IMPROVEMENTS IN THE PRODUCTION OF COLOURING MATTERS
Year: 1882

page_text: LETTERS PATENT to Joseph Anthony Dixon of 151 St. Vincent Street
Glasgow in the County of Lanark North Britain Solicitor for an invention
of IMPROVEMENTS IN THE PRODUCTION OF COLOURING MATTERS A communi-
cation from abroad by Dr. Carl Koenig of Hochst-am-Main in the Empire of
Germany, a Director of the Farbwerke vorm: Meister, Lucius and Brüning,
PROVISIONAL SPECIFICATION left by the said Joseph Anthony Dixon at
the Office of the Commissioners of Patents on the 27th March 1882..
JOSEPH ANTHONY DIXON, of 151 St Vincent Street, Glasgow, in the County of
Lanark, North Britain, Solicitor, "IMPROVEMENTS IN THE PRODUCTION OF
COLOURING MATTERS" [A. communication from abroad by Dr. Carl Koenig of
Hochst-am-Main in the Empire of Germany, a Director of the Farbwerke vorm:
Meister, Lucius and Brüning a Company carrying on business as Chemical
Manufacturers.]
My Invention has for its object the production of Artificial Indigo and of sub-
stituted Indigos.-When Monobenzylidene-acetone C, H. C, H. CH. CO. CH, is
Nitrated, a mixture of Ortho- and of Para-Nitrobenzylideneacetone is formed.-
The separation of the isomeric compounds can be effected by means of Alcohol, in
which the Paranitro-benzylideneacetone dissolves with difficulty, whereas the
Orthonitro-Compound dissolves in it easily.
If
orthonitrobenzylideneacetones left for some time in the Cold in Contact with
an aqueous or with an Alcoholic Soda-lye, it is converted into a new substance,
which appears to be contained in the liquid in the form of a Sodium Salt and
which, after being separated from this Salt by Means of Acids, will produce
artificial Indigo by heating or by treating with diluted alkaline lyes.
The substituted Orthonitrobenzylideneacetones behave exactly like their Mother
substance, and under equal conditions they produce substituted Indigos.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joseph Anthony Dixon in the Great Seal Patent Office on the
2nd September 1882.
JOSEPH ANTHONY DIXON, of 151 St Vincent Street, Glasgow, in the County of
Lanark, North Britain, Solicitor, "IMPROVEMENTS IN THE PRODUCTION OF
COLOURING MATTERS." A communication from abroad by Dr. Carl Koenig of
Hochst-am-Main in the Empire of Germany a Director of the Farbwerke vorm:
Meister Lucius and Brüning, a Company carrying on business as Chemical
Manufacturers.
The Invention has for its nature and object the production of Artificial Indigo
and of substituted Indigos and the manner of performing. the said Invention is
hereinafter described.
.
When Monobenzylidene-acetone, C, H, CH. C H. CO. CH, is nitroylized a
mixture of Ortho and of Para Nitro-benzylidene-acetone is formed. The separation
of the isomeric compounds is effected by means of alcohol in which the Paranitro-
benzylidene-acetone dissolves with difficulty. whereas the Orthonitro compound
dissolves in it easily.
If
ortho-nitro-benzylidene-acetone is. left for some time in the cold in contact
with an alcoholic Soda-lye, it is converted into a new substance which appears to
be contained in the liquid in the form of a Sodium salt, and which after being
separated from its Sodium combination by means of acids yields artificial Indigo
by heating to boiling point or by treating with diluted Alkaline lyes in manner
aftermentioned.
The ortho-nitro-benzylidene-acetones substituted in the Benzol nucleus (whether
before or after introduction of the ortho-nitro group) behave exactly like their
mother substance, and under equal conditions they produce correspondingly
substituted indigos.
In working the process, the period of time during which the ortho-nitro-
benzylidene-acetone may require to be kept in contact with the alcoholic soda or
alkaline lye to complete the production of the indigo yielding substance may be.
ascertained by keeping up a series of small testings of the mass undergoing re-
action in order to determine the course and the completion of the conversion.
When out of one of these small test samples-which will of course be always of
the same size, the experimenter by addition of acids till acid re-action sets in
and then by subsequently rendering it alkaline, has attained the maximum yield of
Indigo, he will interrupt the action of the alkaline lye.
Besides soda and the alkalis proper, the alkaline earths (as Baryta Strontia and
Lime) may also be used to act as aforesaid on the said Ortho-nitro-keton, but the
alkalis and the alkaline earth's so act only in presence of Alcohol and not in
aqueous solution. In place of Acthyl-Alcohol, other alcohols (as the Methyl and
Propyl alcohols) may be used to form the alkaline solutions.
The body or substance which is, as hereinbefore described, formed by the action
of the alkalis or alkaline earths on ortho-nitro-benzylidene-acetone is very unstable.
It may be extracted with ether, from acid solutions; and after removal of the ether
obtained as an oil, this oil decomposes spontaneously both per se and in the
solution, with depositation of Indigo, so that isolation and purification of it as a
separate body is practically without any advantage.
The indigo-yielding substance remains in solution after the addition of the acid
to the alcoholic liquor in which it is formed, and in order to produce or obtain the
Indigo there is added direct to the said solution of the Indigo-yielding substance
after treatment as aforesaid with acid, sufficient soda lye in the cold to make the

page_text: liquor alkaline, whereupon the reaction which gives the Indigo follows immediately
-a voluminous precipitate of Indigo being formed at once.
Or the solution may
be heated to boiling point. The precipitate of Indigo which is obtained as above
described is collected on a filter and washed with water and alcohol. If we treat
the mass or substance which results from the action of Alcoholic Soda or other
Alcoholic Alkali on Ortho-Nitro-benzylidene-acetone with acetic acid, we do not
by subsequent treatment with Alkalis, or by boiling the acid liquor, obtain any
indigo.
I desire to explain here that the production of the said Ortho and Para Nitro-
Benzylidene-Acetones (whether further substituted or not in the Benzol Kernel)
is new; as also the separation of the Ortho from the Para Nitro compounds; as also
the formation from the Ortho nitro bodies substituted as aforesaid or not of the
said Indigo yielding substances and the production from the latter of Indigo and
the substittued Indigos respectively herein before described.
Having now described and particularly ascertained the nature of the said
Invention and the system, mode, or manner, in or under which the same is, or
may be used or practically carried into effect I would observe in conclusion that
what I 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 production in manner hereinbefore described or in manner sub-
stantially the same of Indigo and of the substituted Indigos hereinbefore mentioned
from Mono Benzylidene acetone:
Second. Separatim, and as steps of the process for producing Indigo and the
said substituted Indigos, (First) the production in manner hereinbefore described
of Ortho Nitro and Para Nitro Benzylidene Acetones substituted or not sub-
stituted, (Second,) The separation in manner hereinbefore mentioned of the
Ortho Nitro from the Para Nitro compounds so produced, (Third,) The production
in manner hereinbefore described of the new Indigo yielding substances from Ortho
Nitro benzylidene acetone and its further substituted derivatives aud (Fourth,)
The production in manner hereinbefore described of Indigo and substituted Indigos
from the Indigo yielding substances hereinbefore described as producible from
Ortho-Nitro-Benzylidene-Acetone and its substitution derivatives.
In witness whereof, I the said Joseph Anthony Dixon have hereunto set
my hand and seal this Eighteenth day of May in the year of Our
Lord One thousand eight hundred and eighty two.