The Manufacture and Production of New Alizarin Derivatives.
Year: 1892

page_text: Date of Application, 7th July, 1892.
Complete Specification Left, 5th Apr., 1893-Accepted, 13th May, 1893
PROVISIONAL SPECIFICATION.
The Manufacture and Production of New Alizarin Derivatives.
I, BENJAMIN WILLCOX of 47 Lincolus 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 to be as follows:-
In the Specification of Letters Patent No. 12715 granted to me and dated
13th August 1890 alizarin colouring matters are described which are soluble in
water and result from the sulphurising of alizarin bordeaux or analogues thereof.
My foreign correspondents have now found that similar blue dye-stuffs of value
are obtained by sulphonating alizarin pentacyanine and alizarin hexacyanine
described in the Specification of Letters Patent No. 4871 granted to me and
dated 18th March 1891 and hexaoxyanthaquinone described in the Specification of
my application for Letters Patent No. 13677 dated 13th August 1891 and isomeric
with alizarin hexacyanine. In order to effect the sulphonation fuming sulphuric
acid, sulphuric acid monochlorhydrine, a mixture of sulphuric acid and meta-
phosphoric acid, and the like, can be employed.
The production of the sulpho acid of hexaoxyanthraquinone is illustrated by the
following example.
FIRST EXAMPLE.
MANUFACTURE OF HEXAOXYANTHRAQUINONE SULPHO ACID.
50 kilos. of dried hexaoxyanthraquinone are introduced into 125 kilos. of
fuming sulphuric acid containing 20 per cent. of anhydride and the solution thus
obtained is heated at about 100 degrees centigrade until a sample, when poured
into water, dissolves clearly. The whole liquid is then poured into 2000 liters of
water and the colouring-matter is salted out, filtered off, pressed and dried. It.
forms a dark powder soluble in water with a red colour and in soda-lye with a
violet-blue colour and produces, on wool mordanted with alumina salts, violet
shades and on wool, mordanted with chromium salts, blue shades.
In a similar manner the sulpho acids of alizarin pentacyanine and alizarin
hexacyanine are obtained.
These products possess the following properties: The sulpho acid of alizarin
pentacyanine dissolves in acidulated water with a yellowish-red colour in sodium,
carbonate and ammonia liquid with a violet colour and in soda-lye with a violet-blue
colour whilst by employing an excess of soda-lye a violet-blue precipitate is separated.
It is dissolved by concentrated sulphuric acid with a blue colour and produces,
on wool mordanted with alumina salts violet shades and on wool mordanted with
chromium salts blue shades. The sulpho derivative of alizarin hexacyanine is
dissolved in acidulated water with a bluish-red colour and in sodium carbonate with
a blue colour whilst by using an excess of the latter reagent a blue precipitate.
separates. In ammonia liquid it dissolves with a pure blue colour which becomes
greenish-blue when the liquid is allowed to stand in the open air. It dissolves in
soda-lye with a greenish-blue colour whilst an excess of this reagent yields a
bluish-green precipitate. Its solution in concentrated sulphuric acid is of a violet
colour and it yields on wool mordanted with alumina salts, blue shades, and on wool
mordanted with chromium salts greenish-blue shades. The sulpho acid obtained
from hexaoxyanthraquinone dissolves in acidulated water with a brilliant yellowish
MAGA
1:1 L
aulous and in coda lvo with

page_text: violet-blue colour; whilst by employing an excess of these two latter reagents a
violet precipitate is separated. In ammonia liquid it dissolves with bluish-violet
colour which becomes more bluish when the atmospheric air is allowed to come
into contact therewith. Its solution in concentrated sulphuric acid is of a red
colour when in a layer of some depth whilst it possesses when in a thin layer a
violet-blue colour. On wool mordanted either with chromium or with alumina salt,
it produces shades similar to those produced by the sulpho derivative of alizarin
pentacyanine.
