Abstract

Nitrobenzene is a pale yellow to yellowish brown liquid with a boiling point of 207–212°C, depending on its purity. It is a very toxic substance with a maximum allowable concentration (PEL) of 1 ppm. The commercial production of nitrobenzene involves the direct nitration of benzene using a mixture of nitric and sulfuric acids, with typical yields of 96–99%. The main derivatives of nitrobenzene are ortho-, meta-, and para-nitrochlorobenzene. These are toxic, with a PEL of 0.1 ppm for p-nitrochlorobenzene.

Nitrotoluene exists as three isomers: o-, m-, and p-nitrotoluene. The o- and m-nitrotoluenes are clear yellow liquids at 25°C, whereas p-nitrotoluene is a crystalline solid (mp 53.5°C). The nitrotoluenes are fairly toxic, with a PEL of 2 ppm.