| 摘要 |
PURPOSE:To obtain high-quality acetylacetone at low cost by a simple treating means, purifying a crude reaction solution of acetylacetone by using batch distillation method of combined total reflux process, vacuum evaporation process, etc. CONSTITUTION:For example, in purifying acetylacetone fro a reaction solution of formed acetyl acetone containing acetic acid by reaction between an acetoacetic ester and acetic anhydride or by gas phase heat rearrangement of isopropenyl acetate, first a low-boiling fraction and acetic acid are separated by distillation, then total reflux is carried out under pressure from 500 mmHg-normal pressure until acetic acid concentration in vapor in an evaporation still becomes <=0.3wt%, then acetic acid stored in the column is separated by distillation and acetylacetone is evaporated under pressure of <=500mmHg and recovered. When isopropenyl acetate is used, preferably water is added to the reaction solution to eliminate acetic anhydride contained, acetylacetone is evaporated and purified.
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