Patent GB-794075-A (GB)
Title: Production of halofluoroacetones
Inventor: MILLER CHARLES BORDFELD
IPC: C07C45/63
Filed: 1956-03-09
Abstract: The invention comprises perchlorofluoroacetones containing 1-5 fluorine atoms in the molecule and boiling in the range of about 7-166 DEG  C. at atmospheric pressure, and the production thereof by reacting a perhalogenated acetone (containing no hydrogen), wherein all halogens are chlorine or fluorine, with a fluorinating or chlorinating agent, while maintaining the perhalogenated acetone substantially in the liquid phase, for a time sufficient to effect fluorination or chlorination of a substantial amount of the perhalogenated acetone.  Preferably a perhalogenated chloroacetone containing 0-4 fluorine atoms in the molecule, the remaining halogen atoms being chlorine, is reacted at elevated temperature (e.g. 30-200 DEG  C., preferably 60-150 DEG C.) with a fluorinating agent (e.g. anhydrous hydrogen fluoride, antimony fluoride or mixtures thereof) in the presence of antimony pentahalide in an amount of at least about 5 mol. per cent based on the total of starting material and antimony pentahalide, while maintaining the starting material substantially in the liquid phase, for a time sufficient to effect fluorination of a substantial amount of the starting material so as to form a perchlorofluoroacetone having a fluorine content of 1-5 atoms and greater than that of the starting material.  The antimony pentahalide is a compound of the formula SbFxCl5-x (wherein x is 0-5, preferably 1-3), and may be used in an amount of about 5-60 mol. per cent.  In examples: (1)-(3) hexachloroacetone is heated with SbF3 and various proportions of SbCl5 to produce (1) CClF2.CO.CClF2, (2) CCl2F.CO.CCl2F, and (3) a mixture of CCl2F.CO.CClF2, CClF2.CO.CClF2 and CF3.CO.CClF2; (4), (5) and (7) mainly similar results are obtained using gaseous HF in place of SbF3, an additional product being CCl3.CO.CCl2F; (6) CCl2F.CO.CClF2 is treated with gaseous HF in the presence of SbF5 to form CClF2.CO.CClF2; (8)-(10) by the action of anhydrous AlCl3 there are produced (8) CF3.CO.CCl3 from CF3.CO.CClF2; (9) CClF2CO.CCl3 from CClF2.CO.CCl2F, and (10) CClF2.CO.CCl3 from CClF2.CO.CClF2; (11) CF3.CO.CCl3 is heated with SbF3 and SbCl5 to give CF3.CO.CCl2F.  Fluorinated acetic acids.  The preparation of these from the products of the invention is illustrated by the following further examples: (12)-(14) and (18) by the action of aqueous caustic soda, followed by acidification, there are produced (12) CCl2F.COOH (together with chloroform) from CCl2F.CO.CCl3, (13) CCl2F.COOH (together with CHCl2F) from CCl2F.CO.CCl2F, (14) CClF2.COOH (together with chloroform) from CClF2.CO.CCl3, and (18) CF3.COOH (together with chloroform) from CF3.CO.CCl3; (15) CClF2.CO.CCl2F is added to a suspension of potassium hydroxide in benzene, yielding (after acidification) CClF2.COOH and CHCl2F; (16) and (17) using sodium hydroxide instead of potassium hydroxide there are similarly produced (16) CClF2.COOH from CClF2.CO.CClF2, and (17) CF3.COOH from CF3.CO.CClF2; (19) CF3.CO.CCl3 and aqueous ammonia yield a solution containing CF3.COONH4 from which, after acidification, chloroform and CF3.COOH are distilled out.