发明名称 |
PROCESS FOR PREPARING L-ASCORBIC ACID |
摘要 |
L-ascorbic acid is prepared from sodium 2-keto-L-gulonate by introducing gaseous hydrogen chloride in a molar ratio of about 1.5-2.0 to the sodium-2-keto-L-gulonate into a mixture composed of the sodium 2-keto-L-gulonate, ethanol and acetone at a ratio of 1:0.25-1.00:0.5-2.5 by weight at a temperature of about 25 DEG -75 DEG C. until precipitation of sodium chloride ends, removing the precipitated sodium chloride before L-ascorbic acid begins to crystalize out, maintaining the filtrate or supernatant at a temperature of about 25 DEG -75 DEG C. for a period of 5-100 hours and cooling it to yield crystals of L-ascorbic acid as a final product. A solvent inert to the L-ascorbic acid and 2-keto-L-gulonate may be added to the filtrate or supernatant with a favorable result in obtaining purer intended product. |
申请公布号 |
DE3368056(D1) |
申请公布日期 |
1987.01.15 |
申请号 |
DE19833368056 |
申请日期 |
1983.04.08 |
申请人 |
SHIONOGI & CO., LTD. |
发明人 |
IKAWA, KENJI;TOKUYAMA, KANJI;KIYOKAWA, MASUMI |
分类号 |
C07D307/62;(IPC1-7):C07D307/62 |
主分类号 |
C07D307/62 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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