Organic Syntheses, CV 1, 231
Submitted by F. C. Whitmore, N. Thurman, and Frances H. Hamilton.
Checked by J. B. Conant and F. C. Whidden.
1. Procedure
In a
2-l. round-bottomed flask fitted with a
reflux condenser and an
efficient glass stirrer, are placed
700 cc. of 95 per cent ethyl alcohol,
100 g. (0.3 mole) of recrystallized p-tolylmercuric chloride (p. 519), and
160 g. (1.1 moles) of sodium iodide (Note 1) (75 per cent excess). The mixture is boiled with vigorous stirring (Note
2) for fifteen hours; the solid does not entirely enter into solution at any time. The mixture is then thoroughly cooled and filtered by suction and the solid washed with water until free of inorganic halide. It is then dried in an
air oven at 40° and recrystallized from
500 cc. of boiling xylene (Note
3). In this way
45–50 g. (
78–85 per cent of the theoretical amount) of a product melting at
238° is obtained.
2. Notes
1. Mercury compounds of the type RHgX can be changed to those of the type R
2Hg, by almost any neutral or alkaline reagent which tends to change
mercuric ions to
metallic mercury or to a stable complex ion. Some of these reagents are
inorganic iodides, thiocyanates, thiosulfates, sulfides, hydrosulfites, ferrous hydroxide, sodium amalgam, metallic sodium, and sodium stannite. Preliminary experiments indicated that
potassium thiocyanate was a good reagent for preparing
di-p-tolylmercury; but it was later found that the use of
sodium iodide with vigorous stirring gave even better results.
2. Stirring decreases the time required for the reaction and increases the yield. Without stirring it is practically impossible to obtain a product which is free from halogen.
3. Since the
di-p-tolylmercury has practically the same solubility in
xylene as the
tolylmercuric iodide and chloride, the latter will be present in the recrystallized product if the reaction has not gone to completion. A trace of unchanged product may readily be detected by the
metallic sodium test for inorganic halides.
3. Discussion
This preparation is referenced from:
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