Pentane yields

Evaporation to dryness under reduced pressure gives 20.9-22.1 g. (90-95%) of crude product. Purification by recrystallization from 500 ml. of pentane yields 15.5 g. (67%) of p-nitrobenzyl fluoride as colorless needle-shaped crystals, m.p. 36-37 (Note 2). 

The organic layer is separated, evaporated on a steam bath, and the dark semicrystalline residue is distilled with steam to remove biphenyl. The contents of the steam-distillation flask are then extracted with ether (Note 3), and the ethereal layer is separated, dried over magnesium sulfate, and percolated through a short column of chromatographic alumina (Notes 4 and 5). Evaporation of the ethereal solution gives crude triphenylene which is sublimed at 175-180° and 0.1 mm. pressure. After rejection of an initial sublimate of impure biphenyl, the sublimed material forms nearly colorless crystals, m.p. 186-194° (Note 6). Yield 8-9 g. (53-59%). It may be further purified by recrystallization from a mixture of methylene chloride and pentane yielding colorless crystals, m.p. 199° (Note 7). 

The product, isolated as above, is dissolved in pentane solution and chromatographed on 100 g of alumina. The initial fraction eluted with pentane, yields 1.02 g (48%) of 2,2-dimethyl-5a-cholestan-3-one mp 111-113°, after crystallization from ether-methanol. The subsequent fraction, eluted with pentane and pentane-benzene (9 1) gives 0.12 g (6%) of 2a-methyl-5a-cholestan-3-one mp 119-120°, after crystallization from methanol-ether. 

Phenylquinoline 1-oxide (10.0 g, 45.2 mmol) in acetone (1.25 L) was irradiated for 12 h with a Hanovia Q-700 medium-pressure Hg lamp, equipped with a Pyrex cooling mantle placed in the center of the reaction vessel, when TLC showed the absence of starting material. The solution was evaporated in vacuo and the residue was extracted with boiling hexane. The extract was evaporated under reduced pressure and the residue was crystallized (pentane) yield 9.0 g (90%) mp 65-66 C. 

Irradiation of a 1 1 molar mixture of benzene and butadiene (—80°C in pentane) yielded only (55). Alkylbenzenes are reported to yield similar products with butadiene although structures were not identified/72 ... 

Klabunde (JJL) was the first to describe alkane activation by metal atoms. He showed that cocondensation of nickel atoms and pentane yielded a solid material which contained Ni,C and H. 

Solvent Conversion (%) pent-l-ene Yield (%) pentane Yield (%) pent-2-ene TOF (min )... 

The photochemical reaction of bis(hydridodimethylgermyl)methane/ethane, HMe2Ge (CH2) GeMe2H (n = 1, 2) with metal carbonyls of Fe, Co and Ru in pentane yielded a series of cyclic derivatives 1 and 273-79. 

Bis[di-t-bntylphosphano] Tellurium5 Disodium telluride is prepared from 5.4 g (22 mmol) of sodium and 16.6 g (13 mmol) of tellurium and suspended in 100 ml of toluene. A solution of 3.7 g(20 mmol) ofchlorodi-t-butylphosphane in 50 ml of toluene is added to the suspension and the mixture is stirred for 12 h. The resultant mixture is filtered and the solid is washed with toluene. The filtrate and washings are combined, the solvent is removed under reduced pressure, and the residue is recrystallized from pentane yield 32 g (80%) m.p. 77°. 

Pentacarbonyl(diphenyl telluroketone)tungsten(II)3 Under dry nitrogen solutions of 980 mg (2 mmol) of pentacarbonyl(diphenylmethylene)tungsten in 20 ml of dichloromethane and of 1.38 g (2 mmol) of bis[triphenylphosphine]iminium tellurocyanate in 10 ml of dichloromethane, both at — 90°, are combined and stirred for 10 min at that temperature- The mixture is then chromatographed on silica gel at — 50° with pentane/dichloromethane (10 1 v/v) as the mobile phase. The blue fractions are collected, the solvent is distilled under high vacuum, and the residue is recrystallized from pentane, yield 220 mg (18%) m.p. 35° (dec.). 

