Improvements in the Manufacture of Colouring Matters Derived from Anthraquinone.
Year: 1891

page_text: Date of Application, 18th Mar., 1891
Complete Specification Left, 16th Dec., 1891-Accepted, 12th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Colouring Matters Derived
from Anthraquinone.
I, BENJAMIN WILLCOX, of 47 Lincoln's Inn Fields, in the County of Middlesex,
Patent Agent, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Farbenfabriken vormals Friedrich Bayer & Co.,
of Elberfeld, in the Empire of Germany,) to be as follows
:-
I. When the formulæ of the constitutions of alizarin, oxychrysazin (oxyanthra-
rufin) and alizarin bordeaux as represented in the following diagram
are compared, the oxychrysazin appears as an intermediate compound situated
between the other two oxyanthraquinones. In a corresponding way the properties
of the oxychrysazin occupy an intermediate or middle position between those of
alizarin and of alizarin bordeaux as is indicated for instance by the colour of the
solution in concentrated sulphuric acid and (contrarily to what has been stated in
chemical literature according to which oxychrysazin should produce colours inter-
mediate between those of alizarin and purpurin) the colours obtained on previously
mordanted wool.
It might consequently be anticipated that by oxidising oxychrysazin, either
alizarin bordeaux itself or its derivatives would be arrived at.
This expectation has been confirmed by trials. My foreign correspondents have
now discovered that oxychrysazin, when submitted to the process described in the
Specification accompanying my application for Letters Patent dated June 5th 1890,
No. 8725, can be converted into a colouring matter which greatly resembles
alizarin bordeaux and in the same way as the latter dyes bordeaux colours on
wool mordanted with alumina and a violet-black on wool mordanted with chromium
salts.
In this case also by the action of fuming sulphuric acid of high percentage upon
the oxychrysazin there results in the first place a sulphuric acid ether which by
heating with acids or by dissolving in alkaline lye and decomposing the boiling
alkaline solution with acids is converted into the colouring matter itself.
The following is given as an example of the process by which it is manu-
factured.
1 part by weight of finely pulverised and dried oxychrysazin is gradually intro-
duced into 10 parts by weight of fuming sulphuric acid containing 70 per cent. of
anhydride and the mixture is allowed to stand at a temperature of from about
35 to 40 degrees Centigrade for two or three days. It is then poured out into
20 parts by weight of sulphuric acid (66 degrees Baumé) and this mixture is
poured into 200 parts by weight of water. The materials are then boiled up and.
filtered;
the deposit is dissolved in soda lye and 200 parts by weight of boiling.
water the colouring matter is precipitated with acid, filtered and washed.

page_text: When an equal weight of erithro-oxyanthraquinone is employed in place of the
oxy-chrysazin in the foregoing example a colouring matter is obtained the properties
of which present great similarity to the dyestuff derived from anthrarufin according
to the Specification accompanying my application for Letters Patent dated
November 19th 1890 No. 18729 and which dyes a blueish-red colour upon alumina
mordants and a violet upon chromium mordants.
there is
In the manufacture of this bordeaux from erithro-oxyanthraquinone
likewise formed in the first instance a sulphuric acid ether which may be converted
into the colouring matter itself in the manner herein before described.
My
II. In my aforesaid Specification No. 1872900 and in the Specification No. 1883
accompanying my application for a Patent dated February 2nd 1891 I have
described colouring matters which result from the action of sulphuric acid
anhydride upon anthraquinone or on dichloro- or dibromo-anthracene.
foreign correspondents have now discovered that in addition to these substances
a large number of other anthracene or anthraquinone derivatives can be con-
verted into new alizarin colouring matters by the action of sulphuric acid
anhydride.
Colouring matters can thus be obtained from tribromo-anthracene, tetra-bromo-
anthracene, dibromo-anthracene - tetra - bromide, mono-bromo-anthra-quinone,
anthranol and the like for example by introducing 1 part by weight of these sub-
stances into 10 parts by weight of sulphuric acid anhydride and leaving the mixture
to stand at a temperature not higher than 60 degrees Centigrade.
The reacting mass is treated in the manner described under head I. In this
case also there is obtained as the direct product of the reaction a sulphuric acid
ether which by heating with acids or dissolving in alkali and decomposing the
boiling alkaline solution with diluted acids is converted into the colouring matter
itself. These colouring matters are similar to those described in the Specifications
Nos. 18729 of 1890 and 1883 of 1891. They dye on alumina and chromium
mordants colours more or less violet or blue respectively.
III. In the Specification accompanying my application for a Patent dated
August 13th 1890 No. 12715 I have described a new colouring matter termed
"alizarin cyanine R" which is obtained by treating alizarin bordeaux in a sul-
phuric acid solution with oxidizing agents.
In making this dyestuff my foreign correspondents observed the appearance of
an intermediate product which by the action of ammonia produced a new
colouring matter namely alizarin cyanine G (see Specification No. 17712 dated
November 4th 1890).
Further investigation of the reactions that take place in this process has
led my foreign correspondents to the technically valuable inventions hereinafter
described.
In treating alizarin bordeaux in a sulphuric acid solution with oxidising agents
there result according to the conditions under which the operation is conducted,
two different colouring matters which possess in common the property of forming
blue chromium lakes and which on this account are hereinafter briefly designated
by the terms "alizarin cyanine I" and "alizarin cyanine II."
It may here be observed that these two cyanines are seen to differ best and very
distinctly in the absorption band of the spectra of their sulphuric acid solution.
Under certain conditions intermediate products are also formed which are herein-
after more fully described.
The alizarin cyanine I is exclusively formed when the oxidation of the alizarin
bordeaux is caused to take place at not too high a temperature and with not too
large a quantity of manganese. The following proportions for example may be
employed with good effect. 10 parts by weight of dry alizarin bordeaux are dis-
solved in 200 parts of sulphuric acid at 66 degrees Baumé and 10 parts by weight
of finely pulverised manganese at 88 per cent. are gradually introduced being well
stirred and without allowing the temperature to rise above 25 degrees Centigrade.
