Sodium fluonde

Anhydrous hydrogen fluonde, potassium fluonde, and sodium fluonde have all been used to promote the chlorine-fluonne exchangein tetmchloropyrukizine All three fliionne sources replace the chlonne in position 3 first Both sodium and potassium... 

As a result, the electromotive force (EMF) of the cell is zero In the presence of fluoride ions, cerium(IV) forms a complex with fluoride ions that lowers the cerium(IV)-cerium(IIl) redox potential The inner half-cell is smaller, and so only 5 mL of cerium(IV)-cenum (III) solution is added To the external half-cell, 50 mL of the solution is added, but the EMF of the cell is still zero When 10 mL of the unknown fluonde solution is added to the inner half-cell, 100 mL of distilled water IS added to the external half-cell The solution in the external half-cell is mixed thoroughly by turning on the stirrer, and 0 5 M sodium fluonde solution is added from the microburet until the null point is reached The quantity of known fluonde m the titrant will be 10 times the quantity of the unknown fluoride sample, and so the microburet readings must be corrected prior to actual calculations... 

Treatment of glyoxal with sulfur tetrafluoride in the presence of sodium fluonde results in the formation of difluoroethylene glycol orthosulfite [174] (equation 89) Similarly, perfluonnated 1,2-diketones react with sulfur tetrafiuonde to give tetraoxyspirosulfuranes as the only products Thus, perfluorobiacetyl gives a crystalline product, perfluorobutylene glycol 2,3 orthosulfite [175] (equation 89)... 

The tnmethylsilyl enol ether of 1 mdanone (3 2 mmol) in 2 mL of methylene chlonde is added to a mixture of xenon difluonde (4 mmol) and a catalytic amount of pyndimum poly (hydrogen fluonde) m 5 mL of methylene chlonde The mixture IS stured at 0 C for 2 h and poured into dilute sodium bicarbonate solution, tlie organic layer is separated and dned After concentration and column chromatogra phy (silica gel, hexanes), 2-fluoro-1 -mdanone (mp, 59 C) is obtamed in 87% yield... 

The well-known reduction of carbonyl groups to alcohols has been refined in recent studies to render the reaction more regioselective and more stereoselective Per-fluorodiketones are reduced by lithium aluminum hydride to the corresponding diols, but the use of potassium or sodium borohydride allows isolation of the ketoalcohol Similarly, a perfluoroketo acid fluonde yields diol with lithium aluminum hydnde, but the related hydroxy acid is obtainable with potassium borohydnde [i f] (equations 46 and 47)... 

Simple a-fluorosulfides are reduced to the fluoroalkanes by sodium-ethanol [9J (equation 75). Clean conversion of bis(trifluoromethyl) diiulfide to trifluoromethyl mercaptan is accomplished with hydrogen sulfide and ultraviolet irradiation (941 (equation 76). Perfluoroalkanesulfonyl fluondes are converted to the sulfmate salts by hydrazine [95] (equauon 77)... 

Difluorododecane is unaffected by sodium methoxide in methanol, but its treatment with potassium tert-butoxide in tetrahydrofuran eliminates hydrogen fluonde stereospecifically rneso and dl compounds give, respectively, ( )- and (2) 6 fluoro 6 dodecene [12] (equation 11)... 

Fluorodediazoniation of 2-fIuoro-2-phenylethylammes with sodium nitrite in Olah s reagent (70% anhydrous hydrogen fluonde-30% pyridine) gives high yields of 1,1 -difluoro-2-phenylethanes arising from 1,2 migration of phenyl P] (equation 2)... 

Condensation of sodium phenoxide with 2,2,2-trifluoroethyl iodide gives a product of direct substitution in a low yield, several other ethers are formed by elimination-addition reactions [7] Use of mesylate as a leaving group and hex amethyl phosphoramide (HMPA) as a solvent increases the yield of the substitution [5] Even chlorine can be replaced when the condensation is performed with potassium fluonde and acetic acid at a high temperature [9] (equations 6-8)... 

In its precipitation reactions ameiicium(IIl) is very similar to the other tripositive actinide elements and to the rare earth elements. Thus the fluonde and the oxalate are insoluble and the phosphate and iodate are only moderately soluble in acid solution, whereas the nitrates, halides, sulfates, sulfides, and perchlorates are all soluble. Americium(VI) can be precipitated with sodium acetate giving crystals isostructural with sodium uranyl acetate,... 

Another approach is to omit the solvent andrun the reaction mAet supercritical conditions where potassium fluoride dissolves in the superheated reactant This approach is illustrated by the conversion of 2-chloromethoxy-l,l,l,3.3,3-hexa fluoropropane to 2-fluoromethoxy-l,1,1,3.. hexafluoropropane with either potassium fluonde or sodium fluoride as the fluorine source (equation 31)... 

An example of fluorodediazoniation of a-ammo acids is the preparation of P-fluoroaspartic acid m 25% yield from a,P-diaminosuccmic acid tind sodium mtnte in anhydrous hydrogen fluonde [4]... 

Nitrosyl chloride [55], nitrosyl fluoride-hydrogen fluonde liquid complexes (NOF3HF, NOF 6HF) [56], nitrous acid-hydrogen fluonde solutions [57, 5 nitrogen tnoxide (prepared in situ from nitric oxide and oxygen) [59] and fert-butyl nitrite-hydrogen fluonde-pyridine [60] have been substituted for sodium nitrite in the diazotization step... 

Burgstahler et al. diazotized the sparingly soluble hydrochloride of 3,4-di-r-butylaniline at O-S", treated the filtered solution with sodium fluoroborate, and obtained the diazonium fluond>orate. This salt underwent slow solvolysis in a mixture of acetic acid — acetic anhydride with formation of the corresponding acetate. 

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