Manufacture of O- and P-amidobenzylideneaniline, their Homo- logues, and their Sulphonic Acids, and of Amidobenzaldehydes. therefrom.
Year: 1898

page_text: Date of Application, 7th May, 1898
Complete Specification Left, 3rd Feb., 1899-Accepted, 4th Mar., 1899.
PROVISIONAL SPECIFICATION.
Manufacture of O- and P-amidobenzylideneaniline, their Homo-
logues, and their Sulphonic Acids, and of Amidobenzaldehydes.
therefrom.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, Chancery
Lane, in the County of London, Chartered Patent Agent, do hereby declare the nature
of this invention (as communicated to me from abroad by The Farbwerke vormals:
Meister Lucius & Brüning, of Hoechst a/ Main, in the Empire of Germany, Chemical.
Manufacturers) to be as follows :-
For the reduction of o- and p- nitrobenzyl-aniline with ammonium-sulphide, two
methods are to be found in literature. Strakosch (Ber. VI 1063) obtained by a
short action of an excess of ammonium-sulphide upon p- nitrobenzylaniline under
pressure a base melting at 88°C, which he considered to be amidobenzulaniline,
but which was, according to later researches (Germ. Lett. Pat. 56908) diamido-
diphenylmethane.
The second method emanates from C. Paal (German Lett. Pat. 52647 now void),.
who states, that by the action of ammonium-sulphide upon o-nitrobenzylaniline the
o-amidobenzylaniline may bo obtained.
In taking up the study of this subject, my foreign correspondents have found,
that the action of sulphur-alkalies upon the two nitrobenzylanilines mentioned,
their homologues and sulphonic acids in an aqueous or alcoholic solution and under
certain conditions takes a very peculiar course.
By the action of sulphur alkalies (for instance sodium sulphide, preferably with
an addition of sulphur) the nitrobenzylanilines of the simplest general formula:
'
? (NH,. CH. CH. N. C,H,)
If, instead of the said nitrobenzylanilines their sulphonic acids NO.. CH "CH..
NH. CH. SO,H. (or their respective salts) are subjected to the same treatment.
the corresponding amidobenzylidene-aniline-sulphonic acids of the general
formula NH. CH. CH: N. CH. SO,H. are obtained.
In both combining methods, the amidobenzylidene-bases and their sulphonic
acids take up 1 molecule of water under the conditions below described and

page_text: decompose, as is known, into the aniline-base (or its sulphonic acid) and
amidoaldehyde.
114 parts by weight of p-nitrobenzylaniline are dissolved in 400 parts by
weight of alcohol, to which is added a solution of 120 parts by weight of sodium-
sulphide (NaS + 9H2O) and 32 parts by weight of sulphur in 100 parts by
weight of water.
The mixture becomes heated and soon becomes of an intense red-yellow
colour.
The reaction is facilitated by the introduction of heat so as to keep the liquid
on a gentle boil. The reaction is generally completed within 2-3 hours; the
alcohol is distilled off and the remaining oil is repeatedly washed with water
to remove the inorganic salts.
The p-amidobenzylideneaniline thus obtained, is of a red-yellow, thick-fluid, not
distillable oil, of weak aniline odour; it turns sometimes after standing for a
considerable time into a vivid amorphous mass (evidently a product of polymerisation).
If diluted mineral acids be poured over it the p-amidobenzylideneaniline solidifies
to a crystalline paste of the well known red product of polymerisation of p-amido-
benzaldehyde. In the same way as the p-amidobenzylideneaniline, its homologues
may be obtained from the homologous nitrobenzylanilines, especially the
following
The p-amidobenzylidene-bases thus obtained are quite identical in their physical
properties and chemical behaviour with the p-amidobenzylideneaniline.
II. P-AMIDOBENZYLIDENE-ANILINE-SULPHONIC ACIDS.
230 parts by weight of p-nitrobenzylsulphanilate of sodium are dissolved in
1000 parts by weight of water, to which is added a solution of 250 parts by weight
of sodium sulphide (Na,S+ 9H,O) and 65 parts by weight of sulphur in 200 parts
by weight of water and heated for 4 to 5 hours on the water-bath. From this
solution the separated sulphur is filtered off, whereupon, after the filtrate is cooled
down, the p-amidobenzylidenesulphanilate of sodium crystallizes out in yellow
laminae. Heated with diluted acids, the p-amidobenzylidenesulphanilic acid
decomposes into sulphanilic acid and the above mentioned red product of
polymerisation of p-amidobenzaldehyde.
In the same way as the p-amidobenzylidenesulphanilic acid is derived from
p-nitrobenzylsulphanilic acid, thus from the two isomerides of the latter the isomeric
p-amidobenzylideneaniline-sulphonic acids are obtained and from the homologues
of p-nitrobenzylanilinesulphonic acids the homologous p-amidobenzylidene-aniline-
sulphonic acids, especially:

page_text: CH..N.CH.CH.NH,+2 H,O = CH.NH, + HUC.U DẠNH,.
In this case, however, as already stated, the amido-benzaldehydes are not obtained
as such, but in form of their products of polymerisation.
My foreign correspondents, succeeded, however, in finding methods which permit
the isolation of the simple, not polymerised amido-aldehydes.
These methods are based upon observations, that, on the one hand amido-benzyli-
dene-bases and their sulphonic acids, being so little stable, decompose when boiled
with water into amido-aldehyde and the aniline-base (or sulphonic acid)--and on the
other hand, amidobenzylidene-bases and their sulphonic acids, when treated with a

page_text: compound the aldehyde may be separated by diluted alkalies.
The method to be employed depends upon the physical properties of the products
of decoinposition of a given amido-benzylidene-compound, especially upon its solu-
bility and volatility with steam.
The process may be as follows
f
1. O-AMIDOBENZALDEHYDE.
o-amidobenzylidene-aniline-sulphonic acid or one of its homologues or its salts, is
simply distilled with steam; the resulting o-amido-benzaldehyde goes over with the
steam, whilst the not volatile aniline-sulphonic acid remains behind. From the
distillate the o-amido-benzaldehyde may be obtained according to the directions of
Friedländer and Goehring (Ber. XV. 2572 XVII. 456).
This method would be less suitable for the manufacture of p-amido-benzaldehyde
it is not volatile with steam. It is preferable here to use the bisulphite
method.
as
:
2). P-AMIDOBENZALDEHYDE.
On 50 parts by weight of amido-benzylidene-aniline or the equivalent quantity of
one of its homologues are poured 100 litres of a bisulphite solution of 45% and the
mixture is distilled with steam for so long as aniline (or its respective homologue)
is still to be traced in the distillate. The remaining yellow solution in the retort is
filtered off from some resin'and heated with an excess of a fixed alkali or alkaline
carbonate. A small portion of the p-amidobenzaldehyde thus set free is precipitated
as a yellow amorphous powder and is filtered off; from this filtrate is obtained the
greater quantity of p-amido-benzaldehyde as a quickly solidifying yellow-oil.
If p-amidobenzylidene-aniline or its homologues be distilled with steam, in the
absence of bisulphite, the base in question goes likewise over and the aldehyde
remains as an amorphous yellow-red mass.
Dated this 7th day of May 1898.
ABEL & IMRAY,
Agents for the Applicant.
Manufacture of Ortho- and Para-Amidobenzylideneaniline, their
Homologues, and their Sulphonic Acids, and of Amidobenzalde-
hydes therefrom.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, Chancery
Lane, in the County of London, Chartered Patent Agent, do hereby declare the
nature of this invention (as communicated to me from abroad by The Farbwerke
vormals Meister Lucius & Bruning of Hoechst a/ Main, in the Empire of Germany,
Chemical Manufacturers) and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
For the reduction of ortho- and para-nitrobenzylaniline with ammonium
sulphide, two methods are to be found in literature. Strakosch (Ber. VI 1063)
obtained by a short action of an excess of ammonium sulphide upon para-nitrobenzyl-
aniline,under pressure a base melting at 88° C. which he considered to be amido-
benzylaniline, but which was, according to later researches (Gerin. Lett. Pat. 56908),
1

