The Manufacture of Aromatic Compounds by Means of Hydrocyanic Acid and Certain Derivatives thereof.
Year: 1898

page_text: [Communicated from abroad by the FARBENFABRIKEN vormals FRIEDRICH BAYER &
Co., of Elberfeld, Germany.]
The Manufacture of Aromatic Compounds by Means of Hydrocyanic
Acid and Certain Derivatives thereof.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6, Bream's Buildings, Chancery
Lane, in the County of London, Patent Agent, do hereby declare the nature of this
invention to be as follows :-
My foreign correspondents discovered some time since a process for producing
aromatic aldehydes, which process consists in first allowing either hydrochloric and
hydro-cyanic acid (or salts of the latter), or the completed double compound of hydro-
chloric and hydrocyanic acid, to act, in the presence of aluminium chloride, on
aromatic hydrocarbons, phenolic ethers, or the like bodies, and, secondly, splitting up
the so-called aldimides thus obtained by means of acids.
My foreign correspondents have now found that if, instead of phenolic ethers, free
phenols or acid phenolic ethers are subjected to the action of the above mentioned
re-agents, aromatic hydroxyaldehydes are obtained.
In case phenol is used, the new process proceeds most probably according to the
following equations :-

page_text: EXAMPLE A.
To an icy cold mixture of 20 parts of phenol and 20 parts of dry hydrocyanic acid
(boiling at 27 degrees Centigrade) 30 parts of aluminium chloride (AIC) are
gradually added. Into the resulting mass, a current of dry hydrochloric acid gas is
introduced for about five hours. During this reaction, the temperature of the mixture
is profitably kept icy cold for the first three hours; subsequently it is allowed to rise
slowly up to from about 40 to 50 degrees Centigrade. The mass is then cooled again.
and subsequently poured on ice. The reaction product so obtained is boiled for a
short time with dilute hydrochloric acid, and the parahydroxybenzaldehyde thus set
free is extracted by the aid of ether from the liquid which has been previously saturated
with common salt. The ethereal extract is subsequently mixed with a concentrated
sodium bisulphite solution, and the sodium bisulphite double compound of the
hydroxyaldehyde thus separated is filtered off. On treating this double compound
with dilute sulphuric acid, the free parahydroxybenzaldehyde results in a pure
state.
The process proceeds in an analogous manner if, instead of phenol, as above
mentioned, other phenols such as pyrogallol or the like, or acid phenolic ethers, are
employed. Thus, for instance, from the monomethylic ether of resorcinol, the known
aldehyde melting at 153° Centigrade, and having the formula
18 Obtained.
My foreign correspondents have further found that if, instead of hydrocyanic and
hydrochloric acid, or of the completed double-compound from the said acids, the
so-called sesquihydrochloride of hydrocyanic acid, having the formula :-
2 CNH. 3 HCl (see Berichte der Deutschen Chemischen Gesellschaft Vol. 16
p. 309) is allowed to act, in the presence of aluminium chloride, on aromatic
hydrocarbons, phenols, or phenolic ethers, the process proceeds in a different manner.
It may be remarked that according to the researches of my foreign correspondents,
the said compound does not act like a mixture of hydrocyanic and hydrochloric acid,
but like a body having the formula -
-
If this body is allowed to act on hydrocarbons, phenolic ethers, or the like, two
atoms of chlorine are substituted by two radicles of hydrocarbons or phenolic ethers,

page_text: To an icy-cold mixture of 12 parts of benzene and 10 parts of the sesquihydroch-
loride of hydrocyanic acid (2 CNH. 3 HCI), 10 parts of aluminium chloride are
gradually added, with stirring. When the development of hydrochloric acid has
ceased, the mixture is poured on ice; an intermediate product having the above
given formula A is thus obtained in the shape of colorless crystals. In order to
prepare therefrom directly benzyhydrylamine (see the above formula C), this inter-
mediate product is boiled with a caustic soda lye (free from carbonic acid) until
ammonia is no longer developed and the oil separated during the reaction (which is
the benzhydrylamine) is found to be soluble in dilute hydrochloric acid.
Analogous results are obtained, if, instead of benzene, other aromatic hydrocarbons,
or phenolic ethers or the like, are employed in the foregoing example.

