Dibutyl ether as solvent

Non-polar coumarins like coumarin itself and its precxirsors [237, 238] can be chromatographed on silica gel layers with benzene or with the solvents II, III or V (Table 166, p. 694). hB/-values were quoted first by Stahl and Schorn [203], then by Tschesche and co-workers [218] and Horhammer et al. [103]. Beyrich [15] has found that especially good separations of the furocoumarins could be achieved on silica gel layers, impregnated with formamide he used dibutyl ether as solvent. 

Phenylindole (X) reacts with methyl propargyl ether in the presence of InNfs (30mol%) in dibutyl ether as solvent at 70-100°C to give a product A (91% conversion, 65% isolated yield. (Nf = nonaflate, —O-SO2-C4F9)... 

Iron pentacarbonyl and l-methoxy-l,4-cyclohexadiene react as shown by Birch and oo-workera, but in dibutyl ether this solvent has been found superior. The tricarbonyl(methoxy-l,3-cyclohexadiene)iron isomers undergo hydride abstraction with triphenylmethyl tetrafluoro-borate to form the dienyl salt mixture of which the 1-methoxy isomer is hydrolyzed by water to the cyclohexadienone complex. The 2-methoxy isomer can be recovered by precipitation as the hexafluoro-phosphate salt. By this method the 3-methyl-substituted dienone complex has also been prepared from l-methoxy-3-methylbenzene. The use of the conjugated 1-methoxy-1,3-cyclohexadiene in Part B led to no increase in yield or rate and resulted chiefly in another product of higher molecular weight. An alternative procedure for the dienone is to react tricarbonyl(l,4-dimethoxycyclohexadiene)iron with sulfuric acid. ... 

Dibutyl ether as the solvent. The use of isopropylmagnesium bromide leads to some halogen exchange. It is noteworthy that this old work has scarcely been bettered [6], Together with tetramesityldiphosphine (6%). 

In order to explain the linearity in dibutyl ether and the nonlinearity in toluene of the second-order rate constant as a function of the triethylamine concentration, Burkus considers the role of the solvent. In dibutyl ether the solvent-alcohol interaction causes the absence of monomeric alcohol. The addition of the base does not affect the nature of the alcohol... 

Because they are widely used as solvents many simple dialkyl ethers are commercially available Diethyl ether and dibutyl ether for example are prepared by acid catalyzed condensation of the corresponding alcohols as described earlier m Section 15 7... 

Actinide ions form complex ions with a large number of organic substances (12). Their extractabiUty by these substances varies from element to element and depends markedly on oxidation state. A number of important separation procedures are based on this property. Solvents that behave in this way are thbutyl phosphate, diethyl ether [60-29-7J, ketones such as diisopropyl ketone [565-80-5] or methyl isobutyl ketone [108-10-17, and several glycol ether type solvents such as diethyl CeUosolve [629-14-1] (ethylene glycol diethyl ether) or dibutyl Carbitol [112-73-2] (diethylene glycol dibutyl ether). 

Phenyllithium can be used as a solution in ethyl ether, but because of its limited stabUity (t 2 = 12 d at 35° C) it is commercially available in solution in mixtures, usuaUy 70 30 wt % cyclohexane ethyl ether (117). In this particular mixture of solvents, a 20 wt % solution, free of chlorobenzene, is stable for at least four months under an inert atmosphere (argon or nitrogen) in sealed containers at room temperature. Phenyllithium is also available in dibutyl ether solution (117). It is classified as a flammable Hquid. 

Lithium hydride is perhaps the most usehil of the other metal hydrides. The principal limitation is poor solubiUty, which essentially limits reaction media to such solvents as dioxane and dibutyl ether. Sodium hydride, which is too insoluble to function efficiently in solvents, is an effective reducing agent for the production of silane when dissolved in a LiCl—KCl eutectic at 348°C (63—65). Magnesium hydride has also been shown to be effective in the reduction of chloro- and fluorosilanes in solvent systems (66) and eutectic melts (67). 

Pyrolysis of pyrazolines in high boiling solvents such as dibutyl ether or ethylene glycol alfords only the 16-methyl-A -steroids (3). The same products are obtained by refluxing (2) in carbon tetrachloride in the presence of acidic alumina. 

Purified MeHNL was crystallized by the sitting-drop vapor-diffusion method. The 10-20 mm bipyramidal crystals formed were cross-linked with glutaraldehyde and used as biocatalyst for the synthesis of optically active cyanohydrins. The cross-linked crystals were more stable than Celite-immobilized enzymes when incubated in organic solvents, especially in polar solvents. After six consecutive batch reactions in dibutyl ether, the remaining activity of the cross-linked crystals was more than 70 times higher than for the immobilized enzymes. Nevertheless, the specific activity of the cross-linked crystals per milligram protein was reduced compared with the activity of Celite-immobilized enzymes [53],... 

Butex A process for separating the radioactive components of spent nuclear fuel by solvent extraction from nitric acid solution, using diethylene glycol dibutyl ether (also called Butex, or dibutyl carbitol) as the solvent. Developed by the Ministry of Supply (later the UK Atomic Energy Authority) in the late 1940s. Operated at Windscale from 1952 until 1964 when it was superseded by the Purex process. 

Compounds which dissolve in concentrated sulphuric acid may be further classified as those which are soluble in syrupy phosphoric acid and those which are insoluble in this solvent in general dissolution takes place without the production of appreciable heat or colour. Those compounds soluble in phosphoric acid include alcohols, esters, aldehydes, methyl ketones and cyclic ketones provided that they contain less than nine carbon atoms. The solubility limit is somewhat lower than this for ethers thus dipropyl ether dissolves in 85 per cent phosphoric acid but dibutyl ether and anisole do not. Ethyl benzoate and diethyl malonate are insoluble. 

Optically active 19a was previously obtained by inclusion complexation with N -benzylcinchon idi um chloride 21 [36], Compound 21 was also a very efficient resolving agent for rac-17 [37], Crystal structure analysis of a (1 1) complex of 21 and selectively included (+)-17 showed that the molecular aggregate was associated by formation of a Cl HO hydrogen bond. Racemic compound 20 could be efficiently resolved only by complexation with (R,R)-(—)-trans-2,3-bis(hydroxydiphenylmethyl)-l,4-dioxaspiro[4.4]nonane 3b. A crude inclusion complex of 1 1 stoichiometry of 3b was formed selectively with (+)-20 in a 2 1 mixture of dibutyl ether/hexane. One recrystallization from the above combination of solvents gave a 34 % yield of the pure complex. Optically active (+)-20 was obtained by dissolving the complex in 10% NaOH, followed by acidification with HC1 and then recrystallization. The optical purity determined by HPLC (Chiralpack As) was >99.9 %. As far as we know, this is the only report of the resolution of 4,4 -dihydroxybiphenyl derivatives. Conversely, an inclusion... 

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