In a
500-ml. three-necked flask equipped with a
stirrer, a
dropping funnel, and a
thermometer is placed a solution of
57.0 g. (0.30 mole) of ethyl phenylcyanoacetate (
p. 461) in
80 ml. of tert-butyl alcohol. The solution is heated to 40°, and with stirring the dropwise addition of a solution of
33.0 g. (0.62 mole) of acrylonitrile (Note
1) in
30 ml. of tert-butyl alcohol is started. After the addition of about 10–15 drops,
1.0 ml. of a 30% solution of potassium hydroxide in methanol is added, and the temperature is maintained at 40–45° by occasional external cooling while the remaining solution is added slowly. When about one-half of the
acrylonitrile has been added, an additional
1.0 ml. of the potassium hydroxide solution is added to ensure the presence of a basic catalyst throughout the reaction. When the addition is completed (after about 30 minutes) and the temperature is no longer maintained above 40° by the exothermic reaction (another 30 minutes), the mixture is heated with a
hot-water bath to keep the temperature at 40–45° for 1 hour.
The solution is diluted with 250 ml. of water and acidified with
30–40 ml. of 10% hydrochloric acid. The product is separated after the addition of
100 ml. of ether, and the aqueous solution is extracted with two
50-ml. portions of ether. The combined extracts are washed with 50 ml. of water and dried over anhydrous
magnesium sulfate. The
ether is distilled at atmospheric pressure, and the residue is distilled under reduced pressure through a
short (15-cm.) Vigreux column. After a fore-run of a few grams, the product is collected at
157–167° /0.5–1 mm. (Note
2). The yield is
50–61 g. (
69–83%).