IMPROVEMENTS IN PREPARING COLOURING MATTERS SUITABLE FOR DYEING AND PRINTING, AND IN MATERIALS USED IN THE MANUFACTURE OF THE SAME
Year: 1880

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
PREPARING COLOURING MATTERS SUITABLE FOR DYEING AND PRINTING, AND
IN MATERIALS USED IN THE MANUFACTURE OF THE SAME." A communi-
cation from abroad by Adolphus Baeyer, Doctor of Philosophy and Professor
of Chemistry, in the University of Munich, in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 18th March 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN PREPARING COLOURING MATTERS SUITABLE FOR
DYEING AND PRINTING, AND IN MATERIALS USED IN THE MANUFACTURE OF THE
SAME. A communication from abroad by Adolphus Baeyer, Doctor of Philosophy
and Professor of Chemistry, in the University of Munich, in the Empire of
Germany.
"
This Invention relates to the synthetical formation of indigo blue and allied
colouring matters, and to the production of materials used in the preparation of the
same. The said materials are derivatives of orthonitrocinnamic acid, and more
particularly the orthonitro substitution compounds of dibromohydrocinnamic acid,
of phenyloxyacrylic acid, of phenylpropiolic acid, and analogous substances.
According to this Invention the above materials are prepared by submitting
orthonitrocinnamic acid, _or_any_mixture_or_compound_containing_the_same,_to_a_
treatment analogous to that by which cinnamic acid may be converted into
dibromobydrocinnamic acid, or into phenyloxyacrylic acid, or into phenylpropiolic
acid, or into analogous substances, as is well understood by chemists. For example,
orthonitrocinnamic acid may be changed into its dibrominated compound by direct
treatment with liquid or gaseous bromine at an ordinary or at an elevated
temperature, with or without the presence of suitable solvents. From the nitro-
dibromohydrocinnamic acid thus produced, hydrobromic acid may be abstracted by
means of alcoholic potash, or otherwise. By the partial elimination of bydrobromic
acid the nitrobromocinnamic acids may be obtained, whilst the complete with-
drawal of hydrobromic acid results in the preparation of orthonitrophenylpropiolic
-
7

page_text: acid. Analogous results may be obtained by substituting chlorine for bromine in
the above process.
In order to obtain the orthonitro substitution products of
phenylchlorolactic or phenylbromolactic acid and of phenyloxyacrylic acid, ortho-
nitro-cinnamic acid may be submitted to the action of hypochlorous or hypobromous
acids and of alkalies, in substantially the same manner by which cinnamic acid can
be converted into its corresponding derivatives, as is well known to chemists. In
some instances however the before mentioned derivatives of orthonitrocinnamic acid
may be conveniently prepared by the action of nitric acid upon the corresponding
derivatives of cinnamic or hydrocinnamic acid.
As an example of the manner in which the aforesaid materials may be employed
for the synthetical formation of indigo-blue and allied coloring matters, I proceed
as follows:-
Orthonitrophenylpropiolic acid when submitted to the action of suitable reducing
or deoxydising agents, such as mixtures of glucose, or similar bodies, with solutions
of caustic or carbonated alkalies or of alkaline earths is gradually changed into
indigo blue. A mixture of the said substances upon being gently heated quickly
turns blue, and deposits the coloring matter in its crystalline condition. In the
above process orthonitrophenylpropiolic acid may be employed in its pure state, or
in any mixture or compound of the same, either prepared by my above mentioned
method, or by any other method whatsoever, either ready formed or in its nascent
condition; for instance, indigo blue may be prepared by essentially the same
process, by submitting the brominated orthonitrocinnamic acid to the successive
action of alkoholic potash and of reducing agents.
Another process for the formation of coloring matter consists in the action of
heat upon orthonitrophenyl-oxyacrylic acid, whereby the said acid is decomposed
under simultaneous evolution of gas, and production of indigo blue coloring matters
allied to indigo blue may be produced from the homologues of orthonitrocinnamic
acid, or from its chlorine, bromine, iodine, or nitro substitution compounds by
submitting the same to a treatment analogous to that by which orthonitrocinnamic
acid may be converted into artificial indigo blue, as above described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 17th
September 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN PREPARING COLORING MATTERS SUITABLE FOR
DYEING AND PRINTING, AND IN MATERIALS USED IN THE MANUFACTURE OF THE
SAME. A communication from abroad by Adolphus Baeyer, Doctor of Philosophy
and Professor of Chemistry, in the University of Munich, in the Empire of
Germany.
