Org. Synth. 1959, 39, 73
DOI: 10.15227/orgsyn.039.0073
α,α,β-TRIPHENYLPROPIONITRILE
[Propionitrile, 2,2,3-triphenyl-]
Submitted by C. R. Hauser and W. R. Dunnavant
1.
Checked by Virgil Boekelheide and Donald R. Arnold.
1. Procedure
Caution! This preparation should be conducted in a hood to avoid exposure to ammonia.
A suspension of potassium amide (0.23 mole) in liquid ammonia is prepared in a 1-l. three-necked flask equipped with an air condenser (without drying tube), a ball-sealed mechanical stirrer, and a dropping funnel. Commercial anhydrous liquid ammonia (500 ml.) is introduced into the flask from a cylinder through an inlet tube. To the stirred ammonia is added a small piece of potassium metal. After the appearance of a blue color, a few crystals (about 0.25 g.) of ferric nitrate hydrate are added, followed by small pieces of potassium (Note 1) until 9.0 g. (0.23 g. atom) has been added. After all the potassium has been converted to the amide (Note 2), 44.6 g. (0.23 mole) of diphenylacetonitrile (Note 3) is added and the resulting greenish-brown solution is stirred for 5 minutes. To this is added, over 10 minutes, 30.5 g. (0.24 mole) of benzyl chloride (Note 4) in 100 ml. of anhydrous ether. The orange solution is stirred for 1 hour, and the ammonia is then evaporated on a steam bath as 300 ml. of anhydrous ether is being added. To the ether solution is added 300 ml. of water, whereupon the crude nitrile precipitates. The ether is then removed by distillation and the crude nitrile is collected on a Büchner funnel. The yield of crude, light-tan α,α,β-triphenylpropionitrile is 64 g. (98–99%). The nitrile is dissolved in 1.3 l. of hot ethanol, treated with Norit, and filtered. The filtrate is held at room temperature overnight, and the product collected by filtration. A second crop is obtained by concentration of the mother liquor. The total yield of α,α,β-triphenylpropionitrile, m.p. 126.5–127.5°, is 62.2–65.5 g. (95–99% yield) (Note 5).
2. Notes
1.
The
potassium is cut in about 0.5-g. pieces, stored under kerosene, and blotted with
filter paper before addition.
2.
Conversion is indicated by the discharge of the deep-blue color. This generally requires about 20 minutes.
3.
Diphenylacetonitrile supplied by the Eastman Kodak Company was used without purification.
4.
Eastman Kodak Company practical grade benzyl chloride was vacuum-distilled; the fraction, b.p.
63°/12 mm., was used.
5.
Under comparable conditions the corresponding alkylations of
diphenylacetonitrile with
α-phenethyl chloride and
benzhydryl chloride have been effected to form
2,3,3-triphenylbutyronitrile and
2,2,3,3-tetraphenylpropionitrile in yields of 88 and 96% respectively.
2
3. Discussion
The method used is that of Hauser and Brasen.
2The benzylation of
diphenylacetonitrile with
benzyl chloride to form
α,α,β-triphenylpropionitrile has been previously effected in
83% yield by
sodium ethoxide in
ethanol,
3 in
67% yield by
methylmagnesium iodide in
ether,
4 and in unreported yield by
sodium amide in
ether.
5
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
ethanol (64-17-5)
ammonia (7664-41-7)
ether (60-29-7)
Norit (7782-42-5)
sodium ethoxide (141-52-6)
benzyl chloride (100-44-7)
potassium (7440-09-7)
methylmagnesium iodide (917-64-6)
α-phenethyl chloride (622-24-2)
sodium amide (7782-92-5)
Diphenylacetonitrile (86-29-3)
potassium amide
ferric nitrate hydrate
benzhydryl chloride (90-99-3)
α,α,β-TRIPHENYLPROPIONITRILE,
Propionitrile, 2,2,3-triphenyl- (5350-82-3)
2,3,3-triphenylbutyronitrile
2,2,3,3-tetraphenylpropionitrile
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