Manufacture of New Safranine Derivatives.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Manufacture of New Safranine Derivatives.
I, OLIVER IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (which has been communicated to me from abroad by The Farbwerke
vormals Meister Lucius and Brüning, of Hoechst a/Main, in the Empire of
Germany, Chemical Manufacturers) to be as follows:-
My foreign correspondents have found that new valuable dyestuffs may be
obtained by condensation of onesided alkylated safranines with unsaturated
aldehydes and ketones or their generators and subsequent oxidation, or by conden-
sation combined with oxidation. The non-alkylated safranines, on being sub-
jected to the same reactions, produce no valuable products.
The new process is as follows:--
EXAMPLE I. 70 parts of dimethylsafranine (made from 1 molecular propor-
tion of dimethyl-p-phenylenediamine + 2 molecular proportions of aniline),
20 parts of nitrobenzene, 60 parts of glycerine and 50 parts of concentrated
sulphuric acid, all taken by weight, are heated in an apparatus with an inverted
condenser. The melt thus obtained, the colour of which changes during the
reaction from green to dark-brown, is dissolved in water and the reddish gray
solution, thus obtained, is precipitated with chloride of zinc. The dyestuff is easily
soluble in water with a reddish gray colour, insoluble in alcohol or ether, soluble
in concentrated sulphuric acid with an olive green colour. Acetate of soda and
ammonia precipitate the dyestuff.
Diethylsafranine gives, under similar conditions, a dyestuff soluble in water
with a bluish red colour. The other properties correspond with those of the pro-.
duct mentioned. Both dyestuffs produce on tanned cotton valuable pure gray
tints, characterized by their great fastness to soda and alkali.
EXAMPLE II. 50 parts of dimethylsafranine, 100 parts of concentrated hydro-
chloric acid, 75 parts of paraldehyde, all taken by weight, are mixed. After some
time, heat is evolved and the green colour of the mixture turns to a dirty brown.
The reddish blue condensation product is dissolved in water and oxidised with
oxidising agents such as, bichromate, ferric chloride, persulphate or peroxide of
lead in an acid or alkaline solution, the best method being oxidation by means
of air in an ammoniacal solution. Oxidation may also be combined with the dye-
ing process on the fibre.
After oxidation, the dyestuff thus formed is precipitated with chloride of zine
from an acid solution; it is soluble in water or alcohol with a blue colour and
in concentrated sulphuric acid with a green colour; the aqueous solution is not
precipitated by acetate of sodium or ammonia.
If, in the above example, the diethyl compound be employed instead of the
dimethylsafranine, a dyestuff of very similar properties is obtained. The con--
densation of safranines with paraldehyde can also be effected with sulphuric acid
or in alcoholic or acetic acid solution. The reaction process is the same, it only
requires more time.

page_text: EXAMPLE III. A mixture of 50 parts of safranine (from amido-diethyl-
anilineo-anisidine + aniline,) 100 parts of concentrated hydrochloric acid,
75 parts of paraldehyde, all taken by weight, becomes heated spontaneously; it
becomes yellow and finally brown. After dilution with water to about 1000 cubic
centimetres, the mixture is made alkaline with ammonia; the original grayish-
violet solution becomes gradually dark greenish-blue. The whole is heated to
boiling point, slightly acidulated with hydrochloric acid and the green solution
is precipitated with chloride of zinc.
In the same way dyestuffs very similar in tint and properties may be produced
from safranine, obtained from amidodiethylaniline + o-phenetidine and aniline,
as well as from safranine produced from amidodiethylaniline + 2 molecules
o-anisidine. They are all soluble in water with a blue colour, and in alcohol with
a red fluorescence; in concentrated mineral acids with a dirty brown colour,
which, on dilution with water, becomes first gray and then blue.
In an aqueous solution acetate of sodium and ammonia produce a blue and in
concentrated soda-lye a dirty olive green precipitate. Pure greenish-blue tints
very fast to alkali may be obtained on cotton mordanted with tannin.
EXAMPLE IV. 50 parts of safranine (from 1 molecular proportion of diethyl-p-
phenylene diamine and 2 molecular proportions of aniline) 100 parts of concen-
trated hydrochloric acid and 80 parts of acetone, all taken by weight, are slightly
heated for several hours. A green solution results which turns blue on dilution
with water. The oxidation is effected at boiling point with bichromate and the
violet blue dyestuff is precipitated with chloride of zinc.
The safranine from dimethyl-p-phenylene-diamine gives a similar but redder
dyestuff. Both dyestuffs are readily soluble in water and alcohol. The alcoholic
solution exhibits a strong red fluorescence. In concentrated sulphuric acid both
dissolve in a dirty colour and the solution turns reddish-blue on addition of water.
The aqueous solution of both dyestuffs is not precipitated by acetate of sodium
and ammonia, but by soda-lye. On cotton treated with tannin both give vivid
violet blues, characterized by their great fastness to soap and alkali.
Dated this 20th day of March 1897.
ABEL & IMRAY,
Agents for the Applicant.
Manufacture of New Safranine Derivatives.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings,
Chancery Lane, in the County of London, Chartered Patent Agent, do
hereby declare the nature of this invention (which has been communicated to me
from abroad by The Farbwerke vormals Meister Lucius and Brüning, of Hoechst
a/Main, in the Empire of Germany, Chemical Manufacturers) and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement:-
My foreign correspondents have found that new valuable dyestuffs may be
obtained by condensation of onesided alkylated safranines with unsaturated alde-
hydes and ketones or their generators and subsequent oxidation, or by condensa-
tion combined with oxidation. The non-alkylated safranines on being subjected
to the same reactions produce no valuable products.
The process is as follows:-
EXAMPLE I. 70 parts of dimethylsafranine (made from 1 molecular proportion
of dimethyl-p-phenylenediamine + 2 molecular proportions of aniline) 20 parts

