| 摘要 |
1,196,896. Purifying chloropentafluoro- and hexafluoro-acetones. ALLIED CHEMICAL CORP. 22 Jan., 1969 [14 March, 1968], No. 3707/69. Heading C2C. Chloropentafluoro- and hexafluoro-acetones are purified from accompanying HX(HCI and/or HF) by (a) contacting with sufficient liquid phase water to provide at least 1 mole per mole ketone, the temperature being controlled so that any free water is kept in liquid phase and part of the HX is evolved, (b) treating the product with alkali or alkaline earth metal hydroxide, the pH being maintained at 3À5- 7-0, (c) distilling the neutralized hydrated ketone and (d) recovering purified anhydrous or hydrated ketone. The starting material, which in examples is prepared from hexachloroacetone and HF in presence of Cr 2 O 3 , may contain HX in the form of addition compounds, e.g. (CF 3 ) 2 C(OH)Cl, (CF 3 ) 2 C(OH)F, CF 2 ClC(OH)(F)CF 3 and [CF 3 (CF 2 Cl)CZ] 2 O where one Z is F and the other OH. The intermediate product of stage (a) may contain mono- or trihydrates of the initial ketones. |
