| 摘要 |
<p>Impure acetic anhydride, obtained by absorbing ketene in acetic acid, is purified by treatment with hydrogen peroxide or peracetic acid, preferably at a temperature between 70 DEG C. and the b.pt. of the anhydride, and subsequently distilling off the acetic anhydride. In examples (1) crude acetic anhydride is treated with sulphuric acid and 35 per cent aqueous hydrogen peroxide at 70 DEG C., the mixture allowed to stand and acetic anhydride then distilled off. (2) Crude acetic anhydride is treated with peracetic acid in acetic acid at 50 DEG C., and the purified anhydride distilled off.</p> |
