The Manufacture and Production of New Colouring-matters Related to the Rhodamine Series.
Year: 1897

page_text: Date of Application, 31st Aug., 1897
Complete Specification Left, 27th May, 1898-Accepted, 20th Aug., 1898
PROVISIONAL SPECIFICATION,
The Manufacture and Production of New Colouring-matters Related
to the Rhodamine Series.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by the Badische Anilin & Soda Fabrik of Ludwigs-
hafen-on-Rhine, in the Empire of Germany) to be as follows:-
It is known that rhodamine dyes derived from mono-basic acids can readily
be prepared. Thus benzo-rhodamines can be obtained from benzo-tri-chloride
and the meta-amido-phenol derivatives, or from benzaldehyde and the said deriva-
tives, with subsequent oxidation of, and, splitting off water from, the intermediate
condensation products obtained.
Further by the use of ortho-sulpho-benzaldehyde, in the above reaction, with
dimethyl and diethyl-meta-amido-phenol-derivatives, ortho-sulphonated benzo-
rhodamines have been prepared and the explanation has been given that the
ortho-sulpho group exercises an effect similar to that due to the ortho-carboxyl-
group in the phthalic acid rhodamines (see the Specification of German Patent
No. 90487).
More recently it has been shewn by my foreign correspondents that the rhoda-
mines of the phthalic acid series, derived from benzylated amido-phenol by
sulphonation, yield useful acid dyestuffs.
The present invention relates to the production of such sulpho-acids of benzy-
lated benzo-rhodamines and substitution derivatives thereof, as contain, at least,
one sulpho-group in the benzyl-group.
In their production the following steps ar reactions take place:-
(1) Condensation of benzaldehyde, or a substitution derivative thereof, with a
benzylated meta-amido-phenol-compound.
(2) Splitting off of water, whereby the so-called pyrone ring is formed.
(3) Oxidation.
(4) Sulphonation.
It is not material to this invention that these reactions take place separately,
or in the order described; it is, for instance, possible, amongst other variations,
to effect the steps 2, 3, and 4 in one operation.
The first reaction, it is preferred to effect in aqueous, or alcoholic, solution, in
the presence of free mineral acid. Thus benzyl-ethyl, (or methyl), meta-amido-
phenol and benzaldehyde, or its substitution derivatives, combine, when heated
together in such a solution, in the presence of a mineral acid, at the temperature
of the water-bath, in a vessel furnished with an inverted condenser.
If the condensation products thus obtained, and after isolation and purification,
be heated, for say about an hour and a half, at a temperature of one hundred and
thirty degrees Centigrade with concentrated sulphuric acid, then the water is split
off and the pyrone-ring is formed and, at the same time, some sulphonation and
oxidation is effected. If the temperature of treatment with sulphuric acid be
Price 871

page_text: raised to a higher temperature say about 140° to 150° Centigrade the sulphonating
and oxidizing effect is increased, and evolution of sulphur dioxide takes place.
But the best result appears to be obtained if the pyrone body, obtained by the
treatment at about 1300 Centigrade, as aforesaid, be further oxidized and, in cases
where it is necessary, further sulphonated in separate operations; and the sulpho-
nation in cases where the finished colouring-matter would otherwise not be
sufficiently soluble can be effected either before, or after, the oxidation.
The said further sulphonation can be effected by the aid of fuming sulphuric
acid at a low temperature.
The oxidation can be effected by the aid of ferric chloride or by any of the
ordinary oxidizing agents.
Instead of using benzyl-alkyl-amido-phenols, the sulpho acids thereof can be
used for condensation with benzaldehyde, or its substitution derivative; and then
a sulphonated condensation product is at once obtained which, upon conversion
into the pyrone-derivative by the splitting off of water, and oxidation, without
further treatment is a sulphonated dye of the new class.
The substitution derivatives of benzaldehyde which can be used are, for in-
stance, the chloro-, sulpho-, disulpho-, amido-, methyl-, oxy-, and alkyl-oxy-
derivatives thereof.
Instead of the condensation products from two molecular proportions of the
benzylated meta-amido-phenols, and one molecular proportion of an aldehyde-
derivative, the mixed leuco-bodies from one molecular proportion of a benzylated
and one molecular proportion of an un-benzylated meta-amido-phenol and one
molecular proportion of an aldehyde derivative can be used without any sub-
stantial difference in the result.
The following examples will serve to further illustrate the nature of the inven
tion; but the details can, in all cases, be varied without departing from tho
nature of the invention. The parts are by weight.