The melt is treated as directed in the Specification No. 12715 of 1890 or pre-

page_text: ferably according to the new method of conducting the process as hereinafter
described.
The alizarin cyanine II is formed by the further oxidation of the cyanine I and
consequently can be obtained directly from alizarin bordeaux by oxidising the
latter more energetically than in the foregoing example. It is also advantageous
to keep the temperature of the reaction somewhat higher. The following is given
as an example of the method of conducting the operation:
10 parts by weight of dry alizarin bordeaux are dissolved in 200 parts by weight
of sulphuric acid at 66 degrees Baumé and 14 parts of manganese are introduced
into the solution the temperature being so regulated as to stand at between 50
and 60 degrees Centigrade to the end of the operation. The melt is then main-
tained at this temperature until a test portion treated and dissolved in concentrated
sulphuric acid shews in the spectroscope only the characteristic absorption bands
of the alizarin cyanine II.
This second cyanine is also exclusively formed when the oxidation of the alizarin
bordeaux is performed with arsenic acid in which case a more elevated temperature
of from about 140 to 150 degrees Centigrade for example is necessary in order to
produce the required reaction. As an example take :-
10
وو
"
,, dry arsenic acid.
These materials are to be heated for about 6 hours to from 140 to 150 degrees
Centigrade. In this case naturally there is no formation of an intermediate
product, the melt is poured out into water, the deposit is filtered off and
redissolved.
The alizarin cyanine II also results when alizarin cyanine I is oxidised at an
elevated temperature with sulphuric acid only. For example 10 parts by weight
of dry alizarin cyanine I and 200 parts by weight of sulphuric acid at 66 degrees
Baumé are heated to 190 degrees Centigrade until a test portion dissolved in con-
centrated sulphuric acid affords only the characteristic spectrum of the cyanine II.
The melt is then poured into water and treated in the usual manner.
The two dyestuffs or colouring matters thus obtained resemble one another in
many respects but in a state of purity they nevertheless shew striking differences.
The alizarin cyanine I is more readily dissolved in nitro-benzene, glacial acetic
acid and the like than is the cyanine II. The latter is consequently enabled to be
easily isolated from a mixture of. the two by fractional crystallization out of nitro-
benzene or the like. In concentrated sulphuric acid the cyanine II dissolves with
a somewhat redder colour than does the cyanine I the latter dissolving with a
bluish-green colour. In gas light this difference especially in a diluted solution is
very evident. The sulphuric acid solution of cyanine II possesses in addition a
far stronger fluorescence than that of the cyanine I. As already mentioned the
spectra of these solutions shew extremely characteristic absorption bands and the
same effect is observed with the solutions in glacial acetic acid. Cyanine II dyes
with chrome mordants a somewhat greener colour than does cyanine I.
My foreign correspondents regard the latter as a penta-oxy-anthraquinone.
Cyanine II being the result of further oxidation of the cyanine 1 is most probably
a hexa-oxy-anthraquinone.
IV. My foreign correspondents have also found that the intermediate product,
formed in the manufacture of the aforesaid cyanine I and cyanine II with the
employment of manganese as the oxidising agent, belongs to a hitherto unknown
class of anthraquinone derivatives which may be regarded as true quinones that is
to say as anologues of benzoquinone and which consequently contain another true
quinone group along with the double ketone group of anthraquinone. This product
is termed anthra-diquinone by my foreign correspondents.
These intermediate products also display all the properties of true quinone
and especially possess the same facility for reduction by sulphurous acid to the

page_text: corresponding hydroquinones (cyanines).
The latter may inversely be easily
converted by oxidation into the quinone (intermediate product).
There being under the circumstances a technical advantage in adopting the latter
method of conducting the process in manufacturing the intermediate product
(quinone) it is illustrated by the following examples. The oxidation may be effected
in a solution of sulphuric acid or of an alkali.
-
In the former case the operation is conducted as follows for example :-
10 parts by weight of dry alizarin cyanine R (this term includes the two cyanines
hereinbefore described in part III or mixtures thereof) are dissolved in 150 parts
by weight of sulphuric acid and parts by weight of pulverised manganese are
introduced at a temperature not higher than 30 degrees Centigrade.
The formation of quinone is known to be concluded when a test portion poured
into pure concentrated sulphuric acid does not shew any fluorescence. The
separation of the quinone (intermediate product) is effected as described in the
Specification accompanying my application for a Patent dated November 4th 1890
No. 17712.
The quinone may also be very conveniently prepared in an alkaline solution.
In this case the oxidation is performed by the action of the atmosphere. The
potassium or sodium salts of the quinone being more difficultly soluble than are the
corresponding salts of the hydroquinone (cyanine) they may be easily obtained or
separated in the solid form. By taking for example :-
100 parts by weight of a 10 per cent. paste of alizarin cyanine R diluted with
1000 parts by weight of water and mixed with 20 parts by weight of caustic alkali
and passing a strong current of air through the solution the potassium salt of the
quinone soon appears in the form of deep blue flakes. When the quantity of those
flakes ceases to increase the materials are filtered and the free colouring matter can
be obtained by decomposing with an acid at a low temperature.
By boiling with water or diluted acids the quinones thus obtained may be converted
into their hydro-quinones or cyanines.
V. The characteristic nature of the intermediate product (as a quinone) obtained
in the production by the aid of manganese of the two cyanines hereinbefore referred
to under head III shews that treatment of the intermediate product with reducing
agents is the rational way to convert the latter into the cyanine or its hydro-
quinone.
