Preparation process and apparatus for alpha-acetyl-gamma-butyrolactone

The technology of butyrolactone and acetyl group is applied in the field of preparation of α-acetyl-γ-butyrolactone and its special equipment, and can solve the problems of material punching, combustion and explosion, difficulty in recycling by-products, intractable waste water and the like, Achieving the effects of less pollution, good economic benefits, and gentle neutralization reaction

Inactive Publication Date: 2006-07-12
LINHAI LIANSHENG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, in these documents, ethylene oxide is used as the reaction raw material, and ethylene oxide belongs to the first-class flammable and explosive chemicals, and there are serious safety hazards in the reaction
In addition, in Chinese Journal of Pharmaceutical Industry 1994, 25 (10) there is the improvement of the synthesis process of α-acetyl-γ-butyrolactone reported, it adopts γ-butyrolactone and ethyl acetate to react under the effect of alkali metal, uses Ethanol is used as a solvent, and acetic acid is used as a neutralizing agent. Although the yield is improved, the by-products are difficult to recover, which causes waste to a certain extent, and the waste water is also very difficult to treat and causes environmental pollution.
The process of synthesizing α-acetyl-γ-butyrolactone using γ-butyrolactone as the starting material generally uses γ-butyrolactone to directly react with metal sodium, but because the reaction is too violent, the production process There are often incidents of punching, burning and explosions, causing many foreign companies to stop producing this product with this process
[0003] Moreover, the current general-purpose reactors in production generally use enamel glass reactors, which have problems such as slow heat dissipation and difficult temperature control.

Method used

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  • Preparation process and apparatus for alpha-acetyl-gamma-butyrolactone
  • Preparation process and apparatus for alpha-acetyl-gamma-butyrolactone

Examples

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Embodiment 1

[0025] In the method for producing α-acetyl-γ-butyrolactone, relative to γ-butyrolactone, 1.6 to 1.8 equivalents of ethyl acetate, 0.2 to 0.3 equivalents of alkali metal, 1.0 to 1.4 of benzene solvent and 1.1 to 1.4 1.4 equivalents of phosphoric acid; this embodiment uses 500KG of gamma-butyrolactone, 138KG of sodium metal, 850KG of ethyl acetate, and 600KG of toluene. The whole process is divided into reaction section, neutralization section and distillation section, the specific operation is as follows:

[0026] In the reaction stage, put the solvent toluene into the reaction kettle first, then put in 138KG of sodium metal, heat to 100-105°C, stir for 15 minutes, then quickly cool to 65°C, wait for sodium sand to form at the bottom of the kettle, and then add γ-butyrolactone and For the mixture of ethyl acetate, the temperature is controlled at 65-92°C. After the dropwise addition, the temperature is controlled at 80-85°C, and the temperature is kept at 10 hours; then the so...

Embodiment 2

[0029] In conjunction with Fig. 1, the special-purpose reactor of the present embodiment is described, the reactor of the present embodiment, the buffer reflux tank and the recovery tank are made of special stainless steel, and a group of buffer reflux devices are arranged above the reactor (13). It consists of two buffer return tanks (8, 9) and a recovery tank (10). The top of the two buffer return tanks is connected by a pipe (5), and the bottom is connected by a return pipe (7). Among them, the buffer return tank (9) Link to each other with the top of recovery tank (10) by pipeline (6); Another buffer reflux tank (8) top links to each other by pipeline (4) and condenser (11), and the bottom is provided with return pipe (3) and reactor (13 ) is connected; its function is that if there is improper operation, or when the reaction is difficult to control, a large amount of metal sodium sand will run out with the solvent, which will cause a great safety hazard, because metal sodi...

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Abstract

The preparation process of alpha-acetyl-gamma-butyrolactone includes reaction section, neutralization section and distillation section, and features the reaction section, which includes adding catalyst into benzene solvent, heating while stirring, fast cooling and dropping the liquid mixture of gamma-butyrolactone and acylating agent; the neutralization section before extraction; and the distillation section to prepare alpha-acetyl-gamma-butyrolactone. The present invention also relates to the reactor with one increased buffering reflux unit for preparing alpha-acetyl-gamma-butyrolactone.

Description

technical field [0001] The invention relates to a preparation method of vitamin B1 and other pharmaceuticals and intermediates of organic industrial medicines, in particular to a preparation method of α-acetyl-γ-butyrolactone. The present invention also relates to the special equipment used in the above method, especially the reaction kettle used in the preparation of α-acetyl-γ-butyrolactone. Background technique [0002] α-acetyl-γ-butyrolactone is used as a raw material or intermediate of pharmaceuticals in the fields of medicine and organic chemical industry, and various production methods have been proposed. At present, there are mainly two routes for the preparation of α-acetyl-γ-butyrolactone. One is the process using ethylene oxide as the starting material, and the other is the process using γ-butyrolactone as the starting material. craft. In the Publication No. 40-23006, the disclosed preparation method is to react acetoacetate and ethylen...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D307/34
Inventor 俞小鸥
Owner LINHAI LIANSHENG CHEM
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