| 摘要 |
PURPOSE:Acetic anhydride is treated with chromic anhydride and distilled or it is distilled simultaneously under treatment with chromic anhydride to give acetic anhydride of high quality which is used as a starting material of acetylcellulose, medicines, agrochemicals or dyes economically with advantage. CONSTITUTION:Crude acetic acid of 5-6min or less according to the reductive substance test with permanganate is treated with chromic anhydride or its aqueous solution at room temperature for 30min and distilled. Or the distillation is effected simultaneously under the treatment with chromic anhydride to give the objective compound of high quality of more than several 10min-20hr permanganate value. The amount of the chromic anhydride added is about 0.01-1wt% based on the crude acetic anhydride.
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