Benzene → Nitrobenzene

The starting substances, benzene and nitric acid, are reacted in a large excess of sulfuric acid, which takes up the heat of reaction liberated and the water formed during the reaction. For the process of carrying out the reaction, nitric acid and sulfuric acid are mixed to give so-called mixed acid, and benzene is metered into this. The benzene reacts with the nitric acid to give water and substantially nitrobenzene. The temperature of the reaction mixture and the concentrations of benzene, nitric acid and sulfuric acid are preferably chosen such that after a reaction zone, conventionally in the nitrating reactor, a mixture of benzene, nitrobenzene, sulfuric acid and water is obtained. This mixture is substantially free from nitric acid. The temperatures required for this are conventionally between 70° and 145° C. To establish the mixed acid, nitric acid having a concentration of from 60 to 98 wt. %, and sulfuric acid having a concentration of from 60 to 96 wt. % are conventionally employed. Benzene is preferably employed at least in the stoichiometric amount, based on the amount of nitric acid. It is more preferred, however, that benzene is employed in an excess of 2 to 10%, compared with the amount of benzene required stoichiometrically.

1. temperatureheat of reaction liberated
2. additionare mixed

ORD record

ord-f0e8022a538f4cc086b8bb8ba6e1cdfd

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07781624B2