My foreign correspondents have further found that the oxyanthraquinones
containing but a few hydroxylic groups can be changed into analogous dye stuffs
either by oxidizing them at first by means of sulphuric anhydride or manganese
dioxide and subsequently sulphonating the so formed oxyanthraquinones containing
a greater number of hydroxylic groups than the original products or inversely by
sulphonating at first the oxyanthraquinones containing but a few hydroxylic groups
and subsequently oxidizing the resulting sulpho acids. My foreign correspondents
have found that the corresponding products obtained by either of these two methods
are identical.
Of the oxyanthraquinones. which contain but a few hydroxylic groups the
following can be employed for example.
.
(a) Alizarin bordeaux which is the product to start from in producing alizarin
pentacyanine as described in the Specification of Letters Patent No. 4871 dated
18th March 1891.
(b) Oxyflavopurpurine and flavopurpurine which have been employed for
producing hexaoxyanthraquinone described in the Specification of my application
for Letters Patent No. 13677 dated 13th August 1891.
(c) Alizarin pentacyanine oxyanthrapurpurine and anthrapurpurine which may
be used for the production of alizarin hexacyanine described in the said Specifi-
cation of Patent No. 487191.
My foreign correspondents subjected to the above mentioned oxidizing process
those sulpho acids which result by a moderate treatment of the aforesaid coloring
matters or analogues thereof and most probably contain the sulpho groups in
juxta position to the two hydroxylic groups of the alizarin nucleus.
By further research my foreign correspondents have found that it is not necessary
to employ the above sulpho acids after having been isolated in a solid state but the
mixture obtained in the sulphurizing process after a suitable addition of concentrated
sulphuric acid can be directly employed.
The oxidation process and the proportion of the oxidizing agents such as
manganese dioxide and the like may be the same as those described in the Specifi-
cation of Letters Patent No. 4871 dated 18th March 1891 and in the Specification
of my application for Letters Patent No. 1657 dated 27th January 1892.
It is to be observed that in effecting the oxidation for example by means of
manganese dioxide at a comparatively low temperature the reaction mixture contains
the colouring matters not as such but as the quinone derivatives thereof (so called
anthradiquinones) which are generally to be termed oxyanthradiquinone sulpho
acids. The latter are extremely unstable and even if their solutions in water are
allowed to stand or instantly in treating them with reducing agents they change
into the hydroquinones viz. oxyanthraquinone sulpho acids.
The following is given as an example for the conversion of alizarin bordeaux
sulpho acid into the sulpho acid of alizarin pentacyanine.

page_text: reactions products analogous to nitropurpurine vi. nitrooxyflavopurpurine and
nitrooxyanthrapurpurine probably are formed at first and the latter are changed
by subsequent oxidation into the alizarincyanine like colouring matters. In a
manner the same as in all such oxidations the dye-stuffs are in the reaction
mixture as quinones or anthradiquinones which are converted into the dye-stuff's
either by heating with water or, by acids or, more advantageously by treatment
with reducing agents.
The following example is given in order to illustrate the said method.
OXIDATION OF BETA NITROANTHRAPURPURINE.
A thorough mixture of 10 kilos. of betanitroanthra purpurine and 16 kilos. of
finely pulverised manganese dioxide (containing 90 per cent. of MnO2) is slowly
and whilst continually stirring introduced into 300 kilos. of sulphuric acid at
66 degrees Baumé, taking care that the temperature does not rise above
20 degrees centigrade. As the reaction proceeds the colour of the sulphuric acid
solution changes from brownish-red to strong greenish-blue. The resulting
mixture does not contain the complete dye-stuff, but an intermediate product
thereof, which belongs to the series of the so called oxyanthradiquinones. This
intermediate product readily dissolves in cold water with a violet-red colour and
the oxidation of the beta-nitroanthrapurpurine is complete when a test portion
of the sulphuric acid mixture poured into water dissolves with a clear violet red
colour.
The transformation of the intermediate product formed next into the dye-stuff
itself is based on the property of the former to be changed into the colouring
matter by boiling with water or acids or more practically by treating with reducing
agents such as alkaline sulphites, sulphur dioxide, and the like. The whole liquid
is then poured into 3000 litres of water mixed with 10 kilos. of a watery solution
of sodium bisulphite at 34 degrees Baumé.