page_text: The second method emanates from C. Paal (German Lett. Pat. 52647 now
void), who states, that by the action of ammonium sulphide upon ortho-nitro-
benzylaniline the ortho-amidobenzylaniline may be obtained. In taking up the
study of this subject, my foreign correspondents have found, that the action of
alkali sulphides upon the two nitrobenzylanilines mentioned, their homologues
and sulphonic acids in an aqueous or alcoholic solution and under certain conditions
takes a very peculiar course.
By the action of alkali sulphides (for instance sodium sulphide, preferably with
an addition of sulphur) the nitrobenzylanilines of the simplest general formula
2 (NO.CH¸CH₂.NH.C₁H) + NaS = N₁₂SO̟ + 2 (NH.CH.CH : N.C¸¸)
If, instead of the said nitrobenzylanilines their sulphonic acids NO.CH.CH.
NH.C.H..SO,H. (or their respective salts) are subjected to the same treatment, the
corresponding amidobenzylideneaniline-sulphonic acids of the general formula
NH.CH.CH: N.CH.SO H. are obtained. In both combining methods, the amido-
benzylidene-bases and their sulphonic acids take up 1 molecule of water under the
conditions below described and decompose as is known, into the aniline-base (or its
sulphonic acid) and amidoaldehyde.
NH.C.H..CH: N.C.H. + H₂O
=
NH.CH.COH + NH.C.H.
The amidobenzylidene-bases (or their respective sulphonic acids) as well as their
orresponding amidobenzaldehydes are used for the manufacture of aniline dyestuffs
f various groups, and in particular of triphenylmethane-dyestuffs. To manufacture
he said compounds, the following methods may be employed.
144 parts by weight of para-nitrobenzyl-aniline are dissolved in 400 parts by
weight of alcohol, to which is added a solution of 120 parts by weight of sodium
sulphide (Na, S + 9 H₂O) and 32 parts by weight of sulphur in 100 parts by weight
of water.
The mixture becomes heated and soon becomes of an intense red-yellow colour.
The reaction is facilitated by heating so as to keep the liquid on a gentle boil.
The reaction is generally completed within from 2 to 3 hours; the alcohol is
distilled off and the remaining oil is repeatedly washed with water to remove the
inorganic salts.
The para-amidobenzylideneaniline thus obtained, is a red-yellow viscid, not
distillable oil, of weak aniline odour; it turns sometimes after standing for a
considerable time into a vivid amorphous mass (evidently a product of polymerisa-
tion). If diluted mineral acids be poured over it the para-amidobenzylideneaniline
solidifies to a crystalline paste of the well-known red product of polymerisation of
para-amidobenzaldehyde."

page_text: In the same way as the para-amidobenzylideneaniline, its homologues may be
obtained from the homologous nitrobenzylanilines, especially the following:
n amidobenzylidene-o-toluidine from p. nitrobenzyl-o-toluidine
p.
"
"
-m-xylidine
"
p.
"
-in-xylidine
The p-amidobenzylidene-bases thus obtained are quite identical in their physical
properties and chemical behaviour with the p-amidobenzylideneaniline..
II. P-AMIDOBENZYLIDENE-ANILINE-SULPHONIC ACIDS.
230 parts by weight of para-nitrobenzyl-sulphanilate of sodium are dissolved in
1000 parts by weight of water, to which is added a solution of 250 parts by weight
of sodium sulphide (Na, S + 9 H₂O) and 65 parts by weight of sulphur in 200
parts by weight of water, and heated for 4 to 5 hours on the water-bath. From
this solution the separated sulphur is filtered off, whereupon, after the filtrate is
cooled down, the para-amidobenzylidene-sulphanilate of sodium crystallizes out in
yellow laminae. Heated with diluted acids, the para-amidobenzylidenesulphanilic
acid decomposes into sulphanilic acid and the above mentioned red product of
polymerisation of para-amidobenzaldehyde.
In the same way as the para-amidobenzylidenesulphanilic acid is derived from
para-nitrobenzylsulphanilic acid, thus from the two isomerides of the latter
the isomeric para-amidobenzylideneaniline-sulphonic acids are obtained and from
the homologues of para-nitrobenzylanilinesulphonic acids the homologous para-
amidobenzylideneaniline-sulphonic acids, especially :
From para-nitrobenzyl-ortho-toluidinesulphonic acid the para-amidobenzylidene-
ortho-toluidinesulphonic acid
From para-nitrobenzyl-para-toluidinesulphouic acid the para-amidobenzylidene-
para-toluidinesulphonic acid
From para-nitrobenzyl-xylidine sulphonic acid the
xylidine sulphonic acids.
para-amidobenzylidene-
The properties of all coincide closely with those of the above mentioned para-
amido-benzylidenesulphanilic acid.
III. ORTHO-AMIDOBENZYLIDENE-ANILINE
AND ITS HOMOLOGUES, ORTHO-AMIDOBENZYLI-
DENESULPHANILIC ACID, ITS ISOMERIDES AND HOMOLOGUES.
If in the above examples I and II for the para-nitrobenzylaniline and its homologues
or the para-nitrobenzylsulphanilic acid, its isomerides and homologues be substituted
the corresponding ortho-nitro-compounds, there are obtained on the one hand
ortho-amidobenzylideneaniline and its homologues and on the other hand ortho-
amidobenzylidene-anilinesulphonic acids, their isomerides and homologues.
Thus is obtained:

page_text: are
The ortho-amido-benzylideneanilines thus obtained are orange-yellow, not
distillable oils. The said ortho-amidobenzylideneaniline-sulphonic acids
soluble in form of their alkali salts in water with a yellow colour; the free acids
are exceedingly unstable, as they decompose when heated with water into auiline-
5 sulphonic acid and ortho-amido-benzaldehyde. On being treated with mineral
acids, the ortho-amido-benzylideneanilines as well as their sulphonic acids
decompose while forming products of polymerisation of ortho-amido-benzaldehyde.
The para- and ortho-amidobenzylideneaniline and their sulphonic acids are
decomposed by the action of diluted mineral acids into the aniline-base (or its
sulphonic acid) and the amido aldehyde, according to the following equation:
C.H.. N. CH. C.H. NH, + H,O = C.H. NH, + HỌC. C,H. NH,
Ortho-amido benzylidene-aniline-sulphonic acid or one of its homologues or its
salts, is simply distilled with steam; the resulting ortho-amido-benzaldehyde goes
over with the steam, whilst the not volatile aniline-sulphonic acid remains behind.
From the distillate the ortho-amido-benzaldehyde may be obtained according to the
directions of Friedländer and Gochring (Ber. XV. 2572 XVII. 456.)
This method would be less suitable for the manufacture of para-amidobenzalde-
hyde as it is not volatile with steam. It is preferable here to use the bisulphite
method.
2. PARA AMIDOBENZALDEHYDE.
On 50 parts by weight of amido-benzylidene-aniline or the equivalent quantity
of one of its homologues are poured 100 litres of a bisulphite solution of 45 per cent.
strength and the mixture is distilled with steam for so long as aniline (or its
respective homologue) is still to be traced in the distillate. The remaining yellow
solution in the retort is filtered from some resin and heated with an excess of a
fixed alkali or alkaline carbonate. A small portion of the para-amidobenzaldehyde
thus set free is precipitated as a yellow amorphous powder and is filtered off: from
this filtrate is obtained the greater quantity of para-amidobenzaldehyde as a quickly
solidifying yellow-oil.
If para-amidobenzylidene-aniline or its homologues be distilled with steam, in the
absence of bisulphite, the base in question goes likewise over and the aldehyde
remains as an amorphous yellow-red mass.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described manufacture of ortho- and para-amidobenzylideneaniline,
their homologues and sulphonic acids by heating ortho- and para-nitrobenzylaniline,
their homologues or sulphonic acids with alkali sulphides, with or without addition
of sulphur.
2. The herein described manufacture of ortho- and para-amidobenzaldehyde
from ortho- and para-amidobenzylidene bases or their sulphonic acids obtained
as above set forth, by heating those bases with water or alkali bisulphite
solutions.
1
1
1
ALL