The Manufacture or Production of Colouring Matters.
Year: 1895

page_text: [Communicated from abroad by THE FARBENFABRIKEN, vormals FRIEDRICH
BAYER & Co., of Elberfeld, Germauy.]
The Manufacture or Production of Colouring Matters.
I HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:-
Safranines have not hitherto been prepared from monalkylorthotoluidine,
probably because it was supposed that these dye-stuffs would not materially differ
from those safranine coloring matters which can be produced by means of the
known materials obtainable with greater ease.
My foreign correspondents have now found, that surprising results are obtained
on using, in the so-called safranine processes, monalkylorthotoluidine in place of
dialkylaniline, or aniline or the like. According to the researches of my foreign
correspondents, the brightness and brilliancy of the shades produced by means of
these dye-stuff's increase to such an extent, owing to the alkyltoluidine radicles
contained therein, that some of the new coloring matters hereinafter defined are
equal to the rhodamine dye-stuffs. The latter property is possessed especially by
those coloring matters which contain twice the monalkylorthotoluidine radicle.
In order to produce the new dye-stuffs, all those methods can be employed
For
which are known and in use for preparing safranine coloring matters.
instance, paramidomonalkylorthotoluidine is allowed to act, in the presence of a
suitable oxidising agent, on a primary, secondary, or tertiary aromatic monamido
compound, not substituted in the "para" position relatively to the amido or
alkylamido group,
and the so formed indamine products are subsequently subjected
to a joint oxidation, together with any primary amine,-the new safranine coloring
matters being thus obtained. In place of starting from paramidomonalkylortho-
toluidine, paraphenylenediamine, or paramidodiaikylaniline, or the like, can be
first oxidised, together with monalkylorthotoluidine, and the indamine compounds
thus produced are then subjected to a joint oxidation, together with any
primary aromatic amine, or amido phenolether, to form the safranine dye-stuffs.
The two operations, viz., the formation of the indamines, and their conversion into
the safranines, can also be effected in a single operation, that is to say, by
subjecting paramidomonalkylorthotoluidine to a joint oxidation, either together
with two molecular proportions of a primary amido compound, not substituted in
the "para" position relatively to the amido group, or together with a mixture
consisting of a molecular proportion of a primary, secondary, or tertiary amido
compound, not substituted in the " para" position relatively to the amido or
alkylamido group, and a molecular proportion of any primary amido product.
The process for producing the new safranine dye-stuffs is illustrated by the
following two examples, which however are merely typical. The parts are by
weight

page_text: SAFRANINE COLORING MATTER OBTAINED
FROM EQUIMOLECULAR PRO-
PORTIONS OF PARAMIDOMONOMETHYLORTHOTOLUIDINE, MONOMETHYL-
ORTHOTOLUIDINE, AND ORTHOTOLUIDINE.
18-6 parts of nitrosomonomethylorthotoluidine hydrochloride, dissolved in about
500 parts of water, are converted, in the usual manner, by means of zinc dust and
muriatic acid, into the corresponding paradiamine (paramidomonomethylortho-
toluidine). The neutral solution of this diamine is mixed with a solution, in
water, of 15.8 parts of monomethylorthotoluidine hydrochloride. A 5 per cent.
solution of potassium dichromate, prepared from 20 parts of potassium dichromate,
is then added to the above liquid, which is kept cool, and continually stirred. After
the formation of the indamine is complete, a solution, in water, of 14.5 parts of ortho-
toluidine hydrochloride is introduced, and the resulting liquid is heated until the
original bluish-green color has turned into a pure red. At this stage, 20 parts of
potassium dichromate are added, and heating is continued until the formation of
the dye-stuff is finished. After filtering, the so-formed safranine colouring
matter is salted out from the resulting filtrate, and isolated in the usual manner.
It produces on cotton prepared with tannic acid or the like, very bright red
shades, which are similar to those obtained with the aid of the coloring matter
known in commerce as Rhodamine S.
SAFRANINE DYE STUFF PRODUCED FROM ONE MOLECULAR PROPORTION OF
PARAMIDOMONOMETHYLORTHOTOLUIDINE, AND TWO MOLECULAR PRO-
PORTIONS OF ORTHOTOLUIDINE.
A solution of paramidomonomethylorthotoluidine, obtained, as mentioned in
the foregoing first example, from 18.6 parts of nitrosomonomethylorthotoluidine
hydrochloride, is mixed with a solution prepared by dissolving 29 parts of ortho-
toluidine hydrochloride in 500 parts of water. The formation of the safranine is
effected by adding a 5 per cent. solution of potassium dichromate containing
40 parts of potassium dichromate, and subsequently heating.
The safranine dye-stuff thus formed yields, on cotton prepared with tannic acid,
or the like, shades which are somewhat less bright and a little more yellow than
the shades produced by means of the dye-stuff described in the preceding
example.
Dye-stuffs similar to those obtained as mentioned in the foregoing two examples
are produced, if either the monomethylorthotoluidine used therein is replaced by
another secondary base (such as monomethylaniline, monoethylaniline, or the like),
or by a tertiary aromatic amido compound (such as dimethylaniline), or if
aniline ortho anisidine, or other primary aromatic amido compounds, are used in
place of ortho toluidine used in the first example, or if equivalent quantities of
aniline, ortho anisidine, or the like, or mixtures, containing a molecular proportion
of a primary aromatic amine, and a molecular proportion of a secondary or tertiary
aromatic amido compound, are employed, in place of orthotoluidine used in the
above second example.
In the production of the dye-stuffs herein before defined, my foreign corre-
spondents do not limit themselves to the processes illustrated by the foregoing
two examples. As above mentioned, all methods can be used which are known
and in use for preparing safranine coloring matters.
Dated this 9th day of February 1905

