A Manual of the Chemistry of the Carbon Compounds

378 THE OBEMISTItY OP
Paratoluonitrile forms fine white needles, melting at 30°, and
smelling like oil of bitter almonds. By heating it with concentrated
hydrochloric acid to 200°, it is converted into paratoluic acid.
1*3 Isotoluic Add is formed by oxidizing isoxylene, but is more
conveniently prepared by heating the calcium-salt of uvitio acid
CyEI^CHg^COjHjj with slaked lime above the melting-point of lead;
this reaction is quite analogous to the formation of benzoic acid
from phthalio acid, Isotoluic acid crystallizes from water in needles,
melting at 105°.
1*2 Orthotoluic Jcidhas been obtained by boiling orthoxylene with
dilute nitric acid. It crystallizes from a hot, dilute, aqueous solution
in long, transparent, pointed prisms, melting at 102°,
OrthotolwmitriU is produced by converting paendotoluidine into
the corresponding mustard-oil, and distilling the latter with finelydivided
copper. It is a refractive liquid, smelling like nitrobenzene,
and boiling at 204°. By heating it with hydrochloric acid to 200°, it
is converted into orthotoluic acid; but alcoholic potash acts only
( PTT
slowly on it, converting it into orthotoluylamide C6H4 < no ilH ' cr ^ 8 "
tallizing from boiling water in very long and slender needles,
melting at 138°.
TOLYLENE-COHPOUNDS.
Tolylme Qlyeol C6H4| cH*OBr~ The chloride of &"» alcoh °l
produced d by b passing chlorine into boiling methyl-toluene. It is
easily converted into the glycol by heating it with thirty parts of
water for three hours to 180°. To isolate the glycol, the solution is
allowed to evaporate at the ordinary temperature, and not on a waterbath,
beoause when the hydrochloric acid becomes concentrated a
part of the alcohol is reconverted into the chloride. The concentrated
solution is neutralized and shaken with other, the ether
evaporated, and the residue orystallized from water in vamw. Tolylene
glyool forms white, opaque, interlaced needles, melting at 113°,
By heating it with chromic acid solution, it is oxidized to terephthalio
idCH^COH)
Tolylene DioMmde CpH4(CHaCl)g is also produced by distilling the
glycol with hydrochloric acid; it crystallizes from alcohol in hard,
large, transparent, clinorhombic lamina, melting at 100°, and boiling
at 240° to 245°. By dissolving it in fuming nitric acid, it is converted
into uitrotolylene dieliloride C6Hs(NOa)(CH2Cl)o. crystallizing from
alcohol in small brilliant plates, melting at 35 , and possessing an
agreeablo smell.
Tolylme Dibromide C6H4(CH2Br),j is produced by adding bromine
drop by drop to boiling methyl-toluene, and by distilling the glycol