Manufacture of Colouring Matters of the Acridinium Series.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Manufacture of Colouring Matters of the Acridinium Series.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention (as communicated to me from abroad by
The Actien-Gesellschaft für Anilin Fabrikation, of Berlin, in the Empire of Germany,
Chemical Manufacturers) to be as follows:-
The colouring matters of the acridine series which have been used hitherto are
little fast to alkalies. The acridine group being only feebly basic, the free colour
bases are easily precipitated from the dyestuffs by means even of sodium carbonate
or ammonia; the colour bases thus formed are nearly colourless or at least of much
lighter shade than are the corresponding salts.
My foreign correspondents have now fonnd that acridine dyestuffs can be con-
verted into easily soluble colouring matters which are completely fast to soap by the
addition of alkyl-halides to the acetyl-derivatives of the colour bases. The acetyl
amido-acridinium compounds thus obtained can be directly employed as dyestuffs.
By saponification they are converted into the free amido-derivatives, which dye
tannin-mordanted cotton somewhat redder shades than do the acetyl derivatives.
The production of the new dyestuffs may be represented by the following typical
thebromide
The observation that alkyl-halides react with acridine derivatives was first made
by Graebe and Caro (Liebig's Annalen 158, page 265) and Bernthsen (Liebig's
Annalen 224, page 20). These authorities obtained some acridinium and phenyl-
acridinium compounds which however cannot be used as colouring matters.
Later, there has been described in the Specification No. 18,589 of 1894 the inter-
action of alkylising agents with acridine dyestuffs. The process described in this
Specification however does not lead to the formation of acridinium derivatives as
there are employed in the process salts of diamidoditolyl acridine (acridine yellow)
and diamidoditolylphenyl-acridine (benzoflavine).
The alkylisation accordingly takes place in the amido-group, and the colouring

page_text: matters produced by the process described in the aforesaid Specification are pre-
cipitated by sodium carbonate, the colour bases being separated, which clearly
proves that these dyestuffs do not belong to the acridinium series.
The present invention consists in allowing alkyl halides to act in neutral solution
on the acetyl-derivatives of the colour bases. The products obtained by this new
process are single compounds whereas mixtures alone result from the process described
in Specification No. 18,589 of 1894.
The new dyestuffs produced as above described are easily soluble in water, less
soluble in alcohol. Their solutions have an intensely bitter taste and are not altered
by addition of ammonia, ammonium carbonate or so:lium carbonate.
Concentrated soda lye precipitates the free acridinium base.
The invention is illustrated by the following examples.
EXAMPLE 1.
Acetylamidotolunaphthacridine described in Specification No. 16474 of 1898 is
suspended in chloroform or benzene and heated under pressure with a little more than
the calculated quantity of ethyl iodide or ethyl bromide at 140° to 150° C. during
3 to 4 hours. After refrigeration the brown-red crystals are filtered off and dissolved
in water; the orange coloured solution, after traces of unaltered acridine compound
have been precipitated by addition of sodium carbonate or ammonia, is acidified and
precipitated with either hydrobromic acid, sodium bromide or iodide, nitre or common
salt. The corresponding salt of the acridinium compound is thus obtained in the
form of an orange coloured crystalline powder. With the exception of the iodide all
these salts are easily soluble in water. The ethobromide crystallizes especially well
from alcohol, being very little soluble in this solvent in the cold.
The yellow coloured aqueous solution of the ethobromide of acetylamidotolunaphth-
acridinium is not altered by addition of ammonia or alkali carbonates; by addition of
soda lye the free colour base is separated as a red precipitate, which is only little
soluble in ether yielding a red-violet solution.
If the acetyl derivative above described is saponified by dilute mineral acids the
free ethobromide of amidotolunaphthacridinium formed. This product is easily
soluble in water to an orange-red coloured solution and crystallizes well from alcohol
in the form of large red leaflets arranged in stellate groups. From the solution of
this acridinium compound the free colour base is precipitated only by caustic soda.
This base forms a red precipitate which easily dissolves in ether to a red coloured
solution having a green fluorescence.
