A Manual of the Chemistry of the Carbon Compounds

368 TEE CHEMISTRY OF
out in colourless prisms. It explodes violently when heated, and is
decomposed by boiling water, 1*3 oxybenzoic acid being formed :—
The free acid is obtained by adding an alkali to a solution of the
nitrate; it is a yellow body, which soon undergoes spontaneous decomposition
Dum-amidobemnc Acid C0H4 j gjj^H)QlHrCOiH ifJ preeipitated
in orange crystals by adding aniidobenzoio acid to an aqueous solution
of diazobemoic acid, It is almost insoluble in water, and a bibasic
acid. When heated, it is decomposed with a slight explosion.
UramidobmzoieAdd C6H4 j gJ^ 0NH 2_This compound is distinguished
by the great number of derivatives which it yields. It is
produced by fusing urea with 1'3 amidobenzoic acid, By the action
of strong nitric acid it yields three isomeric dinitro-acids, which,
owing to tbo great similarity of their properties, cannot be separated
from each other.
When an ammoniacal solution of these acids is boiled, they are converted
into the mononitro-acids;—
N( V° H
The mononitro-com pounds can easily be separated, their barium
salts possessing a very different solubility in water. On acting with
nitric acid on the pure mononitro-acids, the dinitro-acids are obtained
perfectly pure. They form yellowish-white needles, and are freely
soluble in alcohol, but scarcely soluble in water. By boiling them
with water for a long time, they are converted into amido-nitrobenzoie
acids}—
WNO^-J ^H° N H 2 = CATO { g ^ + COa + NaO
When these amido-nitro-acids are gently heated with tin and
hydrochloric acid, they are reduced to diamidobenzoic acids,
a Diamidobenzoic Acid C8H8 -I QQ j¥ a " 8 P ar "igly soluble in hot
water, and forms minute prisms, lte sulphate CgHgCCOgHXNH^aSO^a
is almost insoluble in water. On distilling the acid, it is resolved in
carbon dioxide and orthodiamidobenzene (see page 327),
0 JXamidobenzwc Acid is more freely soluble, and crystallizes in
pale-yellow plates. The sulphate has the composition 2[06Hs(C03H)
(NH2}JSO4H2, and is more soluble than the a compound