Drying, diethyl ether

In the flask were placed 800 ml (note 1) of dry diethyl ether. Twenty grams of lithium (note 2) were flattened (thickness about 1 mm) with a hammer (note 3) and cut into small pieces (about 10 x 2 1 mm ), which were introduced at the same time into the flask. The contents of the flask were cooled to -30°C, after the air in the flask had been replaced with nitrogen. From the dropping funnel, which contained 1.12 mol of ethyl bromide, were added 10-15 g of ethyl bromide. 

The flask was charged with 48 g of magnesium and 200 ml of dry diethyl ether. 1,2-Dibromoethane (4 ml) was added. After a few minutes a vigorous reaction started and the diethyl ether began to reflux. When this reaction had subsided, 500 ml of dry diethyl ether were added. Stirring was started and 1.0 mol of chlorocyclohexane (note 1) was added from the dropping funnel at a rate such that the diethyl ether gently refluxed (note 2). After this addition, which was carried out in 1 h, the flask was heated under reflux for a further 1 h. 

A mixture of 0.40 mol of propargyl chloride and 150ml of dry diethyl ether was cooled at -90°C (liquid nitrogen bath) and a solution of 0.40 mol of ethyl-lithium (note 1) in about 350 ml of diethyl ether (see Exp. 1) was added with vigorous stirring and occasional cooling (note 2). The temperature of the reaction mixture was kept between -70 and -90°C. The formation of the lithium derivative proceeded almost instantaneously, so that the solution obtained could be used directly after the addition of the ethyl 1ithium, which was carried out in 15-20 min. This lithium acetylide solution is very unstable and must be kept below -60°C. 

A solution of 0.60 mol of ethyllithium (note 1) in about 400 ml of diethyl ether (see Chapter II, Exp. 1) was added in 30 min to a mixture of 0.25 mol of 1,4-diethoxy-2-butyne (see Chapter VIII-6, Exp. 8) and 100 ml of dry diethyl ether. The temperature of the reaction mixture was kept between -40 and -45°C. Fifteen minutes after the addition had been completed, 0.5 mol of methyl iodide was added at -40 C, then 100 ml of dry HMPT (for the purification see ref. 1) were added dropwise in 15 min while keeping the temperature at about -40°C. Thirty minutes after this addition the cooling bath was removed, the temperature was allowed to rise and stirring was continued for 3 h. The mixture was... 

In the flask was placed a solution of 0.44 mol of butyllithium in about 300 ml of hexane. To this solution were added, with coaling below -20°C, 800, 600 and 400 ml of dry diethyl ether (note 1) in the case of R = CH3, C2H5 and tert.-CuHj or Me3Si, respectively. Subsequently 0.46 mol of the alkyne [in the case of R = CH3, C2H5 a cooled (-30°C) solution in 50 ml of diethyl ether] was added in about 10 min, while keeping the temperature below -20 c. The suspension (in the... 

A solution of 0.40 mol of ethyllithium in about 350 ml of diethyl ether (see Chapter II, Exp. 1) was transferred into the flask, which previously had been filled with nitrogen. The solution was cooled to -50°C and a cold solution (-30°C) of 0.43 mol of propyne in 50 ml of dry diethyl ether was added at a rate such that the temperature could be kept below -20°C. A solution of 0.45 mol of cyanogen chloride in 100 ml of diethyl ether, cooled at about 0°C, was then added in... 

To a solution of 0.20 mol of butyllithium in about 140 ml of hexane were added 250 ml of dry diethyl ether below -10°C. Subsequently a solution of 0.25 mol of propyne in 25 ml of ether, cooled below -25°C, was added in 10 min, keeping the temperature of the reaction mixture below -20 C. Powdered sulfur (0.20 at) was... 

A mixture of 0.10 mol of freshly distilled 3-methyl-3-chloro-l-butyne (see Chapter VIII-3, Exp. 5) and 170 ml of dry diethyl ether was cooled to -100°C and 0.10 mol of butyllithium in about 70 ml of hexane was added at this temperature in 10 min. Five minutes later 0.10 mol of dimethyl disulfide was introduced within 1 min with cooling betv/een -100 and -90°C. The cooling bath vjas subsequently removed and the temperature was allowed to rise. Above -25°C the clear light--brown solution became turbid and later a white precipitate was formed. When the temperature had reached lO C, the reaction mixture was hydrolyzed by addition of 200 ml of water. The organic layer and one ethereal extract were dried over potassium carbonate and subsequently concentrated in a water-pump vacuum (bath... 

