Preparation technology of 5,6-0-isopropylidene-L-ascorbic acid

Abstract

The invention discloses a preparation technology of 5,6-0-isopropylidene-L-ascorbic acid, and belongs to the technical field of drug processing. The preparation technology disclosed by the invention takes ascorbic acid and acetone as raw materials, ascorbic acid is enabled to react completely with acetone under the action of an acid catalyst and a dehydrating agent, raw material loss is avoided, and cost saving is facilitated; the preparation technology disclosed by the invention has the advantages that technological conditions are mild, a method is simple and a process is easy to control. Theyield of a 5,6-0-isopropylidene-L-ascorbic acid product prepared by the preparation technology disclosed by the invention reaches 90% or above and the purity reaches 98% or above.

Description

technical field [0001] The invention relates to the technical field of pharmaceutical processing, in particular to a preparation process of 5,6-O-isopropylidene-L-ascorbic acid. Background technique [0002] L-Ascorbic acid is a biologically active substance having strong antioxidant activity, and has been used as a drug for treating scurvy, and because it has a wide range of physiological activities (such as the inhibition of melanin known to be the cause of melasma or freckles) Cumulative), is widely used in cosmetics. However, ascorbic acid is easily oxidized by heat, light and oxygen in the air so that it loses its activity, and because ascorbic acid is insoluble in oil, its application is limited. [0003] In order to improve the stability and lipophilicity of L-ascorbic acid, the four hydroxyl groups of L-ascorbic acid are usually modified to form ether or ester. Among them, the preparation of 3-O-substituted-ascorbic acid and 2-O-substituted-ascorbic acid usually ne...

AI Technical Summary

Problems solved by technology

Use fuming sulfuric acid as catalyst in US 4999437, wherein fuming sulfuric acid is inconvenient to use

Hydroiodic acid is used as catalyst in CN102453052A, and hydroiodic acid is not only inconvenient to use but also expensive

Use anhydrous copper sulfate as catalyst in CN103588759A, the reaction time is long, and once the anhydrous copper sulfate absorbs moisture, the catalytic effect will be greatly reduced

Acetyl chloride is used as a catalyst in Japanese Patent Laid-Open No. 1-228977, which is too active, and a part of it reacts with the four hydroxyl groups on VC, making it difficult to remove impurities; and the reaction process produces a large amount of acid gas, causing relatively large pollution.

Phosphorus oxychloride is used as catalyst in CN1488635A. Phosphorus oxychloride is a colorless and transparent liquid with irritating odor. It fumes violently in humid air and is inconvenient to operate.