For example the "cyanine melt" obtained from alizarin bordeaux and manganese
in a sulphuric acid solution is poured into water taking care to avoid a too high
temperature and to the acid liquid so much sodium sulphite is added as to cause an
odour of sulphurous acid to be perceptible even after standing for a time. The
transition from quinone into hydro quinone is known by the violet colour of the
intermediate product changing to the red-brown of cyanine. The materials are
then boiled up and filtered and the dyestuff is redissolved. It dyes with stronger
and purer colours than does the dye obtained according to the Specification
No. 12715 of 1890 by simply boiling the intermediate product with water or
diluted acids.
VI. According to the process described in the Specification No. 17712 of 1890 a
new colouring matter namely alizarin cyanine G" is obtained by the action of
ammonia upon the cyanine intermediate product.
In this case also two different colouring matters can be obtained (being probably
quinone imides) by employing the two intermediate products corresponding to the
two cyanines herein before described under heading III. The intermediate product,
quinone, directly obtained from alizarin bordeaux and manganese in a sulphuric
acid solution may be employed or the quinone obtained from the cyanines (hydro-
quinones) as herein before described under head IV.
My foreign correspondents have further discovered that the same or similar
colouring matters can be very conveniently obtained by oxidizing in an ammoniacal
solution the two cyanines obtained according to head III or mixtures thereof
preferably by means of air.

page_text: For example 100 parts by weight of a 10 per cent. paste of alizarin cyanine R are
dissolved in 1000 parts of water and 100 parts of 20 per cent. ammonia. A strong
current of air is caused to pass through the solution until a test portion precipitated.
out with acid dissolves in concentrated sulphuric acid with the red-currant colour
of cyanine G. The materials are then diluted with 3000 parts of water, the
colouring matter is precipitated by boiling with acid, filtered and washed neutral.
VII. The processes hereinbefore described under heads IV, V and VI for the
manufacture of anthra-diquinones and of hydro-quinones and ammoniacal derivatives
from diquinones can also be applied with great advantage to the quinoline
derivative of alizarine bordeaux (a dioxy-alizarin blue) described in the Specifi-
cation No. 8725 of 1890 or to the product resulting from the action of sulphuric
acid upon alizarin bordeaux according to the Specification No. 17712 of 1890 or
to the product (a hexa-oxy-anthra-quinone) resulting from the action of sulphuric
acid anhydride upon anthra quinone according to the Specification No. 18729
of 1890.
In order to manufacture the colouring matter obtained from the quinoline
derivative of the alizarin bordeaux the process is conducted as follows for
example :-
==
10 parts by weight of the dry quinoline derivative of alizarin bordeaux are dissolved
in 200 parts by weight of sulphuric acid at 66 degrees Baumé and 5 parts by
weight of finely pulverised manganese are introduced into the solution at a
temperature of from 20 to 30 degrees Centigrade.
The progress of the reaction is indicated by the change from the blue colour
of the sulphuric acid solution of the quinoline derivative to the green of the
quinone.
On pouring out the melt on to ice a deep red solution is obtained, by neutralising
the greater part of the free sulphuric acid with alkali taking care to prevent any
rise of temperature by the application of ice the quinone separates in the form of a
brown-red precipitate which is filtered off and washed with ice water.
The quinoline derivative in question can also be oxidized into a diquinone in an
alkaline solution. 100 parts by weight of a 10 per cent. paste of the quinoline
derivative are stirred into 1000 parts by weight of water the coloured matter being
dissolved by means of a suitable quantity of soda lye. A strong current of air is
caused to pass through the solution until a test portion in an excess of diluted
sulphuric acid dissolves completely without heat. The materials are then acidulated
and the separated quinone filtered off.
This product dissolves in concentrated sulphuric acid with a blue-green colour
and dissolves readily in diluted acid without heat with a red colour. By means of
reducing agents such as sulphurous acid for example the quinone is directly
reconverted into its hydro-quinone the corresponding quinoline derivative (dioxy-
alizarin-blue).
In the like manner as hereinbefore described with regard to the quinoline
derivative of alizarin bordeaux, the hexa-oxy-anthra-quinone, which as herein-
before explained is obtained from alizarin bordeaux by oxidation with sulphuric
acid or from anthra-quinone by oxidation with sulphuric acid anhydride, may be
converted into a diquinone.
In the process of obtaining the latter in a sulphuric acid solution by oxidation
by the aid of manganese the reaction is known to be ended when a test portion
poured into concentrated sulphuric acid ceases to display any fluorescence.
The materials subjected to reaction are then poured out on to ice and the
precipitate is separated by filtration and washed.
In order to obtain the oxidation in an alkaline solution the process is preferably
conducted as follows, for example:
100 parts by weight of a 10 per cent. paste of hexa-oxy-anthra-quinone are
dissolved in 1000 parts of water and 12 parts of soda lye at 34 degrees
Baumé.
A strong current of air is caused to pass through the solution whereupon the

page_text: soda salt of the oxy-diquinone separates almost quantitatively in the form of
blue flakes. These are filtered off, made into slime with water and the
diquinone being set free by acidulation at a low temperature, is filtered off and
washed.
The colouring matter obtained by these means is in the form of a violet precipi-
tate which is fairly permanent in comparison with the quinones of the cyanines.
In cold water it is soluble with difficulty, but dissolves readily in hot water
with a blue violet colour. In glacial acetic acid it dissolves readily with a red
violet colour. Its solution in caustic alkali is greenish blue with alkali in excess
the corresponding alkaline salts are readily precipitated.
The solution of the pure material is concentrated sulphuric and is of a bright
green blue and displays no fluorescence.
Reducing agents such as sulphurous acid for example convert this colouring
matter readily and smoothly into its hydro quinone, the hexa-oxy-anthra-quinone.
Mordants colour the oxy-diquinone in similar shades to the hexa-oxy-anthra-
quinone but the colours are much stronger or more intense. On chrome mordants
for example a very beautiful violet-blue is obtained.
The two diquinones lastly described similarly to cyanine quinone react readily
with ammonia to form new colouring matters the manner of whose preparation
is illustrated by the following examples.
