Org. Synth. 1928, 8, 52
Submitted by Charles F. H. Allen
Checked by C. S. Marvel and C. G. Gauerke.
In a 2-l. three-necked, round-bottomed flask, fitted with a stirrer, a reflux condenser and a separatory funnel are placed 82 g. (1.2 moles) of potassium cyanide (95 per cent) (Note 1) and 100 cc. of water. The mixture is warmed and stirred until the cyanide is completely dissolved. To this solution is added 350 cc. of 95 per cent alcohol, followed by 158 g. (1 mole) of trimethylene chlorobromide (Note 2), and the mixture is heated under a reflux condenser (best on a water bath) with stirring for about one and one-half hours.
The solution is cooled and then diluted with 450 cc. of water. The oily layer of chloronitrile is collected in about 80 cc. of chloroform and separated from the water solution. The chloroform solution is washed with about 125–150 cc. of calcium chloride solution (prepared by adding one volume of water to an equal volume of a saturated solution of crystallized calcium chloride) and once with 125–150 cc. of water, and then dried over fused calcium chloride.
The dried solution is then fractionally distilled in a modified 100-cc. Claisen flask (p. 130)
. The chloroform
is removed by distilling at ordinary pressure until the temperature reaches 120° (Note 3)
. The remainder may be fractionated under ordinary pressure but it is better to use reduced pressure. After two or three distillations the yield of pure product boiling at 93–96°/26 mm. (Note 4)
and (Note 5)
is 42–49 g.
per cent of the theoretical amount based on the chlorobromide used, or 40–47
per cent based on the total amount of chlorobromide taken) (Note 5)
and (Note 6)
An equivalent amount (58 g., 1.2 moles) of sodium cyanide
dissolved in 90 cc. of water may be used instead of the potassium salt
without materially altering the yields.
The trimethylene chlorobromide
used boiled at 142–147°
. It may be prepared in 75–85
per cent yields from trimethylene chlorohydrin (p. 533)
by the general method for the preparation of alkyl bromides described on p. 25
. Directions are also available1
for its preparation in higher yields by the action of phosphorus tribromide
on trimethylene chlorohydrin
fraction has a very strong odor of isonitrile
. Only a trace is noted in the redistilled product.
When the distillation is carried out under ordinary pressures (about 745 mm.) the product boils at 194–197°
The lower-boiling fraction is mainly unchanged trimethylene chlorobromide
and amounts to 15–20 g.
It may be refractionated or used directly in a subsequent run. The high-boiling residue is mainly trimethylene cyanide
. If the residues from several runs are combined and redistilled, an average of 6–7 g.
per run of product boiling at 160–165°/26 mm.
Larger runs have been made and the yields are proportional; thus a five-mole run gives 210–245 g.
and 30–35 g.
of trimethylene cyanide
has always been prepared by the action of potassium cyanide
on trimethylene chlorobromide
This preparation is referenced from:
Chemical Abstracts Nomenclature (Collective Index Number);
calcium chloride (10043-52-4)
sodium cyanide (143-33-9)
phosphorus tribromide (7789-60-8)
potassium cyanide (151-50-8)
Trimethylene chlorobromide (109-70-6)
Trimethylene chlorohydrin (627-30-5)
Trimethylene cyanide (544-13-8)
potassium salt (140-89-6)
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