Organic Syntheses, Coll. Vol. 1, p.228 (1941); Vol. 9, p.54 (1929).
In a 1-l. round-bottomed flask
fitted with a reflux condenser
are placed 900 g. of 3 per cent sodium amalgam (Note 1)
, 180 g. (1.15 moles) of bromobenzene
, 200 cc. of dry toluene or dry xylene
, and 10 cc. of ethyl acetate
. The mixture is refluxed with frequent shaking for twelve hours in an oil bath
The mixture is transferred (Hood
) (Note 2)
while still hot to a fluted filter paper
in a 20-cm. glass funnel
, leaving behind as much mercury
as possible (Note 3)
. The funnel is made part of a special extraction apparatus as described on p. 375
. The diphenylmercury
is extracted with 600 cc. of boiling benzene
for about ten hours (Note 4)
The solution is distilled under reduced pressure on an oil bath, the temperature of which is raised to 110° near the end of the distillation. The solid residue left in the flask after removal of the solvent is taken out and washed until nearly white with 95 per cent alcohol
which has been cooled in an ice bath
. This requires about four washings of 50 cc. of alcohol
each (Note 5)
. The yield is 65–75 g.
per cent of the theoretical amount). The melting point is 121–123°
Care must be taken to remove all the diphenylmercury
; but if too much mercury
is removed, it may break the filter paper or weight it down so that the benzene
vapors cannot rise around it. It is sometimes best to put stirring rods down around the sides of the paper to insure a free path for the benzene
In some cases the extraction may not be complete in this length of time.
may be recovered by combining the washings from several runs.
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