Cyclohexanes ethers

Anionic polymerization of vinyl monomers can be effected with a variety of organometaUic compounds alkyllithium compounds are the most useful class (1,33—35). A variety of simple alkyllithium compounds are available commercially. Most simple alkyllithium compounds are soluble in hydrocarbon solvents such as hexane and cyclohexane and they can be prepared by reaction of the corresponding alkyl chlorides with lithium metal. Methyllithium [917-54-4] and phenyllithium [591-51-5] are available in diethyl ether and cyclohexane—ether solutions, respectively, because they are not soluble in hydrocarbon solvents vinyllithium [917-57-7] and allyllithium [3052-45-7] are also insoluble in hydrocarbon solutions and can only be prepared in ether solutions (38,39). Hydrocarbon-soluble alkyllithium initiators are used directiy to initiate polymerization of styrene and diene monomers quantitatively one unique aspect of hthium-based initiators in hydrocarbon solution is that elastomeric polydienes with high 1,4-microstmcture are obtained (1,24,33—37). Certain alkyllithium compounds can be purified by recrystallization (ethyllithium), sublimation (ethyllithium, /-butyUithium [594-19-4] isopropyllithium [2417-93-8] or distillation (j -butyUithium) (40,41). Unfortunately, / -butyUithium is noncrystaUine and too high boiling to be purified by distiUation (38). Since methyllithium and phenyllithium are crystalline soUds which are insoluble in hydrocarbon solution, they can be precipitated into these solutions and then redissolved in appropriate polar solvents (42,43). OrganometaUic compounds of other alkaU metals are insoluble in hydrocarbon solution and possess negligible vapor pressures as expected for salt-like compounds. 

Phenyllithium ("2.0 M" in cyclohexane/ether, 70/30, found to be 1.8 M by titration as described in Note 3) was obtained from the Aldrich Chemical Company, Inc., as a black solution and was added to the solution of fluorenone via Teflon cannula under positive nitrogen pressure. 

The hot cyclohexane layer is carefully decanted, and the aluminum bromide layer is extracted with five 200-ml. portions of hot cyclohexane. Ether (400 ml.) is added to the cooled cyclohexane extracts (Note 11), and the combined solvent fractions are washed with two 100-ml. portions of water and dried over anhydrous magnesium sulfate. Evaporation of the solvent leaves a semi-solid residue that is partially dissolved in about 100 ml. of pentane. The undissolved white solid, diamantane, is collected by suction filtration. Additional diamantane is obtained by concentrating the pentane solution to a small volume and collecting the solid that precipitates. The total amount of diamantane obtained, after drying, is 60-62 g. (60-62%), m.p. 240-241° (closed tube) (Note 12). This product is sufficiently pure for most purposes, but it may be purified further by recrystallization from pentane to give white crystals, m.p. 244.0-245.4°. 

Methylene iodide is a very heavy, highly refractive liquid, which darkens on exposure to light, air, and moisture. It has a melting point of 6 Celsius, and a boiling point of 181 Celsius. Methylene iodide is insoluble in water, but is miscible with alcohol, hexane, cyclohexane, ether, chloroform, and benzene. It dissolves sulfur and phosphorus. Methylene iodide is prepared by reacting iodoform with sodium arsenite, or by heating iodoform with sodium acetate in 95% ethanol. 

Fi = cyclohexane-ether (80 20, by volume) Fj = benzene F3 = chloroform. All-trans compounds. 

As an example, it is difficult to distinguish the structures of the protonated molecules MH produced from isomeric compounds with the elemental formula CgHioO (cyclohexanone, cyclohexane oxide and 1,4-cyclohexane ether) [152] on the basis of their respective unimolecular decomposition spectra. Indeed, only the loss of water was observed in the MIKE spectra of these products. Collision-induced decomposition spectra (MIKE/CAD), on the other hand, lead to an easy structural distinction (Fig. 28). 

Figure 28. MIKE/CAD spectra of various protonated molecules of 1,4-cyclohexane ether (a), cyclohexanone (b) and cyclohexane oxide (c) produced under tC4,H9/CI [152].