page_text: I HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
-
Safranines have not hitherto been prepared from monalkylorthotoluidines,
probably because it was supposed that dye-stuffs so prepared would not materially
differ from the safranine coloring matters which can be produced from more easily
obtained materials.
My foreign correspondents have, however, found that surprising results are
obtained on using, in the safranine processes, monalkylorthotoluidine, in place of
dialkyl aniline, or aniline, or the like, their researches showing that the intensity
and brilliancy of the shades produced by means of these dye-stuffs are so increased
by the introduction of alkyltoluidine radicles, that some of the new coloring
matters hereinafter defined are equal to the rhodamine dye-stuffs.
especially true of the coloring matters containing two monalkylorthotoluidine
radicles.
This is
In order to produce the new dye-stuffs, all the known methods of preparing
safranine coloring matters can be used. For instance, paramidomonalkylortho-
toluidine may be allowed to act, in the presence of a suitable oxidising agent, on a
primary, secondary, or tertiary aromatic monamido compound, unsubstituted in the
para position relatively to the amido or alkylamido group, and the indamine
products thus formed may be subsequently subjected to oxidation in conjunction
with any primary amine. Instead of starting from paramido monalkylorthotoluidine
or paraphenylene diamine, a paramidomonalkylaniline, or paramidodialkylaniline,
or the like (such as toluylene diamine), can be first oxidised, together with
monalkyl orthotoluidine, and the indamine compounds thus produced may then be
subjected to oxidation in conjunction with a primary aromatic amine or amido-
phenolether. The two operations, viz., the formation of the indamines, and their
conversion into the safranines, can also be effected in a single operation, that is to
say, by subjecting paramidomonalkylorthotoluidine to oxidation either in conjunction
with two molecular proportions of a primary amido compound unsubstituted in the
para" position relatively to the amido group, or with a mixture of a molecular
proportion of primary, secondary, or tertiary amido compound unsubstituted in
the " para" position relatively to the amido or alkylamido group, and a molecular
proportion of any primary amido product.
"
The process for producing the new safranine dye-stuffs is illustrated by the
following examples, which, however, are merely typical. The parts are by
0 SAFRANINE COLORING MATTER OBTAINED FROM MOLECULAR PROPORTIONS OF
PARAMIDOMONOMETHYLORTHOTOLUIDINE, MONOMETHYLORTHOTOLUIDINE,
AND ORTHOTOLUIDINE.
18.6 parts of nitrosomouomethylorthotoluidine hydrochloride, dissolved in about
500 parts of water, are converted in the usual manner, by means of zinc dust and
5 muriatic acid, into the corresponding paradiamine (paramidomonomethyl ortho-
toluidine). The neutral solution of this diamine is mixed with a solution in water
of 15-8 parts of monomethyl orthotoluidine hydrochloride. A 5 per cent. solution
of potassium dichromate, prepared from 20 parts of potassium dichromate, is then

