The Chemistry of Powder and Explosives - Sciencemadness Dot Org

MERCURY FULMINATE 407
water, filtering, and reprecipitating by the addition of 30% acetic acid.
The pure fulminate is filtered off, washed several times with cold water,
and stored under water, or, if a very small amount is desired for
experimental purposes, it is dried in a desiccator.
The chemical reactions in the preparation appear to be as
follows. (1) The alcohol is oxidized to acetaldehyde, and (2) the
nitrous acid which is formed attacks the acetaldehyde to form a
nitroso derivative which goes over to the more stable, tautomeric,
isonitroso form.
CHi—CHO CH—CHO
CHj—CH2—OH -» CHr-CHO > | ^ ||
NO N—OH
Nitrosoacetajdehyde Isonitrosoacetaldehyde
(3) The isonitrosoacetaldehyde is oxidized to isonitrosoacetic
acid, and (4) this is nitrated by the nitrogen dioxide which is
present to form nitroisonitrosoacetic acid.
CH—CHO CH—COOH
NO2
C—COOH
N—OH N—OH ~" N—OH N-
Isonitrosoacetic acid Nitroisonitrosoacetic acid
(5) The nitroisonitrosoacetic acid loses carbon dioxide to form
formonitrolic acid which (6) decomposes further into nitrous
acid and fulminic acid, and (7) the fulminic acid reacts with the
mercury nitrate to form the spa-ingly soluble mercury fulminate
which precipitates.
NO, [NO"; _, HONC
C-K3OOIH ^ CIHJ ^ ^ \
N-OH N-OH Hg(0NC)2
Formonitrolic acid Mercury fulminate
Fulminate can be prepared from acetaldehyde instead of from
alcohol, and from substances which are convertible into acetaldehyde,
such as paraldehyde, metaldehyde, dimethyl- and diethylacetal.-Methyl
alcohol, formaldehyde, propyl alcohol, butyraldehyde,
glycol, and glyoxal do not yield fulminate. 6
Fulminate can, however, be prepared from a compound which
contains only one carbon atom. The sodium salt of nitromethanc
gives with an aqueous solution of mercuric chloride at 0° a white
e W6hler and Theodorovits, Ber., 38, 1345 (1905).