Lithium bromide fluoride

The reactions of A -steroids with nitrosyl fluoride parallel those of their A -isomers. Thus, 17 -acetoxyandrost-4-ene (37) is converted to the nitrimine (38), in 67 % yield and thence to the 4-ketone (39), which can be dehydrofluorinated to the A -4-ketone (40) with lithium bromide in di-methylformamide. In the corresponding 19-nor series the nitroso dimer is also formed. 

Metal halide salts other than sodium iodide have been used sparsely to prepare halodeoxy sugars from sulfonate esters. Lithium chloride (107) and lithium bromide (33) have found limited application. Potassium fluoride (dihydrate) in absolute methanol has been used (51, 52) to introduce fluorine atoms in terminal positions of various D-glucose derivatives. The reaction is conducted in sealed tube systems and requires... 

Terminal alkynes can be converted readily into alkynylsilanes by reaction of the corresponding alkyne anion or its metalloid equivalent with a suitable chlorosilane (/). The reverse reaction, that of liberation of the alkyne, is quite facile, being effected by several reagent combinations, including hydroxide ion, methanolysis, fluoride anion, silver(i) followed by cyanide anion, and methyl lithium-lithium bromide (2). 

Perfluoro(l,2-dimethylenecyclobutane) (17) isomerizes in 98% yield to perfluoro(2-methyl-3-methylenecyclobutcnc) (18) by heating at 100 C with cesium fluoride for 1 hour. No reaction was observed with potassium fluoride, cesium chloride, potassium chloride, or lithium bromide.48... 

When refractory linings are intended to contain moderate to high temperature environments having products of combustion or reaction containing compounds of sodium, lithium, potassium, vanadium and titanium and bromides, fluorides, chlorides, sulfides, phosphates along with the usual CO2, CO, H2, and O2, extreme care must be taken in their design. In these highly corrosive atmospheres, refractories perform differently than they do in clean environments. 

A small amount, 2.5 to 3.0 g of representative gypsum specimen, was calcined for 1 h at 1000°C in a platinum crucible, and the loss on ignition was recorded. A portion of 1.0000 g of the calcined specimen was mixed with 6.000 g of dense lithium tetraborate (Spectroflux 100 , Johnson and Matthey Co.) and 0.3000 g of lithium fluoride. Approximately 3 mg of lithium bromide was added to the mixture as a release (nonsticking) agent. Fusions were carried out on a propane flame, using a Claisse fluxer (2] equipped with crucibles and molds made from 95% platinum-5% gold alloy. The volume of molten flux was adequate to fill the 32-mm diameter mold to a sufficient height and produce a disk approximately 4 mm thick. 

The advantages of using sodium tetraborate for the fusions outweigh the loss of sodium as an analyzed element. Times required for the fusion and swirling of the flux on flame (Table 1) were quite short. The use of lithium fluoride and lithium bromide was eliminated completely. The disks prepared from sodium tetraborate release easily from the molds each time, without any sign of sticking, cracking, or crystallization. 

I n that case chloride or bromide ions should compete with fluoride ion. And indeed reaction of 1 lct-hydroxy-19-norsteroids with the reagent in the presence of excess lithium chloride in THF gives 11/3-chlorosteroids in good yield. 11/3-Bromo-steroids are obtained in lower yield by use of lithium bromide in methylene... 

Dehydrobromination of the 16a-bromo-17-ketone (330) with dimethylaceta-mide containing lithium bromide and carbonate gave a mixture of the 14-en-17-one (331) and the 14j3-15-en-17-one (332). " Although it was possible to separate these products by fractional crystallization, a more satisfactory use for the mixed products involved enol acetylation, which gave the A " -dien-17-ol acetate (333) in overall yield of 65%. Perchloryl fluoride treatment of the dienol... 

I) calcium oxide (v) aluminium fluoride (viii) lithium bromide... 

A further patent for the production of codeine, via codeinone, from thebaine has been published. " Codeine has been shown to be oxidized by manganese dioxide to 14-hydroxycodeinone the reaction is presumed to proceed via codeinone since 6-acetylcodeine is not affected by the same reagent. 6-O-Methanesulphonyl-dihydrocodeine has been shown to react with tetra-butylammonium fluoride, lithium chloride, and lithium bromide, with inversion at C-6, to give the related 6-halogeno-dihydrocodides, but when the ester is heated with sodium iodide in dimethylformamide the product is A -deoxycodeine (deoxycodeine-C) (143). Reductive amination of naltrexone with 2,2 -dihy-droxydiethylamine and sodium cyanoborohydride yields the 6-amino-compound (144 R = OH), which can be converted by carbon tetrachloride and tri-... 

The g = h term has been considered by P. Pyykkoo and J. Linderbarg in On Nuclear Pseudoquadrupole Interactions in Lithium Fluoride and Lithium Bromide Molecules, Chem. Phys. Lett. 5, 34 (1970) and is shown to yield a very small effect. 

The electrolyte used in lithium (aluminium)-iron sulphide secondary cells is commonly a mixture of lithium chloride and potassium chloride. A lithium fluoride-lithium chloride-lithium bromide mixture has also been used. With the latter electrolyte the discharge occurs in two steps ... 

Its high decomposition potential allows the use of alkali earth electrodes. At the working temperature of 400-600 C it is almost fully ionized. Various other electrolytes arc now being studied including lithium chloride-lithium bromide, lithium fluoride-sodium fluoride-potassium fluoride (both liquid electrolytes which can be solidified by adding about 35% magnesium oxide). Lithium iodide-alumina solid electrolyte is also being studied. 

Refer to the reaction between lithium bromide and potassium fluoride ... 

A. Idris, I. Ahmed, M.A. Limin, Influence of lithium chloride, lithium bromide and lithium fluoride additives on performance of polyethersulfone membranes and its application in the treatment of palm oil mill effluent, Desalination, 250 (2010) 805-809. 

Lithium Halides. Lithium haHde stabiHty decreases with increasing atomic weight of the halogen atom. Hence, the solubiHty increases from the sparingly soluble Hthium fluoride to the very soluble bromide and iodide salts. The low melting points of Hthium haHdes are advantageous for fluxes in many appHcations. 

Organolithium reagents (Section 14.3) Lithium metal reacts with organic halides to produce organolithium compounds. The organic halide may be alkyl, alkenyl, or aryl. Iodides react most and fluorides least readily bromides are used most often. Suitable solvents include hexane, diethyl ether, and tetrahy-drofuran. 

Due to the above requirements, typical optically-transparent materials, such as oxides (glass, quartz, alumina, zirconium oxide etc.) and halides (sodium chloride, lithium fluoride, calcium fluoride, potassium bromide, cesium bromide etc.) are usually unsuitable for use with fluoride melts. Therefore, no standard procedure exists at present for the spectral investigation of fluoride melts, and an original apparatus must be created especially for each particular case. 

---