Solvents etheric

Another method for the hydroxylation of the etliylenic linkage consists in treatment of the alkene with osmium tetroxide in an inert solvent (ether or dioxan) at room temperature for several days an osmic ester is formed which either precipitates from the reaction mixture or may be isolated by evaporation of the solvent. Hydrolysis of the osmic ester in a reducing medium (in the presence of alkaline formaldehyde or of aqueous-alcoholic sodium sulphite) gives the 1 2-glycol and osmium. The glycol has the cis structure it is probably derived from the cyclic osmic ester ... 

Commercially, anionic polymerization is limited to three monomers styrene, butadiene, and isoprene [78-79-5], therefore only two useful A—B—A block copolymers, S—B—S and S—I—S, can be produced direcdy. In both cases, the elastomer segments contain double bonds which are reactive and limit the stabhity of the product. To improve stabhity, the polybutadiene mid-segment can be polymerized as a random mixture of two stmctural forms, the 1,4 and 1,2 isomers, by addition of an inert polar material to the polymerization solvent ethers and amines have been suggested for this purpose (46). Upon hydrogenation, these isomers give a copolymer of ethylene and butylene. 

For use in anesthesia the USP (22) also recognizes slightly less pure grades ethyl oxide (solvent ether), ether abs, and reagent-grade ether. 

The common impurities found in amines are nitro compounds (if prepared by reduction), the corresponding halides (if prepared from them) and the corresponding carbamate salts. Amines are dissolved in aqueous acid, the pH of the solution being at least three units below the pKg value of the base to ensure almost complete formation of the cation. They are extracted with diethyl ether to remove neutral impurities and to decompose the carbamate salts. The solution is then made strongly alkaline and the amines that separate are extracted into a suitable solvent (ether or toluene) or steam distilled. The latter process removes coloured impurities. Note that chloroform cannot be used as a solvent for primary amines because, in the presence of alkali, poisonous carbylamines (isocyanides) are formed. However, chloroform is a useful solvent for the extraction of heterocyclic bases. In this case it has the added advantage that while the extract is being freed from the chloroform most of the moisture is removed with the solvent. 

Those in which solvent molecules are directly involved in formation of the ion association complex. Most of the solvents (ethers, esters, ketones and alcohols) which participate in this way contain donor oxygen atoms and the coordinating ability of the solvent is of vital significance. The coordinated solvent molecules facilitate the solvent extraction of salts such as chlorides and nitrates by contributing both to the size of the cation and the resemblance of the complex to the solvent. 

Preparation of carotenoid extract from plant oleoresin and hydrolysis with alkahne reagent in polar organic solvents (ether, polyhydroxyl alcohol, and ether alcohol)... 

The aluminium-solvent slurry produced by metal atom/solvent co-condensation at — 196°C is so reactive that oxygen is abstracted from the solvent ether as the mixture is allowed to melt. Hydrocarbon solvents are more suitable (but halocarbon solvents would react explosively). 

To avoid rapid spontaneous decomposition of the compound, solvent ether must only be partially distilled out of the extracted product, and from a water bath maintained at below 60°C. 

Evaporation of (peroxide-contacted) solvent ether from 9.8 g of crude peroxide led to an explosion. Subsequent preparations were effected on a smaller scale. 

It ignites in air, explodes dining uncontrolled hydrolysis [1], and chars during controlled hydrolysis [2], When isolated as the etherate, attempts to remove solvent ether caused violent decomposition [3],... 

Interaction of anhydrous hydrazine and titanium isopropoxide is explosive at 130° C in absence of solvent. Evaporation of solvent ether from the reaction product of tetrakis(dimethylamino)titanium and anhydrous hydrazine caused an explosion, attributed to formation and ignition of dimethylamine. /V-Metal derivatives may also have been formed. 

The mild detonations reported when the crystalline salt was disturbed [1] were thought to have been caused by presence of solvent ether in the crystals (6 mols of water may be replaced by 2 of ether) [2], This was later confirmed [3], and the formation of ethyl nitrate or diethyloxonium nitrate may have been involved, as the anhydrous salt functions as a powerful nitrator. Solutions of the nitrate in ether should not be exposed to sunlight to avoid the possibility of explosions. 

This has been used to rank hydrocarbons in a series of increasing acidity in the solvent ether 842... 

The mixed solvent ether-acetone-hexane-heptane (2 1.1 1) proved to be an excellent solvent system for the residue analysis of all three compounds with the shaking method. Soxhlet extraction with chloroform, gave quite... 

In order to extract from water a dissolved reaction product, or one which is not sufficiently solid or crystalline to be removed by filtration, or else to separate a substance from insoluble material which accompanies it, it is taken up in a suitable solvent. Ether is most commonly used for this purpose. Thus, for example, the distillate from a steam distillation is treated in this way unless it spontaneously separates into two layers. 