"
The said Invention relating to the preparation of coloring matters suitable for
dyeing and printing, and the preparation of materials used in the manufacture of
the sanre, has reference, First, to the synthetical or artificial formation of indigo-
blue and allied coloring matters; Second, to the production of materials capable of
being used in the preparation of the same.
The said materials are derivatives of orthonitro cinnamic acid, and more especially
the orthonitro-substitution compounds of dibromohydrocinnamic acid, of phenyl-
oxyacrylic acid, of phenylpropiolic acid, and analogous substances.
I will now proceed to describe the production of the said materials.
According to the said Invention the above materials are prepared by submitting
orthonitrocinnamic acid, or any mixture or compound containing the same, to a
treatment analogous to that by which cinnamic acid may be converted into
dibromobydrocinnamic acid, or into phenyloxyacrylic acid, or into phenylpropiolic
acid, or into analogous substances, as is well understood by chemists.
For example, orthonitrocinnamic acid may be changed into its dibrominated
compound by direct treatment with liquid or gaseous bromine at an ordinary or at
an elevated temperature, with or without the presence of suitable solvents. In
practice the following process has been found to give good results:-About one part
by weight of dry and finely powdered orthonitrocinnamic acid is introduced into
a closed chamber and spread out in thin layers. In the upper part of the chamber a
vessel is placed containing an excess of liquid bromine, say, about from nine tenths to
one part by weight of bromine, and which is allowed to volatilize at an ordinary
temperature and with the exclusion of day light. The absorption of bromine by the
orthonitrocinnamic acid being completed, which process generally requires about
from twelve to twenty hours, the excess of gaseous bromine in the chamber is
removed by the injection of a strong current of air or otherwise, and the
dibrominated compound of orthonitrocinnamic acid thus produced may be directly
applied to the subsequent operations. A further purification of the dibromohydro-
cinnamic acid may however be effected by crystallisation from alcohol, benzole, or
other suitable solvents, or it may be conveniently dissolved in an aqueous solution
of acetate of soda, and afterwards reprecipitated from the filtered solution by the
addition of a strong mineral acid, say, for instance, hydrochloric acid.
As an example of the manner in which_a_compound_of_orthonitrocinnamic acid
may be converted into its corresponding dibrominated derivative, the ethereal
compounds, say, for instance the methylic or ethylic ethers of orthonitrocinnamic
acid, may be treated with gaseous bromine in the manner above described, or they
may be directly mixed with a slight excess of liquid bromine in the cold and with
the exclusion of day light. The methylic or ethylic ethers of orthonitro-dibromo-
hydrocinnamic acid thus produced may be further purified by crystallisation from
alcohol, benzole, or other suitable solvents.
From the orthonitro-dibromohydrocinnamic acid produced by any of the above
described methods or otherwise, bydrobromic acid may be abstracted by means of
alcoholic potash or otherwise, in a manner analogous to that in which the
corresponding dibrominated derivative of cinnamic acid may be changed into

page_text: phenylpropiolic acid. In this manner I am enabled to convert the orthonitro-
dibromocinnamic acid, or any mixture or compound containing the same, into the
orthonitro-derivative of phenylpropiolic acid.
As an example of the manner in which it is preferred to effect the complete
elimination of hydrobromic acid from the dibrominated compound of orthonitro-
cinnamic acid, the process may be carried out in the following manner :-
About ten pounds by weight of orthonitro-dibromo-hydrocinnamic acid are
intimately mixed with about one gallon of an aqueous solution of caustic soda of
about 14 specific gravity, care being taken to prevent any rise of temperature
above about twenty five degrees centigrade. The crystalline mass thus obtained is
allowed to stand for some time, say, from two to three hours, or until a sample of
the same after dissolving in water, precipitating with dilute sulphuric acid, filtering,
and washing no longer contains any bromine, or any considerable quantity thereof.