After boiling the separated colouring matter is filtered off and washed with water
in order to remove the adherent acid.
It produces on wool mordanted with alumina salts a dull violet colour and on
wool mordanted with chromium salts valuable greenish-blue shades.
A similar dye-stuff is obtained from betanitroflavopurpurine.
By further researches my foreign correspondents have found that the oxidation
of Aavopurpurine, anthrapurpurine, oxyflavopurpurine, and oxyanthrapurpurine
and analogues thereof into alizarin cyanines as described in the Specification of my
application for Letters Patent No. 1657 dated 27th January 1892, can be effected
more advantageously by employing the arsenic acid ethers of the said colouring
matters. These arsenic acid ethers are very readily and almost instantly formed
by mixing a solution of the aforesaid colouring matters in concentrated sulphuric
acid with dry arsenic acid, at ordinary temperatures, oxidation not taking place in
this process. They are characterised by the colour of their alkaline solutions
which is of but little intensity and varies from yellowish to brownish. By boiling
with water or diluted acids they are decomposed into their components. It is an
advantage that the oxidation of these arsenic acid ethers by means of manganese
dioxide proceeds slowly and smoothly and therefore can be better superintended.
The following is given as an example for this process.

page_text: soon as a test portion on being poured into water and having an excess of soda-lye
added to it yields a clear brownish-yellow solution the formation of the ether is
complete. Whilst constantly stirring 17 kilos. of finely pulverised manganese
dioxide (90 per cent. MnO,) are introduced and the temperature is so regulated
that at the end of the operation it is about 45 degrees centigrade. When the
temperature ceases to rise the whole liquid is poured into water and the dye-stuff
can be isolated as described in the Specification of my application for Letters
Patent No. 1657 dated 27th January 1892.
Dated this 7th day of July 1892.
J. H. JOHNSON & Co.,
47 Lincoln's Inn Fields, London, W.C., Agents.:
COMPLETE SPECIFICATION.
The Manufacture and Production of New Alizarin Derivatives.
I BENJAMIN WILLCOX of 47 Lincolns 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 Farbenfabriken vorm. Fried. 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:-
In the Specification of Letters Patent No. 12715 granted to me and dated
13th August 1890 soluble alizarin colouring matters are described which are formed
by sulphonating alizarin bordeaux or analogues thereof.
My foreign correspondents have now found that similar valuable dye-stuffs are
obtained by sulphonating the alizarin pentacyanine and alizarin hexacyanine
described in the Specification of Letters Patent No. 4871 granted to me and
dated 18th March 1891 and the hexaoxyanthraquinone described in the Specification
of Letters Patent No. 13677 dated 13th August 1891 isomeric with alizarin
hexacyanine. In order to effect the sulphonation, fuming sulphuric acid, sulphuric
monochlorhydrin, a mixture of sulphuric acid and metaphosphoric acid, and the
like, can be employed.
The production of the sulpho acid of hexaoxyanthraquinone is illustrated by the.
following example. The parts are by weight.
FIRST EXAMPLE.
MANUFACTURE OF HEXAOXYANTHRAQUINONE SULPHO ACID.
50 kilos. of dried nexaoxyanthraquinone are introduced into 125 kilos. of fuming
sulphuric acid containing 20 per cent. of anhydride, and the solution thus obtained
is heated at about 100 degrees centigrade until a sample dissolves in water forming
a clear solution. The liquid mass is then poured into 2000 liters of water and the
colouring-matter is salted out, filtered off, pressed and dried. It forms a dark
powder which dissolves in water forming a red and in soda-lye forming a violet-
blue coloured liquid and produces violet shades on wool, mordanted with alumina
salts, and blue shades on wool, mordanted with chromium salts.
The sulpho acids of alizarin pentacyanine and alizarin hexacyanine are obtained
in a similar manner.
