A Manual of the Chemistry of the Carbon Compounds

THE CARBON COMPOUNDS. 445
from hot benzene in hard, colourless needles. By the action of heat
it is resolved into bromine, hydrobromic acid, and tribi'omantkracene
Clt,B8
Tekabromanthraccne CuH0Br4 is a body resembling the di- and
tri-bromo-eompound, and obtained by the action of hot alcoholic
potash on dibroinanthracene tetrabromide.
MITJtO- AND AMID0-C0MFOUNDS.
These compounds are but little known; dilute, as well as concentrated
nitric acid, converts anthracene into antliraquinone, but by the
action of nitric acid on an alcoholic solution of anthracene the following
nitro-compounds have been obtained.
Bed Nitro-anthraeene O^HjNOg is insoluble in cold alcohol, and
crystallizes from hot alcohol in red needles. When treated with tin
and hydrochloric neid, it yields iso-anthracene and amido-anthracene
CuH0.NH2, which is precipitated by alkalis in yellow flakes; it is a
very unstable body, turning rapidly brown in the air. It dissolves
acids, but does not form definite salts.
White Nitro-anthracenc is more freely soluble in alcohol than the
red compound, and readily in benzene, from which it crystallizes in
colourless needles.
Dinitro-anthraccne C14H8(NO4) is readily soluble in hot alcohol
and benzene, and sublimes in small colourless plates.
Isonitro-atUhracene C^H^NOj ha3 been obtained by boiling isoanthracenc
with nitric acid; it is sparingly soluble in alcohol, freely
in benzene, and sublimes in pale-yellow needles, melting at 209°.
ANTHRACENESULPHOX1C ACIDS.
AnthraccncmonomlpJiomc Acid CuHj.SOsH is formed by dissolving
anthracene in concentrated sulphuric acid at 100°; ita lead salt
crystallizes in yellowish-white prisms, having the composition
(CuH0.SQ,)2Pb, By heating anthracene with sulphuric acid to 150°,
the disulphonic acid is produced.
Dichloranthracmcdisulphonic Add CuH0Clo(S08H)? is obtained by
heating dichlorantfiracenc with fuming sulphuric acid on a water*
bath. It forms orange-yellow crystals, which are solnble in water,
but not in dilute acids.
ANTHRAQUHiONE, OK OXYANTHRACENE CUH8O&
Tliis compound is readily obtained by boiling anthracene with
dilute sulphuric acid and potassium dichromate, or with nitric acid.
It crystallizes from hot nitric acid in pale-yellow needles, melting at