The whole result of the operation is then mixed with about three to five gallons of
cold water, and the mixture thus obtained is precipitated with dilute sulphuric
acid in order to separate the orthonitro-phenylpropiolic, and which is filtered,
washed with cold water, and may afterwards be dried at a gentle heat.
In an analogous manner orthonitrophenylpropiolic acid may be prepared from
the above named ethereal compounds of the orthonitro dibromohydrocinnamic
acid. For instance, one part by weight of the ethylic ether of orthonitro-dibromo-
hydrocinnamic acid is mixed with about one half part by weight of alcohol, and
about four parts by weight of caustic soda solution of about 1.4 specific gravity.
The mixture is then allowed to stand for sometime until the complete elimination
of hydrobromic acid has been effected, as hereinbefore described. In the said
operation the decomposition of the ethereal compound takes place. The sodium
salt of the orthonitro-phenylpropiolic acid thus produced may then be dissolved in
water and decomposed by dilute sulphuric acid, as above described.
Analogous results may be obtained by substituting chlorine for bromine in the
above process for preparing orthonitrophenylpropiolic acid from the ethereal com-
pounds of orthonitrocinnamic acid or from any mixture or compound containing
the same.
For instance the methylic ether of orthonitro cinnamic acid may be
exposed in a chlorine chamber to the action of dry gaseous chlorine in the cold and
with the exclusion of daylight until the calculated increase of weight has been
arrived at or nearly so, and the chlorinated compound thus obtained may afterwards
be treated in order to eliminate hydrochloric acid therefrom by means of alcoholic
solutions of caustic alkalies, when orthonitrophenylpropiolic acid will be produced,
substantially in the manner described in the above bromine process.
I prefer
however to employ bromine in the above described process.
I now proceed to describe the process by which another class of derivatives of
orthonitro cinnamic acid may be produced, and which derivatives may serve as
materials for the synthetical or artificial formation of indigo blue and allied coloring
matters. For instance, in order to obtain the orthonitro substitution products of
phenylchlorolactic or phenylbromolactic acids and of phenyloxyacrylic acid, I
submit orthonitrocinnamic acid to the action of hypochlorous or hypobromous
acids and of alkalies, in substantially the same manner as that by which cinnamic
acid can be converted into its corresponding derivatives, as is well known to chemists.
As an example I proceed as follows:-
About one part by weight of orthonitro cinnamic acid is dissolved in an aqueous
solution of carbonate of soda containing about three parts by weight of soda
crystals dissolved in, say, about from 25 to 30 parts of water, and afterwards a
current of chlorine gas is passed into the said solution until the production of free
hypochlorite of soda may be discerned by means of the bleaching properties of the
latter or otherwise. The excess of the hypochlorite thus produced is then destroyed
by the addition of sulphurous acid in slight excess, and the clear solution after
being strongly acidulated with hydrochloric acid is repeatedly agitated with
sulphuric ether or any other suitable solvent in order to extract therefrom the
orthonitro-phenylchlorolactic acid, which, after evaporation of the solvent, may be

page_text: obtained in the solid condition. In an analogous manner orthonitro-phenylbromo-
lactic acid may be produced by the action of nascent hypobromous acid upon
orthonitro-cinnamic acid, that is to say, by substituting bromine for chlorine in the
above described process.
The said orthonitro-phenylchlorolactic acid or orthonitro-phenylbromolactic acid
may be changed further into orthonitro-phenyloxyacrylic acid by eliminating
therefrom hydrochloric acid or hydrobromic acid, as the case may be, substantially
in the manner in which phenylchlorolactic acid or phenylbromolactic acid may be
changed into phenyloxyacrylic acid, as is well understood by chemists.
instance, the said compounds may be treated with alcoholic potash in slight excess
until no longer a separation of chloride or bromide of potassium, as the case may be,
takes place.
For
From the alkaline solutions thus obtained orthonitrophenyloxyacrylic acid may
be liberated by means of a stronger mineral acid, say, by means of dilute sulphuric
acid.