Diphenyl Tellurium Bis[4-methylphenoxide]5 1.85 g (5 mmol) of diphenyl tellurium diethoxide are dissolved in 60 ml of diethyl ether/pentane and the solution is stirred under an atmosphere of dry nitrogen. A solution of 1.08 g (10 mmol) of 4-methylphenol dissolved in diethyl ether is added dropwise and the mixture is stirred at 20" for 12 h. The white precipitate is filtered offand recrystallized from chloroform/pentane yield 1.5 g (61%) m.p. 148". 

Attempts to generate a Cu(i) complex by reacting the sterically hindered potentially tridentate 1,5-diazocine 67 with one phenolate and two amine donors, with CuCl or [Cu(MeCN)4]X (X = C104 or Sbl 6 ) under an inert atmosphere in a variety of solvents only led to green mixtures indicative of disproportionation. However, treatment of 67 with CuxMesx (X = 2 and 5) in THF under stringent anaerobic conditions, followed by precipitation with pentane yielded the complex 68, as a white powder (Equation 2) <1998CC2521>. 

A solution of 2.75 g (0.025 mol) of a f/-bicyclo[2.2.1]hept-2-cn-7-ol in 20 mL of pentane is slowly added to freshly distilled 3.57 g (0.03 mol) of phenyl azide and the solution is allowed to stand in the dark for4d. T he solution is concentrated under reduced pressure and the solid product recrystallized to give colorless needles from Et20/pentane yield 85% mp 187-188°C. 

The crude product may be purified by vacuum distillation or by crystallization from degassed pentane at 0°.t A single crystallization from pentane yields 31 g (57%) of analytically pure (C6H5)2PCH2CH2P(H)C6H5. Anal Calcd. for C20H20P2 C, 74.5 H, 6.2 P, 19.2. Found C, 74.3 H, 6.1 P, 19.3. 

Preparation. The cr-chloronitrone is prepared by reaction of a-chloropropanaP with N-cyclohexylhydroxylaminc (Fluka) in dry ether at 0° after the second hour additional ether and methylene chloride are added. The solution is allowed to stand for 15 hr. over MgSO at 0°. After filtration of the drying agent, the solvent is removed and the product crystallized from ethane-pentane. Yield is 79%. The reagent is stable... 

Extraction of tar sands with benzene or toluene yields a bitumen fraction and a mineral fraction. Further treatment of the bitumen with heptane or n-pentane yields asphaltenes and petrolene, which are the insoluble and soluble fractions, respectively. Depending on the source, these fractions contain varying amounts of vanadium (117,118). 

Fmoc-Asp(OtBu)-OH or Fmoc-Glu(OtBu)-OH was refluxed in neat allyl bromide (5mL-g Fmoc derivative) in the presence of DIPEA (2 equiv with respect to the Fmoc derivative) for 30 min. The mixture was diluted with EtOAc, extracted successively with 0.1 M HCl, carbonate buffer (pH 9.5), and brine. The soln was dried (MgS04) and the solvent removed. The solid was dissolved in TFACH2CI2 (1 1), and after 30min, the solvent was removed to provide a solid which was recrystallized (Et20/ pentane) yield of Fmoc-Asp-OAl 84% mp 92-93 °C yield of Fmoc-Glu-OAl 66% mp 120-121 °C. 

It was also of interest to establish the fate of acids, bases, and neutral nitrogen compounds on silica and alumina. For this purpose, the acids, bases, and neutral nitrogen compounds isolated on ion exchangers and Fe /clay, respectively, were applied on a silica column. Elution of hydrocarbons with n-pentane yielded 0.29% material, which was separated on alumina into mono + diaromatics (0.1%) and polyaromatics (0.24% ) (Figure 4). Thus, if ion exchangers and the Fe /clay column are omitted, there remains only about 0.8% impurities stemming from acid and base fractions present in the total mono- and diaromatic fractions. 

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