Di-w-butyl ether

The preparation of di-w-butyl ether is illustrative (Scheme 2.6). No reaction occurred with n-butanol alone for 2 h at 200 °C. However, in the presence of 10 mol % n-butyl bromide, 26% conversion of the alcohol to the ether was obtained after 1 h, without apparent depletion of the catalyst. It is known that addition of alkaline metal salts can accelerate solvolytic processes, including the rate of ionization of RX [41]. This was confirmed when the introduction of LiBr (10 mol %) along with n-butyl bromide, afforded a conversion of 54% after 1 h at 200 °C. Ethers incorporating a secondary butyl moiety were not detected, precluding mechanisms involving elimination followed by Markovnikov addition. 

Di-tert-butyldiperphthalate [2155-71-7] M 310.3. Crystd from ethyl ether. Dried over H2SO4. Di-w-butyl ether see n-butyl ether. 

If, however, the water formed is removed as formed (compare the preparation of di-w-butyl ether, Section 111,57), the sulphuric acid may react completely and the method may be employed for the preparation of the free sulphonic acid. 

This procedure has been used successfully to convert simple aliphatic ethers into their corresponding iodides. Yields of iodides obtained in the reaction of di-w-butyl ether and diisopropyl ether with potassium iodide and 95% orthophosphoric acid were 81 and 90% respectively. Small quantities of the corresponding alcohols were also isolated as products from these reactions. 

Di-w-butyl ether is used in preference to other possible compounds because it permits the formation of a homogeneous reaction mixture. 

The first fractions consist of a little alcohol, water, and di-w-butyl ether (Note 5). The next fraction is diethyl sebacate, b.p. 156-158° at 6 mm. (Note 6). Ethyl hydrogen sebacate is collected at 183-187° at 6 mm. The product melts at 34-36° and weighs 114-124 g. (50-54 per cent of the calculated amount, based on the sebacic acid used). Refracfionation of the fore-run (b.p. i75-i83°/6 mm.) and after-run (b.p. i87-i95°/6 mm.) gives an additional 24-26 g. of pure monoester. The total yield is 138-150 g. (60-65 per cent of the theoretical amount) (Notes 7 and 8). 

Separations based upon differences in the chemical properties of the components. Thus a mixture of toluene and anihne may be separated by extraction with dilute hydrochloric acid the aniline passes into the aqueous layer in the form of the salt, anihne hydrochloride, and may be recovered by neutralisation. Similarly, a mixture of phenol and toluene may be separated by treatment with dilute sodium hydroxide. The above examples are, of comse, simple apphcations of the fact that the various components fah into different solubihty groups (compare Section XI,5). Another example is the separation of a mixture of di-n-butyl ether and chlorobenzene concentrated sulphuric acid dissolves only the w-butyl other and it may be recovered from solution by dilution with water. With some classes of compounds, e.g., unsaturated compounds, concentrated sulphuric acid leads to polymerisation, sulphona-tion, etc., so that the original component cannot be recovered unchanged this solvent, therefore, possesses hmited apphcation. Phenols may be separated from acids (for example, o-cresol from benzoic acid) by a dilute solution of sodium bicarbonate the weakly acidic phenols (and also enols) are not converted into salts by this reagent and may be removed by ether extraction or by other means the acids pass into solution as the sodium salts and may be recovered after acidification. Aldehydes, e.g., benzaldehyde, may be separated from liquid hydrocarbons and other neutral, water-insoluble hquid compounds by shaking with a solution of sodium bisulphite the aldehyde forms a sohd bisulphite compound, which may be filtered off and decomposed with dilute acid or with sodium bicarbonate solution in order to recover the aldehyde. 

NC13, mw 120.38, N 11.64% yel, vol, pungent-smelling oil, mp <-40° (Porret in 1813 reported —27°), bp about 71° (explds at 93-95°), d 1.653g/cc. Sol in cold w (decompd by hot w), ale, eth, chlf, bz, CCl CS2 phosphorous oxychloride. Prepd (with great care) by the action of sodium hypochlorite on amm chloride. The compd also forms at the anode in the electrolysis of coned amm chioride soln. Another prepn consists of bubbling chlorine into a cooled aq soln of amm sulfate di-n-butyl ether (Refs 1,... 

A new organotin hydride with a polar tail, di-w-butyl(4,7,10-trioxaundecyl)stannane, useful for various syntheses in organic chemistry, is prepared by the following sequence of reaction237 (Scheme 23). Bu2HSnCl is prepared in ether from LiAlH4 and Bu2SnCl2 at low temperatures. 

PA = 226 kcal mol-1), the predominant formation (6.4 to 1) of the (/ ,.S )-di-2-hutyl ether over the (R,R)- and (S,S)-forms is attributed to a simple backside displacement in the proton-bound adduct of the starting 2-butanol enantiomer with inversion of configuration of the reaction site and loss of a molecule of water. When tri-w-propylamine is replaced by the less basic NH3 (PA = 196 kcal mol-1), fast neutralization of the proton-bound dimers of the starting 2-butanol is prevented and, therefore, they can grow, producing aggregates that resemble solution microenvironments in which S l pathways may be accessible as well. In them or in their primary substituted derivatives, consecutive nucleophilic displacements may take place. As a consequence, the stereospecificity of the process is lost and the [(/ ,5)-di-2-butyl ether]/[(/ ,/ )- and (S,S)-di-2-butyl ethers] ratio falls down to 1.2. In this case,... 