The diquinone obtained from 10 parts by weight of the quinoline derivative of
alizarin bordeaux for example is stirred with 100 parts by weight of ammonia
of 20 per cent. strength; this mixture being diluted with water the colouring
matter is precipitated with an acid.
In
This colouring matter is clearly distinguishable from the original material.
a soda lye it dissolves with a much greener colour and even an excess of alkali
does not cause precipitation.
The solution in concentrated sulphuric acid is of a dirty brown red colour
possessing relatively small intensity. On chrome mordants the colouring matter
produces shades of a greener tinge than the original product.
With alkaline bisulphites the colouring matter forms compounds, which are
soluble in water and which can be advantageously employed for dyeing and
printing.
A very similar colouring matter is also obtained by treating an ammoniacal solution
of the quinoline derivative of alizarin bordeaux with oxidising agents air being
employed with advantage for this purpose. The operation is conducted as directed
under head VI for the diquinone of the two alizarin cyanines.
In an analogous manner the herein before described diquinone of the hexa-oxy-
anthra-quinone by treatment with ammonia or the hexa-oxy-anthra-quinone itself
by treatment with ammonia and air can be converted into their ammonia derivatives.
A paste is thus obtained which when held up to the light displays a beautiful blue
violet colour and dissolves with the same colour in soda lye. The solution in
glacial acetic acid and alcohol is violet red, in concentrated sulphuric acid cherry
red. The new colouring matter colours mordants with a greener tinge than hexa-
oxy-anthra-quinone.
VIII. In the same way as the true quinones the anthra diquinones also react
with hydrochloric or hydrobromic acid forming chloro- or bromo-hydro-quinones.
The process for their production consists in mixing together the anthra-diquinone
in the form of a paste with an excess of concentrated hydrochloric or hydrobromic
acid and leaving the mixture until the end of the reaction is shown by the change
in the colour of the mixture. In certain cases it is advantageous to accelerate the
reaction by the application of heat.
The colouring matters thus obtained from the diquinones of the alizarin cyanines I
and II as well as those derived from the diquinones of the hexa-oxy-anthra-quinone
and the quinoline derivative of alizarin bordeaux produce on mordanted fibre
greener tones than does the corresponding original product.
IX. As already stated under head I the oxy-chrysazin stands midway between

page_text: alizarin and alizarin bordeaux and there is also formed from oxy-chrysazin by
oxidation with fuming sulphuric acid, a product which is probably identical with
alizarin bordeaux. My foreign correspondents have now discovered that by the
oxidation of oxy-chrysazin in a sulphuric acid solution with manganese or other
like oxidising agents the diquinones of the alizarin cyanine I (quinone of a penta-
oxy-anthra-quinone) hereinbefore described under head IV is obtained which in
turn can be further oxidised into the diquinone of the alizarin cyanine II (quinone
of a hexa-oxy-anthra-quinone).
The manufacture of this colouring matter is conducted according to the process
hereinbefore described under head IV the oxidising being carried on to a greater
or lesser extent according to the nature of the oxy-anthra-quinone to be obtained.
With 10 parts by weight of oxy-chrysazin for example about 16 parts by weight of
manganese are required in order to produce the diquinone of the alizarin cyanine I
and about 24 parts for the quinone of the alizarin cyanine II.
By means of this process extremely important colouring matters of the alizarin
cyanine class are obtained without the necessity for employing a great quantity of
sulphuric acid anhydride.
Dated this 18th day of March 1901
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Colouring Matters Derived
from Anthraquinone.
I, BENJAMIN WILLCOX of 47 Lincoln's Inn Fields in the County of Middlesex,
Patent Agent, do hereby declare the nature of this invention (which has
been communicated to me from abroad by The Farbenfabriken vormals Friedrich
Bayer & Co. of Elberfeld in the Empire of Germany) and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement :-
I. When the constitutional formula of alizarin oxychrysazin (oxyanthrarufin)
and alizarin bordeaux as represented in the following diagrams :-
are compared, oxychrysazin is seen to occupy an intermediate position. In accordance
therewith the properties of oxychrysazin are found to be intermediate between those
of alizarin and those of alizarin-bordeaux for example, on comparing the colours
of their solutions in concentrated sulphuric acid and (though it is on record in
chemical literature that oxychrysazin produces colours intermediate between those
of alizarin and purpurin) the shades produced by their agency on mordanted
wool.
My foreign correspondents have discovered that when submitted to the process
described in the Specification of Letters Patent No. 8725 dated June 5th 1890
oxychrysazin is converted into a colouring-matter which greatly resembles alizarin-
bordeaux and like the latter dyes wool, mordanted with alumina a bordeaux, and
wool mordanted with chromium salts, a violet-black.

page_text: In this case also the action of fuming sulphuric acid of high percentage on
oxychrysazin leads to the formation in the first place of a sulphuric-ether which
may be converted into the colouring matter either by heating it with acids or by
dissolving it in alkaline lye and then treating the boiling alkaline solution with
acid. The following is given as an example of this process.
1 part, by weight, of finely pulverised and dried oxychrysazin is gradually
introduced into 20 parts, by weight, of fuming sulphuric acid containing 80 per cent.
of anhydride and the mixture is allowed to stand at a temperature of from about 3.5
to 40 degrees Centigrade for two or three days. It is then added to 20 parts, by
weight, of sulphuric acid (66 degrees Baumé) and the whole is poured into 200 parts,
by weight, of water. The resulting mixture is then boiled and filtered. After
the deposit has been dissolved in soda-lye and 200 parts, by weight, of boiling
water the colouring matter is precipitated from the hot alkaline solution by the
addition of acid. It is filtered off and washed.
up
When the corresponding quantity of erythroxyanthraquinone is employed in the
place of oxychrysazin in the foregoing example a colouring matter is obtained the
properties of which shew great similarity to those of the dyestuff prepared from
anthrarufine according to the Specification of Letters Patent No. 18729 dated
November 19th 1890 and which produces a bluish red colour on wool mordanted
with alumina salts and a violet on wool mordanted with chromium salts. In the
manufacture of this bordeaux from erythroxy-anthraquinone there is also formed
.in the first instance a sulphuric ether which may be converted into the colouring-
matter in the manner herein before described.