Materials Required Benzylpenicillin sodium (say) 0.12 g amyl acetate (previously saturated with 1-ethylpiperidinium benzylpencillin at room temperature, cooled in ice and filtered) 5.0 ml phosphoric acid (20% v/v) 0.5 ml anhydrous sodium sulphate (freshly ignited and powdered) 0.5 g dry acetone (previously saturated with 1-ethylpiperidinium benzylpenicillin at room temperature cooled in ice and filtered) 3.0 ml 1-ethylpiperidine amyl acetate solution (prepared from 1-ethyl piperidine, 1. 0 ml, and amyl acetate, 8.0 ml, saturated at room temperature with 1-ethylpiperidinium benzylpenicillin, cooled in ice and filtered) 1.5 ml dry acetone in amyl acetate (1 1) previously saturated with 1-ethylpiperidinium benzylpenicillin 2.0 ml solvent ether 4.0 ml. 

Procedure Dissolve accurately 22.5 mg of /ram-clomiphene citrate and 52.5 mg of cis-clomiphene citrate (approx. 1 2.3) into 10 ml of DW in a clean 50 ml separating funnel. Add to it 1 ml solution of sodium hydroxide (5% w/v in DW). In the alkaline medium the base is liberated which is extracted successively with 3 portions of solvent ether (10 ml each). The combined ethereal layer is washed with two portions of DW (10 ml each). The resulting ethereal fraction is dried over anhydrous sodium sulphate, filter, evaporate to diyness carefully over an electric water-bath and dissolve the residue in 1 ml of CS2. Now, record the absorption curve in a 0.2 mm cell over the range 12.50 to 14.00 pm. Calculate the absorbance for the peaks at 13.16 and 13.51 pm respectively by employing the base-line method (see section 3. l. B in this chapter) between the minima at 12.66 and 13.89 pm. 

V-methylephedrine is the chiral component. Reaction temperature - 15°C,solvent ether (88). 

Synonyms Aether AI3-24233 Anaesthetic ether Anesthesia ether Anesthetic ether Diethyl ether Diethyl oxide EINECS 200-467-2 Ether Ethoxyethane Ethyl oxide NSC 100036 l,l -0 Qr-bis(ethane) RCRA waste number U117 Solvent ether Sulfuric ether UN 1155. 

With sodium sulphide hydrate (general procedure) The diorganyltellurium dihalide is mixed with a 15 times molar excess of Na2S 9H2O and the mixture heated at 95-100°C for 10 min or more, until aU the solid has melted. Sufficient HjO is added to dissolve the sulphide and then the mixture is filtered if the obtained telluride is a solid, or extracted with a solvent (ether or petroleum ether) if the telluride is a liquid. The products are purified by crystallization or distillation. Yields are high or quantitative (except for diphenyl telluride or di-p-tolyl telluride). 

This reaction has a general character and can be applied to the different types of telluride. The halogenation is accomplished in inert solvents (ether, benzene, dichloromethane and chloroform) and the dihatides are normally easily crystaUizable products. 

Solvent ether. n-BuLi added to the telluride in the presence of pinacolone at -100°C. ... 

In keto steroids the reductions were also achieved by electrolysis in 10% sulfuric acid and dioxane using a divided cell with lead electrodes (yields 85-97%) [862], hy specially activated zinc dust in anhydrous solvent (ether or acetic anhydride saturated with hydrogen chloride) (yields 50-87%) [155, 86J], and by the above mentioned reduction of tosylhydrazones with sodium borohydride (yields 60-75%) [811]. 

Preparation of various enantiomerically pure sulfoxides by oxidation of sulfides seems feasible in the cases where asymmetric synthesis occurs with ee s in the range of 90% giving crystalline products which can usually be recrystallized up to 100% ee. Aryl methyl sulfides usually give excellent enantioselectivity during oxidation and are good candidates for the present procedure. For example, we have shown on a 10-mmol scale that optically pure (S)-(-)-methyl phenyl sulfoxide [a]p -146 (acetone, o 1) could be obtained in 76% yield after oxidation with cumene hydroperoxide followed by flash chromatographic purification on silica gel and recrystallizations at low temperature in a mixed solvent (ether-pentane). Similarly (S)-(-)-methyl o-methoxyphenyl sulfoxide, [a]p -339 (acetone, o 1.5 100% ee measured by HPLC), was obtained in 80% yield by recrystallizations from hexane. 

GaUium(III) chloride is used to prepare other gaUium salts and in solvent extraction. The chloride is highly soluble in solvent ether. This high solubility of metal chloride in ether allows metal extraction from ore. 

The flask is connected to a reflux condenser to condense down solvent ether back into the flask. Phosphine is collected over water as a moist gas. Dry phosphine may alternatively be condensed in a U-tube placed in freezing mixture. 

Solvent ether molecules may be bound effectively and flexibly to Mg atoms in retaining their tetravalency. When only the reactants (R MgX)2 and (R R C=0)2 are taken into account (e.g. in Scheme 13), trivalentMg states such as 28 and 30 are inevitably formed. The solvent molecules compensate for the lack of chemical bonds to the Mg atoms, through formation of appropriate Mg—O coordination bonds. Even in this case they do not interfere with intrinsic reaction channels. 

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