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.
Bottger of Frankfort and Otto and Knop, all of whom added to our knowledge of the subject, the last-named introducing the use of sulphuric along with nitric acid in the nitration process.
The solubility in ether-alcohol may be owing to a lower degree of nitration, or to the temperature conditions under which the process of manufacture has been carried on.
Guncottons are examined for degree of nitration by the nitrometer, in which apparatus they are decomposed by sulphuric acid in contact with mercury, and all the nitrogen is evolved as nitric oxide, NO, which is measured and the weight of its contained nitrogen calculated.
Being an unsaturated acid it combines directly with hydrochloric acid, hydrobromic acid, bromine, &c. On nitration it gives a mixture of ortho and para nitrocinnamic acids, the former of which is of historical importance, as by converting it into orthonitrophenyl propiolic acid A.
H 3 C CO NH 3 CO CH 3 H3C C - NH - C CH3 On nitration it yields chiefly meta-nitro-benzaldehyde, crystallizing in needles which melt at 58° C. The ortho-compound may be obtained by oxidizing ortho-nitrocinnamic acid with alkaline potassium permanganate in the presence of benzene; or from ortho - nitrobenzyl chloride by condensing it with aniline, oxidizing the product so obtained to ortho-nitrobenzylidine aniline, and then hydrolysing this compound with an acid (Farben fabrik d.
A-Nitronaphthalene, C10H, N02, is formed by the direct nitration of naphthalene.
Nitration of benzoic acid gives chiefly meta-nitro-benzoic acid.
Meta-dinitrobenzene is formed by the direct nitration of nitrobenzene with fuming nitric acid, the product being poured into water and recrystallized from dilute alcohol.
It is readily brominated and nitrated; when the nitration is carried out in the presence of sulphuric acid, the nitro-groups take up the meta position with regard to the amino-groups.
Guaiacol may be obtained directly from beechwood tar, from pyrocatechin by methylation with potash and potassium methyl sulphate at 180°, or from anisol by nitration, reduction of the ortho-nitroanisol to amino-anisol, which is then diazotized and boiled with water.
On nitration it gives orthoand para-nitrotoluenes - which on reduction yield the valuable toluidines, C6H4(CH3)(NH2) - and on sulphonation the parasulphonic acid is formed with a little of the ortho acid.
The so-called collodion cottons are nitrated celluloses, but of a lower degree of nitration (as a rule) than guncotton.