II. In the Specification of the aforesaid Letters Patent No. 18729 of 1890 and
in the Specification accompanying my application for Letters Patent No. 1883
dated 2nd February 1891 there are described colouring-matters which result from
the action of sulphuric anhydride on anthraquinone or on dichloro- or dibromo-
anthracene. My foreign correspondents have discovered that in addition to these
substances a large number of other anthracene or anthraquinone derivatives can
be converted into new alizarin colouring matters by the action of sulphuric
anhydride.
Colouring-matters can in this way be obtained from tribromanthracene, tetra-
bromanthracene, dibromanthracene-tetrabromide, monobromo-anthraquinone, an-
thranol, and the like; for example, by introducing 1 part by weight of these
substances into 10 parts, by weight, of sulphuric anhydride and leaving the mixture
to stand at a temperature not higher than 60 degrees Centigrade.
The product of the reaction is treated in the manner described under head I.
In this case also the direct product of the reaction is a sulphuric ether which is
converted into the colouring matter either by heating it with acids or by dissolving
it in alkali and treating the boiling alkaline solution with diluted acid. These
colouring matters are similar to those described in the Specifications of Letters
Patent No. 18729 of 1890 and of the application for Letters Patent No. 1883
of 1891 and dye wool, mordanted with alumina salts, a violet, and wool mordanted
with chromium salts, a blue colour.
III. In the Specification of Letters Patent No. 12715 dated August 13th 1890
I have described a new colouring-matter termed "alizarin-cyanine" which is now
called "
alizarin-cyanine R." It is obtained by treating alizarin-bordeaux in a
sulphuric acid solution with oxidising agents.
In the manufacture of this dye-stuff my foreign correspondents observed the
formation of an intermediate product which when submitted to the action of
ammonia yields a new colouring matter (see Specification of Letters Patent
No. 17712 dated November 4th 1890).
Further investigations of the reaction taking place in this process have led my
foreign correspondents to the technically valuable results which are hereinafter
described.
When alizarin-bordeaux is treated in a sulphuric acid solution with oxidising
agents, according to the conditions under which the operation is conducted, two

page_text: different colouring matters are forined, which possess, in common, the property of
forming blue chromium lakes and which have been briefly designated, "alizarin
penta cyanine" and "alizarin hexa cyanine" in order to indicate the shades
produced by them and to express their composition.
It may be mentioned that the absorption spectra of sulphuric acid solutions of
these two cyanines differ very distinctly. Under certain conditions intermediate
products (anthradiquinones) are also formed which are hereinafter more fully
described.
The alizarin penta cyanine is exclusively formed when the oxidation of the
alizarin-bordeaux is effected at not too high a temperature and with not too large
a quantity of oxide of manganese. The following proportions for example may be
employed with good results.
10 parts, by weight, of dry alizarin-bordeaux are dissolved in 200 parts of
sulphuric acid at 66 degrees Baumé and 10 parts, by weight, of finely pulverised
88 per cent. oxide of manganese are gradually introduced with constant agitation
and without allowing the temperature to rise above 25 degrees Centigrade. The
melt which contains the anthradiquinone first produced is treated as mentioned
in the Specification of Letters Patent No. 12715 of 1890 or preferably according
to the new method of conducting the process as hereinafter described.
The alizarin hexacyanine is formed by the further oxidation of the penta-cyanine
and consequently can be obtained directly from alizarin-bordeaux by oxidising the
latter more energetically than in the foregoing example. It is also advantageous
to keep the temperature of the reaction somewhat higher. The following is given
as an example of the method of conducting the operation.
10 parts by weight of dry alizarin bordeaux are dissolved in 200 parts by weight,
of sulphuric acid of 66 degrees Baumé and 14 parts of manganese oxide are
introduced into the solution the temperature being kept at between 50 and 60 degrees
Centigrade during the operation. The mixture is then maintained at this tem-
perature until a test portion dissolved in concentrated sulphuric acid when examined
in the spectroscope shews ouly the absorption bands characteristic of the alizarin
hexa cyanine..
This hexa cyanine is also exclusively formed when the oxidation of the alizarin-
bordeaux is performed with arsenic acid in which case a more elevated temperature
of from about 140 to 150 degrees Centigrade for example is necessary in order to
bring about the required reaction.
The following may be given as an example:
A mixture of 10 parts by weight, of dry alizarin-bordeaux and 150 parts by
weight of sulphuric acid (of 66 degrees Baumé) and 10 parts by weight of dry
arsenic acid are heated for about 6 hours to from 140 to 150 degrees Centigrade.
In this case of course no intermediate product is formed. The mixture is poured
out into water, the deposit is filtered off, dissolved in alkali and again separated by
the addition of acid.
The alizarin hexa cyanine is also formed when alizarin penta-cyanine is oxidised
at an elevated temperature with sulphuric acid only. For example 10 parts by
weight of dry alizarin penta-cyanine and 200 parts, by weight, of sulphuric acid
of 66 degrees Baumé are heated to 190 degrees Centigrade until a test portion
dissolved in concentrated sulphuric acid exhibits only the spectrum characteristic
of the hexa-cyanine. The product of the reaction is then poured into water and
treated in the usual manner.
The two dye-stuffs or colouring matters thus obtained resemble one another in
many respects however in a state of purity they shew striking differences.