To a mixture of 0.40 mol of neohexene ( commercially available) and 200 ml of dry diethyl ether 0.35 mol of bromine was added with cooling between -40 and -50°C. The diethyl ether and excess of neohexene were then completely removed by evaporation in a water-pump vacuum.In the second flask was placed a solution of 90 g of commercial KO-tert.-C9H9 (see Chapter IV, Exp. 4, note 2) in 250 ml of DMSO. The dibromo compound was added in five portions during 15 min from the dropping funnel after the addition of each portion the flask was swirled gently in order to effect homogenization. Much heat was evolved and part of the tert.-butylacetylene passed over. After the addition the flask was heated for 30 min in a bath at B0-100°C. 

To a mixture of 0.20 mol of 1,1,4-triethoxy-2-butyne [see Chapter III, Exp. 40), 60 ml of dry THF and 50 ml of dry diethyl ether was added at -45 to -50°C a solution of 0.42 mol of ethyllithium in about 280 ml of diethyl ether (see Chapter II, Exp. 1). Stirring at -5o°C was continued for 30 min, then the reaction mixture was poured into 300 ml of saturated ammonium chloride solution. After shaking, the layers were separated and the aqueous layer was extracted twice with small portions of diethyl ether. The combined ethereal solutions were dried over magnesium sulfate and concentrated in a water-pump vacuum and the residue wasdistilled at about... 

The distillate was dissolved in a mixture of 350 ml of dry diethyl ether and 45 g of dry triethylamine (dried over powdered KQH). Trimethylchlorosilane (45 g) was added in 20 min with cooling at about 10°C. After standing for 1 h at room temperature the precipitate was sucked off on a dry sintered-glass funnel and rinsed with pentane. The filtrate was concentrated in a water-pump vacuum- The small amount of salt which precipitated during this operation was removed by a second suction filtration. Subsequent distillation afforded the trimethyl silyl ether, b.p. 100°C/15 mmHg, 1.4330, in 944 yield. 

The 120 g of residue were dissolved in 350 ml of dry diethyl ether and a solution of 0.35 mol of butyllithium in about 280 ml of hexane was added dropwise during 30 min, while maintaining the temperature at about -60°C. After the addition the temperature was allowed to rise to -25°C and stirring at that temperature was continued for an additional 30 min. The mixture was then poured with swirling into 1 1 of ice-water and the upper layer and two extracts of the aqueous layer were combined and dried over magnesium sulfate. The solvents were removed... 

A mixture of 0.20 mol of the adduct from cyclooctene and dibromocarbene (note 1) and 250 ml of dry diethyl ether was cooled to -65°C. A solution of 0.23 mol of ethyllithium (note 2) in 200 ml of diethyl ether (see Chapter II, Exp. 1) was added in 15 min with cooling between -60 and -50°C. The reaction was very exothermic (note 3). After the addition the cooling bath was removed and the temperature was allowed to rise to about -10°C and the reaction mixture was poured into 200 ml of ice-water. The aqueous layer was extracted twice with diethyl ether. After drying, the solvent was removed in a water-pump vacuum and the remaining liquid was distilled through a 40-cm Vigreux column. 1,2-Cyclononadiene, b.p. 62°C/22 mmHg, 1.5059, was obtained in 86 yield. 

To a mixture of 0.30 mol of l-diethylamino-4-methoxy-2-butyne (see Chapter V, Exp. 15) and 175 ml of dry diethyl ether were added 2.5 g of copper(I) bromide. 

After the air in the flask had been replaced completely with nitrogen, 100 ml of dry diethyl ether, 0.20 mol of the cumulenic ether (see Chapter V, Exps. 7, 8 and 11) and 1 g (note 1) of copper(l) bromide were placed in it. A solution of the Grignard-reagent, prepared from 0.50 mol of the chloride (see Chapter II,... 

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