Method for synthesizing 1,4-dioxane

A dioxane and hydroxide technology, applied in 1 field, can solve the problems of high production cost, heavy pollution, low reaction yield, etc., and achieve the effects of increasing product added value, extending industrial chain, and high product purity

Active Publication Date: 2011-01-19
锦西化工研究院有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The price of raw materials ethylene oxide and ethylene glycol used in these two kinds of process routes is relatively high, and the reaction yield is low, making the production cost of 1,4-dioxane on the high side; Ethylene oxide is a flammable, explosive and dangerous chemical products, transportation and use are very inconvenient; in addition, these two methods all use acid catalysts, the post-treatment is complicated, and the pollution is heavy

Method used

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  • Method for synthesizing 1,4-dioxane

Examples

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Embodiment 1

[0020] In the 2L stainless steel pressure-resistant stirred reactor, add 300g 2-chloroethoxyethanol (industrial product, purity 98%), 752g potassium hydroxide (industrial product, 158g, 98%) aqueous solution (mass fraction is 20%) respectively, Heating and raising the temperature, maintaining 165°C to 175°C for 2.5 hours, then lowering the temperature, pumping the reaction solution into a distillation pot for rectification, and collecting the mixture of 1,4-dioxane and water at 86°C to 90°C (1.33kPa) Azeotropic fraction, add an entrainer to the azeotropic fraction to separate water, and obtain 178g of 1,4-dioxane (chromatographic method, purity ≥ 99.1%; 25°C refractive index 1.4222).

Embodiment 2

[0022] In the 2L stainless steel pressure-resistant stirred reactor, add 300g 2-chloroethoxyethanol (industrial product, purity 98%), 790g sodium hydroxide (industrial product, 106g, 98%) aqueous solution (mass fraction is 13%) respectively, Heating and raising the temperature, maintaining 180°C to 190°C for 1.0 hour reaction, then lowering the temperature, pumping the reaction liquid into a distillation pot for rectification, and collecting the mixture of 1,4-dioxane and water at 86°C to 90°C (1.33kPa) Azeotropic fraction, add an entrainer to the azeotropic fraction to separate water, and obtain 146g of 1,4-dioxane (chromatographic method, purity ≥ 98.6%; 25°C refractive index 1.4219).

Embodiment 3

[0024] In the 2L stainless steel pressure-resistant stirred reactor, add 300g 2-chloroethoxyethanol (industrial product, purity 98%), 577g sodium hydroxide (industrial product, 164g, 98%) aqueous solution (mass fraction is 28%) respectively, Heating and raising the temperature, maintaining 145°C to 155°C for 1.5 hours, then lowering the temperature, pumping the reaction solution into a distillation pot for rectification, and collecting the mixture of 1,4-dioxane and water at 86°C to 90°C (1.33kPa) Azeotropic fraction, adding an azeotropic agent to the azeotropic fraction to separate water, to obtain 194g 1,4-dioxane (chromatographic method, purity ≥ 98.6%; 25°C refractive index 1.4219).

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Abstract

The invention discloses a method for synthesizing 1,4-dioxane by reacting 2-chlorine-ethoxyethanol with a caustic alkali such as the low-concentration solution of the hydroxide of an alkali metal or an alkaline-earth metal. The molecular ratio of the 2-chlorine-ethoxyethanol to the hydroxide of the alkali metal or the alkaline-earth metal is 1.10-1.40:1; and the mass fraction of hydroxide aqueoussolution is 5 to 25 percent. The method comprises the following steps of: adding the 2-chlorine-ethoxyethanol into a stainless steel stirred reactor; controlling the reaction temperature to be between 85 and 190 DEG C and the reaction time to be 1 to 4 hours; rectifying obtained reaction solution; collecting azeotropic distillate of the 1,4-dioxane and water; adding an entrainer; separating water; and obtaining a 1,4-dioxane product of which the purity is over 98 percent. The method solves the problems of storage and transportation difficulties of ethylene oxide, corrosion caused by strong acidic catalyst, more byproducts and the like in a 1,4-dioxane process which takes an ethylene oxide gas as a raw material, so that the production of the 1,4-dioxane gets rid of the dependence on ethylene oxide and the like; and production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of organic chemical production, and in particular relates to a synthesis method of 1,4-dioxane. Background technique [0002] 1,4-dioxane, also known as 1,4-dioxane, is a colorless transparent liquid with a boiling point of 101.1°C (101.35kPa), a melting point of 11.8°C, a relative density of 1.0336 (20 / 4°C), and a refractive index of 1.4224 (25°C). It is an important high-efficiency organic solvent, which is widely used in reaction medium and solvent extraction. It is widely used as a reaction solvent for polyurethane synthetic leather and amino acid synthetic leather, and is also an ideal stabilizer for 1,1,1-trichloroethane. It is also widely used in the manufacture of special chemicals, pharmaceuticals, cosmetics, spices, pesticides, etc. [0003] Since the 1970s, industrialized countries have produced 1,4-dioxane from ethylene oxide or ethylene glycol. At present, my country still mainly adopts the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D319/12
Inventor 宋琳珩孙天鹤
Owner 锦西化工研究院有限公司
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