EXAMPLE 1.
:
1: 4,
ACID COLOURING-MATTER FROM ETHYL-BENZYL-META-AMIDO-PHENOL AND
BENZALDEHYDE.
Dissolve about fifty-three parts of benzaldehyde and about two hundred and
thirty parts of ethyl-benzyl-meta-amido-phenol in about one thousand parts of
spirit, and heat it with about one thousand parts of dilute sulphuric acid (con-
taining about ten per cent. H₂SO) for twelve hours in a vessel furnished with an
inverted condenser..
After cooling, the condensation product crystallizes out in compact crystals,
which are purified by once recrystallizing from spirit.
To convert it into the sulphonated pyrone-derivative heat about ten parts of the
pure leuco-body with about thirty parts of ordinary concentrated sulphuric acid
for an hour and an half, at about one hundred and thirty degrees Centigrade. Pour
the melt so obtained onto ice; filter and press; dissolve the precipitate in about
four hundred parts of water adding the necessary quantity of carbonate of soda,
and oxydize the solution (which is already strongly red coloured) on the water-bath
with a ten per cent. solution of ferric chloride containing about five parts of ferric
chloride and about ten parts of hydrochloric acid.
Dissolve the colouring-matter sulpho acid which separates out, in carbonate of
soda, filter and salt the solution. out.
The dry dyestuff is a brilliant brownish-red powder which dissolves in water
with an intensively crimson-red colour and a yellow fluorescence. With concen-
trated sulphuric acid a brownish-yellow solution is obtained; on diluting with
water dark-red flocks separate out and the solution assumes the colour of the
ordinary aqueous solution. It dyes wool and silk in the acid bath beautiful
bluish-red shades, which are fast against the action of acids and alkalies.
On substituting for the benzaldehyde in the above mentioned process its various

page_text: substitution derivatives; as for instance, the chloro-, sulpho-, disulpho-, amido-,
methyl-, oxy-, and alkyloxy-benzaldehydes, and otherwise proceeding in the same
manner, colouring-matters are obtained of only slightly different properties, the
shades of which vary from a yellower to a dark bluish-red.
EXAMPLE 2.
COLOURING-MATTER FROM META-SULPHO-BENZALDEHYDE AND ETHYL-BENZYL-META-
AMIDO-PITENOL.
Dissolve about two hundred and eight parts of benzaldehyde-meta-sulpho acid
sodium salt in about two thousand parts of dilute sulphuric acid (containing about
ten per cent. HSO) and mix it with about four hundred and sixty parts of
ethyl-benzyl-meta-amido-phenol dissolved in one hundred parts of spirit.
Heat about ten to twelve hours on the water-bath, and convert the crystallized.
condensation product into the pyrone-body by heating ten parts thereof with
thirty parts of concentrated sulphuric acid, at a temperature of one hundred and
thirty degrees Centigrade as herein before described. The original condensation
product, although it already contains a sulpho group is very difficultly soluble
in dilute alkalies; but after splitting off the water the product obtained is very
readily soluble in dilute alkalies and has therefore been further sulphonated at the
same time. Work up further as described under Example 1.
The finished colouring-matter is a brownish-red powder which is readily soluble;
its properties as a dye and also its shade are about the same as those of the
colouring-matter obtained from benzaldehyde. The amber-yellow solution in con-
centrated sulphuric acid does not give a precipitate on diluting with water.
On substituting for the benzaldehyde-meta-sulpho acid the ortho-sulpho acid,
a rather yellower red is obtained. The benzaldehyde disulpho acids give also very
similar results.
EXAMPLE 3.
21.
COLOURING-MATTER FROM 1.2.5 DICIILOR BENZALDEHYDE AND ETHYL-DENZYL-META-
AMIDO-PHENOL.
Dissolve about eighty-seven and a half parts of 1.2.5-dichlorbenzaldehyde in
about five hundred parts of spirit; add to this solution a solution of about two
hundred and thirty parts of ethyl-benzyl-meta-amido-phenol in one thousand
parts of dilute sulphuric acid (containing about ten per cent. H₂SO). Heat for
ten hours and convert the crystallized leuco-body into the pyrone-body as herein-
before described.
Although the pyrone-body so obtained is readily soluble in dilute carbonate of
soda the colouring-matter obtained therefrom is difficultly soluble. Therefore the
pyrone-body after separating out, should be dried and converted into a higher
sulpho acid by dissolving it in about fifty parts fuming sulphuric acid (containing
about twenty-four per cent. free anhydride, SO3). Pour onto ice, when the
sulpho acid separates out, filter and dissolve in a solution of carbonate of soda,
the solution is intensively bluish-red, so that only little ferric chloride is necessary
for oxidizing as herein before described.
