Organic Syntheses, CV 1, 220
Submitted by Marston T. Bogert and Arthur Stull.
Checked by Frank C. Whitmore, W. F. Singleton, and F. E. Smith.
1. Procedure
In a
3-l. round-bottomed flask fitted with a
reflux condenser are placed
360 g. (1.5 moles) of crystalline sodium sulfide (Note
1) and
1.5 l. of 95 per cent alcohol. The flask is heated on a
steam bath until the sulfide dissolves. Then
48 g. (1.5 atoms) of finely ground sulfur is added, and the heating is continued until the
sulfur has dissolved, forming a brownish-red solution of
sodium disulfide (Note
2). A solution of
315 g. (2 moles) of ochloronitrobenzene (Note
3) in
500 cc. of 95 per cent alcohol is prepared in a
5-l. round-bottomed flask fitted with a reflux condenser. The
sodium disulfide solution is added slowly to this solution through a
funnel placed in the top of the reflux condenser. The addition should be slow until the violence of the reaction abates somewhat.
The mixture is then heated on a steam bath, gently at first (Note
4), and then at full heat for two hours. After cooling, it is filtered by suction. The mixture of the organic disulfide and the
sodium chloride is transferred to a
1-l. beaker and stirred thoroughly with 500 cc. of water to remove the
sodium chloride. It is then filtered by suction and the crystalline residue is washed on the filter with
100 cc. of alcohol to remove any
o-chloronitrobenzene. The product melting at
192–195° weighs
180–210 g. (
58–66 per cent of the theoretical amount).
2. Notes
1. Crystals as dry as possible should be selected. If desired, an equivalent amount of analyzed fused
sodium sulfide may be used. In this case, solution takes a longer time. Since an excess of
sodium sulfide is added, slight inaccuracies in the amount used are not important.
2. In case a small amount of
sodium disulfide separates in a layer at the bottom, it should be taken up with a little more alcohol and added to the
chloronitrobenzene solution.
4. If too much heat is applied at first, the reaction becomes very violent.
3. Discussion
This preparation is referenced from:
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