Arylmethyl cleavage reactions have also been studied in less polar solvents like saturated hydrocarbons (hexane, cyclohexane), ethers (diethyl ether, tetrahy-drofiiran, dioxane), and methylene chloride. In these solvents, ion pair chemistry is less likely and valuable information can be obtained about the photogenerated radical pairs. 

The reactions of biacetyl in fluorocarbons and mineral oil parallel the gas phase except that quantum yields were appreciably reduced 61>. Hydrogen abstraction is the major process in less inert solvents but products containing an acetyl group (e. g. acetylcyclohexane) were observed 20> to an appreciable extent from irradiations in cyclohexane, ether, and dioxane cyclohexene, ethylbenzene, and 2-propanol reacted only by H-abstraction. Photoirradiation of biacetyl and phenylacetic or phenoxyacetic acid in acid medium produced 12> benzyl methyl ketone... 

Mass fractions (in percent) of the mineral component, the water-soluble components, and the total organic material soluble in acetone, cyclohexane, ether and/or methanol. From Winkler (1974). 

Fig. 7-19. Distribution of water-soluble (ws), organic solvent-soluble (os), and insoluble mass fractions associated with the rural continental aerosol at Deuselbach, West Germany, according to measurements of Winkler (1974). The organic fraction comprises material soluble in cyclohexane, ether, acetone, and part of the methanol-soluble fraction. The uncertainty range assumes that 0-40% of the methanol-soluble fraction contains organic compounds, and the remainder is due to inorganic salts. The water-soluble fraction of organics averages about 0.66 for all size ranges combined.

AZOTE (French) (10102-44-0) A powerful oxidizer. Reacts with water, forming nitric acid and oxygen. Violent reaction with strong reducing agents, anhydrous ammonia, alcohols, chlorinated hydrocarbons, cyclohexane, ethers, fluorine, formaldehyde, fuels, nitrobenzene, oxygen difluoride, petroleum, sodium, toluene. Incompatible with combustible materials, red phosphorus, petroleum products. Forms explosive material with propylene. Vapor reacts violently with phospham. Attacks many metals in the presence of moisture. 

Oligomers Benzene, chloroform, THE Acetone, hexane, cyclohexane, ether, carbon tetrachloride, MIBK, isobutyl ether (3)... 

Solvent Chloroform Benzene Benzene/ methanol 98 2 Petroleum ether/ether 85 15 Cyclohexane/ ether 4 1... 

A soln. of N-methoxy-N,N N -trimethylurea in tetrahydrofuran added dropwise with stirring over 9 min to a 2 M soln. of phenyllithium in cyclohexane/ether and tetrahydrofuran at —78° under N2, stirred for 1.5 h, a 2.44 M soln. of /i-butyllithium in hexanes added at the same temp., the cooling bath removed, and stirred at room temp, for 2 h valerophenone. Y 60%. Best results were obtained when aryl- and hetaryl-lithiums were added first Grignard compds. were less effective. F.e. incl. sym. ketones s. D.J. Hlasta, J.J. Court, Tetrahedron Letters 30, 1773-9 (1989). 

Fig. 110. Solvent purity. Residue from evaporation of 400 ml applied and chromatographed with cyclohexane-ether (80 + 20). Chromatogram photographed after spraying with molybdophosphoric acid reagent and heating. 1 peroxide-free ether ...

Fig. 111. Oils in which fat-soluble vitamins are dissolved. Solvent cyclohexane-ether (50 + 50). Chromatogram photographed in UV light (365 nm) after spraying with cone, sulphuric acid and heating. 500 xg of each applied 1 peanut oil 2 cottonseed oil 3 wheat-germ oil...

Fig. 112. Stability of vitamin A-acetate on silica gel. Solvent cyclohexane-ether-pyridine (79 + 20 + 1). Chromatogram photographed in UV light (365 nm). 30 (xg amounts applied at intervals and chromatographed after 5 min (2), 3 min (2),...

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