The colouring-matter is a dark-red powder; it dissolves readily in water with
a bluish-red colour and only a very weak fluorescence; it dyes wool and silk-much
more bluish shades than do the products obtained according to Examples 1 and 2.
The isomeric 1.2.4 dichlorbenzaldehyde and the ortho-chlor-benzaldehyde yield
very similar products; the colouring-matters obtained from meta- and para-mono-
chlor-benzaldehyde are less bluish.
Dated this 31st day of August 1897

page_text: The Manufacture and Production of New Colouring-matters Related
to the Rhodamine Series.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London.
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by the Badische Anilin & Soda Fabrik of Ludwig-
shafen-on-Rhine, 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:-
It is known that rhodamine dyes derived from mono-basic acids can readily
be prepared. Thus benzo-rhodamines can be obtained from benzo-tri-chloride
and the meta-amido-phenol-derivatives or from benzaldehyde and the said deriva-
tives with subsequent oxidation of, and splitting off water from, the intermediate
condensation products obtained.
Further by the use of ortho-sulpho-benzaldehyde in the above reaction with
dimethyl- and diethyl-meta-amido-phenol-derivatives, ortho sulphonated benzo-
rhodamines have been prepared and the explanation has been given that the ortho-
sulphogroup exercises an effect similar to that due to the ortho-carboxyl-group in
the phthalic acid rhodamines (see the Specification of German Patent No. 90487).
More recently it has been shewn by my foreign correspondents that the rhoda-
mines of the phthalic acid series derived from benzylated amido-phenol by sul-
phonation, yield useful acid dyestuffs.
The present invention relates to the production of such sulpho acids of benzy-
lated benzo-rhodamines and substitution-derivatives thereof, as contain at least
one sulpho-group in the benzyl-group.
In their production the following steps or reactions take place:
(1.) Condensation of benzaldehyde, or a substitution-derivative thereof, with
a benylated meta-amido-phenol-compound,
(2.) Splitting off of water, whereby the so-called pyrone-ring is formed;
(3.) Oxidation;
(4.) Sulphonation.
It is not essential to this invention that these reactions be caused to take place
separately, or in the above order. It is, for instance, possible, amongst other
variations, to effect the above steps or reactions 2, 3, and 4 in one operation.
The first reaction it is preferred to effect in aqueous or alcoholic solution in the
presence of free mineral acid. Thus benzyl-ethyl- (or -methyl) meta-amido-phenol
(two molecular proportions) and benzaldehyde or a substitution-derivative thereof
(one molecular proportion) combine, when heated together in such a solution in
the presence of a mineral acid, at the temperature of the water-bath in a vessel
furnished with an inverted condenser.
⚫ If the condensation-products thus obtained, and after isolation and purification,
be heated for say about an hour and a half, at a temperature of one hundred and
thirty degrees Centigrade, with concentrated sulphuric acid, then the water is split off
and the pyrone-ring is formed, and at the same time some 'sulphonation and oxida-
tion is effected. If the temperature of treatment with sulphuric acid be raised
to a higher temperature, say about 140 to 150 degrees Centigrade, the sulphonating
and oxidizing effect is increased, and evolution of sulphur dioxide takes place.
But the best result appears to be obtained, if the pyrone-body obtained by the
treatment at about 130 degrees Centigrade as aforesaid, be further oxidized, and
in cases where it is necessary, further sulphonated in separate operations. The

page_text: sulphonation can, in cases where the finished colouring-matter would not other-
wise be sufficiently soluble, be effected either before, or after, the oxidation.
The said further sulphonation can be effected by the aid of fuming sulphuric
acid at a low temperature.
The oxidation can be effected by the aid of ferric chloride, or by any of the
ordinary oxidizing agents.
Instead of using benzyl-alkyl-amido-phenols, the sulpho-acids thereof can be
used for condensation with benzaldehyde or a substitution-derivative thereof, and
then a sulphonated condensation-product is at once obtained which, upon conver-
sion into the pyrone-derivative by the splitting off of water, and oxidation, is
without further treatment, a sulphonated dye of the new class.
'
The substitution-derivatives of benzaldehyde which can be used, are for instance
the chloro- sulpho-, disulpho- amido-, methyl- oxy-, and alkyl-oxy-derivatives
thereof.
