IN a 3-l. round-bottom flask, fitted with an efficient
reflux condenser, are mixed 750 g. of 95 per cent alcohol, 750 g.
of concentrated sulfuric acid and 450 g. of benzyl cyanide.
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
to remove small amounts of phenylacetic acid which may have been formed,
and then distilled _in vacuo_. A small amount of water goes
over first and then a pure product boiling 132-138'0/32 mm.
(120-125'0/17-18 mm.). The yield varies in general between 525 and 550 g.
(83-87 per cent of the theoretical amount).