[2] Chem. Zentr. 1910, (1), 960; 1910, (11), 1561.

[3] J. Chem. Soc. 97, 2485 (1910).

[4] C. A. 14, 3406 (1920)

[5] J. Chem. Soc. 99, 1334 (1911).



XIII

_p_-NITROBENZOIC ACID

(_p_)NO2C6H4CH>3s> + 3O(Na2Cr2O7 + H2SO4)--> (_p_)NO2C6H4CO2H + 3H2O

Prepared by O. KAMM and A. O. MATTHEWS. Checked by H. T. CLARKE
and W. W. HARTMAN.

1. Procedure

IN a 5-l. round-bottom flask, fitted with a mechanical stirrer,
are placed 680 g. of sodium dichromate, 1500 cc. of water,
and 230 g. of _p_-nitrotoluene. Stirring is started, and 1700 g.
of concentrated sulfuric acid are allowed to flow in during about
thirty minutes. The heat of dilution of the sulfuric acid will cause
the nitrotoluene to melt, and rapid oxidation will soon take place.
The last half of the sulfuric acid must be added gradually,
in order to prevent too violent a reaction. Since a small amount
of nitrotoluene is volatilized, it is advisable to carry on this