These products possess the following properties:
The sulpho acid of alizarin pentacyanine dissolves in acidulated water forming
a yellowish-red coloured liquid; it dissolves in solutions of sodium carbonate and
ammonia forming violet coloured liquids and its solution in soda-lye is of a
violet-blue colour, an excess of soda-lye causing the separation of a violet-blue
precipitate. It is dissolved by concentrated sulphuric acid forming a blue coloured

page_text: liquid and produces violet shades on wool mordanted with alumina salts and blue
shades on wool mordanted with chromium salts.
The sulpho derivative of alizarin hexacyanine dissolves in acidulated water
forming a bluish-red and in a solution of sodium carbonate forming a blue coloured
liquid, an excess of the latter agent however causes the separation of a blue
precipitate. It dissolves in a solution of ammonia forming a pure blue coloured
liquid which becomes greenish-blue in colour when allowed to stand in the open
air. It dissolves in soda-lye forming a greenish-blue coloured solution an excess of
this agent causing a bluish-green precipitate. Its solution in concentrated
sulphuric acid is of a violet colour and it produces blue shades on wool mordanted
with alumina salts and greenish-blue shades on wool mordanted with chromium
salts.
The sulpho acid obtained from hexaoxyanthraquinone dissolves in acidulated
water producing a brilliant yellowish rose colour, in sodium carbonate solution
producing a bluish violet colour and in soda-lye producing a violet-blue colour
if an excess of these two latter agents be used a violet precipitate is separated. It
dissolves in ammonia solution forming a bluish-violet coloured liquid which becomes
bluer in shade when atmospheric air is allowed to come into contact therewith. Its
solution in concentrated sulphuric acid is of a red colour when viewed in a layer of
some depth, whilst when a thin layer is inspected a violet blue colour is seen.
wool mordanted either with chromium or with alumina salts it produces shades
similar to those produced by the sulpho derivative of alizarin pentacyanine.
On
My foreign correspondents have further found, that the oxyanthraquinones
containing few hydroxylic groups can be changed into analogous dye-stuffs either
by oxidising them at first by means of sulphuric anhydride, manganese dioxide or
the like and subsequently sulphonating the resulting oxyanthraquinones containing
a greater number of hydroxylic groups than the original products or inversely by
at first sulphonating the oxyanthraquinones containing but few hydroxylic groups
and subsequently oxidising the resulting sulpho acids. My foreign correspondents
have found that the corresponding products obtained by either of these two methods
are identical.
Of the oxyanthraquinones which contain but few hydroxylic groups the following
can be employed for example:-
(a) Alizarin bordeaux, which is the initial product used in producing alizarin
pentacyanine as described in the Specification of Letters Patent No. 4871 dated
18th March 1891.
(b) Oxyflavopurpurin and flavopurpurin, which have been employed for producing
hexaoxyanthraquinones as described in the Specification of Letters Patent
No. 13677 dated 13th August 1891.
(c) Alizarin pentacyanine, oxyanthrapurpurin and anthrapurpuriu which may be
used for the production of alizarin hexacyanine as described in the said Specifi-
cation of Letters Patent No. 487191.
My foreign correspondents subjected to the above mentioned oxidising process
those sulpho acids which are formed by a moderate treatment of the aforesaid
colouring-matters, or analogues thereof and which most probably contain the sulpho
groups in juxta position to the two hydroxylic groups of the alizarin nucleus.
By further research my foreign correspondents have found that it is not necessary
to first isolate the above mentioned sulpho acids in a solid state but that the mixture
obtained in the sulphonating process can be directly employed after adding a
suitable amount of concentrated sulphuric acid.
The oxidation process and the proportion of the oxidising agents such as manganese
dioxide and the like may be the same as those described in the Specification
of Letters Patent No. 4871 dated 18th March 1891 and in the Specification of
Letters Patent No. 1657 dated 27th January 1892.
It is to be observed that on effecting the oxidation for example by means of
manganese dioxide at a comparatively low temperature the product does not contain
the colouring-matters as such but as the quinone derivative thereof (so called

page_text: PRODUCTION OF ALIZARIN PENTACYANINE SULPHO ACID FROM THE SULPHO
ACID OF ALIZARIN BORDEAUX.
