Lithium bromide carbonate

Chemical Lithium metal Sulfur dioxide Acetonitrile Lithium bromide Carbon blaek... 

Lithium Bromide. Lithium biomide [7550-35-8] LiBi, is piepaied from hydiobiomic acid and lithium carbonate oi lithium hydroxide. The anhydrous salt melts at 550°C and bods at 1310°C. Lithium bromide is a component of the low melting eutectic electrolytes ia high temperature lithium batteries. 

A solution of 16jS-methyl-l la,17a,21-trihydroxy-5j5-pregnane-3,20-dione 21-acetate (52), 45 g, in dioxane (297 ml) is cooled to 15° and treated over a 5 min period with a solution of bromine (34.2 g) in dioxane (594 ml) precooled to 18°. After 2 min a solution of sodium acetate (60 g) in water (600 ml) is added and the mixture poured into ice water (8 liters). The precipitate is filtered off, washed to neutrality with water, and dried to give the crude dibromide (53), 55.7 g mp 125-126° (dec.) [aJu 58°. A mixture of dibromide (53), 55.5 g, lithium bromide (27.8 g), lithium carbonate (27.8 g) and DMF (1.11 liters) is refluxed under rapid stirring for 6 hr. The mixture is concentrated under vacuum to about 250 ml, poured into ice water (8 liters) containing hydrochloric acid (250 ml), and extracted with methylene dichloride. The extracts are washed to neutrality with water and evaporated to dryness. The residue is dissolved in acetone, evaporated to dryness under reduced pressure, redissolved in acetone and crystallized by the additon of hexane. This gives the dienone (54) 24.4 g, mp 236-239°. 

The acid-catalyzed opening of 16,17-epoxy-20-ketones has also been studied in some detail. In this instance, jS elimination to give a, -unsaturated ketone cannot occur, and in the simplest examples 16 -substituted 17a-alcohols are formed. However, in the presence of a 16jS-methyl substituent, 16-methylene compounds are produced [(167), (168), for example]. Lithium bromide-lithium carbonate in refluxing dimethylformamide gives the A -17a-alcohol. ... 

Brom-jod, n. iodine bromide, -kalium, n. potassium bromide, -kalzium, n., kalk, tn. calcium bromide, -kampher, tn. bromo-camphor, Pharm.) monobromated camphor, -kohlenstoff, tn. carbon (tetra)bromide. -korper, tn. Colloids) "bromide body (bromide ion), -kupfer, n. copper bromide, lauge, /. bromine lye (solution of sodium hypobromite and bromide made by passing bromine into sodium hydroxide solution), -lithium, n. lithium bromide. -Idsung, /. bro-nune solution, -magnesium, n. magnesium bromide. -metall, n. metallic bromide. 

Lithium acetate ammonium sulfate azide benzoate borate (meta-) bromate bromide carbonate chlorate chloride... 

Ethyl (2Z)-3-bromopropenoate. To a three-necked, round-bottomed flask are added lithium bromide (10.0 g, 0.115 mol, Note 1), acetonitrile (100 mL, Note 2), acetic acid (7.0 g, 0.116 mol, Note 3), and ethyl 2-propynoate (9.0 g, 0.092 mol, Notes 4, 5) under nitrogen. The reaction is carried out with magnetic stirring under reflux and monitored by GLC (Note 6). The reaction is complete after 24 hr. The reaction is cooled, water (20 mL) is added to the flask, and the mixture is cautiously neutralized with solid potassium carbonate, added in portions (Note 3). The organic layer is separated, and the aqueous layer Is extracted with ether (3 x 20 mL) (Note 3). The combined organic layers are dried with magnesium sulfate and filtered. After removal of the solvent, ethyl (2Z)-3-bromopropenoate is obtained by vacuum distillation (14.0 g, yield, 85%, Note 7). 

Comparison of the configuration of the stannane with the prodncts of reaction reveals that primary alkyl halides that are not benzyhc or a to a carbonyl react with inversion at the lithium-bearing carbon atom. In the piperidine series, the best data are for the 3-phenylpropyl compound, which was shown to be >99 1 er. In the pyrrolidine series, the er of the analogous compound indicates 21-22% retention and 78-79% inversion of configuration. Activated alkyl halides such as benzyl bromide and teri-butyl bromoacetate afford racemic adducts. In both the pyrrolidine and piperidine series, most carbonyl electrophiles (i.e. carbon dioxide, dimethyl carbonate, methyl chloroformate, pivaloyl chloride, cyclohexanone, acetone and benzaldehyde) react with virtually complete retention of configuration at the lithium-bearing carbon atom. The only exceptions are benzophenone, which affords racemic adduct, and pivaloyl chloride, which shows some inversion. The inversion observed with pivaloyl chloride may be due to partial racemization of the ketone product during work-up. 

Lithium bromide is prepared by neutralizing lithium hydroxide or hthium carbonate with an aqueous solution of hydrobromic acid, followed by concentration and crystallization ... 

