Novel method for refining methyl chloroacetate

Abstract

The invention discloses a novel method for refining methyl chloroacetate, and belongs to the technical field of organic synthesis. By means of the method, a crude methyl chloroacetate product generated through an esterification reaction of methanol and chloroacetic acid is subjected to freezing layering to separate chloroacetic acid and a water layer. According to the refining method, the purity of methyl chloroacetate can reach 99.4% or above only by simply freezing the crude methyl chloroacetate product to minus 15 DEG C without simple distillation or rectification, little time is needed, the production time is greatly shortened, the production cost is greatly reduced, and the green chemical industry requirements are met.

Description

technical field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a novel method for refining methyl chloroacetate. Background technique

[0002] Methyl chloroacetate is a colorless transparent liquid with a pungent odor, slightly soluble in water, flammable, and may cause combustion and explosion when exposed to open flame, high heat or contact with oxidants. Emit highly toxic fumes when heated, exposed to acid or acid mist. As an important organic synthesis raw material and intermediate, it plays an important role in the fields of synthetic pesticides and medicines. Methyl chloroacetate is used in the production of organophosphorus insecticide dimethoate, chemically synthesized cod liver oil (vitamin methadone), vitamin B6, and sulfa drug sulfa-o-dimethoxine. It can also be used as a raw material for solvents, adhesives and surfactants. At present, the refined production method of methyl chloroacetate mainly adopts ...

Examples

Embodiment 1

[0021] Take 1000g of methyl chloroacetate crude product at 20°C, the mass contents of its components are 93.0% methyl chloroacetate; 2.0% water; 4.50% methanol; 0.06% chloroacetic acid; 0.39% methyl dichloroacetate), freeze to 10 ℃ for 2 hours, and the upper aqueous phase was reused until the esterification reaction; the mass content of each component of methyl chloroacetate in the lower layer was methyl chloroacetate 99.25%; water 0.15%; methanol 0.20%; chloroacetic acid 0.04%; dichloroacetic acid Methyl ester 0.39%.

Embodiment 2

[0023] Take 1000g of crude methyl chloroacetate at 30°C, the mass content of each component is 92.52% methyl chloroacetate; 1.98% water; 4.9% methanol; 0.05% chloroacetic acid; 0.38% methyl dichloroacetate, freeze to 5°C for minutes Layer 0.5h, the upper aqueous phase reused until the esterification reaction; the mass content of each component of methyl chloroacetate in the lower layer is methyl chloroacetate 99.31%; water 0.08%; methanol 0.15%; chloroacetic acid 0.05%; ester 0.38%).

Embodiment 3

[0025] Take 1000g of methyl chloroacetate crude product at 30°C, the mass content of each component is 91.0% methyl chloroacetate; 2.0% water; 6.50% methanol; 0.05% chloroacetic acid; Layer 3h, the upper aqueous phase was reused until the esterification reaction; the mass content of each component in the lower layer of methyl chloroacetate was 99.36% of methyl chloroacetate; 0.05% of water; 0.14% of methanol; 0.04% of chloroacetic acid; 0.39%.

technical field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a novel method for refining methyl chloroacetate. Background technique

[0002] Methyl chloroacetate is a colorless transparent liquid with a pungent odor, slightly soluble in water, flammable, and may cause combustion and explosion when exposed to open flame, high heat or contact with oxidants. Emit highly toxic fumes when heated, exposed to acid or acid mist. As an important organic synthesis raw material and intermediate, it plays an important role in the fields of synthetic pesticides and medicines. Methyl chloroacetate is used in the production of organophosphorus insecticide dimethoate, chemically synthesized cod liver oil (vitamin methadone), vitamin B6, and sulfa drug sulfa-o-dimethoxine. It can also be used as a raw material for solvents, adhesives and surfactants. At present, the refined production method of methyl chloroacetate mainly adopts ...

Examples

Embodiment 1

[0021] Take 1000g of methyl chloroacetate crude product at 20°C, the mass contents of its components are 93.0% methyl chloroacetate; 2.0% water; 4.50% methanol; 0.06% chloroacetic acid; 0.39% methyl dichloroacetate), freeze to 10 ℃ for 2 hours, and the upper aqueous phase was reused until the esterification reaction; the mass content of each component of methyl chloroacetate in the lower layer was methyl chloroacetate 99.25%; water 0.15%; methanol 0.20%; chloroacetic acid 0.04%; dichloroacetic acid Methyl ester 0.39%.

Embodiment 2

[0023] Take 1000g of crude methyl chloroacetate at 30°C, the mass content of each component is 92.52% methyl chloroacetate; 1.98% water; 4.9% methanol; 0.05% chloroacetic acid; 0.38% methyl dichloroacetate, freeze to 5°C for minutes Layer 0.5h, the upper aqueous phase reused until the esterification reaction; the mass content of each component of methyl chloroacetate in the lower layer is methyl chloroacetate 99.31%; water 0.08%; methanol 0.15%; chloroacetic acid 0.05%; ester 0.38%).

Embodiment 3

[0025] Take 1000g of methyl chloroacetate crude product at 30°C, the mass content of each component is 91.0% methyl chloroacetate; 2.0% water; 6.50% methanol; 0.05% chloroacetic acid; Layer 3h, the upper aqueous phase was reused until the esterification reaction; the mass content of each component in the lower layer of methyl chloroacetate was 99.36% of methyl chloroacetate; 0.05% of water; 0.14% of methanol; 0.04% of chloroacetic acid; 0.39%.