A kind of synthetic method of α-acetyl-γ-butyrolactone

Abstract

The invention relates to the technical field of chemical synthesis, and discloses a method for synthesizing α-acetyl-γ-butyrolactone, comprising the following steps: after the first reaction kettle is replaced by an inert gas, metal sodium is added in an inert gas atmosphere, Warming up to the melting of sodium metal to obtain liquid sodium metal in a molten state; adding gamma-butyrolactone and acetate in the second reactor, heating up to the reflux of the system, adding dropwise liquid sodium metal in a molten state in the system, Carry out the condensation reaction, after the liquid metal sodium is added dropwise, keep the system refluxed for 1-16h; after the condensation reaction, neutralize with an acid solution, separate the phases, and obtain the α-acetyl-γ after the organic phase is distilled and rectified under reduced pressure ‑Butyrolactone. The invention adopts a solvent-free method, controls the reaction process by controlling the liquid metal sodium drop rate, has the characteristics of stable and safe reaction, and simultaneously avoids the problems of environmental pollution and difficult separation caused by using benzene substances as solvents and extractants in traditional techniques.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a synthesis method of α-acetyl-γ-butyrolactone. Background technique [0002] α-acetyl-γ-butyrolactone is an important pharmaceutical intermediate and organic chemical raw material. It is an important intermediate for the preparation of vitamins and chlorophyll. Pharmaceutical intermediates of drugs such as thiazole, Yanxintong and chloroquine. At present, there are mainly two routes for the preparation of α-acetyl-γ-butyrolactone. One is a process based on ethylene oxide and ethyl acetoacetate as starting materials, and the other is based on γ-butyrolactone. and acetate as the starting material. [0003] Wherein, Chinese patent application documents (publication number: CN 1357545 A), U.S. Patent US 2443827, British Patent GB 740993 and Japanese Patent JP 4212662 etc. all disclose similar synthesis of starting materials with ethylene oxide and ethyl acetoacetate Pr...

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Problems solved by technology

However, rapid cooling of the molten sodium metal to 50-60°C is easy to agglomerate, which is difficult to implement in industrial production, and also uses a chlorinated solvent, which causes great environmental pollution.

[0008] In addition, the Chinese patent application document (publication number: CN 101092407 A) discloses the synthesis of α-acetyl-γ-butyrolactone through the acylation reaction of ethyl acetate and γ-butyrolactone through the gas phase catalysis of fluorine alkali solid-phase catalyst, although It solves the safety hazard, but due to the large energy consumption, the cost is too high, and the use of solid alkali fluoride as a catalyst has certain hidden dangers to products and environmental pollution, and has not been put into actual production and life at present.

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