A Manual of the Chemistry of the Carbon Compounds

THE CABBON COMPOUNDS. 341
solving in hot water, with a brown colour. In cold water it is almost
insoluble, and.by boiling water it is resolved into hydroquinone and
quinone, which volatilizes with the steam. By oxidation, it is readily
converted into quinone, and by reduction into hydroquinone.
f O OC H
PJicnoguinone C6H4< n OC 6 H B *—^*is beautiful body is produced
by boiling an aqueous solution of one part of pure phenol with two
and a half parts of chromic acid. It readily volatilizes with steam,
and is freely soluble in water. Ether dissolves it from its aqueous
solution, and on evaporation it is left behind as a crystalline mass,
which, by sublimation, yields long, splendid red needles, possessing a
green metallic lustre, and a faint, pungent smell, and melting at 71°.
Phenoquinone has also been obtained by the action of phenol upon
quinone;—
0 s, HO.C0HS r „ f O.0CaH6 p „ f OH
0> + HO.CX = ° MO.OC6H6 + °e H *iOH
Monoehoroquinone (LHgClO/ is obtained by the action of chlorine
on quinone; it forms long, yellow needles, which, by the action of
sulphurous acid, are converted into colourless mmiochlorhydwquirwne
C.H8Cl(OH)g, a compound which is also produced by evaporating a
solution of quinone in strong hydrochloric acid.
DicMoroquinone CJHJCIJOJ" crystallizes in large yellow prisms; by
the action of sulphurous acid, it yields, first, hexacldoroquinhydrone,
which, by further reduction, is converted into dicldorohydroquitwtu.
Trickloroquinone CjHClgO,".—By adding a mixture of phenol and
potassium chlorate to dilute hydrochloric acid, a reddish-yellow crystalline
mass is obtained, consisting of a mixture of trichloroquinone
and tetrachloroquinone. To separate them, they are reduced by means
of sulphurous acid, and the chlorinated hydroquinones exhausted
with boiling water, which only dissolves trichlorohydroquinono, which,
hy oxidation, is reconverted into trichloroquinone, crystallizing in
large, thin, yellow plates, melting at 163°, and easily subliming.
Tetrachlaro^uinom, or Ckloranil C6C14O,",-—This body is produced
(generally together with trichloroquinone) oy the action of potassium
chlorate and hydrochloric acid upon all substances which yield picric
acid, when boiled with nitric acid.
It crystallizes in brilliant, golden-yellow scales, which are insoluble
in water, slightly in cold and freely in hot alcohol, and sublime at a
high temperature. It is a very stable compound, and not acted upon
by concentrated sulphuric acid, nitric acid, and aqua regia. On heating
it with .phosphorus pentachloride, it is converted into kexachlorobenzene
C6CL. By boiling it with a solution of sulphurous acid, it
yields htTachlm'ohydrotiuinonc ox chlorokydmnU, small white plates,
which are insoluble in water.
Cliloranilic Acid (^.Cy)/' \ QJJ.—Chlorauil dissolves in dilute