Lithium bromide perchlorate

The first reported synthesis of acrylonitrile [107-13-1] (qv) and polyacrylonitrile [25014-41-9] (PAN) was in 1894. The polymer received Htde attention for a number of years, until shortly before World War II, because there were no known solvents and the polymer decomposes before reaching its melting point. The first breakthrough in developing solvents for PAN occurred at I. G. Farbenindustrie where fibers made from the polymer were dissolved in aqueous solutions of quaternary ammonium compounds, such as ben2ylpyridinium chloride, or of metal salts, such as lithium bromide, sodium thiocyanate, and aluminum perchlorate. Early interest in acrylonitrile polymers (qv), however, was based primarily on its use in synthetic mbber (see Elastomers, synthetic). 

The bromination of phenol in acetic acid, containing lithium bromide and perchlorate at a constant total concentration of 0.2 M, gave kinetic isotope effects... 

Lithium bromide also combines with gaseous ammonia to form four solid deliquescent substances. The monammine, [Li(NH3)]Br, is formed above 95° C. the diammine, [Li(NIi3)2]Br, between 87° and 95° C. the triammine, [Li(NH3)3]Br, between 71° and 87° C. and the tetrammine about —18° C.2 Ephraim prepared other ammino-salts of lithium, as, for example, tetrammino-lithium nitrate, [Li(NH3)J(N03), which is a colourless syrup at ordinary temperature and is more stable than the chloride tetrammino-lithium chlorate, [Li(NII3)Ll]C103, which is a fairly mobile liquid and tetrammino-lithium perchlorate, [Li(NH3)4]C104, a white solid which liquefies and decomposes at ordinary temperature.3... 

The thermodynamic excess functions for the 2-propanol-water mixture and the effects of lithium chloride, lithium bromide, and calcium chloride on the phase equilibrium for this binary system have been studied in previous papers (2, 3). In this paper, the effects of lithium perchlorate on the vapor-liquid equilibrium at 75°, 50°, and 25°C for the 2-propanol-water system have been obtained by using a dynamic method with a modified Othmer still. This system was selected because lithium perchlorate may be more soluble in alcohol than in water (4). 

The salt effect parameter ko is plotted in Figure 2, and the data for lithium chloride and lithium bromide reported in the previous paper (3) are also plotted for the purposes of comparison. It can be seen from Figure 2 that ko depends markedly on the solvent composition. The values of ko decrease and in the extremely water-rich region k0 is negative at 50° and 25°C. In other words, 2-propanol is salted in by the addition of lithium perchlorate. The salting-in effect of 2-propanol increases with reduction in temperature. 

Olson and Cunningham (6) found that the specific conductance of 0.01m lithium bromide in acetone was increased by 30% when sufficient bromosuccinic acid, was added to make the solution 0.2m with respect to the acid. When dimethyl bromosuccinate was added in lieu of bromosuccinic acid, the specific conductance was diminished by 6% and when lithium perchlorate was substituted for lithium bromide, the specific conductance decreased linearly as bromosuccinic acid was added. These observations motivated Cunningham and his co-workers to continue work in the field. 

Bjornson also measured the specific conductance of a solution of 0.01m lithium bromide in acetone with various amounts of dimethyl bromosuccinate added and found a slight linear decrease in specific conductance with addition of dimethyl bromosuccinate. These results, along with those of Olson and Cunningham, lent support to Bjornson s postulate, in that when the acidic hydrogens of bromosuccinic acid were replaced with methyl groups, or the bromide ions of lithium bromide were replaced with perchlorate ions, the increase in specific conductance was not observed. 

Cyclization of enone (9) in hexane with boron trifluorideetherate in presence of 1,2-ethanedithiol, followed by hydrolysis with mercury (II) chloride in acetonitrile, yielded the cis-isomer (10) (16%) and transisomer (11) (28%). Reduction of (10) with lithium aluminium hydride in tetrahydrofuran followed by acetylation with acetic anhydride and pyridine gave two epimeric acetates (12) (32%) and (13) (52%) whose configuration was determined by NMR spectroscopy. Oxidation of (12) with Jones reagent afforded ketone (14) which was converted to the a, 3-unsaturated ketone (15) by bromination with pyridinium tribromide in dichloromethane followed by dehydrobromination with lithium carbonate and lithium bromide in dimethylformamide. Ketone (15), on catalytic hydrogenation with Pd-C in the presence of perchloric acid, produced compound (16) (72%) and (14) (17%). The compound (16) was converted to alcohol (17) by reduction with lithium aluminium hydride. 

Epoxides may undergo rearrangement in the presence of protic or Lewis acids to give carbonyl compounds. However, the nature of the products may depend quite subtly on the reaction conditions. For example, 1-methylcyclohexene oxide has been reported to give the ring-contracted aldehyde as the major product with lithium bromide, but with lithium perchlorate, 2-methylcyclohexanone is the major product (Scheme 2.22a). In the presence of a strong base such as lithium diethylamide, an allylic alcohol may be formed from an epoxide (Scheme 2.22b). 

N-Bromosuccinimidc. Formic acid. Hydrogen chloride. Lithium bromide. Phosphoric acid. Silver perchlorate. 

Cyclization of lunacridine can also be achieved more simply by fusion of its perchlorate which is thereby converted into a crystalline quaternary perchlorate corresponding to the intermediate XXXIII. The perchlorate anion is insufficiently nucleophilic to be capable of removing the 4-0-methyl group of XXXIII, but if the perchlorate is heated with lithium bromide in acetonitrile solution demethylation to (-1- )-lunacrine occurs (130). Lunacridine can also be converted directly to (+ )-lunacrine by the action of strong acid (131). 

Lithium bromide in large excess in refluxing acetonitrile slowly (12 hrs.) converts the quinolinium perchlorate (4) into the base (5). ... 

Lithium bromide catalyses the decomposition of phenyldiazomethane in ether at room temperature to give stilbene (68%) consisting almost exclusively of the Z-isomer. It is postulated that this remarkable stereoselectivity results from an intermediate in which two lithium ions are sandwiched between two molecules of phenyldiazomethane. In a related study it was shown that formation of the Z-stilbene is also favoured (up to 71%) when the same decomposition is catalysed by copper perchlorate or copper bromide in acetonitrile. ... 

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