A Manual of the Chemistry of the Carbon Compounds

326 THE GRBMISVBY OF
The nitrobenzene being first reduced to aniline, free bromine is
formed, which substitutes hydrogen in aniline,
Todaniline C6H4I.NH2 is readily formed by the action of iodine
upon aniline, but it is not produced by heating nitrobenzene with
bydriodic acid, because free iodine acts only upon free aniline, but
not on its salts. lodaniline is a weak base, crystallizing in white
prisms.
Orthonitraniline CflH4 \ -A—This compound is not formed by
the action of nitric acid upon aniline. To obtain it, an anilide, as
acetanilide, is dissolved in strong nitric acid, and the nitro-acetanilide
thus formed boiled with potash-solution:—
K0H " C « H * { NO* + aK
Orthonitraniline crystallizes in long yellow needles or plates, melting
at 146° and subliming without decomposition.
Paranitraniline C0H4 j JJQ 8 .—This isomeride is obtained by reducing
dinitrobenzene with an alcoholic solution of ammonium
sulphide. It forms yellow needles, melting at 110°, and subliming
readily on heating.
Paranitraniline is the starting-point for a series of substituted
anilines, which are isomerio with those just described. To obtain
these paranitraniline is converted, first, into a diazo-compound, and
this decomposed by hydrochloric hydrobxomio, or hydroiodio acid.
The substituted nitrobenzenes thus formed are then reduced by a
suitable agent.
Paraehlor- and parabromniline are liquids, Para-iodaniline crystallizes
in silvery soales, melting at 25°.
Metaniimniline.—By the action of nitric acid on bromobenzene,
two isomerio bromonitrobenzenes are formed, one melting at 125°, and
the other at 38°. When the former is heated with concentrated
alcoholic ammonia for twelve hours to 190", it is converted into orthonitraniline,
whilst the second modification yields by this reaction
metanitrauiline; which is more volatile and more soluble than its
two iaomerides. It forms yellow needles, melting at 66°; its aqueous
solution stains the akin yellow.
The mtranilines are weak bases, forming salts, which are decomposed
by water.
StUphanUic Add or Amidobetavne'SulpJimic Add COH44 QO 8 QTT
—This powerful monobosio acid is obtained by dissolving aniline in
fuming sulphuric acid. It is not freely soluble in cold water, and
crystallizes from a hot solution in rhombic plates containing one
molecule of water. Its salts are soluble in water, and crystallize
well.