and shortening reaction time

Active Publication Date: 2014-03-26
宁夏海利科技有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The purpose of the invention is to analyze the phosgene reaction process of o-hydroxybenzamide in the prior art, propose measures to strengthen the mass transfer of the phosgenation reaction process, solve problems such as blockage and flushing, and realize the continuation of the reaction process , increase production capacity

Method used

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  • 2-cyanophenol preparing method

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Effect test

Embodiment 1

[0029] In a 2000L glass-lined batching kettle, put 180kg of o-hydroxybenzamide, 0.5kg of catalyst dioxane and 1150L of solvent toluene for batching (1330L in total), turn on the jacket steam and heat to 105°C, stir for 15min, and o-hydroxybenzene After the formamide is completely dissolved in the solvent, the ingredients are put into a 5000L glass-lined storage kettle. Repeat the above process to keep the batching amount in the storage kettle to support extraction. The batching is pumped out with a raw material pump, and the flow rate is 665L / h, and it is input into a raw material mixer, where it is mixed with phosgene with a flow rate of 14700L / h. Control the temperature of the tube pass in the tubular reactor at 100-105°C, and the heat transfer area of ​​the reactant flow is 20m 2 The tube side of the tubular reactor, the gas generated by the reaction passes through the gas-liquid separator and condenser, and then goes to the tail gas treatment system. The liquid material e...

Embodiment 2

[0031]In a 2000L glass-lined batching kettle, put 180kg of o-hydroxybenzamide, 0.5kg of catalyst dioxane and 1150L of solvent toluene for batching (1330L in total), turn on the jacket steam and heat to 105°C, stir for 15min, and o-hydroxybenzene After the formamide is completely dissolved in the solvent, the ingredients are put into a 5000L glass-lined storage kettle. Repeat the above process to keep the batching amount in the storage kettle to support extraction. The batching is pumped out with a raw material pump, and the flow rate is 443L / h, and it is input into a raw material mixer, where it is mixed with phosgene with a flow rate of 9800L / h. Control the temperature of the tube pass in the tubular reactor at 100-105°C, and the heat transfer area of ​​the reactant flow is 20m 2 The tube side of the tubular reactor, the gas generated by the reaction passes through the gas-liquid separator and condenser, and then goes to the tail gas treatment system. The liquid material ent...

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Abstract

The invention discloses a 2-cyanophenol preparing method which is implemented by steps that salicylamide and phosgene are subjected to continuous reactions by a recycling continuous reaction system under the action of a catalyst dioxane and a solvent toluene. According to the method, a tubular reactor is adopted, the provided heat transfer specific surface area is large, the contact area of phosgene and a liquid-state material is increased, heat is transferred timely to a reactant, reaction temperature control is facilitated, and a fast reaction requirement is met. Transition-state continuous reaction is promoted through enhancement of mass transfer of a gas-liquid heterogeneous material, a forward reaction process is facilitated, and the reaction time is shortened; a material circulation mode of a raw material mixer, the tubular reactor and an insulation kettle is adopted, so that a gas-solid-liquid three-phase reaction formation is converted into a gas-liquid two-phase reaction formation, and a pipe blockage problem and a phosgene flow velocity limit problem are solved simultaneously; and further, automation control is facilitated, manual labor intensity is reduced, manual contact with the materials is avoided, and the productivity is increased effectively.

Description

technical field [0001] The invention relates to a method for preparing o-hydroxybenzonitrile, in particular to a method for continuously preparing o-hydroxybenzonitrile by a phosgene method. Background technique [0002] O-hydroxybenzonitrile is an important intermediate for the synthesis of a new type of high-efficiency broad-spectrum methoxyacrylate fungicide azoxystrobin. The production process currently used is: (1) Under the action of a catalyst, phosgene and o-hydroxybenzamide React in a solvent, release carbon dioxide to form a transition state Schiff base, continue to release hydrogen chloride to form o-hydroxybenzonitrile; (2) remove part of the solvent, cool down to precipitate o-hydroxybenzonitrile crystals, filter and dry the filter cake to obtain the product o-hydroxybenzonitrile Benzonitrile. The key step is (1), because: ① o-Hydroxybenzamide reacts with phosgene to form a transition state Schiff base, causing pipeline blockage and gas-solid-liquid three-phase...

Claims

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Application Information

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IPC IPC(8): C07C255/53C07C253/00
Inventor 周勇臧阳陵陈明周锦萍黄炜
Owner 宁夏海利科技有限公司
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