A Manual of the Chemistry of the Carbon Compounds

THE CARBON COMPOUNDS. 375
METHYL-TOLTJENE, OB 1'4'DIMKrH-iri^BESZENE,
Occurs sometimes in quantity in coal naphtha. The pure hydrocarbon
is obtained by the action of sodium on a mixture of methyl
iodide, and crystallized bibromobenzene, or 1*4 bromotoluene.
It is a colourless liquid, boiling at 136°, solidifying at 15° to a
crystalline mass, and possessing a peculiar smell, which is quite
different from that of benzene. Fuming nitrio acid converts it into
two dinitro-compounds, which are separated by crystallizing tbem
from alcohol.
a Dimtrmethyl-iolwne G6'St(JSOX(GK^t forms long, thin, colourless
needles, melting at 123°*5. p Dimtromethjl-toluene is more
freely soluble, and forms long, transparent, monoclinic crystals,
melting at 93°,
Trimtrmethyl-toluetoR CgH^Oj^CHg^ is produced by treating the
hydrocarbon with a mixture of nitric and sulphuric acids; it crystallizes
from alcohol in long colourless needles, melting at 137°,
Jtf«w&«wwme%^fofomC6H8BT(CH3)a.—Toprejparo this compound,
bromine is slowly added to the hydrocarbon, which is cooled down
to 0°. It is a colourless liquid, boiling at 205°, and possessing an
agreeable odour. By the further action of bromine, it is converted
into dibromomthyl-tolitene C JlgBr^CH,),, crystallizing from alcohol
in pearly scales, melting at 72°,
ISOXYLENB, OB 1*3 DIMETHYL-BENZENE,
Forma generally the chief portion of coaltar-xylene, and is
obtained pure by distilling mesitylenio acid C6H3(CH3)aC'O2H with
lima It is a limpid liquid, boiling at 138°, and smelling like
methyl-toluene. It is only slowly acted upon by nitric acid, whilst
metliyl-toluene is readily oxidized by it to toluic acid, und theretove
an almost pure isoxylene may be prepared by heating coaltar-xykne,
which contains much isoxylene, with dilute nitric acid.
The substitution-products of this hydrocarbon have mostly been
obtained from crude xylene, and many of them are, therefore, probably
mixtures*
Monockloro-isoscykne GJSsCl(GVi^3 is, produced when xylene is
acted on by chlorine either in the cold or in presence of iodine; it
is a colourless liquid, boiling at 183°.
Monobrom-isoxykne CgHgB^CH^ is a liquid, boiling at 205°,
and possessing an aromatic odour.
LibromO'isoseylene C8HoBr2(CHg)2 crystallizes in pearly scales, melts
at 69°, and boils at 256°.
N i h OaH^NOj)(CH8)a ia formed, together with dimtr*-