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Refining method of o-hydroxybenzonitrile

A technology of o-hydroxybenzonitrile and refining method, which is applied in the purification/separation of carboxylic acid nitrile, organic chemistry, etc., can solve the problems of unsuitable o-hydroxybenzonitrile scale application, easy deterioration of cyano groups, etc., and prolong the thermal stability time , Improve stability and facilitate operation

Active Publication Date: 2020-02-21
HUNAN CHEM RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] There are also literature reports that a small amount of o-hydroxybenzonitrile is purified by simple distillation, but under the condition of the boiling point of o-hydroxybenzonitrile of 149°C / 1.9kPa, as the heating time prolongs, the cyanide on the o-hydroxybenzonitrile molecule The base is easily deteriorated, so simple distillation purification is not suitable for large-scale application of o-hydroxybenzonitrile

Method used

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  • Refining method of o-hydroxybenzonitrile

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Embodiment 1

[0031] A method for purifying o-hydroxybenzonitrile of the present invention, comprising the steps:

[0032] (1) Put 1800g (80%, 12.1mol) of o-hydroxybenzonitrile crude product in a 3000ml constant temperature funnel, heat up to 95°C, the crude product is completely melted into a liquid state, and 0.18g of 4,4'- Dihydroxybiphenyl, mixed uniformly to prepare distillation bottom material.

[0033] (2) Turn on the vacuum pump of the molecular distillation apparatus, the vacuum degree in the distillation apparatus is 5 mbar, the distillation heating temperature of the distillation apparatus is set to 120 °C, the cooling temperature of the condenser is 95 °C, and the light fraction receiver is kept warm to 95 °C; Turn on the feed pump, The distillation bottom material was pumped into the molecular distillation apparatus, the feed rate was 10ml / min, and the distillation was completed after 180min, and the obtained light fraction was put into the flake machine for flakes to obtain 13...

Embodiment 2

[0035] A method for purifying o-hydroxybenzonitrile of the present invention, comprising the steps:

[0036] (1) 1800g (90%, 13.6mol) o-hydroxybenzonitrile crude product was placed in a 3000ml constant temperature funnel, heated to 95°C, the crude product was completely melted into a liquid state, and 1.8g of 4,4'- Dihydroxybiphenyl, mixed uniformly to prepare distillation bottom material.

[0037] (2) Turn on the vacuum pump of the molecular distillation apparatus, the vacuum degree in the distillation apparatus is 8 mbar, set the heating temperature of the distillation apparatus to 130 °C, the cooling temperature of the condenser to be 100 °C, and the heat preservation of the light fraction receiver to be 100 °C; The distillation bottom material was pumped into a molecular distillation apparatus, the feed rate was 40ml / min, and the distillation was completed after 45min, and the obtained light fraction was put into a flaker for flakes, to obtain 1511g of white flaky o-hydrox...

Embodiment 3

[0039] A method for purifying o-hydroxybenzonitrile of the present invention, comprising the steps:

[0040](1) 1800g (80%, 12.1mol) o-hydroxybenzonitrile crude product was placed in a 3000ml constant temperature funnel, heated to 95°C, the crude product was completely melted into a liquid state, and 0.18g of 4,3'- Dihydroxybiphenyl, mixed uniformly to prepare distillation bottom material.

[0041] (2) Turn on the vacuum pump of the molecular distillation apparatus, the vacuum degree in the distillation apparatus is 5 mbar, set the heating temperature of the distillation apparatus to 120 °C, the cooling temperature of the condenser to be 95 °C, and the heat preservation of the light fraction receiver to be 95 °C; The distillation bottom material was pumped into the molecular distillation apparatus, the feed rate was 20ml / min, and the distillation was completed after 90min, and the obtained light fractions were put into the flake machine for flakes, to obtain 1311g of white fla...

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Abstract

The invention discloses a refining method of o-hydroxybenzonitrile. The method includes the steps of: (1) melting an o-hydroxybenzonitrile crude product into a liquid state, keeping a constant temperature, adding at least one of 4, 4'-dihydroxybiphenyl, 4-hydroxybiphenyl or 4, 3'-dihydroxybiphenyl, and mixing the substances uniformly to prepare a distillation base material; and (2) setting the evaporation temperature of the distillation base material, carrying out molecular distillation on the distillation base material, and flaking the light fraction at the end of distillation to obtain a white flake o-hydroxybenzonitrile product. The method disclosed by the invention is simple in process, low in cost, high in efficiency, and is suitable for large-scale application. The o-hydroxybenzonitrile refined by the method has the advantages of high purity, high recovery rate and high thermal stability.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for purifying o-hydroxybenzonitrile. Background technique [0002] o-Hydroxybenzonitrile is an important intermediate for the synthesis of bunilolol, a fungicide, azoxystrobin, dyes, and liquid crystal materials. [0003] At present, the post-processing of o-hydroxybenzonitrile synthesis mainly adopts three ways: organic solvent crystallization, water treatment, molecular sieve purification and recrystallization. Organic solvent crystallization generally refers to the crystallization of o-hydroxybenzonitrile from an organic solvent reaction solution. DE2533245, WO0130746, CN201210572630.7, etc. disclose that o-hydroxybenzonitrile is crystallized by cooling from an organic solvent, and o-hydroxybenzonitrile is obtained after filtration and drying. For formonitrile products, the product content is generally 95% to 98%. The reaction liquid system cont...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C253/34C07C253/32C07C255/53
CPCC07C253/34C07C253/32C07C255/53
Inventor 周勇罗先福全春生王燕黄炜刘国文臧阳陵杜升华刘卫东
Owner HUNAN CHEM RES INST
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