In a
1-l., three-necked, round-bottomed flask equipped with a sealed Hershberg stirrer,
2 a
125-ml. dropping funnel, and a
thermometer is placed
200 g. (250 ml., 3.78 moles) of acrylonitrile (Note
1). The flask is immersed in an
ice-water bath, and then
75 ml. of concentrated
sulfuric acid is added dropwise over a period of about 1 hour while the temperature is maintained at 0–5°. From a clean dropping funnel (Note
2),
108.1 g. (105 ml., 1.0 mole) of benzyl alcohol (Note
3) is added dropwise over about 1 hour at the same temperature. The clear, yellow mixture is held below 5° for about 3 hours longer and is then allowed to warm slowly to room temperature. After 2 days of stirring at room temperature the mixture is poured into a
2-l. separatory funnel containing about 1 l. of water and chopped ice. The mixture is shaken thoroughly and the resulting oil is taken up with
200 ml. of ethyl acetate. The aqueous phase is separated and extracted twice more with 200-ml. portions of solvent. The organic extracts are combined and washed successively with four
250-ml. portions of saturated sodium chloride solution, four
250-ml. portions of saturated sodium bicarbonate solution, and again with four portions of the salt solution. The neutral
ethyl acetate extract is dried over
20 g. of anhydrous magnesium sulfate and filtered. The filtrate is concentrated and the residue is distilled under reduced pressure. A fore-run of 1–3 g. of semisolid is obtained up to 120°/0.02 mm. The product is then collected as a light-yellow oil, b.p.
120–130°/0.01–0.02 mm., which solidifies in the chilled receiver. The distillate (
97–101 g.) is melted on a
steam bath and dissolved in a mixture of
50 ml. of benzene and 50 ml. of hexane. The solution is transferred quantitatively to a
500-ml. Erlenmeyer flask and the solvent evaporated on a steam bath. The oily residue is placed in a refrigerator for at least 1 day to ensure complete crystallization. The white solid is transferred to a
Büchner funnel with the aid of a little ice-cold
hexane. After drying in air, the yield is
95–100 g. (
59–62%) of
N-benzylacrylamide, m.p.
65–68° (Note
4).