Recently a practical and convenient synthesis was described starting from linalool via linalyl acetate [8]. It involves the ene-type chlorination of linalyl acetate prepared from linalool which results in the formation of y-chloro-a-linalyl acetate (Scheme 13.8). Dehydrochloronation with lithium bromide and lithium carbonate in dimethylformadide followed by hydrolysis of dehydro-a-linalyl ac-ylate results in hotrienol. 

A flame-dried 2-liter reactor was charged with (oxiran-2-yl) methyl acrylate (312 mmol), lithium bromide (1 g), and 300 ml THF and then treated with the dropwise addition of carbon disulfide (410 mmol). The mixture was stirred at ambient temperature for 4 hours and then at 45°C for 30 hours and concentrated. The residue was purified by column chromatography using silica gel with hexane/acetone, 70 30, respectively, and the product isolated as an orange-colored liquid. 

The trapping of lithiohalocyclopropanes by carbon dioxide, aldehydes and acid chlorides, respectively, constitutes a useful route to the corresponding cyclopropanecarboxylic acids, alcohols and ketones. In the case of ketones an intramolecular loss of lithium bromide may take place yielding spiroepoxides which in turn may be isomerized to cyclobutanones. 

The preparation oi the alkali bromides.—While V. Merz and W. Weith 2 found that metallic sodium reacts very slowly with bromine such that even after the two elements have been kept for 8 hrs. at 200°, the conversion of sodium into the bromide is but superficial potassium, caesium, and rubidium unite with bromine more quickly, forming the alkali bromide. The bromides are also formed when hydro-bromic acid is neutralized with the alkali hydroxide or carbonate, and the soln. evaporated. This method, for example, has been used for preparing rubidium bromide, RbBr. C. Chaubrie and N. N. Beketofi made a soln. of caesium bromide, CsBr, by the double decomposition of caesium sulphate, and barium bromide. P. Klein 3 made lithium bromide by digesting calcium bromide with lithium carbonate... 

Reaction of 4-bromo-2,3,4,5-tetrahydrobenzo[6]thiepin-5-one (340) with lithium bromide-lithium carbonate in refluxing DMF led to the isolation of two crystalline compounds (341) and (342) in 15% and 1% yield, respectively. The benzothieno[3,2-6]furan derivative (341 m.p. 58-60 °C) was assigned its structure on the basis of its NMR spectrum. The mass and UV spectra were also in accord with structure (341). The mechanism of its... 

A mixture of lithium bromide and lithium carbonate in DMF effects the same process again the formation of a five-membered ring is observed (81CB147). 

The use of lithium in medicine has been the subject of recent reviews by Birch,81 Birch and Sadler29 and references therein, and Tosteson.82 Historically, the use of lithium in medicine began with the treatment of gout and rheumatics in 1859. For the following 90 years, lithium was proposed for a variety of disorders and then discarded for example, lithium bromide was considered to be an effective sedative. In 1949 lithium was introduced into psychiatric practice and lithium carbonate, LijCOj, became the first of the modern psychotropic drugs. In a review of double-blind trials Schou and Thomsen (1975) support the prophylactic use of this drug in bipolar (manic-depressive) illness. 

Chlorotrimethylsilane (2.7 g, 25 mmol) (1) (CAUTION) is added to a solution of lithium bromide (1.74g, 20 mmol) in dry acetonitrile (20 ml) (2) with good stirring under a nitrogen atmosphere. Cinnamyl alcohol (1.34 g, 10 mmol) is then added and the reaction mixture heated under reflux for 12 hours. The progress of the reaction is monitored by t.l.c. on silica gel plates with hexane as the eluant. On completion of the reaction (12 hours), the reaction mixture is taken up in ether (50 ml), washed successively with water (2 x 25 ml), sodium hydrogen carbonate solution (10%, 50 ml) and finally brine, and dried over anhydrous sodium sulphate. Evaporation of the ether affords the pure bromide in 93 per cent yield. The product may be recrystallised from ethanol and has m.p. 31-32 °C CAUTION this compound is lachrymatory. 

The enone 445 was then converted to ( )-oxocrinine (415) by a sequence that commenced with the bromination of 445 using excess 5,5-dibromo-2,2-di-methyl-4,6-dioxo-l,3-dioxane to provide a mixture of bromo ketones 446. Removal of the jV-carbobenzyloxy protecting group according to the protocol previously detailed gave 448 as a mixture (a-Br (3-Br = 3 1) of diastereomers, but only the a-bromo isomer underwent dehydrobromination on heating with lithium bromide and lithium carbonate in dry DMF to furnish 415. Interestingly, treatment of the (3-bromo derivative of 448 under similar conditions afforded the debrominated product 447 (200). 

Lithium-base greases, especially the stearate, are efficient over an extremely wide temperature range up to 160°C. Lithium hydroxide (LiOH) is a component of the electrolyte in alkaline storage batteries and is employed in the removal of carbon dioxide in submarines and space capsules. Lithium bromide (LiBr) brine is used for air conditioning and dehumidification. Lithium hypochlorite (LiOCl) is a dry bleach used in commercial and home laundries. Lithium chloride (LiCl) is in demand for low-temperature batteries and for aluminum brazing. Other uses of lithium compounds include catalysts, glass manufacture, and, of course, nuclear energy. 

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