Organic Syntheses, Coll. Vol. 2, p.602 (1943); Vol. 11, p.98 (1931).
In a 3-l. three-necked flask
, fitted with a mechanical stirrer
, a 500-cc. separatory funnel
, and an efficient reflux condenser
to which a calcium chloride tube
is attached, are placed 107 g. (4.4 gram atoms) of magnesium turnings
and 800 cc. of anhydrous ether
. The reaction is started by adding 5 cc. (7 g., 0.06 mole) of ethyl bromide (Note 1)
without stirring. The stirrer is started, and a solution of 480 g. (4.4 moles) of ethyl bromide in 1 l. of anhydrous ether
is added as rapidly as the refluxing of the ether
allows. The addition requires about two hours (Note 2)
. The reaction is practically complete when all the halide has been added, but stirring should be continued for fifteen minutes longer.
A solution of 156 g. (1.32 moles) of ethyl carbonate (Note 3) in 200 cc. of ether
is added to the Grignard reagent
, with rapid stirring, over a period of approximately three hours. The reaction is vigorous, and the ether
refluxes continually. After all the diethyl carbonate
has been added, the flask is heated on a water bath
and stirring is continued for another hour.
The reaction mixture is hydrolyzed by pouring it, with frequent shaking, into a 5-l. round-bottomed flask
containing 1.5 kg. of cracked ice and a solution of 300 g. of ammonium chloride in 600 cc. of water
. The ether
layer is separated in a large separatory funnel
, and the aqueous residue is extracted with two 500-cc. portions of ether (Note 4)
is distilled from the combined extracts, and the crude triethyl carbinol
is dried with 10 g. of anhydrous potassium carbonate
. The alcohol is then distilled at atmospheric pressure, and the portion (80–90 g.
) boiling at 139–142°
is collected. The low-boiling distillate is treated with 5 g. of anhydrous potassium carbonate
, filtered, and redistilled, whereby another portion (about 25 g.
) of triethyl carbinol
boiling at 139–142°
is obtained. The process is repeated once, or twice if necessary, and an additional 20 g.
is collected (Note 5)
. The total yield is 125–135 g.
per cent of the theoretical amount) (Note 6)
. Triethyl carbinol
is a viscous liquid with a penetrating, camphor-like odor.
The time of addition may be decreased by cooling the flask externally. A towel is folded in a narrow strip and wrapped about the flask above the ether
line, and cracked ice is packed on top of the flask. This arrangement allows the ether
vapor to be condensed without appreciable cooling of the reaction mixture.
The commercial "99 per cent" ester was used. It was purified according to the description given in Note 2 on p. 283
In checking this preparation the first drying was allowed to continue for fifteen hours. The first fractionation of the carbinol yielded 122 g.
, the second 10 g.
, and the third yielded none.
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