Fluoroform bromination

At 225—275°C, bromination of the vapor yields bromochloromethanes CCl Br, CCl2Br2, and CClBr. Chloroform reacts with aluminum bromide to form bromoform, CHBr. Chloroform cannot be direcdy fluorinated with elementary flourine fluoroform, CHF, is produced from chloroform by reaction with hydrogen fluoride in the presence of a metallic fluoride catalyst (8). It is also a coproduct of monochlorodifluoromethane from the HF—CHCl reaction over antimony chlorofluoride. Iodine gives a characteristic purple solution in chloroform but does not react even at the boiling point. Iodoform, CHI, may be produced from chloroform by reaction with ethyl iodide in the presence of aluminum chloride however, this is not the route normally used for its preparation. 

Fluoroform is brominated to yield bromotnfluoromethane The reaction rate and yield are both enhanced by vanous catalysts, as summanzed in Table 7 [2J, 24, 25]. 

Chlonne-36-labeled 1,1-dichlorotetrafluoroethane is produced photochemically from chlonne-36 and l-chloro-l,2,2,2-tetrafluoroethane in better than 90% yield [22] Fluoroform is brominated to yield bromotrifluoromethane The reaction rate and yield are both enhanced by various catalysts, as summarized in Table 7 [23, 24, 25]. 

Properties Colorless gas. Noncorrosive. Fp -168C, bp -58C, d at bp 8.71 g/L. Nonflammable. Derivation Bromination of fluoroform or perfluoro-propane in nonmetallic reactor. 

Low-temperature reaction of the model compound 1,1,2,2-tetrafluoroethylbis-(trifluoromethyl)phosphine with one equivalent of bromine and pyrolysis of the product gave a complex mixture containing bromotrifluoromethane, starting material, and other products but after the bromination-pyrolysis sequence had been repeated twice more, the major products were 1-bromo-1,1,2,2-tetrafluoroethane (98%), and bromotrifluoromethane (74%), together with fluoroform (11%) and a similar amount of bromodifluoromethane. 

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See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ , ]

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