10 kilos. of alizarin bordeaux and 25 kilos. of fuming sulphuric acid (containing
20 per cent. of anhydride) are heated at 100 degrees centigrade until when a
sample is poured into water it dissolves forming a clear solution 175 kilos. of
sulphuric acid (66 degrees Baumé) are then added and 10 kilos. of finely powdered
manganese dioxide (90 per cent. of MnO2) are introduced, stirring constantly and
taking care that the temperature does not rise above 20 degrees centigrade. The
conversion of alizarin bordeaux sulpho acid into the pentacyanine quinone sulpho
acid is distinguishable by the change in colour of the sulphuric liquid from violet
to blue. When a portion is poured into water it dissolves communicating to the
liquid a violet colour which is characteristic of solutions of pentacyanine quinone
sulpho acid. After standing during some time or on heating or on adding
sulphurous acid or the like the said colour changes into the red colour of the
corresponding alizarin pentacyanine sulpho acid. The whole liquid is poured into
water and sodium bisulphite is added until the aforesaid change in colour indicates
that complete reduction of the alizarin pentacyanine quinone sulpho acid into the
alizarin pentacyanine sulpho acid has taken place. The dye-stuff is isolated by
salting out and filtering off and is purified by dissolving it in water and salting out
again.
By employing a greater quantity of manganese dioxide and a somewhat higher
temperature a product is formed which is essentially a mixture of sulpho acids of.
alizarin hexacyanine and hexaoxyanthraquinone. The same product is obtained,
when, alizarin pentacyanine is sulphonated and the resulting sulpho acid is oxidised.
The method of preparing alizarin hexacyanine sulpho acid from anthrapurpurin
sulpho acid is illustrated by the following example. The parts are by weight.
•
THIRD EXAMPLE.
PRODUCTION OF ALIZARIN HEXACYANINE SULPHO ACID FROM THE SULPHO
ACID OF ANTHRAPURPURIN.
10 kilos. of anthra purpurin are heated with 25 kilos. of fuming sulphuric acid
containing 20 per cent. of anhydride at 100 degrees centigrade until a test portion
dissolves clearly in water. After adding 300 kilos. of sulphuric acid (66 degrees
Baumé) the mixture is oxidised by means of 19 kilos. of manganese dioxide
(0 per cent. MnO2) at a temperature from about 30 to 40 degrees centigrade. The
action takes place, and the finished dye-stuff is isolated and purified in a manner
similar to that described in the foregoing second example.
The conversion of flavopurpurin sulpho acid into that of hexaoxyanthraquinone is
effected in the same manner.
My foreign correspondents have further found that in starting from the sulpho
acids of anthrapurpurin flavopurpurin, oxyflavopurpurin and oxyanthrapurpurin it
is possible to produce the alizarin hexacyanine described in the Specification of
Letters Patent No. 4871 dated 18th March 1891 and hexaoxyanthraquinone
described in the Specification of Letters Patent No. 13677 dated 13th August 1891

page_text: MANUFACTURE OF ALIZARINIIEXACYANINE.
The alizarin hexacyanine sulpho acid obtained as described in the foregoing third
example is heated with 100 kilós. of sulphuric acid (60 degrees Baumé) during
about 6 hours at 180 degrees centigrade. The liquid is poured into water, and the
separated alizarin hexacyanine is filtered off and purified by dissolving it in alkali,
filtering the alkaline solution and treating it with acids.
My foreign correspondents have further found that betanitroflavopurpurin and
betanitroanthrapurpurin can also by suitable oxidation be changed into dye-stuffs
belonging to the alizarin cyanine series. In these actions products analogous to
nitropurpurin viz. nitro-oxyflavopurpurin and nitrooxyanthrapurpurin are probably
at first formed and these latter are changed by subsequent oxidation into the
alizarin-cyanine-like colouring matters. As is the case in all such oxidations the
dye-stuffs are present in the product as quinones or anthradiquinones which are
converted into the dye-stuffs either by heating with water or by acids or more
advantageously by treatment with reducing agents.
