Chlorodifluoroacetyl fluoride

Chlorotrifluoroethene (22) is oxidized by oxygen to chlorodifluoroacetyl fluoride (24), which is probably formed by rearrangement of the initially formed unstable chlorotri-fluorooxirane (23).41 The epoxide 23 can be prepared at low temperatures,42 while under irradiation of the reaction mixture with UV light the yield of the epoxide is low and the formation of the acid fluoride is preferred.43,44 Similar results are obtained for l,l-dichloro-2,2-di-fluoroethene (25a).44... 

Etzler and Rollefson reported carbon monoxide and methyl halide to be the major products from the continuous photolysis of acetyl bromide, iodide and chloride in the vapour phase. Similarly halogenated alkanes were found as major products from chlorodifluoroacetyl fluoride and from other polyfluoroacyl fluorides, chlorides and bromides . The mechanisms of these reactions are not clear. 

Chlorotrifluoroethylene is a colorless gas at room temperature and pressure. It is fairly toxic with an LC50 (rat), 4 hr of 4000 ppm. It has a critical temperature and pressure of 105.8°C and 4.03 MPa. Oxygen and liquid CTFE react and form peroxides at fairly low temperatures. A number of oxygenated products are generated by the oxidation of chlorotrifluoroethylene, such as chlorodifluoroacetyl fluoride.The same reaction can occur photochemically in the vapor phase. Chlorotrifluoroethylene oxide is a by-product of this reaction. The peroxides act as initiators for the polymerization of CTFE, which can occur violently. 

Work on the production of trifluoroacetyl fluoride via electrochemical fluorination (Simons process) of ethylene glycol, ethylene chlorohydrin, or l,3-dichloro-2-hydroxypropane (the last two also give chlorodifluoroacetyl fluoride) has been reported." Similar electrochemical conversion of benzoyl chloride into perfluoro(fluorocarbonylcyclohexane) and its ring-contracted... 

Sodium salts of fluoroacids react with chlorine fluoride at —112 to —78°C to give explosively unstable fluoroacyl hypochlorites. Trifluoroacetyl hypochlorite and its pentafluoropropionyl, heptafluorobutyryl, difluoroacetyl and chlorodifluoroacetyl analogues explode without fail if the partial pressure exceeds 27—67 mbar. Hexafluoroglutaryl dihypochlorite explodes above —10°C [1]. Of the 4 compounds prepared, acetyl, propionyl, isobutyryl and pivaloyl hypobromites, the 2 latter appeared stable indefinitely at —41 °C in the dark, while the 2 former exploded unpredictably as isolated solids [2]. 

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See also in sourсe #XX -- [ ]

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