Green synthesis process of alpha-acetyl-gamma-butyrolactone

Abstract

The invention relates to a preparation method of a compound alpha-acetyl-gamma-butyrolactone represented by a formula (I). According to the invention, the compound of the formula (II) and ethyl acetate are subjected to condensation, acidification, and rectification under the existence of calcium oxide, such that the compound represented by the formula (I) is obtained. The compound is an important intermediate used for preparing vitamin and chlorophyll raw materials.

Description

technical field [0001] The invention relates to a preparation method of α-acetyl-γ-butyrolactone, a compound of formula (I), which is an important intermediate for preparing vitamins and chlorophyll raw materials. It belongs to the technical field of chemical synthesis. Background technique [0002] α-acetyl-γ-butyrolactone (2-Acetylbutyrolactone, ABL) is an important intermediate for the preparation of vitamins and chlorophyll [1-2] , is an important raw material for the synthesis of 3,4-disubstituted pyridine, 5-(β-hydroxyethyl)-4-methylthiazole, and 4-methyl-5-thiazoleethanol, and is also an important raw material for the synthesis of antipsychotic drugs risperidone, Pharmaceutical intermediates of anticonvulsant and sedative hypnotic drugs such as clomethiazole, Yanxin pain and chloroquine [3-5] , is an irreplaceable long-term product with a large quantity and a wide range. At present, there are two main methods for preparing α-acetyl-γ-butyrolactone: Method 1, using ...

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Problems solved by technology

[0007] Many patent documents have reported the improvement of the synthesis process of α-acetyl-γ-butyrolactone. For example, in Chinese patent 02138773.5, toluene is used as the solvent for metal sodium. Sodium sand is formed at a higher temperature, and then the temperature is lowered to catalyze the reaction. The mixed ester is added dropwise, and a buffer tank is added. However, since toluene and metal sodium are both flammable and explosive, the safety problem of the reaction cannot be solved, and The conversion rate of γ-butyrolactone is low, which is not friendly enough to the environment; Zhang Li used sodium alkoxide instead of metal sodium in the Chinese Journal of Pharmaceutical Industry, but the reaction yield is low and cannot reduce production costs; U.S. Patent US5789603 also uses sodium alkoxide as Catalyst, high temperature and high pressure reaction, high operation requirements, and safety risks; US Patent 2443827[12] reported Method 2, which uses ethylene oxide as the starting material, and ethylene oxide is Class I flammable and explosive chemicals, storage conditions are harsh, there are serious safety hazards in the reaction, and the preparation process is complicated, and the purity and yield of the obtained products are low

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