page_text: added, the liquid being kept cool and continually stirred. When the formation
of the indamine is complete, a solution in water of 145 parts of orthotoluidine
hydrochloride is introduced, and the liquid is heated until the original bluish-green
color has turned into a pure red. At this stage, 20 parts of potassium dichromate
are added, and heating is continued until the formation of the dye-stuff is at an
end. The liquid is then filtered off, and the residue on the filter, having been
extracted with boiling water, the filtrates are mixed with the first filtrate, and the
safranine coloring matter salted out and isolated in the usual manner.
It produces, on cotton prepared with tannic acid or the like, very bright bluish-
red shades, which are similar to those obtained with the aid of the coloring matter
known in commerce as "Rhodamine S."
SAFRANINE DYE-STUFF
PRODUCED FROM A
MOLECULAR PROPORTION OF
PARAMIDOMONOMETHYLORTHOTOLUIDINE AND TWO MOLECULAR PRO-
PORTIONS OF ORTHOTOLUIDINE.
A solution of paramidomonomethyl orthotoluidine, obtained, as mentioned in the
foregoing first example, from 18.6 parts of nitrosomonomethyl orthotoluidine
hydrochloride, is mixed with a solution prepared by dissolving 29 parts of ortho-
toluidine hydrochloride in 500 parts of water. The formation of the safranine is
effected by adding a 5 per cent. solution of potassium dichromate containing 40 parts
of potassium dichromate, and subsequently heating.
The safranine dye stuff thus formed yields on cotton prepared with tannic acid or
the like, shades which are somewhat less bright and slightly more yellow than the
shades produced by means of the dye-stuff described in the preceding example.
Dye-stuffs similar to those obtained as mentioned in the foregoing two examples
are produced by using, instead of the monomethyl orthotoluidine specified in
Example A, an equivalent quantity of another secondary base (such as mouo-
methylaniline, mouethylaniline, or the like), or of a tertiary aromatic amido
compound (such as dimethylaniline), or if a corresponding proportion of aniline,
orthoauisidine, or other primary aromatic amido compounds, be used in place of the
orthotoluidine specified in Example A, or by using, in piace of the orthotoluidine
specified in the above Example B, equivalent quantities of aniline, orthoanisidine,
or the like compounds, unsubstituted in the para position relatively to the amido
group, or mixtures consisting either of molecular proportions of two different
primary amido compounds, the one of which is unsubstituted in the para position
relatively to the amido group, or of a molecular proportion of a primary amine,
and a molecular proportion of a secondary or tertiary aromatic amine, unsubstituted
in the para position relatively to the alkyl-amido group.
As above mentioned, safranines containing a single monalkylorthotoluidine
radicle can also be prepared by using, in place of paramidomonalkylorthotoluidine,
either paraphenylene diamine, paratoluylene diamine, paramidomonalkylaniline, or
paramidodialkylaniline, and subjecting these substances, together with equal
molecular proportions of monalkylorthotoluidine, and any other primary amido
compound, to oxidation conjointly.
The last defined process is illustrated by the following example.
SAFRANINE COLORING MATTER OBTAINED FROM EQUAL MOLECULAR PRO-
PORTIONS OF PARAPHENYLENE DIAMINE, MONETHYL ORTHOTOLUIDINE,
AND ORTHOTOLUIDINE.
18 parts of paraphenylenediaminehydrochloride and 13:5 narts of moneth vl-