Pagliara, A., Caron, G., Lisa, G Fan, W., Garllard, P., Carrupt, P.-A., Testa, B. and Abraham, M.H. (1997) Solvatochromic analysis of di-u-butyl ether/water partition coefficients as compared to other solvent systems./. Chem. Soc. Perkin Trans. 2, 2639-2643. 

This preparation is an example of the use of di- -butyl ether as a solvent in the Grignard reaction. The advantages are it is comparatively inexpensive, it can be handled without excessive loss due to evaporation, simple distillation gives an ether free from moisture and alcohol, and the vapour does not form explosive mixtures with air. w-Butyl ether cannot, of course, be employed when the boiling point of the neutral reaction product is close to 140 . 

In his initial paper in 1975, D6tz reported that the thermal cycloaddition of pentacar-bonyl(methoxyphenylcarbene)chromium with diphenylacetylene in di-n-butyl ether yielded a chromium-complexed 4-methoxy-l-naphthol [2]. Soon thereafter, he related that the same reactants in w-heptane produced not only naphthol product, but also indene, furan, and cyclobutenone products [4]. As it turned out, these results foreshadowed the extraordinary richness of organic structural types that may be derived from cycloadditions of alkynes with Fischer carbenes, as well as very recent contributions to reaction chemoselectivity through control of reaction conditions. Indeed, in the years since, the field has seen the introduction of a number of newly discovered cycloaddition types and, maybe more importantly, has... 

Kovach in, J. W. Seider, W. D. Vapor-liquid and liquid-Uquid equilibria for the system sec-butyl alcohol - di-sec-butyl ether - water. J. Chem. Eng. Data 1988, 33, 16-20. 

Glyoxal-sodium bisulfite, 30, 86 Glyoxylic acid, w-butyl ester, 35, 18 ethyl ester, diethyl acetal, 35, 59 Grignard reaction, addition to ethyl sec-butylidenecyanoacetate, 35, 7 allylmagnesium bromide with of,(3-di-bromoethyl ethyl ether, 36, 61 allylmagnesium chloride with a,/3-di-bromoethyl ethyl ether, 36, 63 ethylmagnesium bromide with tin tetrachloride, 36, 86... 

Tribromo-2 4-diphenylselenophene, C16H9Br3Se, may b< obtained by direct bromination of 2 4-diphenylselenophene, usinj 1 5 grams of the latter to 10 grams of bromine in glacial acetic aci< solution, or by the action of bromine in the presence of water upo] 5-chloromercuri-2 4-diphenylselenophene. It separates from glacia acetic acid as transparent, pale straw-coloured needles, M.pt. 126 7° C (corr.), the yield by the first process being about 36 per cent. It dis solves in ethyl and w-butyl alcohols, acetone or ether, but is practicall insoluble in water. 

CAS 109-46-6 EINECS/ELINCS 203-674-6 Synonyms DBTU 1,3-Dibutyl-2-thiourea 1,3-Di-n-butyl-2-thiourea Di-n-butylthiourea N,N -Dibutylthiourea Empincal C9H20N2S Formula C4H9NHCSNHC4H9 Properties Wh. to It. tan powd. odorless sol. in methanol, ether, acetone, benzene, ethyl acetate, oxygenated soivs. si. sol. in water insol. in gasoline, aliphatic soivs. m.w. 188.34 dens. 1.0 kg/l m.p. 59-69 C... 

Sym. dimethylhydrazine in ether added gradually with stirring during 15 min. below 5° to a mixture of 2 moles valeraldehyde, anhydrous Mg-sulfate, and anhydrous ether, the product isolated after 1 hr. stirring 2,5-di-Ji-butyl-3,4-dimethyl-l,3,4-oxadiazolidine. Y 75%. F. e. s. B. Zwanenburg, W.E. Weening, and J. Strating, R. 83, 877 (1964). 

A mixture of 1 mole phenyl isocyanide and 2 moles p-chlorobenzaldehyde in ether or tetrahydrofuran added dropwise to 1 mole tri-n-butylborane -> 2,2-di-n-butyl-4,5-di-p-chlorophenyl-3-phenyloxazolidine. Y 72%. G. Hesse, H. Witte, and W. Gulden, Ang. Gh. 77, 591 (1965). 

Mono-ix-butyl ether pi-p. 81-2°. Mono-aeo.-wUyl ether m.p. 85-6°. Di-n-Myl edher m.p. 58°. Mono -n-heptyl ether i m.p. 82-3°. Di-n-heptyl ether m.p. 56°. Monio-n-oayl ether m.p. 88 . Di-n-oetyl ether m.p. W°. 

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