Cesium bicarbonate

Apparently, the first who studied the application of liquid membranes with facilitated transport properties for gas separation were Ward and Robb in 1967 [27]. A highly porous cellulose acetate film was soaked with cesium bicarbonate solution, the liquid was kept in the membrane pores by capillary forces. A high selective permeation of CO2 from an O2-CO2 feed mixture was due to its facilitated transport in the bicarbonate solution. 

CO2 from O2 [27]. An aqueous solution of cesium bicarbonate (6.4 M) was immobilized in a porous cellulose acetate film. For a 5% CO2 feed gas at 1 atm and sweep side of CO2 partial pressure at 0.005-0.026 atm the CO2 permeance was about 8.9 x barter/cm and the separation factor... 

Cesium carbonate cesium bicarbonate, CS2CO3 CsHCOa, 7, 57. 

Under anhydrous conditions, cesium carbonate or bicarbonate quantitatively cleaves an aryl dibenzoate or diacetate to the monoester yields are considerably lower with potassium carbonate. ... 

The polymerization catalysts that are preferred because of their selectivity are the alkali metal (especially cesium) carbonates, tetraalkylammonium and bis(triphenylphosphoranylidene)ammonium (PPN) chlorides and bicarbonates (Table 4.2). Undesired side reactions are minimized by using relatively low (< 5% by weight) catalyst levels. Under these conditions, the fraction of cyclic oligomer was usually 5% or less and was easily removed from the desired polymer by Kugelrohr distillation. Conversions of 5 were essentially quantitative as judged by product weights and lack of detectable amounts of unreacted monomer by GPC. 

Another study reported that desilylation occurs when a-triethylsilylated imminium perchlorates are irradiated. /V-AI ky I-a-enaminones are obtained after treatment of the photolysates with aqueous sodium bicarbonate ( 70% yield). These enones are also formed upon fluoride-induced desilylation with cesium fluoride in acetonitrile.128... 

The synthesis of pazopanib (1) involves sequential animation of 2,4-dichloropyrimidine 25 with 6-amino-2,3-dimethylindazole 24 and 5-amino-2-methyl-benzenesulfonamide 28. The 6-amino-2,3-dimethylindazole 24, on the other hand, was prepared from 2-ethylphenylamine 20 via 5-nitration with fuming nitric acid and concentrated sulfuric acid, followed by treatment with isoamyl nitrite and acetic acid to produce 6-nitro-3-methylindazole 22. The 6-nitro group was reduced with stannous chloride and concentrated HC1 in glyme and subsequently methylated at the C2 position of the indazole ring with trimethyloxonium tetrafluoroborate in acetone to produce 6-amino-2,3-dimethylindazole 24. The resultant indazole 24 was condensed with 2,4-dichloropyrimidine 25 in the presence of sodium bicarbonate in ethanol/THF and subsequent iV-methylation with iodomethane and cesium carbonate to produce 27. The 2-chloro group of pyrimidine was then allowed to react with 5-amino-2-methyl-benzenesulfonamide 28 in catalytic HCl/isopropanol and heated to reflux to deliver pazopanib hydrochloride (1) in good yield. 

Rubidium and cesium hydroxides are even stronger bases than NaOH and KOH, but they are of little practical importance because of cost and availability. Solutions of the alkali metal hydroxides often contain traces of the bicarbonates owing to the reaction of C02, an acidic oxide, with the hydroxide ions in the solutions ... 

Dehydrohalogenation Alumina, see Sulfur tetrafluoride. Alumina-Potassium hydroxide. Cesium fluoride. l,5-Diazabicyclo[4.3.0]nonene-5. l,4-Diazabicyclo[2.2.2]octane. 1,5-Diazabicyclo[5.4.0]undecene-5. Dimethylaminotrimethylstannane. Dimethyl sulfoxide. Hexamethylphosphoric triamide. Lithium chloride. Lithium dicyclohexylamide. Magnesium oxide. Potassium r-butoxide. Potassium fluoride. Potassium triethylmethoxide. Pyridine, see Nitrosyl chloride. Silver fluoride. Silver nitrate. Sodium amide. Sodium bicarbonate, see Nitryl iodide. Sodium isopropoxide. Triethylamine, see Sulfur dioxide. 

Cesium acetate was further used to convert a secondary alcohol in the synthesis of (—)-dysiherbaine, a natural product isolated from a marine sponge shown to act as a neurotoxin. In this case, the alcohol to be inverted was first converted into a nosylate using nosyl chloride, DMAP, and triethyl ammonia. The following application of cesium acetate was then used without the addition of crown ether, yielding the inverted alcohol after hydrolysis with potassium carbonate in sodium bicarbonate and methanol (eq 3). Importantly, cesium acetate did not interfere with the epoxide or olefin present in the natural product precursor. ... 

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