page_text: The reaction proceeds in an analogous manner if, in place of aromatic hydrocarbons,
tertiary amines are employed. In this case, the addition of aluminium chloride is
not necessary. On allowing, for instance, dimethylaniline to act on the sesqui-
hydrochloride of hydro-cyanic acid, the leuco-base of auramine, having the
formula:-
15 parts of dimethylaniline are heated with/5 parts of the aforesaid sesqui hydro-
chloride of hydrocyanic acid (2 CNH-3HCl), say, for 5 hours, at about 130° Centi-
grade. The violet-coloured reaction product is then dissolved in water, and the
resulting solution is rendered strongly alkaline by means of caustic soda lye. The
unchanged dimethylaniline is distilled therefrom by means of steam, and the leucobase
of the crystal-violet, which separates in a pure state, is isolated from the liquid by
filtration.
1
My foreign correspondents wish it to be understood that they do not intend to
confine themselves to the particulars given in the above examples, as these are merely
typical, and can be varied within wide limits, without altering thereby the nature of
the present invention.
The Manufacture of Aromatic Compounds by Means of Hydrocyanic
Acid and Certain Derivatives thereof.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6, Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
My foreign correspondents discovered some time since a process for producing
aromatic aldehydes, which process consists in first allowing either hydrochloric and
hydrocyanic acid (or salts of the latter), or the completed double compound of hydro-
chloric and hydrocyanic acid, to act, in the presence of aluminium chloride, or
aromatic hydrocarbons, phenolic ethers, or the like bodies; and, secondly, splitting
up the so-called aldimides thus obtained by means of acids.
My foreign correspondents have now found that if, instead of phenolic ethers, free
phenols, or acid phenolic ethers, are subjected to the action of the above-mentioned
re-agents, aromatic hydroxyaldehydes are obtained.

page_text: To an icy-cold mixture of 20 parts of phenol and 20 parts of dry hydro-cyanic acid
(boiling at 27 degrees Centigrade), 30 parts of aluminium chloride (AIC) are
gradually added. Into the resulting mass, a current of dry hydro-chloric acid gas is
introduced for about five hours. During this reaction, the temperature of the
mixture is advantageously kept icy-cold for the first three hours; subsequently the
temperature is allowed to rise slowly up to from about 40 to 50 degrees Centigrade.
The mass is then cooled again, and subsequently poured on ice. The reaction product
so obtained is boiled for a short time with dilute hydro-chloric acid, and the para-
hydroxybenzaldehyde thus set free is extracted, by the aid of ether, from the liquid
which has been previously saturated with common salt. The etheric extract is
subsequently mixed with a concentrated sodium bisulphite solution, and the sodium
bisulphite double compound of the hydroxyaldehyde thus separated is filtered off.
On treating this double compound with dilute sulphuric acid, free parahydroxybenz-
aldehyde in a pure state results.
The process proceeds in an analogous manner if, instead of phenol, as above
mentioned, other phenols, such as resorcinol, pyrogallol, or the like, or acid phenolic
ethers, are employed. Thus, for instance, from the monomethylic ether of resorcinol,
the known aldehyde, melting at 153° Centigrade, and having the formula
30 is obtained. The reaction can also be performed without the presence of aluminium
chloride, especially if those phenols, or phenolic ethers, are employed which contain
more than one free hydroxy group.
My foreign correspondents have further found that if, instead of hydrocyanic and

page_text: hydro-chloric acid, or of the completed double compound from the said acids, the
so-called sesquihydro-chloride of hydrocyanic acid having the formula:-
2 CNH. 3HCI (see Berichte der Deutschen Chemischen Gesellschaft, Vol. 16,
p. 309) is allowed to act, in the presence of aluminium chloride, on aromatic
hydrocarbons, phenols, or phenolic ethers, the process proceeds in a different manner.
It may be remarked that according to the researches of my foreign correspondents,
the said compound does not act like a mixture of hydrocyanic and hydrochloric acid,
but like a body having the formula

page_text: gradually added with stirring. When the development of hydrochloric acid has
ceased, the mixture is poured on ice; an intermediate product having the above-given
formula a is thus obtained in the shape of colorless crystals. In order to prepare
therefrom directly benzhydrylamine (see the above formula C), this interinediate
product is boiled with a caustic soda lye (free from carbonic acid), until ammonia is
no longer developed, and the oil separated during the reaction (which is the
benzhydrylamine) is found to be soluble in dilute hydrochloric acid.
Analogous results are obtained if, instead of benzene, other aromatic hydrocarbons,
such as toluene or the like, or phenolic ethers, such as anisol or the like, 'are employed
in the foregoing example.
The reaction proceeds in an analogous manner if in place of aromatic hydrocarbons,
tertiary amines are employed. In this case, the addition of aluminium chloride is
not necessary. On allowing, for instance, dimethylaniline to act on the sesquihy-
drochloride of hydrocyanic acid,the leuco-base of auramine, having the formula

page_text: without the presence of aluminium chloride, substantially as herein before
described.
4. As new articles of manufacture, the new bodies obtainable according to the
processes herein before described and claimed.
NEWTON & SON,
Agents for the Applicant.