The ethobromide of acetylamidotolunaphthacridinium dyes tannin-mordanted
cotton orange-yellow shades ; the corresponding free amido-derivative yields
orange-red, very clear tints.
EXAMPLE 2.
This product dissolves easily in water to a yellow coloured solution from which it is 45
only precipitated by means of caustic soda as a feebly red precipitate, which is nearly
insoluble in ether. The free amido-compound produced by saponification forms salts
which easily dissolve in water to red coloured solutions. The acetyl-compound dyes

page_text: tannin-mordanted cotton yellow tints; the free amido-compound yields scarlet-red
tints.
EXAMPLE 3.
By substituting in Example 1) for acetylamidotolunaphthacridine the acetyl
derivative of the amidotoluphenylnaphthacridine described in Specification No. 16474
of 1898, (which acetyl product is a feebly yellow coloured powder melting
at 255° to 256° C.) there is obtained the corresponding acridinium compound. The
reaction is in this case best carried out at a temperature of 160° to 170° C. The
acridinium compound thus obtained is quite analogous to the products described in
Examples 1 and 2. From this compound also the free base can be separated only by
means of soda lye. The colour base dissolves in ether to a violet coloured solution
whereas the free amido-compound obtained by saponification dissolves in ether to a
red-violet coloured solution.
The acetyl-compound of this acridinium derivative dyes tannin-mordanted cotton
orange-yellow tints; the free amido-compound yields very clear orange red shades.
Dated this 28th day of August 1899.
ABEL & IMRAY,
Agents for the Applicant,
COMPLETE SPECIFICATION.
Manufacture of Colouring Matters of the Acridinium Series.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention (as communicated to me from abroad by
The Actien-Gesellschaft für Anilin Fabrikation, of Berlin, 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 :-
The colouring matters of the acridine series which have been used hitherto are
little fast to alkalies. The acridine group being only feebly basic, the free colour
bases are easily precipitated from the dyestuffs by means even of sodium carbonate or
ammonia; the colour bases thus formed are nearly colourless or at least of much
lighter shade than are the corresponding salts.
My foreign correspondents have now found that acridine dyestuffs can be converted
into easily soluble colouring matters which are completely fast to soap by the addition
of alkyl halides to the acetyl-derivatives of the colour bases. The acetyl-amido-
acridinium compounds thus obtained can be directly employed as dyestuffs.
By hydrolysis they are converted into the free amido-derivatives, which dye tannin-
mordanted cotton somewhat redder shades than do the acetyl derivatives.
The production of the new dyestuffs may be represented by the following typical
equation.

page_text: The observation that alkyl halides react with acridine derivatives was first made by
Graebe and Caro (Liebig's Annalen 158, page 265) and Bernthsen (Liebig's
Annalen 224, page 20). These authorities obtained some acridinium and phenyl-
acridinium compounds which however cannot be used as colouring matters.
Later, there has been described in the Specification No. 18,589 of 1894 the inter-
action of alkylising agents with acridine dyestuffs. The process described in this
Specification, however, does not lead to the formation of acridinium derivatives, as
there are employed in the process salts of diamidoditolylacridine (acridine yellow) and
diamidoditolylphenylacridine (benzoflavine).
The alkylisation accordingly takes place in the amido-group, and the colouring
matters produced by the process described in the aforesaid Specification are
precipitated by sodium carbonate, the colour bases being separated, which clearly
proves that these dyestuffs do not belong to the acridinium series.
The present invention consists in allowing alkyl halides to act in neutral solution
on the acetyl-derivatives of the colour bases. The products obtained by this new
process are single compounds whereas mixtures alone result from the process
described in Specification No. 18589 of 1894.
The new dyestuffs produced as above described are easily soluble in water, less
soluble in alcohol. Their solutions have an intensely bitter taste and are not altered
by addition of ammonia, ammonium carbonate or sodium carbonate.
Concentrated soda lye precipitates the free acridinium base.
The invention is illustrated by the following examples.
