The Chemistry of Powder and Explosives - Sciencemadness Dot Org

228 NITRIC ESTERS
Nitration of Ethylene
By passing ethylene into a mixture of concentrated nitric and
sulfuric acids Kekule 51 obtained an oil, specific gravity 1.47,
which broke down when distilled with steam to give glycollic
acid, oxalic acid, nitric oxide, and nitric acid. On reduction with
sodium amalgam it yielded glycol and ammonia among other
products. Wieland and Sakellarios 52 distilled the Kekule oil in
steam and then in vacuum, and obtained nitroglycol, b.p. 105°
at 19 mm., and /3-nitroethyl nitrate, b.p. 120-122° at 17 mm.
These two substances are evidently formed from ethylene by the
reactions indicated below.
CH2 OH CH2—OH
CHr-ONO2
f HNO3 > H2O
CH2 NO2 ~" CH2—N02
CH2—NO,
/J-Nitroethyl nitrate
CH2
Cjjj ONO2
1 OTTWY, --> HONO HhH2O
+ • |
CH2"
CH2—ONO2
Nitroglycol
A considerable amount of nitrous acid is present in the spent
acid. /3-Nitroethyl nitrate is feebly acidic and dissolves in dilute
alkali solutions with a yellow color. It is not sufficiently stable
for use in commercial explosives. On digestion with warm water
or on slow distillation with steam it undergoes a decomposition
or sort of hydrolysis whereby nitrous acid and other materials
are produced. Numerous patents have been issued for processes of
procuring pure nitroglycol from the Kekule oil. One hundred
parts of the last-named material yield about 40 parts of nitroglycol,
and the economic success of the process depends upon the
recovery of valuable by-products from the /3-nitroethyl nitrate
which is destroyed. \
Ohman 53 in Sweden has developed 'an ingenious electrolytic
process for the production of nitric esters direct from ethylene.
The discharge of the nitrate ion (NOj) at the anode liberates the
free nitrate radical (NO3) which in part combines directly with
ethylene to form nitroglycol.
CH2
CHs—ONO2
I + 2NO3 • I
CH2
CHs—ONO,
5l
Ber., 2, 329 (1869).
62
Ber., S3, 201 (1920).
5
3 Z. Elektrochem., 42, 862 (1936); Svensk Kemisk Tid., SO, 84 (1933).