Dinitrobenzene

The dinitrobenzenes ( according to IUPAC nomenclature dinitrobenzene, also DNB ) consist of a benzene ring with two nitro groups (- NO2) as substituents. Different arrangement of the nitro groups to yield three structural isomers with the molecular formula C6H4N2O4. The m- dinitrobenzene falls, inter alia, at the time of manufacture of explosives.

Properties

The dinitrobenzenes are all crystalline solids. The boiling points of the three isomers are relatively close, while they have different melting points clearer. P- dinitrobenzene, which has the highest symmetry, has the highest melting point.

Representation

M- dinitrobenzene is accessible by renewed nitration of nitrobenzene, the reaction with sulfuric acid catalysis from. The - I effect and the - M effect of the nitro group of nitrobenzene to cause 93% of a Directorate in the meta position. The ortho -and para- products occur only at 6 and 1 %.

Use

A reduction of m- dinitrobenzene with sodium sulfide in aqueous solution leads to m- nitroaniline, the complete reduction ( Fe / HCl) to m- phenylenediamine.