The Chemistry of Powder and Explosives - Sciencemadness Dot Org

160 AROMATIC N1TRO COMPOUNDS
3H
-NO2
OH OH / \ ^ OH
NO2 NO2-/\-NO2
O2-OH SO2-OH K V
SO2-OH
The sulfonation of phenol at low temperatures produces the
o-sulfonic acid, and at high temperatures the p-sulfonic acid
along with more or less of the di- and even of the trisulfonic acids
according to the conditions of the reaction. All these substances
yield picric acid as the final product of the nitration." 2
Unless carefully regulated the production of picric acid from
phenol is accompanied by losses, either from oxidation of the
material with the production of red fumes which represent a loss
of fixed nitrogen or from over sulfonation and the loss of unconverted
water-soluble nitrated sulfonic acids in the mother liquors.
Olsen and Goldstein^ 3 have described a process which yields 220
parts of picric acid from 100 parts of phenol. In France, where
dinitrophenol was used during the first World War in mixtures
with picric acid which were loaded by pouring, Marqueyrol and
his associates 54 have worked out the details of a four-stage
process from the third stage of which dinitrophenol may be removed
if it is desired. The steps are: (1) sulfonation; (2) nitration
to the water-soluble mononitrosulfonic acid; (3) nitration to
dinitrophenol, which is insoluble in the mixture and separates out,
and to the dinitrosulfonic acid which remains in solution; and
(4) further nitration to convert either the soluble material or
both of the substances to picric acid. The process is economical
of acid and gives practically no red fumes, but the reported
yields are inferior to those reported by Olsen and Goldstein. The
52 Cf. King, J. Chem. Soc, 119, 2105 (1921).
53 Olsen and Goldstein, Ind. Eng. Chem., 16, 66 (1924).
34 Marqueyrol and Loriette, Bull. soc. chim., 25, 376 (1919); Marqueyrol
and Carre, ibid., 27, 195 (1920).