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A kind of preparation method of o-hydroxybenzonitrile

A technology of o-hydroxybenzonitrile and o-hydroxybenzamide, which is applied in the field of preparation of o-hydroxybenzonitrile, can solve the problems such as difficult complete conversion of raw materials, high energy consumption of water removal process, and a large amount of acid-containing waste water, etc. Avoid the loss of phosgene, simple and convenient post-processing methods, high atom economy effect

Inactive Publication Date: 2016-09-28
尹山红
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The process reported in this literature uses a high-boiling-point solvent reflux reaction, in which chlorobenzene and xylene have a boiling point as high as 140 ° C. Long-term reflux reaction and atmospheric distillation to recover solvents lead to increased energy consumption; in fact, in actual production, high The reflux reaction of the boiling point solvent will increase the loss of phosgene, and it is difficult to completely convert the raw materials; in addition, due to dioxane and tetrahydrofuran will form a salt with the acid, which will be taken out together when the high boiling point solvent is evaporated, making the high recovery rate The boiling point solvent contains a large amount of acid and a small amount of phosgene, which can be reused after further washing and water removal processes. This process will produce a large amount of acid-containing wastewater, and a small amount of phosgene will bring certain safety hazards to the post-treatment. The water removal process It will also bring about the problem of high energy consumption or increased cost
In the process reported in this document, after part of the solvent is evaporated, the product is directly cooled and crystallized to obtain the product with a yield of 95%. After the solvent is recovered and used mechanically, some residues will still be produced.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Embodiment 1, the synthesis of o-hydroxybenzonitrile

[0022] Add 138.5 g (1.0 mol) of o-hydroxybenzamide to the reaction flask, add 0.028 g of arginine, and 700 g of dichloroethane, raise the temperature to 78 ° C, start to feed phosgene, and feed 108.8 g (1.1 mol) for 3 hours , heat preservation reaction 1h;

[0023] After the reaction was finished, about 350 g of dichloroethane was evaporated, the distillation was stopped, the temperature was cooled in an ice bath, and crystals were precipitated, and the temperature was continued to cool to 0° C., stirred for 1 h, filtered, and dried to obtain 118.5 g, the content was 98.5%, and the yield was 98.0% ( as o-hydroxybenzamide).

Embodiment 2

[0024] Embodiment 2, the synthesis of o-hydroxybenzonitrile

[0025] Add 138.5 g (1.0 mol) of o-hydroxybenzamide to the reaction flask, add 0.056 g of arginine, and 700 g of dichloroethane, raise the temperature to 75 ° C, start to feed phosgene, and feed 108.8 g (1.1 mol) for 4 hours , heat preservation reaction 1h;

[0026] After the reaction was finished, about 350 g of dichloroethane was evaporated, the distillation was stopped, the temperature was cooled in an ice bath, and crystals were precipitated, and the temperature was continued to cool to 0° C., stirred for 1 h, filtered, and dried to obtain 118.6 g, with a content of 98.5%, and a yield of 98.1% ( as o-hydroxybenzamide).

Embodiment 3

[0027] Embodiment 3, the synthesis of o-hydroxybenzonitrile

[0028] Add 138.5 g (1.0 mol) of o-hydroxybenzamide into the reaction flask, add 0.028 g of lysine, and 700 g of dichloroethane, raise the temperature to 80°C, start to feed phosgene, and feed 108.8 g (1.1 mol) for 3 hours , heat preservation reaction 1h;

[0029] After the reaction is over, distill about 350g of dichloroethane, stop the distillation, cool down in an ice bath, crystals precipitate out, continue to stir, drop to 0°C, stir for 1h, filter, and dry to obtain 118.8g, content 99.1%, yield 98.8% (calculated as o-hydroxybenzamide).

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Abstract

The invention discloses a preparation method of o-hydroxybenzonitrile. The preparation method comprises the following step: taking o-hydroxybenzoyl amide as a raw material, an amino acidic compound as a catalyst and dichloroethane as a solvent, and dehydrating to prepare o-hydroxybenzonitrile under the action of phosgene. According to the preparation method, the amino acidic compound is used as the catalyst, the catalytic activity is high, the product yield reaches 98%, and the atom economy is high; at the reaction temperature of 75-80 DEG C, a reaction system is in a micro reflowing state and sufficient reaction of the phosgene can be ensured, so that use of a high-boiling point solvent and loss of the phosgene in reflowing reaction are avoided and the energy consumption and the cost are reduced.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation method of o-hydroxybenzonitrile. Background technique [0002] O-Hydroxybenzonitrile is a key intermediate in the synthesis of the high-efficiency fungicide azoxystrobin. The preparation method of the o-hydroxybenzonitrile of existing literature report mainly contains following several kinds: [0003] 1. Using o-hydroxybenzaldehyde as a raw material, react with hydroxylamine hydrochloride to generate the corresponding oxime, and then undergo acidolysis to obtain o-hydroxybenzonitrile. The yield of this method is low, the product content is not high, and produces a large amount of waste water. [0004] 2. Using o-cresol as raw material, through etherification, methylation and cyanation to synthesize o-hydroxybenzonitrile. The technological process of this method is loaded down with trivial details, and yield is low, is not suitable for indust...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C255/53C07C253/20
Inventor 尹山红
Owner 尹山红
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