page_text: orthotoluidine, and 4 parts of concentrated muriatic acid, are dissolved in 700 parts
of alcohol, and the cooled solution is gradually mixed with a concentrated solution,
in water, of 20 parts of potassium dichromate. As soon as the formation of the
indamine is complete, 15 parts of orthotoluidine hydrochloride are added, and a
solution in water of 20 parts of potassium dichromate is then gradually introduced
into the solution, which is meanwhile heated by means of a water bath. After
heating during about an hour, the alcohol is distilled off, and the residue is
extracted with hot water. The filtered extract is then mixed with common salt,
in order to precipitate the safranine dye, which is subsequently filtered off and
purified in a suitable manner.
This coloring matter produces, on cotton prepared with tannic acid or the like,
shades which are somewhat less bright than those obtained by means of the dye-
stuff obtainable as described in the foregoing Example B.
In illustration of the large number of safranine dyes obtainable by means of the
process bereinbefore defined, and the variety of shades which they produce on
cotton mordanted with tannin or the like, the following table is given. The first
column contains the several components used in producing several typical safranine
dyes, whilst in the second column are the shades produced by the respective dye-
stuffs on cotton material treated as hereinbefore mentioned.
1 molecular proportion of paramido-monomethylortho-
toluidine, 1 molecular proportion of monomethylortho- bright
toluidine, and 1 molecular proportion of orthotoluidine
1 molecular proportion of paramido monethylortho-
toluidine, molecular proportion of monethylorthotoluidine,
and 1 molecular proportion of orthotoluidine
1 molecular proportion of paramido monomethylortho-
toluidine, 1 molecular proportion of orthoanisidine, and
1 molecular proportion of orthotoluidine
1 molecular proportion of paramido monomethyltoluidine,
1 molecular proportion of monomethylorthotoluidine, and
1 molecular proportion of orthoanisidine.

page_text: 1 molecular proportion of paramido monomethylortho-
toluidine, 1 molecular proportion of orthotoluidine, and
1 molecular proportion of aniline
1 molecular proportion of paramido monomethylortho-
toluidine, 1 molecular proportion of monomethylaniline, and
1 molecular proportion of paratoluidine
In the production of the dye-stuffs herein before defined, my foreign corre-
pondents do not limit themselves to the processes illustrated by the preceding
xamples, which are merely typical. As above mentioned, all known methods in
se for preparing other analogous or similar safranine coloring matters can be used.
Having now particularly described and ascertained the nature of the said
vention and in what manner the same is to be performed, as communicated to me
om abroad, 1 declare that what I claim is :-
-
1. The production of safranine coloring matters, containing either one or two
onalkylorthotoluidine radicles :-
(a) From one molecular proportion of a paramidomonalkylorthotoluidine and
two molecular proportions of a primary aromatic amido compound unsub-
stituted in the para position relatively to the amido group; or
(6) From a molecular proportion of a paramido monalkylorthotoluidine, a
molecular proportion of a primary, secondary, or tertiary aromatic amido
compound unsubstituted in the para position relatively to the amido or
alkyl-amido group, and a molecular proportion of any primary aromatic
amido compound; or
(c) From a molecular proportion of paraphenylene diamine, paratoluylene
diamine, or alkylated paraphenylene diamines containing, in one of their
amido group, either a single or two alkyl groups, a molecular proportion of
monalkylorthotoluidine, and a molecular proportion of a primary aromatic
amido compound.
2. The process for producing safranine dyes containing either one or two
onallylorthotoluidine radicles, which processes consist :-
(a) In subjecting a molecular proportion of a paramidomonalkylorthotoluidine,
together with two molecular proportions of a primary aromatic amido

page_text: compound, unsubstituted in the para position relatively to the amido group,
to oxidation conjointly; or
(6) In subjecting a molecular proportion of a paramidomonalkylorthotoluidine,
together with a molecular proportion of a primary, secondary, or tertiary
aromatic amido compound, unsubstituted in the para position relatively to
the amido or alkylamido group, conjointly to oxidation, and in subsequently
oxidising the so-lormed indamines, together with a molecular proportion of
any primary aromatic amido compounds; or
(c) In oxidising a molecular proportion of paraphenylene diamine, para-
toluylene diamine, or an alkylated paraphenylene diamine containing, in one
of the amido groups, either a single or two alkyl groups, together with a
molecular proportion of monalkylorthotoluidine, subsequently subjecting
the so-formed indiamines to oxidation in conjunction with a molecular
proportion of a primary aromatic amido compound.
As new products of manufacture the new dye-stuffs produced by the
esses hereinbefore defined, or by any other way affording the same result.
1005
NEWTON & SON,
Agents for the Applicant.
NEWTON & SON,
Agents for the Applicant.