Purification of crude hexafluoroacetone containing nitrogen oxides and sulfur dioxide

摘要

Crude hexafluoroacetone containing as impurities nitrogen oxides and sulfur dioxide is purified by admixing with water to form an aqueous solution, admixing the aqueous solution with concentrated sulfuric acid or oleum to form a vapor and scrubbing the vapor with liquid concentrated sulfuric acid to produce purified anhydrous hexafluoroacetone. The sulfur dioxide and nitrogen oxides interact with the aqueous solution and concentrated sulfuric acid so as not to be found in the purified product, thus obviating the need for a neutralization step.