Fluorine-Sodium trifluoroacetate

Although fluonnation of peroxoanions [S2] has been examined, the major emphasis in the fluonnation of oxygenated material is the preparation offhioroxy compounds The simplest, trifluoromethyl hypofluorite, can be prepared almost quantitatively by the action of fluorine on carbonyl fluoride (fluorophosgene) in the presence of various catalysts [Si, 84] Addition of fluorine to trifluoroacetic acid [S5] or its sodium salt [S6] gives rise to FjCF(OF)2 Long-chain fluoroxy compounds can also... 

The syn addition of pentafluoroethyl hypofluorite (CF3CF2OF), generated in situ by the action of anhydrous, hydrogen-fluoride-free fluorine gas on sodium trifluoroacetate, to 5-acetyl-5//-dibenz[/i,/]azepine (11) has been reported to yield 12.135... 

Thermally unstable at 22°C and explosive in the gas phase at pressures above 27-62 mbar [1], there is also an explosion hazard during distillation and trapping at -78°C [2], The crude (80%) material prepared by action of 3% fluorine in nitrogen on sodium trifluoroacetate [3] has, however, been used synthetically for 3 years without mishap [4]. 

MAS has been applied to a highly viscous cubic phase of a lyotropic LC formed by 1-monooleolyl-rac-glycerol and water in order to obtain liquid-like and 13C spectra.330 Deuterium, sodium, and fluorine NMR spectroscopy have been applied to study the phase behaviour of several dilute lamellar systems formed by low concentrations of an ra-hexadecylpyridinium salt, a sodium salt (e.g., NaBr, NaCl, or sodium trifluoroacetate), 1-hexanol, and D20.331 The 2H, 19F, and 23Na splittings were used to monitor the phase equilibria. The last two studies are motivated by the search of new lyotropic LC for the alignment of biomolecules. 

The course of elemental fluorination reactions with various organic acid salts depends on the reaction conditions. The gas-solid fluorination reaction of sodium trifluoroacetate gives up to four products, whose distribution depends on the temperature of the column containing the sodium salt 1 no trifluoroacctyl hypofluoritc is formed. 

Trifluoroacetyl hypofluorite is the main product in the low-temperature fluorination of sodium trifluoroacetate in suspension in an inert solvent, and can be further transformed to pentafluoro-(fluoroxy)ethane.2 In some cases, the reaction mixture of up to four reactive products [fluoroxy, bis(fluoroxy) and acyl hypofluorites], formed in reactions with various acid salts, c.g. 5, has been directly used for the fluorination of organic molecules.1 " 5... 

Bis(trifluoromethyl) trioxide, CF3OOOCF3, was probably first prepared in low yield (<5%) from the fluorination of sodium trifluoroacetate.1 A substance of this composition was also... 

The preparation of per- and poly-fluorinated carboxylic acids and their derivatives om the corresponding iodides is covered elsewhere (see pp. 47—48), and patents dealing with the conversions of trichloroacetyl chloride into trifluoroacetic acid and trifluoroacetyl chloride and the manufacture of chlorine-free anhydrous trifluoroacetic acid by hydrolysis of trifluoroacetyl chloride have been published. Treatment of sodium or silver perfluorocarboxylates with phosphorus(ni) difluoride halides or phosphorus(v) oxy- and thio-difluoride halides gives the corresponding perfluoroacyl halides in good yield (see Scheme 2) in certain cases the intermediate... 

The analysis has been performed by means of NMR with the sodium salt of trifluoroacetic acid as internal standard for both chemical shift and fluorine content [44]. The notable advantage of the NMR method is the avoidance of interference from fluorine-containing impurities in the polymer. Any such impurities would give rise to signals quite distinct from those originating from the fluorines at the chain-ends. The relaxation times for the end-of-chain fluorines and those in the standard are 0.3 and 1.1s, respectively, and so to ensure valid comparison between peak areas and fluorine contents for standard and polymer, the delay between scans was extended to 5.6 s. 

The Knorr pyrrole synthesis was also employed for the synthesis of 3-trifluoropyrroles [91]. Treatment of ethyl trifluoroacetoacetate 267 with sodium nitrite in acetic acid led to the oxime 268. Refluxing with zinc dust and addition of 1,3-dicarbonyl compounds 269 afforded the 3-trifluoromethylpyrroles 270 in moderate yields. Using more acidic trifluoroacetic acid allowed to lower the reaction temperature to 70 °C [92]. Using a similar approach, the tricarboxylic acid ester 273 was prepared starting from the acetone dicarboxylic acid ester 271 and the fluorinated keto ester 272 [93]. 

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