Diethyl ether, preparation

The lithiation of allene can also be carried out with ethyllithium or butyl-lithium in diethyl ether (prepared from the alkyl bromides), using THF as a cosolvent. The salt suspension which is initially present when the solution of alkyllithium is cooled to -50°C or lower has disappeared almost completely when the reaction between allene and alkyllithium is finished. 

In some experiments the presence of hexane is undesirable in view of the volatility of the products. In these cases one can use butyllithium in pentane (prepared from butyllithium in hexane, by replacing the hexane with pentane see Exp. 10) or ethyllithium in diethyl ether, prepared from ethyl bromide and 11thiurn (see Exp. 1). 

The alkylations proceeded much more slowly, when ethyl- or butyllithium in diethyl ether, prepared from the alkyl bromides, had been used for the metallation of allene, in spite of the presence of THF and HMPT as co-solvents. 

Note 1. Butyl- or ethyllithium in diethyl ether, prepared from the alkyl bromide, contains LiBr, which may react with chlorine to form bromine, so that RCeC-Br will also be formed. 

To a refluxing solution 0. phenylmagnesium bromide in 650 ml of diethyl ether, prepared from 1.15 mol of broraobenzene (see Chapter 11, Exp. 5) was added 1.00 mol of ally] bromide at a rate such that refluxing was maintained (about 30 min). 

A solution of methylmagnesium bromide in 150 ml of diethyl ether, prepared from 0.5 mol of methyl bromide (see Chapter II, Exp. 5) was subsequently added in 20 min with cooling at about 20°C. After the addition the mixture was warmed for 2 h under reflux (the thermometer and gas outlet were replaced with a reflux condenser), a black slurry being formed on the bottom of the flask. The mixture was cooled in a bath of dry-ice and acetone and a solution of 30 g of ammonium chlori.de in 200 ml of water was added with vigorous stirring. The organic layer and four ethereal extracts were combined, dried over potassium carbonate and subsequently concentrated in a water-pump vacuum. Careful distillation of the residue through a 40-cm... 

To a mixture of 0.10 mol of 1-ethoxy-l,2-heptadiene (see this chapter, Exp. 13) and 120 ml of diethyl ether was added 1 g of copper(I) bromide. A solution of butyl magnesium bromide in about 200 ml of diethyl ether, prepared from 0.25 mol of butyl bromide (see Chapter II, Exp. 5) was added in 15 min. The reaction was weakly exothermic and the temperature rose slowly to about 32°C. The mixture was held for an additional 40 min at that temperature, then the black reaction mixture was... 

A solution of diazomethane in diethyl ether, prepared from 5 g (49 mmol) of N-nitrosomethylurea, was added to a cold solution of 4 mmol of the corresponding 2-arylmethylene-l,2,3,4-tetrahydronaphthalen-l-one 1 in 10 ml of benzene, and the mixture was left overnight (Scheme A. 10). The solvent was evaporated and the residue was recrystallized from ethanol. 

Sample preparation 2 mL Plasma + 100 ng tolbutamide + 500 jaL 1 M HCl + 8 mL chloroform, shake on a reciprocal shaker, shake for 10 min in a reciprocal shaker, centrifuge at 2000 g for 15 min. Remove 7 mL of the lower organic layer and evaporate it to dryness under a stream of nitrogen at 45°, reconstitute the residue in 100 (jlL 3 mg mL dinitrofluorobenzene in n-butyl acetate, heat at 120° for 30 min, evaporate to diyness under a stream of nitrogen at 60°, dissolve the residue in 100 p-L mobile phase, inject a 30-70 (jlL aliquot. (Recrystallize dinitrofluorobenzene from diethyl ether. Prepare solutions weekly, store at 4° in the dark.)... 

Lithium aluminum deuteride (LiAlpH4]) solution-1.05 g of LiAlpH4] in 33 mL of dry diethyl ether prepare in a Soxhelet extraction thimble attached to a round-bottomed flask. 

Note 2. Commercial butyllithium in hexane as solvent or butylllthium in diethyl ether, prepared from butyl bromide and lithium, can also be used in principle, but we prefer to use ethyllithium because hexane is not easily separable from the rather volatile cumulenic ether and during the reaction of butyl bromide with lithium some octane is formed which cannot be separated from ethoxybutatriene. 

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