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ChemicalBook CAS DataBase List Ascorbic Acid
50-81-7

Ascorbic Acid synthesis

8synthesis methods
Ascorbic acid is prepared synthetically or extracted from various vegetable sources in which it occurs naturally, such as rose hips, blackcurrants, the juice of citrus fruits, and the ripe fruit of Capsicum annuum L. A common synthetic procedure involves the hydrogenation of D-glucose to D-sorbitol, followed by oxidation using Acetobacter suboxydans to form L-sorbose. A carboxyl group is then added at C1 by air oxidation of the diacetone derivative of Lsorbose and the resulting diacetone-2-keto-L-gulonic acid is converted to L-ascorbic acid by heating with hydrochloric acid.
-

Yield:-

Reaction Conditions:

with sulfuric acid;sodium carbonate in methanol at 40 - 69; for 9 h;Green chemistry;Reagent/catalyst;

Steps:

2 Comparative Example 2 Alkaline Conversion Preparation of Vitamin C.

In a 5L reactor equipped with a reflux condenser, 2ml methanol , an appropriate amount of concentrated sulfuric acid were added, stirred, then 0.45 kg of gulconic acid was added, heated 67 ~ 69 ° C, after the total reflux for 4 h, cooled to below 50 ° C, slowly adding an appropriate amount of active anhydrous sodium carbonate, slowly heated to 67 ~ 69 ° C, whole reflux for 3 h; After the reaction was cooled to below 40 ° C, dilute sulfuric acid was slowly added to adjust the pH value of the solution to 1.8-2.2, acidification at 40 ° C for 1 h, filtered after 1 h of incubation, t filter cake sodium sulfate is washed with appropriate amount of ice methanol, the combined filtrates and washings were heated to 35-40 ° C and the activated carbon is decolorizing in 30-60min, filtered, washed, the filtrate was concentrated at 35-45 ° C under reduced pressure to cool and crystallize, separated to give Vc.

References:

CN104693160,2016,B Location in patent:Paragraph 0049-0052

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