Preparation of haloethoxyacetic acid and esters thereof

A technology of haloethoxy and acetic acid, applied in the field of preparation of haloethoxy acetic acid and its ester, can solve problems such as explosiveness, unfavorable production, explosion, etc., and achieve the effects of low production cost, easy operation and high yield

Active Publication Date: 2012-05-23
CHONGQING HUABANGSHENGKAI PHARM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the raw material used—ethyl diazoacetate is a high-flash point flammable liquid, which is explosive, and even explodes during vacuum distillation, and precious metals are used as catalysts, so it is not conducive to industrial production.
[0006] The above literature methods are all laboratory methods, or need to use poisonous or dangerous substances, or need harsher reaction conditions (high temperature or low temperature, anhydrous), or need to use precious metals, are all unsuitable for industrialized production

Method used

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  • Preparation of haloethoxyacetic acid and esters thereof
  • Preparation of haloethoxyacetic acid and esters thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Add 200g (1.6mol) 2-(2-chloroethoxy)ethanol, 5g (0.032mol) 2,2,6,6-tetramethyl-1-piperidinyloxy radical, 80ml water into the three-necked flask, Add 100g (0.64mol) sodium dihydrogen phosphate dihydrate under stirring, cool down to 20-25°C, slowly add the solution prepared by dissolving 218g (2.4mol) sodium chlorite in 500ml water into the above mixture, and control The temperature does not exceed 45°C. After the dropwise addition, the temperature is controlled at 20-35°C, kept for 2 hours, extracted with 400ml×3 dichloromethane, the extract is dried over anhydrous sodium sulfate, filtered, and the filtrate is concentrated under reduced pressure until the flow is cut off to obtain 2 -(2-Chloroethoxy)acetic acid 200.5g, yield 90.1%, GC purity 98.7%.

[0038] Pour the 2-(2-chloroethoxy)acetic acid obtained from the above concentration into a three-necked flask, add 1500ml of absolute ethanol, add 6.9ml (0.128mol) of concentrated sulfuric acid dropwise while stirring, and h...

Embodiment 2

[0040] Add 500g (4mol) 2-(2-chloroethoxy)ethanol, 6.2g (0.04mol) 2,2,6,6-tetramethyl-1-piperidinyloxy radical, 400ml water in the three-necked flask, Add 248g (1.59mol) sodium dihydrogen phosphate dihydrate under stirring, lower the temperature to 20°C-25°C, and add dropwise the solution prepared by dissolving 491g (5.42mol) sodium chlorite in 800ml water into the above mixture, and control The temperature does not exceed 45°C. After the dropwise addition, the temperature is controlled at 35-40°C, kept for 1 hour, and concentrated under reduced pressure until the flow is cut off. The concentrated mixture was extracted with 1150 ml of n-butanol, and suction filtered to obtain a n-butanol solution of 2-(2-chloroethoxy)acetic acid. Then add 1350ml of n-butanol, dropwise add 10.9ml (0.2mol) of concentrated sulfuric acid, reflux at 115-125°C for 9 hours, cool to 30-40°C, neutralize with saturated sodium bicarbonate solution, concentrate under reduced pressure to remove the solvent,...

Embodiment 3

[0042]Add 50g (0.4mol) 2-(2-chloroethoxy)ethanol, 0.62g (0.004mol) 2,2,6,6-tetramethyl-1-piperidinyloxy radical, 16ml water in the three-necked flask , add 24.8g (0.159mol) sodium dihydrogen phosphate dihydrate under stirring, cool down to 20 ℃ ~ 25 ℃, dissolve 49.1g (0.542mol) sodium chlorite in 80ml water and add dropwise to the above mixture Inside, control the temperature not to exceed 45°C, after the dropwise addition, control the temperature to 25-35°C and keep warm for 3 hours, concentrate under reduced pressure, add 110ml of isopropanol, and filter with suction to obtain isopropanol of 2-(2-chloroethoxy)acetic acid solution. Then add 130ml of isopropanol, add 1.5ml (0.02mol) of thionyl chloride dropwise, heat up to 65-70°C for reflux reaction for 8 hours, cool to 30-40°C, neutralize with saturated sodium bicarbonate solution, and depressurize Concentrate to remove the solvent, extract with 750ml×3 ethyl acetate, wash the ethyl acetate extract with 150ml×3 water, separ...

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Abstract

The invention relates to preparation of 2-(2-haloethoxy) acetic acid and esters thereof. The preparation comprises the following steps of: undergoing an oxidation reaction on 2-(2-haloethoxy) ethanol serving as a raw material under the actions of a catalyst and an oxidant at the temperature of 10-50 DEG C to obtain 2-(2-haloethoxy) acetic acid; and undergoing an esterification reaction on the 2-(2-haloethoxy) acetic acid and corresponding alcohols of a target ester under the action of a catalyst to obtain 2-(2-haloethoxy) acetic ester. According to the preparation method disclosed by the invention, a two-step reaction can be undergone with a one-pot process, so that easy operation is achieved. The preparation process disclosed by the invention is safe and environmentally-friendly, has high yield, and is very suitable for industrial production.

Description

Technical field: [0001] The invention relates to a preparation method of carboxylic acid derivatives containing halogen and ether, in particular to the preparation of haloethoxyacetic acid and its ester. Background technique: [0002] Literature Suomen Kemistilehti B (1944), 17-19. Described taking chloroethanol as raw material, under the action of formaldehyde and hydrogen chloride gas, synthesized chloroethoxychloromethane, then carried out cyanation reaction with cuprous cyanide and benzene to obtain chlorine Ethoxyacetonitrile is hydrolyzed under hydrochloric acid conditions to obtain chloroethoxyacetic acid, and esterified with alcohol to obtain chloroethoxyacetic acid derivatives. The method has about 5 steps of reaction steps, and the yield is low, about 35%, and more toxic substances are used or produced in the reaction process, such as benzene, formaldehyde, chloroethoxychloromethane, etc., which are very harmful to the environment and operators. unfavorable. [0...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C59/135C07C51/16C07C67/08C07C69/708
Inventor 毛启良杨玉金占肖吴芸
Owner CHONGQING HUABANGSHENGKAI PHARM
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