In a
3-l. round-bottomed flask, fitted with an
efficient reflux condenser, are mixed
750 g. (918 cc.) of 95 per cent alcohol,
750 g. (408 cc.) of concentrated sulfuric acid and
450 g. (3.85 moles) of benzyl cyanide (Note
1). The mixture, which soon separates into two layers, is heated to boiling over a low flame, for six to seven hours, cooled, and poured into 2 l. of water, and the upper layer is separated. This is washed with a little
10 per cent sodium carbonate solution (Note
2) to remove small amounts of
phenylacetic acid which may have been formed, and then distilled under reduced pressure. A small amount of water goes over first and then a pure product boiling
132–138°/32 mm. (
120–125°/17–18 mm.) (Note
3). The yield is
525–550 g. (
83–87 per cent of the theoretical amount).