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Preparation method for intermediate epichlorophdrin of herbicide pretilachlor

A technology of pretilachlor and trichlorether, which is applied in the field of compound preparation, can solve the problems of hydrogen chloride source difficulty, pollution, equipment corrosion, etc., achieve good industrialization implementation value and social and economic benefits, safe and reliable operation process, and reduce pollutants The effect of the emissions

Inactive Publication Date: 2008-10-15
HANGZHOU VOCATIONAL & TECHN COLLEGE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Method ①Although the yield is high, a large amount of sulfur dioxide tail gas is released during the reaction process, and DMF is difficult to recover, resulting in a large amount of waste gas and wastewater, and the treatment cost is high; Method ②The yield is low, and ethylene glycol monopropyl ether is under strong acidic conditions Unstable, in addition, the source of dry hydrogen chloride is difficult, and there are safety hazards in the use process
Method ③ The obtained product contains a large amount of by-product phosphoric acid, and phosphorus oxychloride is used as a chlorinated reagent to seriously corrode the equipment, and a large amount of phosphorus-containing wastewater is difficult to treat, and the pollution problem is serious
Above-mentioned several methods are all unsuitable for the industrialized production of chloroether because there are different defectives

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0009] The preparation method of the herbicide pretilachlor intermediate chlorether described in this embodiment is that ethylene glycol monopropyl ether and bis(trichloromethyl) carbonate are under the effect of organic amine catalyst, through the following chemical process in an organic solvent Reaction equation: HOC 2 h 4 OC 3 h 7 +Cl 3 COCOOCCl 3 →ClC 2 h 4 OC 3 h 7 +CO 2 +HCl to obtain the said chloroether. The operation process is: first dissolve the organic amine catalyst in the organic solvent, then add ethylene glycol monopropyl ether, heat the solution to a temperature between 50°C and 150°C, slowly drop the dissolved bis(trichloromethyl) Organic solvent solution of carbonate, keep warm for 3 to 5 hours after dripping, cool the reaction solution to room temperature, neutralize to neutral with dilute alkali, wash twice with 200ml of water, stand for separation, and use anhydrous chlorine for the organic layer Calcium and other drying, vacuum distillation to...

Embodiment 2

[0013] The preparation method of the herbicide pretilachlor intermediate chloroether described in this embodiment, the amount of its described feeding material ratio ethylene glycol monopropyl ether: bis (trichloromethyl) carbonate: catalyst is 1: 0.4 : 0.2, the charging amount of ethylene glycol monopropyl ether is 10.5g (0.1mol), the charging amount of bis(trichloromethyl) carbonate is 12g (0.04mol), the catalyst is pyridine, and the consumption is 1.6g (0.02mol) , the organic solvent is toluene, and the consumption is 40ml, which is 3.3 times of the quality of ethylene glycol monopropyl ether.

[0014] Reaction temperature is 100~110 ℃, other operation is the same as embodiment 1, obtains product 10.8g, product yield 88.5%, purity (GC) 98.5%, boiling point 130~132 ℃.

Embodiment 3

[0016] The preparation method of the herbicide pretilachlor intermediate chlorether described in this embodiment, the amount of its described feeding material ratio ethylene glycol monopropyl ether: bis (trichloromethyl) carbonate: catalyst is 1: 0.35 : 0.1, the intake of ethylene glycol monopropyl ether is 10.5g (0.1mol), the intake of bis(trichloromethyl)carbonate is 10.5g (0.035mol), the catalyst is triethylamine, and the consumption is 1g (0.01 mol), the organic solvent is ethylene dichloride, and the consumption is 35ml, which is 4.2 times of the quality of ethylene glycol monopropyl ether.

[0017] Reaction temperature is 70~80 ℃, other operation is the same as embodiment 1, obtains product 10.5g, product yield 86%, purity (GC) 98.9%, boiling point 128~131 ℃.

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Abstract

The invention relates to a method for preparing the designed herbicide pretilachlor intermediate chloride ether. Under the action of organic amine catalyst, the chloride ether can be obtained by ethylene glycol monopropyl ether and bis (trichloromethyl) hydroxyphenyl in the organic solvent through the following chemical equation: HOC2H4OC3H7+Cl3COCOOCCl3 arrow ClC2H4OC3H7+CO2+HCl. The method replaces the traditional chlorination reagent with the bis (trichloromethyl) hydroxyphenyl, such as, thionly chloride, phosphorus oxychloride and hydrogen chloride, etc., and the potential safety hazard can be eliminated from the process source by using the novel chlorination reagent. Simultaneously, the emissions of pollutants are greatly reduced, and the method is a cleaning process with mild reaction conditions, safe and reliable operating process and high product yield, and has good industrialization implementation value and social economic benefits.

Description

technical field [0001] The invention relates to a preparation method of a compound, in particular to a preparation method of a herbicide pretilachlor intermediate chlorether. Background technique [0002] Chloroethyl propyl ether (2-n-propoxychloroethane), referred to as chloroether, is an important intermediate for the synthesis of the herbicide pretilachlor, which is a high-efficiency, low-toxicity, early-stage broad-spectrum rice field special choice The herbicide at bud stage was successfully developed by Ciba-Geigy in Switzerland. It is widely used and highly appraised by the agricultural plant protection department. As an important intermediate of chloroethers, how to adopt a clean and efficient preparation method has attracted great attention. At present, the preparation methods of chloroether mainly include: 1. in the presence of a large amount of acid-binding agent DMF, chlorination with thionyl chloride, the yield is about 90%; 2. in the presence of anhydrous zinc...

Claims

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Application Information

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IPC IPC(8): C07C43/12C07C41/22
Inventor 童国通谢建武毛伟春
Owner HANGZHOU VOCATIONAL & TECHN COLLEGE
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