The following example is given in order to illustrate the said method.
OXIDATION OF BETANITROANTHRAPURPURIN.
A thorough mixture of 10 kilos. of betanitroanthra purpurin and 16 kilos. of finely
pulverised manganese dioxide (containing 90 per cent. of MnO2) is slowly introduced
into 300 kilos. of sulphuric acid at 66 degrees Baumé, the mixture being kept
stirred the while and care being taken that the temperature does not rise above
20 degrees centigrade. As the action proceeds, the colour of the sulphuric acid
solution changes from brownish-red to intense greenish-blue. The resulting mixture
does not contain the complete dye-stuff but an intermediate product belonging to
the series of the so called oxyanthradiquinones. This intermediate product readily
dissolves in cold water forming a violet-red coloured solution, and the oxidation of
the betanitroanthrapurpurin is complete when a test portion of the sulphuric acid
mixture dissolves in water forming a clear violet-red coloured liquid.
The transformation of the resulting intermediate product into the dye-stuff may
be effected by taking advantage of the property of the former of changing into the
colouring-matter on boiling with water or acids or, more practically, on treatment
with reducing agents such as alkaline sulphites, sulphur dioxide and the like. To
effect the change the whole liquid is poured into 3000 litres of water mixed with
10 kilos. of a solution of sodium bisulphite (34 degrees Baumé). After boiling
the colouring-matter which separates is filtered off and washed with water, in order
to remove the adherent acid.
It produces a blue colour on wool mordanted with alumina salts and valuable
greenish-blue shades on wool mordanted with chromium salts.
A similar dye-stuff is obtained from betanitroflavopurpurin.
The intermediate products (nitroxy anthradiquinones) which are formed in the
production of the last named two cyanine-like dye-stuffs, are easily soluble in water
and can be salted out from the solutions obtained on pouring the oxidised mixture
into water.
By further researches my foreign correspondents have found that the oxidation
of flavopurpurin, anthrapurpurin, oxyflavopurpurin and oxyanthra purpurin into,

page_text: alizarin cyanines as described in the Specification of Letters Patent No. 1657
dated 27th January 1892 can be more advantageously effected by employing the
arsenic acid ethers of the said colouring-matters. These arsenic acid ethers are
very readily and almost instantly formed on mixing a solution of the aforesaid
colouring-matters in concentrated sulphuric acid with dry arsenic acid at ordinary
temperatures, no oxidation taking place at this low temperature. They are
characterised by the colour of their alkaline solutions which is of but slight
intensity and varies from yellowish to brownish. By boiling with water or diluted
acids they are decomposed into their components. It is an advantage, that the
oxidation of these arsenic acid ethers by means of manganese dioxide proceeds more
slowly and smoothly and therefore can be better superintended.
The following is given as example for this new process. The parts are by
10 kilos. of anthrapurpurin are dissolved in 300 kilos. of sulphuric acid (66 degrees
Baumé) and 7.5 kilos. of dry powdered arsenic acid are added. As soon as a clear
brownish-yellow solution is obtained on pouring a test portion into water and
adding an excess of soda-lye the formation of the ether is complete. 17 kilos. of
finely pulverised manganese dioxide (90 per cent. MnO2) are then introduced the
mixture being constantly stirred and the temperature so regulated that at the end
of the operation it is about 45 degrees centigrade. When the temperature ceases
to rise, the whole liquid is poured into water and the dye-stuff can be isolated as
described in the Specification of Letters Patent No. 1657 dated 27th January 1892.
In the foregoing examples distinct methods are described, in order to illustrate
the processes hereinbefore defined but I do not limit myself to the directions given
in the said examples, as they can be varied without departing from the nature of
this invention.
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 production of alizarin pentacyanine sulpho acid, alizarin hexacyanine
sulpho acid or hexaoxyanthraquinone sulpho acid by sulphonating alizarin penta-
cyanine, alizarin hexacyanine or hexaoxyanthraquinone.
