Organic Syntheses, CV 1, 228
Submitted by H. O. Calvery
Checked by Frank C. Whitmore and R. W. Beattie.
1. Procedure
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 at 130°.
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. (
32–37 per cent of the theoretical amount). The melting point is
121–123°.
2. Notes
3. 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 vapors.
4. In some cases the extraction may not be complete in this length of time.
5. Some
diphenylmercury may be recovered by combining the washings from several runs.
3. Discussion
Copyright © 1921-2002, Organic Syntheses, Inc. All Rights Reserved