Although the aforesaid materials for the synthetical or artificial formation of
indigo blue and allied coloring matters are most conveniently prepared by the
above described process by starting from orthonitrocinnamic acid, or from any
mixture or compound containing the same, it is however possible, in some instances,
to produce derivatives of orthonitrocinnamic acid likewise by the action of
nitric acid upon the corresponding and well known derivatives of cinnamic acid or
hydrocinnamic acid. For instance, phenylpropiolic acid may by submitted to the
action of concentrated nitric acid in the cold, when the resulting product will be
found to contain orthonitrophenylpropiolic acid. In a similar manner alphabromo-
cinnamic acid, or the ethereal compounds of the same, or of dibromo and dichloro-
hydrocinnamic acid, may be converted into their corresponding nitrio-substitution
products. But as the action of nitric acid generally leads to the simultaneous
formation of isomeric nitrocompounds, from which the orthonitro compounds can
only be isolated by processes of separation, I prefer to effect the said separation
at the beginning of the process. I therefore, by preference, submit cinnamic acid
or its ethereal compounds first to the action of nitric acid, and afterwards I operate
upon what, in scientific language, is termed the side-chain" of the orthonitro
compound thus produced, in order to obtain the aforesaid derivatives of orthonitro-
cinnamic acid, substantially in the manner herein before described.
"
I now proceed to describe the manner in which the aforesaid materials may be
employed for the synthetical or artificial formation of indigo blue and allied coloring
matters; I accomplish this object by the employment of either of the two following
processes:
The first process is based upon the discovery that orthonitrophenylpropiolic acid
when submitted to the action of suitable reducing or deoxydising agents, such as
mixtures of glucose or similar bodies, with solutions of caustic or carbonated
alkalies, or of alkaline earths, is gradually changed into indigo blue.
As an example of the manner in which I prefer to conduct the said operation I
proceed as follows:-
=
About ten pounds by weight of orthonitro-phenylpropiolic acid are mixed with
about one hundred gallons of water, and about five pounds_by_weight of glucose-
previously dissolved in about five gallons of water. The said mixture is gradually
beated up to about eighty degrees centigrade, and about thirty five gallons of a
saturated aqueous solution of caustic baryta are added thereto in small portions
at a time. The mixture quickly assumes a blue colour, which gradually increases
in intensity owing to the formation of indigo blue in its crystalized condition.
The operation is completed when a filtered portion of the mixture no longer
yields any considerable amount of indigo blue upon the application of heat, nor
upon the addition of a further supply of the deoxydising agent, or of the caustic
baryta solution. The result of the operation is then filtered digested with weak
muriatic acid, in order to free the precipitate from carbonate of baryta, when the

page_text: residue after filtering, washing, and drying, will chiefly consist of indigo blue in an
approximately pure condition suitable for all its known applications as a coloring
matter.
In the above described process caustic baryta can be replaced by its equivalent
amount of caustic lime or of caustic alkalies, but in the latter case great care should
be taken to avoid using an excess of the same, which would diminish the yield of
coloring matter; carbonated alkalies may likewise be used in the above process, but
in a somewhat larger proportion, say, for instance, from two to three parts by weight
of carbonate of potash or soda to every one part by weight of orthonitro phenyl-
propiolic acid employed. Good results are likewise obtainable by substituting milk-
sugar, or similar saccharine substances possessing reducing properties, for the glucose
mentioned in the above described process.
I may also remark that the same or similar reactions take place by employing
orthonitrophenylpropiolic acid not only ready formed, but likewise in its nascent
condition. Any mixture therefore capable of producing orthonitrophenylpropiolic
acid may be used for the preparation of indigo blue, by submitting it to the
action of reducing or deoxydizing agents, substantially in the manner above
stated.
For example, indigo blue may be produced in one operation, and without
separation of the intermediate products, by treating orthonitrodibromohydro-
cinnamic acid, or the ethereal compounds thereof, first with alkalies, and then with
reducing or deoxydising substances, such as glucose or milk sugar.
The second process for the synthetical or artificial formation of indigo blue and
allied coloring matters is based upon the action of beat upon orthonitro-phenyl-
oxyacrylic acid. For example, orthonitrophenyloxyacrylic acid is spread out in thin
layers, and carefully leated to a temperature of about one hundred and ten degrees
centigrade; the said acid first enters into fusion, and then swells up by a
disengagement of gas, whilst gradually the blue color of indigo becomes developed.
The secondary products of decomposition may afterwards be removed by the
application of suitable solvents, such, for instance, as alcohol, when the residue will
chiefly consist of indigo blue in the shape of well defined crystals.