Instead of the condensation-products from two molecular proportions of the
benzylated meta-amido-phenols, and one molecular proportion of an aldehyde-
derivative, the mixed leuco-bodies from one molecular proportion of a benzylated,
and one molecular proportion of an unbenzylated meta-amido-phenol, and one
molecular proportion of an aldehyde-derivative, can be used without any sub-
stantial difference in the result.
The following examples will serve to further illustrate the nature of the inven-
tion and the manner in which it can be performed, but the details can, in all
be varied without departing from the nature of the invention. The parts
are by weight.
cases,
EXAMPLE 1.
ACID COLOURING-MATTER FROM ETHYL-BENZYL-META-AMIDO-PHENOL AND
BENZALDEIIYDE.
Dissolve about fifty-three parts of benzaldehyde and about two hundred and
thirty parts of ethyl-benzyl-meta-amido-phenol in about one thousand parts of
spirit, and heat it with about one thousand parts of dilute sulphuric acid (containing
about ten per cent. H₂SO) for twelve hours, in a vessel furnished with an inverted
condenser.
After cooling, the condensation-product crystallizes out in compact crystals,
which are purified by recrystallizing from spirit.
To convert it into the sulphonated pyrone derivative, heat about ten parts of the
pure leuco-body, with about thirty parts of ordinary concentrated sulphuric acid,
for an hour and a half, at about one hundred and thirty degrees Centigrade. Pour
the melt, so obtained, onto ice; filter and press; dissolve the precipitate in about
four hundred parts of water, adding the necessary quantity of carbonate of soda,
and oxidize the solution (which is already strongly red coloured), on the water-
bath with a ten per cent. solution of ferric chloride containing about five parts of
ferric chloride, and about ten parts of hydrochloric acid.
:.
Dissolve the colouring matter sulpho-acid, which separates out in carbonate
of soda, filter and salt the solution out.
The dry dyestuff is a brownish red powder, which dissolves in water forming
an intensively crimson red solution with a yellow fluorescence. With concentrated
sulphuric acid a brownish yellow solution is obtained; on diluting with water,
dark red flocks separate out, and the solution assumes the color of the ordinary
aqueous solution.
It dyes wool and silk in the acid bath beautiful bluish red shades, which are
fast against the action of acids and alkalies.
་
I
On substituting for the benzaldehyde in the above mentioned process either of
its various substitution derivatives, as for instance, the chloro sulpho; disulpho,
amido methyl, oxy or alkyloxy benzaldehydes, and proceeding in the manner
herein before described, colouring matters are obtained of only slightly different
properties, the shades of which vary from a yellower to a dark bluish red.

page_text: EXAMPLE 2.
COLOURING MATTER FROM META SULPHO BENZALDEHYDE AND ETHYL-BENZYL-META-
AMIDO PHENOL.
Dissolve about two hundred and eight parts of benzaldehyde-meta sulpho acid
sodium salt in about two thousand parts of dilute sulphuric acid (containing about
ten per cent. H₂SO) and mix it with about four hundred and sixty parts of ethyl-
benzyl-meta-amido-phenol dissolved in one thousand parts of spirit.
Heat about ten to twelve hours on the water bath, and convert the crystallized
condensation product into the pyrone body, by heating ten parts thereof with
thirty parts of concentrated sulphuric acid, at a temperature of one hundred and
thirty degrees Centigrade as herein before described.
The original condensation product, although it already contains a sulphogroup,
is very difficultly soluble in dilute alkalies; but after splitting off the water by
sulphuric acid, the product obtained is very readily soluble in dilute alkalies, and
has therefore been further sulphonated at the same time, work up further as
described under Example 1.
The finished colouring matter is a brownish red powder which is readily soluble,
its properties as a dye, and also its shade, are about the same as those of the
colouring matter obtained from benzaldehyde. The amber yellow solution in
concentrated sulphuric acid on strongly diluting with water, gives a clear solution.
In substituting for the benzaldehyde-meta sulpho-acid, the ortho-sulphoacid, a
rather yellower red is obtained. The benzaldehyde disulphoacids give also very
similar results.
EXAMPLE 3.
COLOURING MATTER FROM, 1.2.5 DICHLORBENZALDEITYDE AND ETHYL-BENZYL-META-
AMIDO-PLIENOL.
