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A kind of refining method of o-hydroxybenzonitrile

A technology of o-hydroxybenzonitrile and refining methods, applied in the direction of carboxylic acid nitrile purification/separation, organic chemistry, etc., can solve the problems of easy deterioration of cyano group, unsuitable scale application of o-hydroxybenzonitrile, etc., to improve stability, The effect of strong practicability and convenient operation

Active Publication Date: 2022-06-14
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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  • A kind of 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 method for refining o-hydroxybenzonitrile, which comprises the following steps: (1) melting the crude product of o-hydroxybenzonitrile into a liquid state and maintaining a constant temperature, adding 4,4'-dihydroxybiphenyl, 4 At least one of ‑hydroxybiphenyl or 4,3'‑dihydroxybiphenyl, mixed evenly to make distillation bottom material; (2) Set the evaporation temperature of distillation bottom material, carry out molecular distillation on distillation bottom material, wait After the distillation is complete, the light fraction is flaked to obtain a white flake o-hydroxybenzonitrile product. The method of the invention has simple process, low cost, high efficiency and is suitable for large-scale application, and the refined o-hydroxybenzonitrile obtained by the method has 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 conta...

Claims

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Application Information

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Patent Type & Authority Patents(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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