Nitration of Toluene with Nitric Acid in the Presence of Aromatic Sulfonic Acids on the Various Supports

Abstract

It was found that nitration of toluene with nitric acid in the presence of anhydrous aromatic sulfonic acids on the various supports, greatly increase the ratio of para isomer to ortho isomer and the yield of monenitrotoluene, compared with nitration without any supports.
Viscous liquid sulfonic acids, such as toluene-2, 4-disulfonic acid, m-benzenedisulfonic acid and mixture of e-, m- and P-nitrobenzene sulfonic acid etc., were especiaHy effective and the most suitable support was diatomaceous earth (Celite-545).
Thus, by use of toluene-2, 4-disulfonic acid, m-benzenedisulfonic acid, mixture of o-, mand p-nitrobenzene sulfonic acid, chlorobenzene-2, 4-disulfonic acid and sulfonated polystyrene on the Celite-M5, the P/o ratio and the yield of nitrotoluene were 1.61, 96%, 1.53, 92%, 1.50, 91%, 1.47, 90% and 1.42, 77% but in. the absence of Celite-545 those were 1.05, 72%o, 1.08, 81%, 1.25, 84%, O.91, 83fZa6 and O.70, 50%o, respectively.
The mechanism of the effect of aromatic sulfonic acids and the supports were also discussed.