page_text: of nitro-benzene, 60 parts of glycerine and 50 parts of concentrated sulphuric
acid all taken by weight, are heated in an apparatus with an inverted condenser.
The melt thus obtained, the colour of which changes during the reaction from
green to dark brown, is dissolved in water and the reddish gray solution thus
obtained is precipitated with chloride of zinc. The dyestuff is easily soluble in
water with a reddish gray colour, insoluble in alcohol or ether, soluble in concen-
trated sulphuric acid with an olive green colour. Acetate of soda and ammonia
precipitate the dyestuff.
Diethylsafranine gives under similar conditions a dyestuff soluble in water
with a bluish red colour. The other properties correspond with those of the product
mentioned. Both dyestuffs produce on tanned cotton valuable pure gray tints,
characterized by their great fastness to soda and alkali.
EXAMPLE II. 50 parts of dimethylsafranine, 100 parts of concentrated hydrochloric
acid, 75 parts of paraldehyde, all taken by weight are mixed. After some time
heat is evolved and the green colour of the mixture turns to a dirty brown.
The reddish blue condensation product is dissolved in water and oxidised with
oxidizing agents such as, bichromate, ferric chloride, persulphate or peroxide
of lead in an acid or alkaline solution, the best method being oxidation by means
of air in an ammoniacal solution. Oxidation may also be combined with the
dyeing process on the fibre. After oxidation, the dyestuff thus formed is precipi-
tated with chloride of zinc from an acid solution; it is soluble in water or alcohol
with a blue colour and in concentrated sulphuric acid with a green colour; the
aqueous solution is not precipitated by acetate of sodium or ammonia.
If in the above example the diethyl compound be employed instead of the
dimethylsafranine, a dyestuff of very similar properties is obtained. The conden-
sation of safranines with paraldehyde can also be effected with sulphuric acid or
in alcoholic or acetic acid solution. The reaction process is the same, it only
requires more time.
EXAMPLE III. A mixture of 50 parts of safranine (from amido-diethyl
anilineo-anisidine aniline,) 100 parts of concentrated hydrochloric acid,
75 parts of paraldehyde all taken by weight becomes heated spontaneously; it
becomes yellow and finally brown. After dilution with water to about 1000 cubic
centimetres, the mixture is made alkaline with ammonia; the original grayish-
violet solution becomes gradually dark greenish-blue. The whole is heated to
boiling point, slightly acidulated with hydrochloric acid and the green solution
is precipitated with chloride of zinc.
In the same way dyestuffs very similar in tint and properties may be produced
from safranine, obtained from amidodiethylaniline +o-phenetidine and aniline,
as well as from safranine produced from amidodiethylaniline + 2 molecules o-
anisidine. They are all soluble in water with a blue colour and in alcohol with
a red fluorescence; in concentrated mineral acids with a dirty brown colour,
which on dilution with water, becomes first gray and then blue.
In an aqueous solution acetate of sodium and ammonia produce a blue and in
concentrated soda-lye a dirty olive green precipitate. Pure greenish-blue tints
very fast to alkali may be obtained on cotton mordanted with tannin.
EXAMPLE IV. 50 parts of safranine (from 1 molecular proportion of diethyl-p-
phenylenediamine and 2 molecular proportions of aniline) 100 parts of concen-
trated hydrochloric acid and 80 parts of acetone all taken by weight, are slightly
heated for several hours. A green solution results which turns blue on dilution
with water. The oxidation is effected at boiling point with bichromate and the
violet blue dyestuff is precipitated with chloride of zinc.
The safranine from dimethyl-p-phenylenediamine gives a similar but redder
dyestuff. Both dyestuffs are readily soluble in water and alcohol. The alcoholic
solution exhibits a strong red fluorescence. In concentrated sulphuric acid both
dissolve in a dirty colour and the solution turns reddish-blue on addition of water.
The aqueous solution of both dyestuffs is not precipitated by acetate of sodium

page_text: and ammonia, but by soda-lye. On cotton treated with tannin both give vivid
violet blues, characterized by their great fastness to soap and alkali.
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 herein described manufacture of new safranine derivatives, by condens-
ing one-sided alkylated safranines with unsaturated aldehydes and ketone's or
their generators and at the same time or afterwards subjecting the condensation
products to oxidation.
2. The specific methods of carrying out the process above set forth, that is to
say, heating asymmetric dimethylsafranine or diethylsafranine with glycerine
and sulphuric acid in the presence of nitro-benzene, condensing asymmetric
dimethylsafranine or diethylsafranine with paraldehyde by means of a mineral
acid and oxidising the dyestuff obtained in alkaline solution by the air or in an
acid solution with oxidising agents, condensing the safranines from p-amido-
diethylaniline, aniline and ortho-anisidine or ortho-phenetidin or from p-amido-
diethylaniline and 2 molecules of ortho-anisidine by means of hydrochloric acid
with paraldehyde and then oxidising them in an alkaline solution by the air, or
condensing the safranines from p-amido-diethyl-or-dimethylaniline and 2 molecules
of aniline by means of hydrochloric acid with acetone and then oxidising with
bichromate substantially as set forth.
3. The products obtained as set forth in Claims 1 and 2.
ABEL & IMRAY,
Agents for the Applicant.