Acetylamidotolunaphthacridine described in Specification No. 16,474 of 1898, is
suspended in chloroform or benzene and heated under pressure with a little more
than the calculated quantity of ethyl iodide or ethyl bromide at 140° to 150° C.
during 3 to 4 hours.
After refrigeration the brown-red crystals are filtered off and dissolved in water;
the orange coloured solution, after traces of unaltered acridine compound have been
precipitated by addition of sodium carbonate or ammonia, is acidified and precipitated
with either hydrobromic acid, sodium bromide or iodide, nitre or common salt. The
corresponding salt of the acridinium compound is thus obtained in the form of an
orange coloured crystalline powder. With the exception of the iodide all these salts
are easily soluble in water. The ethobromide crystallises especially well from alcohol,
being very little soluble in this solvent in the cold.
The yellow coloured aqueous solution of the ethobromide of acetylamidotolunaph-
thacridinium is not altered by addition of ammonia or alkali carbonates; by addition
of soda lye the free colour base is separated as a red precipitate, which is only little
soluble in ether yielding a red-violet solution. In order to obtain the free ethobromide
of amidotolunaphthacridinium, the acetyl-derivative above described is hydrolysed as
follows:
10 parts of acetylamidotolunaphtbacridinium-ethobromide are dissolved in 50 parts
of boiling alcohol: to this solution, 10 parts of hydrobromic acid (containing 50 per
cent. of the acid are added and the mixture is heated for some time. On refrigeration,
the product of the hydrolysis separates in the form of red crystals. It is easily
soluble in water to an orange-red coloured solution and crystallises well from alcohol
in the form of large red leaflets arranged in stellate groups. From the solution of
this acridinium compound the free colour base is precipitated only by caustic soda.
This base forms a red precipitate which easily dissolves in ether to a red coloured
solution having a green fluorescence.
The ethobromide of acetylamidotolunaphthacridinium dyes tannin-mordanted cotton
orange-yellow shades; the corresponding free amido-derivative yiel is orange-red, very
clear tints.

page_text: EXAMPLE 2.
If in the preceding example for acetylamidotolunaphthacridine is substituted the
acetylamidonaphthacridine, described in French Patent 280,372 (Brevet d'addition
14.3. 1899) otherwise proceeding in the manner indicated in Example I, there is
5 obtained an acridinium compound having the following constitution
This product dissolves easily in water to a yellow coloured solution from which it is
only precipitated by means of caustic soda as a feebly red precipitate, which is nearly
insoluble in ether. The free amido-compound produced by hydrolysing forms salts
which easily dissolve in water to red coloured solutions. The acetyl-compound dyes
tannin-mordanted cotton yellow tints; the free amido-compound yields scarlet-red
tints.
EXAMPLE 3.
By substituting in Example I for acetylamidotolunaphthacridine the acetyl
derivative of the amidotoluphenylnaphthacridine described in Specification N° 16,474
of 1898 (which acetyl product is a feebly yellow coloured powder melting at 255°
to 256° C) there is obtained the corresponding acridinium compound. The reaction
is in this case best carried out at a temperature of 160° to 170° C. The acridinium
compound thus obtained is quite analogous to the products described in Examples 1
and 2. From this compound also the free base can be separated only by means of
soda lye. The colour base dissolves in ether to a violet coloured solution whereas
the free amido-compound obtained by hydrolysis dissolves in ether to a red violet
coloured solution.
The acetyl-compound of this acridinium derivative dyes tannin-mordanted cotton
orange-yellow tints; the free amido-compound yields very clear orange-red shades.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. The herein described manufacture of colouring matters of the acridinium series
by acting with alkyl halides on acetyl-amido-compounds of derivatives of the acridine
series.
2. The acetyl-amido-acridinium-compounds manufactured as above set forth.
3. The herein described process for converting the acetyl-amido-acridinium-
compounds referred to in Claim 2 into the corresponding amido-compounds by
hydrolysis.
4. The amido-acridinium-compounds manufactured as above set forth.
ABEL & IMRAY,
Agents for the Applicant.