Org. Synth. 1949, 29, 83
DOI: 10.15227/orgsyn.029.0083
[Acrylonitrile, α-β-diphenyl-]
Submitted by Stanley Wawzonek and Edwin M. Smolin.
Checked by Cliff S. Hamilton and Karl W. R. Johnson.
1. Procedure
In a 2-l. beaker fitted with a strong, efficient, mechanical stirrer is placed a mixture of 106 g. (101 ml., 1 mole) of freshly distilled benzaldehyde and 117 g. (1 mole) of purified dry benzyl cyanide (Note 1), in 650 ml. of 95% ethanol (Note 2). To this mixture is added drop-wise, with stirring, a solution of 7 g. of sodium ethoxide in 50 ml. of absolute ethanol (Note 3). When 40–50 ml. has been added, the mixture becomes warm, turns cloudy, and solidifies. Mechanical stirring is continued as long as possible, and then the mixture is stirred by hand with a thick stirring rod in order to break up the lumps that form. The mixture is cooled in an ice bath (Note 4), and the product is separated by filtration. The filtrate is removed and may be saved (Note 5). The white mass is washed first with 200 ml. of distilled water, then with 50 ml. of 95% ethanol to remove unchanged reagents. The nitrile is dried at 25° and melts at 86–88°. The yield is 178–199 g. (87–97%) of product sufficiently pure for most purposes. Recrystallization from 700 ml. of 95% ethanol gives 170–187 g. (83–91%) of a pure, white product melting at 88° (Note 6).
2. Notes
1. The benzyl cyanide may be purified by a procedure described earlier.1 If commercial benzyl cyanide is used, the yield is between 80% and 90% of a slightly yellow product. Two recrystallizations are necessary for purification.
2. Denatured alcohol (Formula 3A) containing 10% absolute methanol is a satisfactory solvent for recrystallization.
3. A 40% solution of sodium hydroxide may also be used as the condensing agent; 35–60 ml. is required. With this reagent, the product is less pure and needs an additional recrystallization. The yields range from 70% to 82%.
4. This preliminary cooling helps to prevent clogging of the 20-cm. Büchner funnel used during filtration.
5. An additional 10–21 g. of crude nitrile melting at 84–86° can be obtained by evaporating the combined alcoholic filtrates to a volume of 300 ml. Two or three recrystallizations from 95% ethanol are necessary to raise the melting point to 88°.
6. Similar yields of substituted α-phenylcinnamonitriles can be obtained using p-methoxybenzyl cyanide and anisaldehyde, or benzyl cyanide and anisaldehyde.2,3
3. Discussion
α-Phenylcinnamonitrile can be prepared from benzaldehyde and benzyl cyanide with no solvent and with sodium ethoxide as a catalyst.4 Sodium hydroxide5 (40%) or piperidine6 may also be used as catalysts. The nitrile has been made by the condensation of benzyl cyanide and excess benzyl chloride with strong sodium hydroxide at 170°7,8 and by heating α,β-diphenylsuccinonitrile with alcohol at 180° in a sealed tube9 or at 230–250° under 100–110 mm. pressure with palladium.10
This preparation is referenced from:

References and Notes
  1. Org. Syntheses Coll. Vol. 1, 108 (1941).
  2. Wawzonek, J. Am. Chem. Soc., 68, 1157 (1946).
  3. Niederl and Ziering, J. Am. Chem. Soc., 64, 885 (1942).
  4. De Schuttenbach, Ann. chim., (11) 6, 90 (1936).
  5. Walther, J. prakt. Chem., (2) 53, 454 (1896).
  6. Knoevenagel, Ger. pat. 94,132 [Chem. Zentr., 69, 228 (1898)].
  7. Neure, Ann., 250, 155 (1888).
  8. Janssen, Ann., 250, 129 (1888).
  9. Chalaney and Knoevenagel, Ber., 25, 297 (1892).
  10. Knoevenagel and Bergdott, Ber., 36, 2861 (1903).

Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

ethanol (64-17-5)

methanol (67-56-1)

sodium hydroxide (1310-73-2)

benzaldehyde (100-52-7)

piperidine (110-89-4)

sodium ethoxide (141-52-6)

palladium (7440-05-3)

benzyl chloride (100-44-7)

Benzyl cyanide (140-29-4)

Acrylonitrile, α-β-diphenyl- (2510-95-4)

α,β-diphenylsuccinonitrile (5424-86-2)

anisaldehyde (123-11-5)

p-methoxybenzyl cyanide (104-47-2)