From meta-brombenzoicacid two nitrobrombenzoic ac i ds are obtained on direct nitration; elimination of the bromine atom and the reduction of the nitro to an amino group in these two acids results in the formation of the same ortho-aminobenzoic acid.
This substance readily yields ortho-oxybenzoic acid or salicylic acid, which on nitration yields two mononitro-oxybenzoic acids.
Direct nitration gives (principally) m-nitrobenzoic acid, also pseudotetragonal with a much shorter principal axis.
The nitro compounds of the lower members of the paraffin series cannot be prepared by the direct action of nitric acid on the hydrocarbons themselves, but, in the case of some of the higher members of the series direct nitration is possible (M.
Three isomers exist, the orthoand para-compounds being the chief products of the direct nitration of toluene.