Alizarin-penta-cyanine is more readily dissolved by nitrobenzene, glacial acetic
acid, and the like, than is the hexa cyanine. The latter, consequently is easily
isolated from a mixture of the two compounds by fractional crystallisation from
nitrobenzene or the like. In concentrated sulphuric acid the hexa-cyanine dissolves
with a somewhat redder colour than does the penta-cyanine, the latter. dissolving
B

page_text: with a bluish-green colour. In gas light this difference is very evident especially
in a diluted solution.
The sulphuric acid solution of hexa-cyanine also possesses a far stronger
fluorescence than that of the penta-cyanine. As already mentioned the spectra of
these solutions shew extremely characteristic absorption bands and the solutions in
glacial acetic acid possess the same quality. Alizarin hexa-cyanine dyes wool
mordanted with chromium salts somewhat greener than does the penta-cyanine.
My foreign correspondents have proved by elementary analysis that the latter
is a pentaoxyanthraquinone and that the hexa-cyanine obtained by the further
oxidation of the penta-cyanine is a hexaoxyanthraquinone.
IV. My foreign correspondents have also found that the intermediate product,
formed in the manufacture of the aforesaid alizarinpenta- and hexa-cyanine, when
manganese dioxide is employed as the oxidising agent, belongs to a hitherto
unknown class of anthraquinone derivatives which may be regarded as true
quinones that is to say as analogues of benzoquinone and which contain another
true quinone group beside the double ketone group of anthraquinone. These
products have been termed anthra-diquinones by my foreign correspondents.
The following may be given as examples for the production of the quinone of
alizarin hexacyanine and the conversion of the quinone of alizarin pentacyanine
into that of alizarin hexacyanine.
PRODUCTION OF THE QUINONE OF ALIZARIN HEXACYANINE BY
OXIDISING ALIZARIN BOrdeaux.
10 parts by weight of dry alizarin bordeaux are dissolved in 200 parts by weight
of sulphuric acid at 66 degrees Baumé and 14 parts by weight of finely pulverised
88 per cent, manganese dioxide are gradually introduced with constant agitation
keeping the temperature at between 50 to 60 degrees Centigrade.
The formed quinone of the alizarin hexacyanine separates in violet flakes when
the melt is poured into cold water.
CONVERSION OF THE QUINONE OF ALIZARIN PENTACYANINE INTO
THAT OF ALIZARIN HEXACYANINE.
By dissolving 10 parts by weight of alizarin bordeaux in 200 parts by weight of
sulphuric acid at 66 degrees Baumé and gradually adding 10 parts by weight of
pulverised 88 per cent. manganese dioxide to the liquid without allowing the
temperature to rise above 25 degrees Centigrade the quinone of alizarin penta-
cyanine is formed. In order to convert this quinone into that of alizarin hexacyanine
4 parts by weight of manganese dioxide are introduced into the sulphuric acid
liquid allowing the temperature to rise to 50 degrees Centigrade at the end of the
operation.
By pouring the melt into water the quinone of alizarine hexacyanine separates in
violet flakes.
These intermediate products possess all the properties of true quinones being
easily reduced by sulphurous acid and being converted into the corresponding
hydro-quinones (cyanines). Inversely the latter may be easily converted by
oxidation into the quinones (intermediate products).
As in practice it may be advantageous to employ the latter method of
manufacturing the intermediate product (quinone), it is illustrated by the
following examples. The oxidation may be effected in sulphuric acid or alkaline
solution.
In the former case the operation is conducted as follows for example.
10 parts, by weight, of dry alizarin penta- or hexa cyanine are dissolved in
150 parts, by weight, of sulphuric acid and 5 parts by weight of pulverised
inanganese oxide are introduced at a temperature not higher than 30 degrees
Centigrade.

page_text: The formation of the quinones is complete when the solution of a test portion, in
pure concentrated sulphuric acid no longer shews either a fluorescence or absorption
bands in the spectroscope. The separation of the quinone (intermediate product)
is effected as described in the Specification of Letters Patent No. 17712 dated
November 4th 1890.
A practical method of preparing the said quinones is to effect the oxidation in
an alkaline solution by means of atmospheric oxygen. The potassium or sodium
salts of the quinones being less soluble than are the corresponding salts of the
hydroquinones (cyanines) they may easily be separated in the solid form. The
following may be given as an example:-
100 parts by weight of a paste containing 10 per cent. of alizarin cyanine R. are
diluted with 1000 parts by weight of water and mixed with 20 parts by weight of
potash. When a strong current of air is allowed to pass through the solution the
potassium salt of the quinone soon separates in the form of deep blue flakes. As
soon as the quantity of those flakes ceases to increase the mixture is filtered and
the free colouring-matter can be obtained by treating the potassium salt thus
produced with an acid at a low temperature.
By boiling with water, or diluted acids, these quinones may be converted into
their hydroquinones or cyanines.
V. The characteristic nature of the intermediate products (quinones) obtained
in the production by means of manganese oxide of the two cyanines herein before
referred to under head III shews that treatment of the intermediate product with
reducing agents is the rational method of converting the latter into the cyanines
(hydro-quinones).
J
For example the mixture obtained by treating alizarin-bordeaux in a sulphuric
acid solution with manganese oxide is poured into water taking care to avoid too
high a temperatue. Such a quantity of sodium sulphite is then added to the acid
liquid as is necessary to produce a lasting smell of sulphurous acid. The conversion,
of the quinone into the hydroquinone is recognised by the change of the violet
colour of the intermediate product into the red-brown of cyanine. The mixture"
is then boiled up, filtered and the dye-stuff is redissolved. It produces stronger
colours than does the dye obtained according to the Specification of Letters Patent
No. 12715 of 1890 by simply boiling the intermediate product with water or with
diluted acids.
VI. According to the process described in the Specification of Letters Patent
No. 17712 of 1890 a new colouring matter namely alizarin cyanine G. is obtained
by the action of ammonia upon the cyanine intermediate product.
