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Synthesizing method of isoxadifen-ethyl for industrialized production

A technology of isoxadifen and its synthesis method, which is applied in the field of production of isoxadifen, can solve the problems of by-products and difficulties, and achieve the effect of low cost and high purity of yield

Active Publication Date: 2018-08-24
重庆化工职业学院
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that by-products are inevitable, and it is difficult to remove these by-products by general crystallization methods.

Method used

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  • Synthesizing method of isoxadifen-ethyl for industrialized production
  • Synthesizing method of isoxadifen-ethyl for industrialized production

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Embodiment 1 (laboratory stage):

[0025] Preparation of phenylmagnesium chloride Grignard reagent: add 4.5g (0.19mol) magnesium chips, 65ml THF, add 0.45g bromoethane and raise the temperature to 65°C, add dropwise 18.7g (about 0.17mol) chlorobenzene, 65ml THF, Keep warm for 4h-5h, lower the temperature to 15°C, and after GC detects that the chlorobenzene reaction is complete, lower the temperature to 15°C to prepare phenylmagnesium chloride Grignard reagent (1), with a content of 98.9%, which is directly used in the next reaction.

[0026] Preparation of 1,1-stilbene: Control the temperature at 10°C-15°C, slowly drop the mixture of 14g (0.12mol) acetophenone and 30ml toluene into the phenylmagnesium chloride Grignard reagent, keep it warm for 30min after dropping, Stop the reaction and set aside. Then add the aqueous solution prepared by adding 6g ammonium chloride and 23g water thereto, then add 60ml toluene, stir for 30 minutes, and adjust pH=1-3 with hydrochloric ...

Embodiment 2

[0029] Embodiment 2 (industrial scale-up experiment):

[0030] Raw material type:

[0031] Raw material 1, magnesium scrap, tetrahydrofuran; the mass ratio of magnesium scrap to tetrahydrofuran is about 1:2.98, of which magnesium scrap is 45kg;

[0032] Raw material 2, chlorobenzene and tetrahydrofuran; the mass ratio of chlorobenzene and tetrahydrofuran is about 1:1.02, of which chlorobenzene is 187kg;

[0033] Raw material 3, acetophenone, toluene; ethyl bromide; the mass ratio of acetophenone, toluene and ethyl bromide is about 31:6.2:1, of which ethyl bromide is 4.5kg;

[0034] In industrial application, the above feeding amount can be converted according to 50kg of magnesium chips.

[0035] Specific implementation steps:

[0036] The 2000L first reaction kettle is first filled with toluene to bring water to anhydrous, then put in raw material 1, add bromoethane at 40°C-50°C, heat up to 65°C and reflux, then drop in raw material 2, add dropwise for about 8-10h, after dr...

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Abstract

The invention provides a synthesizing method of isoxadifen-ethyl for industrialized production. The synthesizing method comprises the following steps of using chlorobenzene as a raw material, using tetrahydrofuran as a solvent, and reacting with magnesium, so as to obtain a phenyl magnesium chloride Grignard reagent; performing nucleophilic addition reaction with acetophenone to generate 1,1-diphenylethanol; adding p-toluenesulfonic acid to dewater, so as to generate 1,1-diphenylethene; reacting with ethyl 2-chloro-2-(hydroxyimino)acetate, so as to generate an isoxadifen-ethyl product, whereinthe purity can reach 99%.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a low-cost and high-purity production method of isoxadifen, which is suitable for industrial production. Background technique [0002] The chemical name of isoxadifen is ethyl 4,5-dihydro-5,5-diphenyl-1,2-oxazole-3-carboxylate, which is an isoxazole safener. Chinese patent CN1133038A discloses a preparation method: 13.52g of stilbene and 5.06g of triethylamine are dissolved in 200ml of ether at 0°C, and then 7.58g of stilbene dissolved in 100ml of ether is added dropwise over 2 hours. Ethyl chlorooximinoacetate was stirred at room temperature for 1 h, 100 ml of water was added, and the mixture was extracted with ether, and then the product was obtained by column chromatography. This method has high cost and is not suitable for industrial production. CN103172582A also discloses a preparation method, mixing 16.2g of 1,1-stilbene and 18.7g of N,N-diethyletha...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D261/04
CPCC07D261/04
Inventor 宋春雨孙治清揭芳芳蒋清梅
Owner 重庆化工职业学院
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