A Manual of the Chemistry of the Carbon Compounds

TEE CABBON COMPOUNDS. 447
a Dinitro-anthraquinone CMHJ(N0J)0J is obtained by boiling
anthraquinone with concentrated nitric acid or a mixture of sulphuric
and nitric acids for some hours. It is a pale-yellow substance, subliming
above 250° in yellow needles.
/3 Dinitro-anthraquinone.—This body is obtained, but only in a
small quantity, together with anthraquinone, when anthracene is
boiled with common nitric acid. It crystallizes in yellow needles,
and forms with anthracene a compound, crystallizing from benzene in
splendid violet plates. It also combines with other hydrocarbons;
all these compounds crystallize well, and are distinguished by their
brilliant colours.
Amid(Mnth,raquinone (^^(NHglOj has been prepared by heating
nitro-anthraqvtinone with a solution of sodium hydiosulphide. It is
a bright brick-red powder, melting at 256°, and subliming in small
needles. It does not appear to combine with acids.
Diazo-anthraqninone Nitrate C14H^O3N5.NO8 is thrown down as a
pale-red powder wheii nitrogen trioxide is passed into a solution of
the amide in ether-alcohoL
Diamido-arUhraqitinone C^H^NH^O;.—By heating a dinitroanthraquinone
with an alkaline solution of stannous chloride or
sodium hydrosulphide, it dissolves with a green colours and soon the
diamido-compound separates out as a vermilion-red colour, subliming
in beautiful gftrnet*red needles having a beetle-green lustre.
AnGiraquinom-monosulphonic And Ci4H.(SOsII)O.j is formed by
heating anthraquinone with concentrated sulphuric acid to 250°. It
is more freely soluble in water than in dilute acids, and crystallizes
in yellow plates. The barium salt (CHH7O3S03)2Ba + H,0 is not
very soluble in water, and forms indistinct plates. The calcium salt
(CMH7OijSO3)3Ca is much more freely soluble, and does not crystallize
well.
Aidhraquinone-distiiphonic Add CuH0O u (SOsH)? is obtained lay
dissolving anthracene in five parts of sulphuric acid at 280°. It is
more soluble than the monosulphonic acid, and forms yellow crystals.
Its salts do not crystallize well.
This acid is also obtained by oxidizing dichlor- or dibvoniantluracene-disulfthonio
acids :—
CMHttCla(S08H)4 + Oa = CMHMO3(SOaH)a + Cl,
or by heating dichlor- or dibromauthraccne with sulphuric acid:—
CuHaCla(SO3H)a + SO2H2 = CUH9(O3)(SO3H)4 + SO2 + 2HC1
The same acid has been produced by heating anthracene-disulphonic
acid with manganese dioxide and dilute sulphuric acid.