A solution of
138 g. (175 ml., 3 moles) of absolute ethanol (Note
1) and
447 g. (477 ml., 3 moles) of freshly distilled diethylaniline in
1 l. of dry petroleum ether (b.p.
40–60°) is placed in a
3-l. three-necked flask fitted with a sealed stirrer, an
efficient reflux condenser, and a
500-ml. dropping funnel (Note
2) which is charged with a solution of
137.5 g. (87.5 ml., 1 mole) of freshly distilled phosphorus trichloride in
400 ml. of dry petroleum ether (b.p.
40–60°). The flask is cooled in a
cold-water bath. With vigorous stirring (Note
3), the
phosphorus trichloride solution is introduced at such a rate that the mixture boils gently towards the end of the addition. After the addition, which requires about 30 minutes, the mixture is heated under gentle reflux for about 1 hour with stirring. The suspension, containing a copious precipitate of
diethylaniline hydrochloride, is then cooled and filtered with suction through a
sintered-glass funnel. The cake of the amine salt is well compressed and washed with five
100-ml. portions of dry petroleum ether (b.p.
40–60°). The filtrate and washings are combined and concentrated by distillation at water-bath temperature through a
75-cm. Vigreux column. The residue is transferred to a
pear-shaped flask and distilled under water-pump vacuum through a 75-cm. Vigreux column. After a small fore-run, the product is collected at
57–58°/16 mm. (
51–52°/13 mm.,
43–44°/10 mm.). The yield of colorless product is
138 g. (
83%),
nD25 1.4104–1.4106,
d420 0.963 (Note
4) and (Note
5).