Org. Synth. 1950, 30, 22
DOI: 10.15227/orgsyn.030.0022
CHLOROACETONITRILE
[Acetonitrile, chloro-]
Submitted by D. B. Reisner and E. C. Horning
1.
Checked by R. L. Shriner and Calvin N. Wolf.
1. Procedure
In a
3-l. round-bottomed three-necked flask fitted with an
efficient mechanical stirrer, a
reflux condenser, and a
thermometer are placed
170 g. (1.2 moles) of phosphorus pentoxide,
187 g. (2 moles) of chloroacetamide2 (Note 1), and
800 ml. of dry technical trimethylbenzene (Note 2). The mixture is refluxed gently with vigorous stirring for 1 hour. The reaction mixture is then allowed to cool to about 100° with continuous stirring, and the reflux condenser is replaced with a
distilling adapter fitted with a thermometer and a
water-cooled condenser.
The crude product and part of the solvent are distilled at atmospheric pressure (Note 3). The yield of crude product boiling at 124–128° is 121–131 g. (80–87%) (nD25 1.441–1.444). In order to obtain a pure product, the crude chloroacetonitrile is mixed with 10 g. of phosphorus pentoxide and redistilled through an efficient packed fractionating column (Note 4). The yield of pure chloroacetonitrile distilling at 123–124° is 93–106 g. (62–70%) (Note 5).
2. Notes
1.
The
practical grade of chloroacetamide obtainable from the Eastman Kodak Company can be used.
2.
Technical
trimethylbenzene with a boiling range of
166–174° is satisfactory.
3.
About 200 ml. of solvent can be recovered. The remainder is left in the flask to facilitate removal of the residue.
4.
A
Fenske column packed with glass helices previously described in
Organic Syntheses3 is satisfactory. The product has
nD20 1.426,
d420 1.1896, in good agreement with reported values.
4 When a
Vigreux column was used the distillate had
d420 1.072 and
nD25 1.430–1.436, indicating incomplete separation from the trimethylbenzenes (
1,3,5-trimethylbenzene has
d420 0.86;
nD25 1.494).
5.
The product can also be distilled under reduced pressure; b.p.
60–61°/100 mm.;
30–32°/15 mm.
3. Discussion
Practical syntheses of
chloroacetonitrile depend upon dehydration of
chloroacetamide with
phosphorus pentoxide. The present method uses a liquid reaction medium; in previous procedures the dry reagents were heated in the absence of solvent or liquid medium.
5,6
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
CHLOROACETAMIDE (79-07-2)
1,3,5-trimethylbenzene (108-67-8)
trimethylbenzene (526-73-8)
Chloroacetonitrile,
Acetonitrile, chloro- (107-14-2)
phosphorus pentoxide (1314-56-3)
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