Process for producing l-ascorbic acid-2-sulfate
AssigneeKumiai Chemical Industry Co., Ltd.
InventorsEiichi Hayashi, Kiyoshi Takita, Hironari Sugiyama, Yukio Nezu
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Abstract
A process for producing a mono- or di-alkali metal salt or alkaline earth metal salt of L-ascorbic acid-2-sulfate which comprises reacting L-ascorbic acid in which the 5 and 6 positions are protected by a ketone or aldehyde, with dimethyl formamide-sulfur trioxide complex, which is produced by a reaction of dimethyl formamide with chlorosulfonic acid and a dehydrohalogenating agent such as pyridine, triethylamine, dimethyl aniline, which is a tertiary amine so as to produce a sulfate, and neutralizing the product with an alkali metal hydroxide or an alkaline earth metal hydroxide, and removing said protecting aldehyde or ketone at 5- and 6-positions.
Claims6
A process for producing a mono- or di-alkali metal salt or alkaline earth metal salt of L-ascorbic acid-2-sulfate which comprises:
- A. reacting L-ascorbic acid in which the 5 and 6 positions are protected by a ketone or aldehyde, with dimethyl formamide-sulfur trioxide complex produced by mixing dimethyl formamide and chlorosulfonic acid in an inert solvent and thereafter adding a dehydrohalogenating agent of a tertiary amine, so as to produce a sulfate, and
- B. neutralizing the product with an alkali metal hydroxide or an alkaline earth metal hydroxide, and
- C. removing said protecting aldehyde or ketone at the 5- and 6-positions.
Dependencies are inferred from the claim text.