In this case also two different colouring matters can be obtained (which are
probably quinone-imides) by employing the two intermediate products corresponding
to the two cyanines hereinbefore described under head III.
The intermediate product (quinone) directly obtained from alizarin-bordeaux
and manganese oxide in a sulphuric acid solution may be employed or the quinone
resulting from the cyanines (hydroquinones) as hereinbefore described under
head IV.
My foreign correspondents have further discovered that the same, or similar,
colouring-matters can be very conveniently obtained by oxidising (preferably by
means of atmospheric air) an ammoniacal solution of either of the two cyanines,
which result according to head III or mixtures thereof.
For example 100 parts, by weight, of a paste containing 10 per cent. of alizarin
cyanine R. are dissolved in 500 parts of water and 100 parts of liquid ammonia
containing 20 per cent. of ammonia. A strong current of air is caused to pass
through the solution until a test portion precipitated with acids dissolves in con-
centrated sulphuric acid with the red-currant-like colour of the alizarin cyanine G.
The materials are then diluted with 3000 parts of water, the colouring-matter is
precipitated by boiling with acids, filtered off and washed until the washings shew
a neutral reaction.

page_text: A colouring-matter is obtained in like manner by treating the hexaoxyanthra-
quinone in an ammoniacal solution with atmospheric air.
VII. The processes hereinbefore described under heads IV and V of manu-
facturing anthra-diquinones and hydroquinones can also be applied with great
advantage to the quinoline derivative of alizarin-bordeaux or dioxyalizarin blue
described in the Specification of Letters Patent No. 8725 of 1890 or to the product
resulting from the action of sulphuric acid on alizarin-bordeaux according to the
Specification of Letters Patent No. 17712 of 1890 or to the same product (a
hexaoxyanthraquinone) formed by the action of sulphuric anhydride on anthra-
quinone according to the Specification of Letters Patent No. 18729 of 1890.
In order to manufacture the colouring-matter obtained from the quinoline
derivative of alizarin-bordeaux the process is conducted as follows for example:
10 parts, by weight, of the dry quinoline derivative of alizarin-bordeaux are
dissolved in 200 parts, by weight of sulphuric acid at 66 degrees Baumé and 5 parts
by weight of finely pulverised manganese oxide are introduced into the solution at
a temperature of from 20 to 30 degrees Centigrade.
The progress of the reaction is indicated by the change of the blue colour of
the sulphuric acid solution of the quinoline derivative to the green colour of the
quinone.
On pouring the mixture on to ice a deep-red solution is obtained, from which on
neutralizing the greater part of the free sulphuric acid with alkali without raising
the temperature the quinone separates in the form of a brown-red precipitate.
The latter is filtered off and washed with ice water.
This product dissolves in concentrated sulphuric acid with a blue-green colour
and readily dissolves in diluted acids at ordinary temperatures with a red colour.
By means of reducing agents, such as sulphurous acid for example, the quinone is
directly reconverted into its hydroquinone, the corresponding quinoline derivative
(dioxy-alizarin blue).
In like manner as hereinbefore described with regard to the quinoline derivative
of alizarin-bordeaux, the hexaoxyanthraquinone, which as hereinbefore explained,
is obtained by oxidising alizarin-bordeaux or purpurin-bordeaux with sulphuric
acid, or by oxidising anthraquinone with sulphuric anhydride, may be converted
into a diquinone.
In the process of obtaining the latter by oxidation in a sulphuric acid solution
with the aid of manganese oxide the end of the reaction is recognised when a test
portion poured into concentrated sulphuric acid ceases to display any fluorescence
and no longer exhibits absorption bands in the spectroscope. The resulting
mixture is then poured on to ice and the precipitate is separated by filtration and
washed.
In order to carry out the oxidation in an alkaline solution the process is
preferably conducted as follows for example:
100 parts by weight of a paste containing 10 per cent. of hexaoxyanthraquinone
are dissolved in 1000 parts of water and 12 parts of soda lye at 34 degrees
Baume. A strong current of air is caused to pass through the solution where-
upon the soda salt of the oxydiquinone separates, almost quantitatively, in the
form of blue flakes. These are filtered off, suspended in water, and, the diquinone
having been separated by acidulation at a low temperature, is filtered off and
washed. The colouring matter is thus obtained in the form of a violet precipitate
which is fairly stable in comparison with the quinones of the cyanines. It
dissolves with difficulty in cold water but readily in hot water with a blue-violet
colour. In glacial acetic acid it dissolves easily with a red-violet colour. Its
solution in caustic alkali is greenish-blue and by the employment of alkali in
excess the corresponding alkaline salts are readily precipitated. The solution of
the pure product in concentrated sulphuric acid is of a bright green-blue and
shews no fluorescence. Reducing agents, such as sulphurous acid, for example,
convert this colouring-matter readily into its hydroquinone hexaoxyanthraquinone.

page_text: The oxydiquinone dyes mordanted wool shades similar to those of the hexaoxy-
anthraquinone but the shades are somewhat stronger, or more intense. By the use
of chrome mordants for example a very beautiful violet-blue is obtained.
The two last named diquinones, which, like cyanine quinone, readily react with
ammonia, yield, when treated with the latter reagent, new colouring-matters.
Their preparation may be illustrated by the following example.
The diquinone obtained from 10 parts, by weight, of the hexaoxyanthraquinone
is stirred up with 100 parts, by weight, of ammonia of 20 per cent. strength. The
mixture is then diluted with water and the colouring matter is precipitated by the
addition of any acid. A paste is thus obtained which, when held up to the light,
displays a beautiful blue-violet colour and dissolves with the same colour in soda-
lye. The solution in glacial acetic acid and alcohol is violet-red that in concen-
trated sulphuric acid cherry-red. The new colouring-matter dyes mordanted wool
a somewhat greener shade than hexaoxyanthraquinone.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The process for converting erythroxyanthraquinone and oxychrysazin by
treatment with fuming sulphuric acid of high percentage according to the process
described in the Specification of Letters Patent No. 8725 of 1890 into so-called
intermediate products which are sulphuric ethers of the bordeaux of erythroxy-
anthraquinone and oxychrysazin.