2. The production of sulpho acids of oxyanthradiquinone dye-stuffs by treating
alizarin bordeaux sulpho acid, alizarin pentacyanine sulpho acid, anthrapurpurin
sulpho acid, flavopurpurin sulpho acid, oxyanthrapurpurin sulpho acid, oxyflavo-
purpurin sulpho acid in sulphuric acid solution with oxidising agents.
3. The process for producing sulpho acids of oxyanthradiquinone dye-stuffs
by sulphonating alizarin bordeaux, alizarin pentacyanine, anthra purpurin, flavo-
purpurin, oxyanthrapurpurin or oxyflavopurpurin, diluting the resulting mixtures
with concentrated sulphuric acid and subsequently oxidising them without isolating
the sulpho products which are first formed.
4. The conversion of the sulpho acids of oxyanthradiquinone dye-stuffs into the
corresponding sulpho acids of oxyanthraquinone dye-stuffs, which process consists
either in allowing the sulpho acids of oxyanthradiquinone dye-stuffs (obtainable as
claimed by the foregoing second and third claiming clauses or in any other way) to
stand for a longer time or in heating them with water or acids, or in treating them
with reducing agents.
5. The production of sulpho acids of oxyanthraquinone dye-stuffs by sulphon-
ating alizarin bordeaux, alizarin pentacyanine, anthrapurpurin, flavopurpurin,
oxyanthrapurpurin or oxyflavopurpurin, oxidising the sulpho acids so formed
(either previously isolating them or not) and subsequently converting the resulting
sulpho acids of oxyanthradiquinone dye-stuffs into the corresponding sulpho acids
B

page_text: of oxyanthraquinone dye-stuffs, either by allowing them to stand for a longer time
in contact with water or by heating them with water or with acids, or by treating
them with reducing agents.
6. The transformation of the sulpho acids of oxyanthraquinone dye-stuffs into
the corresponding oxyanthraquinone dye-stuffs by heating them with diluted watery
acids at elevated temperatures.
7. The process for producing oxyanthraquinone dyestuffs the which process
consists in sulphonating alizarin-bordeaux, alizarin pentacyanine, anthrapurpurin,
flavo-purpurin, oxyanthrapurpurin, oxyflavopurpurin, oxidising the sulpho acids so
formed (either previously isolating them or not), subsequently converting the
resulting sulpho acids of oxyanthradiquinone dye-stuffs into the corresponding
sulpho acids of oxyanthraquinone dye-stuffs (which may be effected by means of
the process defined in the foregoing fourth claiming clause) and finally transforming
these sulpho acids of oxyanthraquinone dye stuffs into the oxyanthraquinone
dye-stuffs by heating them with diluted acids at elevated temperatures.
8. The production of products belonging to the series of the so called. anthra-
diquinones by treating betanitroflavopurpurin or beta-nitro-anthrapurpuriu in
sulphuric acid solution with oxidising agents.
9. The transformation of the anthradiquinone products (obtainable as claimed by
the foregoing eighth claiming clause or by any other process) into the corresponding
dye-stuffs belonging to the series of alizarin cyanines by heating them with water
or acids or by treating them with reducing agents.
10. The production of alizarin cyanine dye-stuffs from beta-nitro-flavopurpurin
or beta-nitro-anthrapurpurin by oxidising the latter nitro products in sulphuric acid
solution and converting the anthradiquinone products so formed into the corre-
sponding alizarin cyanine dye-stuffs, by treating with reducing agents or by heating
them with water or with acids.
11. The process for producing alizarin cyanine dye-stuffs from flavopurpurin,
anthrapurpurin, oxyflavopurpurin or oxyanthrapurpurin by oxidising the arsenic
acid ethers of these products in sulphuric acid solution.
12. As new articles of manufacture the herein before defined products obtainable
by means of the processes herein before defined or by any other way.
Dhin 4th I FA
1000
B. WILLCOX.