Preparation method of clomazone

A technology of clomazone and hydroxyl, which is applied in the field of preparation of the herbicide clomazone, can solve the problems that are not suitable for industrial production, the rate of increase in yield is small, and the processing steps are cumbersome, and achieve good industrial application prospects. Effects with simple controls, easy recycling and post-processing

Inactive Publication Date: 2017-05-31
江苏长青生物科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Liu Weidong, Tang Dexiu and others have proposed improvements to the above methods, but generally the yield is not high when synthesizing 3-chloro-N-hydroxyl-2,

Method used

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  • Preparation method of clomazone

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Experimental program
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Effect test

example 1

[0023] Step 1. Add 18.8g (0.26mol) hydroxylamine hydrochloride, 100ml distilled water, 2g ether catalyst into a 250ml four-neck flask, stir under ice salt bath (-5~0℃), add 30% NaOH solution dropwise to make the solution pH The value reaches 7.2. Then 6ml (0.2mol) of chloropivaloyl chloride was added dropwise, and 30% NaOH solution was added dropwise to keep the system pH 7.2±0.1. After the dropwise addition was completed within 1.5h, the mixture was stirred at room temperature for 3h. After the completion of the reaction, after filtering and drying, the white solid obtained is 3-chloro-N-hydroxy-2,2-dimethylpropionamide. The content is 99.0% (HPLC), and the yield is 95.3%.

[0024] Step two

[0025] Add 15.2g of 3-chloro-N-hydroxy-2,2-dimethylpropionamide (prepared in the first step) to a 250ml reaction flask equipped with a pH meter, a constant pressure dropping funnel, a thermometer, and a mechanical stirring device. 55ml distilled water, stirring vigorously at 45°C. Add 30%...

example 2

[0028] Step 1. Add 18.8g (0.26mol) hydroxylamine hydrochloride, 100ml distilled water, 2g ether catalyst into a 250ml four-neck flask, stir under ice salt bath (-5~0℃), add 50% NaOH solution dropwise to make the solution pH The value reaches 7.2. Then 6ml (0.2mol) of chloropivaloyl chloride was added dropwise, and 50% NaOH solution was added dropwise to keep the system pH 7.2±0.1. After the dropwise addition was completed within 1.5h, the mixture was stirred at room temperature for 3h. After the completion of the reaction, after filtering and drying, the white solid obtained is 3-chloro-N-hydroxy-2,2-dimethylpropionamide. The content is 99.0% (HPLC), and the yield is 93.3%.

[0029] Step two

[0030] Add 15.2g of 3-chloro-N-hydroxy-2,2-dimethylpropionamide (prepared in the first step) to a 250ml reaction flask equipped with a pH meter, a constant pressure dropping funnel, a thermometer, and a mechanical stirring device. 55ml distilled water, stirring vigorously at 45°C. Add 30%...

example 3

[0033] Step 1: Add 18.8g (0.26mol) hydroxylamine hydrochloride, 100ml distilled water, 2g ether catalyst into a 250ml four-neck flask, stir under ice salt bath (-5~0℃), add 30% KOH solution dropwise to make the solution pH The value reaches 7.2. Then 6ml (0.2mol) of chloropivaloyl chloride was added dropwise, while 30% KOH solution was added dropwise to maintain the pH of the system at 7.2±0.1. After the dropwise addition was completed within 1.5 hours, the mixture was stirred at room temperature for 3 hours. After the completion of the reaction, after filtering and drying, the white solid obtained is 3-chloro-N-hydroxy-2,2-dimethylpropionamide. The content is 99.0% (HPLC), and the yield is 94.3%.

[0034] Step two

[0035] Add 15.2g of 3-chloro-N-hydroxy-2,2-dimethylpropionamide (prepared in the first step) to a 250ml reaction flask equipped with a pH meter, a constant pressure dropping funnel, a thermometer, and a mechanical stirring device. 55ml distilled water, stirring vigo...

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Abstract

The invention relates to a preparation method of clomazone, wherein an intermediate, 4,4-dimethylisoxazole-3-one, is synthesized by dropwise adding chloro-pivaloyl chloride to a raw material, hydroxylamine hydrochloride, under the effects of a self-made ether catalyst; and then the intermediate is condensed with o-chlorobenzyl chloride under the effects of a caustic soda flake catalyst to synthesize a raw drug of the clomazone. The preparation method uses easy-to-obtained raw materials and mild reactions, is high in yield and is simple in separation and purification, has low cost, is environment-friendly, and has great industrial application prospect.

Description

Technical field [0001] The invention relates to a new method for preparing the herbicide clomazone, which is a kind of pigment inhibiting pre-emergence herbicide, and relates to the fields of oximation, ring closure, condensation and the like. Background technique [0002] Clomazone is a high-efficiency, low-toxicity, and isoxazolone selective pre-emergence herbicide. It is mainly used to control broadleaf weeds and gramineous weeds in soybean fields. It can also be used for cassava, corn, rape, sugarcane and Tobacco field weeding. The main mechanism of action of clomazone is to inhibit the biosynthesis of carotene and chlorophyll by inhibiting the synthesis of isoprene compounds. At present, the preparation methods reported in the literature are generally as follows: The o-chlorobenzaldehyde method mainly uses o-chlorobenzaldehyde as the starting material. First, o-chlorobenzaldehyde and salt [0003] Acid hydroxylamine reacts to generate oxime, and then the oxime is reduced to o...

Claims

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Application Information

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IPC IPC(8): C07D261/04
CPCC07D261/04
Inventor 于国权孙霞林丁华平周鹏袁宇吕佳杭
Owner 江苏长青生物科技有限公司
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