(_p_)NO2C6H4CN + H2SO4 + 2H2O--> (_p_)NO2C6H4CH2CO2H + NH4HSO4

Prepared by G. R. ROBERTSON. Checked by ROGER ADAMS and H. O. CALVERY.

1. Procedure

IN a 1-l. round-bottom flask are placed 100 g. of _p_-nitrobenzyl
cyanide. A solution of 300 cc. of concentrated sulfuric acid
(sp. gr. 1.84) in 280 cc. of water is prepared, and two-thirds
of this solution is poured on to the _p_-nitrobenzyl cyanide.
The mixture is shaken well, until the solid is all moistened
with the acid. Any solid material sticking to the walls of
the vessel is now washed down into the liquid with the remainder
of the acid, the flask is attached to a reflux condenser, then set,
without shaking, over a 10-cm. hole in a large sheet of asbestos
board which rests on a tripod, and heated until the mixture boils.
The boiling is continued for fifteen minutes.

The reaction mixture, which becomes rather dark, is diluted
with an equal volume of cold water and cooled to 0'0 or below.
The solution is filtered, the precipitate is washed several times
with ice water and then dissolved in 1600 cc. of boiling water.
(A few grams of animal charcoal are added in dissolving the precipitate,
if a technical _p_-nitrobenzyl cyanide has been used.)
This solution is filtered as rapidly as possible through a large
folded filter, preferably with a steam funnel. In spite of
all precautions, however, some solid usually separates on the filter.
This must be redissolved in a minimum quantity of boiling water,
and this solution then filtered into the main solution.