Dissolve about eighty seven and a half parts of 1.2.5 dichlor benzaldehyde in
about five hundred parts of spirit; add to this solution a solution of about two
hundred and thirty parts of ethyl benzyl-meta-amido-phenol in one thousand parts
of dilute sulphuric acid (containing about ten per cent. H₂SO₁). Heat for ten
hours and convert the crystallized leuco-body into the pyrone body as hereinbefore
described.
Although the pyrone-body so obtained is readily soluble in dilute carbonate of
soda the colouring matter obtained therefrom is difficultly soluble. Therefore the
pyrone, body after separating out, should be dried and converted into a higher
sulphoacid by dissolving it in about fifty parts fuming sulphuric acid (containing
about twenty four per cent. free anhydride SO3). Pour on to ice, when the sulpho-
acid separates out, filter, and dissolve in a solution of carbonate of soda, the
solution is an intense bluish red so that only little ferric chloride is necessary for
oxidizing as herein before described.
The colouring matter so obtained is a dark red powder which dissolves readily
in water forming, a bluish-red solution with only a very weak fluorescence. It
dyes wool and silk much more bluish shades than do the products obtained accord-
ing to Examples 1 and 2.
The isomeric 1.2.4. dichlorbenzaldehyde, and the ortho-chlor-benzal-dehyde,
yield very similar products, the colouring matters obtained from meta and para
mono chlorbenzaldehyde are less bluish.
EXAMPLE 4.
ACID COLOURING MATTER FROM ONE MOLECULAR PROPORTION OF BENZALDEHYDE,
ONE MOLECULAR PROPORTION OF ETHYL BENZYL-META-AMIDO-PHENOL, AND ONE
MOLECULAR PROPORTION OF DIETHYL-META-AMIDO-PHENOL
Mix about thirty-two parts of benzal dehyde, about sixty eight parts of ethyl
benzyl-meta-amido phenol, and about seven hundred and fifty parts of concentrated

page_text: hydrochloric acid (containing about 35 per cent. real acid HCI), and heat on the
water bath during twelve hours in a vessel furnished with an inverted condenser.
A brownish resin separates which after cooling becomes solid. It represents the
product of the condensation of equal molecular proportions of benzaldehyde and
ethyl-benzyl-meta-amido-phenol. *If desired, it can be purified by powdering
and repeated extraction with boiling water; it is easily soluble in cold alcohol, and
is precipitated from this solution by water.
Mix the product thus obtained with about forty eight and a half parts of diethyl-
meta-amido phenol, about six hundred parts of alcohol, and about six hundred
parts of sulphuric acid (containing ten per cent. of H₂SO), and heat this mixture
to boiling for about twelve hours in a vessel furnished with an inverted condenser.
Remove the alcohol by distillation, add water, and the new condensation product
separates in a solid form. It dissolves in hot alcohol and separates again on
cooling. Of course the mode of its preparation is capable of considerable varia-
tion.
Its further transformation into the acid colouring matter can be performed in
a manner similar to that described for the condensation product of one molecular
proportion of benzaldehyde, and two molecular proportions of ethyl-benzyl-meta
amido-phenol under Example 1.
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 manufacture and production of sulpho acids of benzylated benzo rhoda-
mines and substitution derivatives thereof, by condensing one molecular proportion
of benzaldehyde, or a substitution derivative thereof, with two molecular propor-
tions of benzyl-alkyl-meta-amido phenol, and treating the condensation product
with dehydrating sulphonating and oxidizing agents, all substantially as herein-
before described.
(2) The manufacture and production of sulpho acids of benzylated benzo-rhoda-
mines, and substitution derivatives thereof, by condensing one molecular proportion
of benzaldehyde, or a substitution derivative thereof, with two molecular propor-
tions of benzyl-alkyl-meta-amido-phenol-sulpho acid, and treating the condensation
product with dehydrating and oxidizing agents, all substantially as hereinbefore
described.
(3) The modification in the processes claimed by the preceding claiming clauses,
consisting in condensing one molecular proportion of benzaldehyde, or a substitu-
tion derivative thereof, with one molecular proportion of a benzyl-alkyl-meta-
amido-phenol, or sulphoacid thereof, and with one molecular proportion of a non-
benzylated-alkyl-amido-phenol, all substantially as hereinbefore described.
(4) The manufacture and production of sulpho acids of benzylated benzo rhoda-
mines, and substitution derivatives thereof, in the manners herein before described
in the foregoing examples.
(5) As new articles of manufacture the sulphoacids of benzylated benzo rhoda-
mines and substitution derivatives thereof containing at least one sulpho-group
in the benzyl-group, such as result from the processes hereinbefore described and
claimed.