2. The process for producing new bordeaux dye-stuffs by heating, either directly,
or in alkaline solution, with acids, the sulphuric ethers which are obtained by the
oxidation of erythroxyanthraquinone and oxychrysazin with fuming sulphuric
acid.
3. The manufacture of new bordeaux colouring matters from erythroxyanthra-
quinone, and oxychrysazin by oxidising them with fuming sulphuric acid of high
percentage and (without isolating the sulphuric ethers first produced) subsequently
heating the products with diluted acids.
4. The process for converting tribromanthracene tetrabromanthracene, dibrom
anthracene tetrabromide, monobromoanthraquinone and anthranol by means of
sulphuric anhydride, according to the process described for the conversion of
anthraquinone dichloro and dibromo anthraquinone in the Specifications of Letters
Patent No. 18729 of 1890 and in the Specification of the application for Letters
Patent No. 1883 of 1891 into so-called intermediate products which are sulphuric
ethers of the bordeaux resulting from the oxidation of tribromanthracene, dibrom-
anthracene-tetrabromide monobromoanthraquinone and anthrano!.
5. The process for producing new bordeaux dre stuffs by heating, either directly,
or after dissolving in alkaline solution, with acids, the sulphuric ethers which are
formed, as so-called intermediate products, when tribromanthracene, dibromanthra-
cenetetrabromide, monobromanthraquinone, and anthranol are treated with sulphuric
anhydride according to the process described in the Specifications of Letters
Patent No. 18729 of 1890 and of the application for Letters Patent No. 1883
of 1891.
6. The manufacture of new bordeaux colouring matters by oxidising tribrom-
anthracene, dibromanthracenetetrabromide monobromoanthraquinone and anthranol
with sulphuric anhydride and (without isolating the first formed sulphuric ethers)
subsequently heating the products with dilute acids.
7. The process for oxidising alizarin-bordeaux into the quinone of a new cyanine
(the so called alizarin pentacyanine) by the action of not too large a quantity of
manganese dioxide upon alizarin-bordeaux in sulphuric acid solution at ordinary
temperature.
8. The conversion of alizarin-bordeaux into the quinone of a new cyanine (the
so-called alizarin hexacyanine) by oxidising the former in sulphuric acid solution
with an excess of manganese dioxide.

page_text: 9. The conversion of the quinone, of alizarin pentacyanine into that of alizarin
hexacyanine by oxidising the former in sulphuric acid solution with manganese
dioxide.
10. The process for producing alizarin hexacyanine, either by further oxidising
alizarin pentacyanine in sulphuric acid solution with oxidising agents, or by
treating alizarin pentacyanine exclusively with concentrated sulphuric acid at
elevated temperatures.
11. The transformation of the alizarin hexacyanine and alizarin pentacyanine
into new colouring matters (the so-called diquinones) either by further oxidising
them in sulphuric acid solution at ordinary temperatures with manganese dioxide
or by oxidising the alkaline solutions of the said two cyanines by means of
atmospheric oxygen.
12. The conversion of the anthradiquinones of alizarin pentacyanine and alizarin
hexacyanine into hydroquinones viz. -alizarin pentacyanine and alizarin hexa-
cyanine by boiling them with water or diluted acids, or, by treating them with
reducing agents.
13. The process for producing new colouring matters by the action of ammonia
upon the anthradiquinones of alizarin pentacyanine and alizarin hexacyanine.
14. The conversion of alizarin-bordeaux quinoline (dioxyalizarin blue) of the
Specification of Letters Patent No. 8725 of 1890 into the corresponding anthra-
diquinone colouring matter by the action of manganese dioxide upon the said
quinoline in sulphuric acid solution.
15. The transformation of hexaoxyanthraquinone into the corresponding anthra-
diquinone colouring matter by acting on the hexaoxyanthraquinone, in sulphuric
acid solution, with manganese dioxide or by oxidising the alkaline solutions of
the hexaoxyanthraquinone with the aid of atmospheric oxygen.
16. The process for reconverting the anthradiquinones obtained from dioxy
alizarin blue and hexaoxyanthraquinone into their hydroquinones (dioxy alizarin
blue and hexaoxyanthraquinone) by the treatment with reducing agents.
17. The production of a new valuable dyestuff by treating with ammonia the
anthradiquinone obtained from hexaoxyanthraquinone.
18. The manufacture of new dye-stuffs by the treatment of alizarin pentacyanine,
alizarin hexacyanine, and hexaoxyanthraquinone, in ammoniacal solution with
atmospheric air.
19. As new products the following compounds :-
a.
Sulphuric ethers of erythroxyanthraquinone bordeaux and oxychrysazin
bordeaux.
b. Erythroxyanthraquinone bordeaux, and oxychrysazin bordeaux.
c. Sulphuric ethers of the bordeaux obtained from tribromanthracene, anthra-
cene tetrabromide, monobromoanthraquinone and anthranol.
d. Bordeaux obtained from tribromauthracene anthracene tetrabromide mono-
bromanthraquinone and anthranol.
e. Alizarin pentacyanine, and alizarin hexacyanine.
f. So-called diquinones of alizarin pentacyanine, alizarin hexacyanine, hexa-
oxyanthraquinone and alizarin bordeaux quinoline.
9. Colouring matters obtained by treating in ammoniacal solution the alizarin
pentacyanine, the alizarin hexacyanine and hexaoxyanthraquinone with
atmospheric air.
h. Dye-stuffs resulting from the action of ammonia on the diquinones of
alizarin pentacyanine, alizarin hexacyanine and hexaoxyanthraquinone.
Dated this 16th day of December 1891.
J. H. JOHNSON & Co.,
Agents.