Fluorocarbon anaesthetics

By far the largest use of hydrogen fluoride is in the manufacture of fluorocarbons which find a wide variety of uses including refrigerants, aerosol propellants and anaesthetics. Hydrogen fluoride is also used in the manufacture of synthetic cryolite, Na3AIFg, and the production of enriched uranium. 

It is important to make sure that any proposed hypothesis applies equally well to the fluorocarbons which are the most used of all general anaesthetics. Actually, fluorinated substances provide an excellent test of the hydration hypothesis because they are noted for the weakness of their intermolecular associations. The tendency of the various anaesthetics to form hydrates was appropriately compared by plotting the reciprocal of the dissociation pressure at 0°C against anaesthetic potency. It was then seen that fluorinated compounds were much less hydrated than other anaesthetics when compared in equi-anaesthetic concentrations (Miller, Paton and Smith, 1965). 

New patent literature dealing with the production of Fluothane (CFa CHBrCl) via reduction of 1,1-dibromo-l-chlorotrifluoroethane with methanolic potash or with isopropanol-u.v. light, the synthesis of the inhalation anaesthetic CHFa CF=CBrCl via dehydrofluorination (soda-lime) of the bromopropane CHFa CFa CHBrCl, the use of fluorocarbon bromides tCFa (CFa) -CFaBr (jf = 4 or 6), Br(CFa) Br (x = 2 or 4), CFa CFBr CFaBr, CeFsBr, or l,2-Br,C,Fa] as contrast media for radio-graphy, and the synthesis of the fluorosilicone —[SiMe(CHa CHa CFa-CFa CCla) 0] — via free-radical addition of the bromide CCla-CFa CFjBr across the double bond in ethylene is now available. Free-radical addition reactions of dihalides of the type X(CF2) X (X = Br or I) are referred to... 

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