A Manual of the Chemistry of the Carbon Compounds

168 TEE CHEMISTRY OF
The same crystalline compound is obtained by the action of
carbonyl chloride upou zinc-methyl. By water it is decomposed,
marsh-gas is evolved, and trimethyl carbinol is formed, the monad
gronp ZnCH8 being replaced by hydrogen :—
In order to isolate the alcohol the liquid is distilled, and to the
distillate potassium carbonate is added, by which the alcohol separates
as a light layer, which must be dried over calcium chloride and
rectified. If quite anhydrous it forms colourless crystals; it melts at
25°, and boils at 82°'5; its smell reminds one at the same time of alcohol
and of camphor. By passing hydriodic acid gas into well-cooled
trimethyl carbinol, tertiary butyl iodide (CH8)2CH.CH4I is obtained, a
heavy colourless liquid boiling at 99°, which in contact with moist
silver oxide is again transformed iiito the alcohol. If the iodide is
acted upon by silver acetate and acetic acid, the acetate of tertiary
butyl is obtained, a colourless liquid which smells like acetic acid
and peppermint, and boils at 96°.
In presence of zinc and water the iodide is converted into trimethyW
methane CH(CH3)g, and isobutene C4Ha:—
y u 3
3 3 3 3 3
2 CI +Zn= Z CH + C
+ZnIa
CH, CH, m3 CI CH2
To separate the two gases they are passed through bromine, which
combines with, the isobutene, whilst the triuiethyl-methaue passes
through unabsorbed. Trimethyl-methane is condensed by a freezing
mixture into a mobile liquid, boiling at — IT- When this hydrocarbon
is acted upon by cWorine it is converted again into tertiary
butyl chloride, which is also formed by the action of iodine chloride
upon isobutyl iodide.
Isobutene has also been produced by heating tertiary butyl iodide
or primary isobutyl iodide with an alcoholic solution of potash:—
S g CHS CHS
(1) Yl + w } o = 0
i
n3
(2) CH +S}o= U
I J II
CH,I OH,