I may, however, remark that this second process is more difficult to conduct,
and less suited for practical application than the first process.
Coloring matters allied to indigo blue may also be produced from the homologues
of orthonitrocinnamic acid or from its halogen-substitution products, which contain
the said substituting elements in the benzole-nucleus of the cinnamic acid; such
homologues or substitution products may for instance be prepared, as is well known,
by employing the corresponding homologues or substitution-products of tolnole in
the synthetical processes, by means of which cinnamic acid can be artificially
produced.
By submitting the said homologues or substitution products of orthonitrocinnamic
acid or any mixture of the same to a treatment analogous to that by which ortho-
nitrocinnamic acid may be converted into indigo blue, substantially as above
described, colouring matters belonging to the indigo group may be obtained. For
example, from orthonitro-para-chloro-cinnamic acid the corresponding dibromide
and phenylpropiolic acid may be produced, the latter of which by the application
of reducing agents leads to the formation of chlorinated indigo blue.
I may however remark that I prefer the synthesis of indigo blue from ortho-
nitrocinnamic acid on account of the superior results which may be obtained by
employing the said acid in its purest possible condition.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same may be practically carried out, I
would observe in conclusion that I do not confine myself to the precise details or.
proportions herein before mentioned, as the same may, from the indications herein-
before given, be varied by any chemist conversant with the rules of synthetical
processes without departing from the principle of the Invention, but what I
”

page_text: consider to be novel and original, and therefore claim as the Invention secured to
me by the hereinbefore in part recited Letters Patent is,―
First. The synthetical or artificial formation of indigo blue and allied coloring
matters by the employment of derivatives of orthonitro-cinnamic acid, substantially
as hereinbefore described.
Second. The synthetical or artificial formation of indigo blue and allied coloring
matters by submitting orthonitro-phenylpropiolic acid, or any mixture or compound
containing or capable of producing the same, to the action of reducing or deoxydising
agents, such as glucose or similar bodies, in the presence of caustic or carbonated
alkalies or of alkaline earths, substantially as hereinbefore described.
Third. The synthetical or artificial formation of indigo blue and allied coloring
matters by submitting orthonitro-phenyloxyacrylic acid to the action of heat and
separating the coloring matter, substantially as hereinbefore described.
Fourth. The preparation of materials capable of being used for the synthetical or
artificial formation of indigo blue and allied coloring matters by operating upon the
'side chain" of orthonitro-cinnamic acid in a manner analagous to that by which
known and corresponding changes are effected in the "side-chain" of cinnamic
acid, or by operating in a similar manner upon the ethereal compounds of ortho-
nitro-cinnamic acid, or upon other compounds or 'mixtures containing the same, or
upon homologues or halogen-substitution products thereof, substantially as herein-
before described.
Fifth. The preparation of the dibrominated compound of orthonitro-cinnamic
or its ethereal compounds by submitting orthonitro cinnamic acid or the ethereal
compounds thereof to the action of bromine, substantially as hereinbefore
described.
Sixth. The preparation of the ethereal compounds of dichlorinated orthonitro-
cinnamic acid by submitting the ethers of orthonitro cinnamic acid to the action of
chlorine, substantially as hereinbefore described.
Seventh. The preparation of orthonitro-phenylpropiolic acid by submitting the
dibrominated compounds of orthonitro cinnamic acid or the ethereal compounds
thereof, or the ethereal compound of dichorinated orthonitrocinnamic acid, or any
mixture or compound containing the before mentioned materials, to. the action of
alkalies, and then liberating the acid from the alkaline compound thus formed,
substantially as hereinbefore described.
Eighth. The preparation of orthonitro-phenylchlorolactic acid or of orthonitro-
phenylbromolactic acid by submitting orthonitro-cinnamic acid to the action of
alkaline hypochlorites or alkaline hypobromites, nascent or otherwise, and separating
the compounds thus formed, substantially as hereinbefore described.
Ninth. The preparation of orthonitro phenyloxyacrylic acid by submitting
orthonitro phenylchlorolactic acid, or orthonitro phenylbromolactic acid, or any
mixture or compound containing the same, to the action of alkalies, and liberating
the acid from the alkaline compound thus formed, substantially as hereinbefore
described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal the Seventeenth day of Santambor