Preparation method for Alpha-acetyl-Gamma-butyrolactone

Abstract

The invention discloses a preparation method for Alpha-acetyl-Gamma-butyrolactone, and belongs to the technical field of compound synthesis. The method comprises the following steps: under the conditions of an organic solvent, using Gamma-butyrolactone and acetaldehyde as initial raw materials, using inorganic base as a catalyst, performing an acetylation reaction, adjusting a pH value of reactionliquid by using diluted acid until the reaction liquid is neutralized, and post-processing to obtain the Alpha-acetyl-Gamma-butyrolactone. The method has the characteristics of economical feasibility, higher yield, safety and environmental protection, and is suitable for industrialization.

Description

technical field [0001] The invention belongs to the technical field of compound synthesis, in particular to a method for preparing α-acetyl-γ-butyrolactone. Background technique [0002] α-acetyl-γ-butyrolactone is an important chemical intermediate, which can be used to prepare 3-mercapto-4-oxo-pentyl acetate, cyclopropylamine, fungicide prothioconazole, anticonvulsant and sedative hypnotic Drugs such as chlormethiazide hydrochloride, chlorophyll, Yanxin pain, chloroquine, antipsychotic drugs risperidone, paliperidone, some spices, etc. α-acetyl-γ-butyrolactone is also a good reagent for pharmaceutical analysis, which can react with primary amines or sulfonamides, and is often used in the analysis of these pharmaceutical preparations. At the same time, α-acetyl-γ-butyrolactone also has the structural characteristics of β-dicarbonyl, and can react with many substances. [0003] The synthesis process route of α-acetyl-γ-butyrolactone can be mainly divided into two types, th...

AI Technical Summary

Problems solved by technology

Sodium metal is used as a catalyst to catalyze the reaction of ethyl acetate and γ-butyrolactone at 100-105°C in the presence of toluene solvent, as reported in Chinese patents CN1548427A and CN101768141A. Due to the good yield and low cost, although there are significant Potential safety hazards, but it is still the main process route adopted by domestic production enterprises

Chinese patent CN101092407B reports that α-acetyl-γ-butyrolactone is synthesized by acylating ethyl acetate and γ-butyrolactone in the gas phase with a fluorine-alkali solid-phase catalyst. The cost is too high and the product quality is problematic. At present, no production enterprise adopts it.

In addition, the current process using sodium metal as a catalyst usually produces ethyl acetate, ethanol and toluene ternary azeotropic waste solvents

[0004] Japanese patent 45 / 009538 reports the acylation reaction of butyl acetate and γ-butyrolactone with solid sodium butoxide catalysis, while Japanese patent 58 / 099473 reports the acylation of ethyl acetate and γ-butyrolactone with solid sodium methoxide catalysis reaction, but due to the use of high-boiling point solvents, the high-boiling point solvents are difficult to remove, resulting in low yields of products, while the patent does not pay attention to the recovery of reaction materials, so the method has not been industrially adopted mass adoption

Simultaneously Japanese patent 58 / 099473 needs to strictly control the charging molar ratio of solid sodium methylate and liquid gamma-butyrolactone in the reaction process, and solid sodium methylate belongs to powdery solid, and feeding speed is difficult to control and easily produces dust, in post-treatment process The sodium sulfate solid produced in the reaction after the middle filter adjusts the pH has a high viscosity and is difficult to filter. At the same time, part of the feed liquid is entrained in the high-viscosity sodium sulfate solid, and the washing is not thorough, which affects the product yield. At the same time, the alcohol and ester of the raw material have a low boiling point. , the follow-up high-pressure reaction is required to make the reaction complete, and the continuous reactor and high-pressure reactor (reaction pressure can reach 4-7Mpa) are not easy to be used in the industry due to high equipment requirements, large investment costs, and strict operating technical requirements. widely used

Sodium metal is used as a catalyst to catalyze the reaction of acetate and gamma-butyrolactone at 100-105°C in the presence of toluene solvent, as reported in Chinese patent CN1548427, because the yield is good and the cost is low, although there are major safety hazards (explosion or fire accident caused by improper handling of sodium metal), but it is still the main process route adopted by domestic production enterprises

Although there are new Chinese patent reports trying to reduce the potential safety hazard of this process by adding sodium metal mode and reaction process control (for example, Chinese patent CN101768141 reports by adding metal sodium in batches and CN102030729 reports by adding once. metal sodium), but because this process route must use metal sodium, in essence, there is no problem that can fundamentally solve potential safety hazards

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