A Manual of the Chemistry of the Carbon Compounds

388 THE CHEMISTRY OF
COMPOUNDS WITH NINE ATOMS OP CARBON.
The compounds of this group are derived from the following
hydrocarbons :—
Methyl-ethyl-benzeue C « H i { CH^
Propyl-benzene C6H6.C3H7
IsopropyUbenzene or Cumene . . CBH6.CH4 CJT S
Allyl-benzene C6H6,C8H6
TRIMETHYL-BENZENES
ME8ITYLENK, OR 1*3*5 TBIMETHTL-BENZENE
\. 3
Occurs together with pseudocumene in coal-tar, and is produced by
acting with sulphuric acid on acetone. Each molecule of this coinpound
loses one molecule of water, and the residues CH3 — C—CH
combine, three metliyl-ethines being condensed to trimethyl-benzene,
just as three niolecnles of ethine form one of benzene. (See page 318.)
This reaction shows that the methyls occupy the symmetrical position
1-3-5.
Pure meaitylene is prepared by pouring one volume of acetone ou
some sand placed in a retort, and then adding a cold mixture of one
volume of sulphuric acid and half a volume of water.
After 24 hours, the mixture is distilled, and the distillate purified
by continued fractional distillation. Pure mesitylene is a refractive
liquid, possessing a peculiar smell, and boiling at 168°.
Monochlorotnesitylene C0HaClCCH^$ is a limpid liquid, boiling
QX AUO f
pichloromesitylene CjHCUCH^ crystallizes from alcohol in shining
prisms, melting at. 59°, and boiling at 205°.
fnchloromesiiykne CjCljCCH^g melts at 204°, and sublimes in long
prisms.
These three compounds are formed by the action of chlorine on
cold mesitylena