Note: Descriptions are shown in the official language in which they were submitted.
lO~ii7~
The present invention provides ne~ cationic azo dyesJ a process
for their manufacture, a method o using them for dyeing or printing synt~etic
acid-modified textile fibres, and, in the form of an industrial product, the
synthetic acid-modified fibrous material which has been dyed or printed with
these dyes.
Accordingly, there are provided useful cationic azo dyes of formula
N = N ~ ~ X ~
~herein R represents an unsubstituted alkyl radical, or an alkyl radical which
is substituted by a hydroxy, cyano, carbamoyl, lower alkoxycarbonyl, phenoxy
or phenyl group, which phenyl group is unsubstituted or is substituted by bro-
la mine, chlorine or lower alkyl, each of Rl and R2 represents hydrogen, an unsub-
stituted alkyl radical or an alkyl radical which is substituted by a cyano,
hydroxy, chlorine, lower carbalkoxy, bromine or a phenyl group which is unsub-
stituted or is substituted by bromine, chlorine or lower alkyl or aryl radical,
X ~is the charge equivalent of an anion, and wherein the benznne ring A and
the pyridine ring B are unsubstituted or substituted by non-ionogenic substi-
tuents, snd wherein the cationic component does not contain any groups which
exhibit acid dissociation in water.
The pyridine ring B can be further substituted, in particular by
lower alkyl groups, especially methyl groups,
~..:'.
-- 2 --
.. . . . .. - ... . ~.; .. . .. - ... .. . ... - . .
.. : . ~ . .. ..
106~7b~
or by~alogen atoms, for example chlorine, fluorine or bromine atoms,
~ here the indole ring A is substituted, ~t carries, for example,
lower alk~l and alkox~ groups as well as halogen atoms, such as chlorine or
bromine atoms.
R is above all a straight-chain alkyl radical and contains 1 to 4
carbon atoms. It can carry as substituents, for example, a hydroxy group, a
cyano group, a carbamoyl group, a lower, alkoxycarbonyl group such as the
carbomethoxy or carboethoxy group, a phenoxy group or a phenyl group which is
unsubstituted or is substituted by chlorine, bromine or lower alkyl. Prefer-
ably R is methyl, benzyl or an alkyl radical of 2 to 3 carbon atoms which isunsubstituted or substituted by hydroxyl, cyano, carbamoyl or low molecular
carbalkoxy.
The anion X ~can be derived from an inorganic or organic acid.
As an inorganic anion, X ~ represents, for example, the chlorine, bromine,
iodine, phosphate or sulphate ion. As an organic ion, X Q represents, for
example, acetate, low molecular alkylsulphate, for example methyl or ethyl
sulphate, arylsulphonate, for example benzenesulphonate or p-toluenesulphonate.
X ~can often be with advantage a complex ion, for example the trichlorozinc
ion.
The term "low molecular" denotes that the group or
~ .:
. . ~ . - . . .: .
-` . ' .. ' :,: .' ', :' :. , ,.' . ~ ~ ' :': '
' : , :: ' , . ' :.: ~' : . : .
: . : ~ .. .: . .
lS~
the organic group component contains not more than 4
carbon atoms; it contains above all 1 or 2 carbon atoms.
An alkyl radical represented by Rl and R2 is
preferably a low molecular alkyl group, for example a
methyl, ethyl or butyl group, which is unsubstituted or
substituted by cyano, hydroxy, chlorine, low molecular
carbalkoxy, a phenyl group or a chlorine or bromine atom or
by an alkylphenyl group containing 1 to 4 carbon atoms in
the alkyl moiety.
An aryl radical represented by Rl and R2 is
preferably the unsubstituted phenyl radical.
Rl is preferably methyl or phenyl, whereas R2 can
also represent the substituted alkyl radicals, for example,
benzyl, ~-cyanoethyl, ~-carboethoxyethyl, ~-hydroxypropyl
etc. Preferably, however, R2 is hydrogen.
The new dyes of formula (1) can be obtained, for
example, by quaternising a 2-aminopyridine of formula
(2) -~
N Nll2
with an alkylating agent of formula R-X, wherein R is as
defined in formula (1) and X is a radical which is split off
as the anion X ~3 during the alkylation, diazotising the
quaternised product and coupling it with an indole of formula
- 4 -
,. . . ~ ,.; .. , . . .
- ; ,, ,, , .~
7 ~ ~
Rl ~ (3)
The preferred dyes of formula (1) are those wherein
the pyridinium radical is attached in 4- or 3-position. They
can be obtained by a process wherein the sequence of the
reaction steps described hereinbefore is altered. Accordingly,
a 3- or 4-aminopyridine of formula (2) is diazotised, coupled
with an indole of formula (3) and the resultant azo compound
of formula
1 ~ (4a)
R2 . --
or
N = ~ b)
is reacted with an alkylating agent of formula R-X. Compared
with the process first described, the diazotisation and
coupling of this process proceed more easily. Thus, for
example, the diazotisation of the 2-aminopyridinium salts
.. . . .. . . . .. , .. .. . . ~ .. . . . .. . .. ., .. , . . .. , . , " .. . .. .~
,, ............ . ~ . .:
, , : ~ ; :.
1(3~1'78~
is carried out with nitrosylsulphuric acid in concentrated
organic carboxylic acids, for example formic acid, acetic
acid or propionic acid, and the subsequent coupling takes
place in organic-acid medium at low temperatures, On the
other hand, the diazotisation of 3- or 4-aminopyridines can
be carried out by the conventional methods in aqueous solution
with sodium nitrite and the coupling also takes place in an
aqueous acid medium.
Examples of suitable aminopyridines of ~ormula (2)
are:
2-aminopyridine, 2-amino-3-, -4-, -5- or -6-methylpyridine,
2-amino-4-ethylpyridine, 2-amino-4,6-dimethylpyridine, 2-
amino-S-chloro-, -fluoro- or -bromopyridine, 4-aminopyridine
and, in particular, 3-aminopyridine, 6-chloro-3-aminopyridine
and 3-amino-4-methylpyridine.
Examples of suitable coupling components of formula
(3) are:
2-methylindole, 1-ethyl-2-methylindole, 1,2-diethylindole,
l-ethyl-2-methyl-5-methoxy- or -ethoxyindole, 1,2-dimethyl-
indole, l-butylindole, 1-ethyl-2,5-dimethylindole, 1-(~-
cyanoethyl)-2-methylindole, 1-(~-chloroethyl)-2-methylindole,
~ -carboethoxy- or -carbopropoxyethyl)-2-methylindole,
l-(~-hydroxypropyl)-2-methylindole, 2-phenylindole, l-methyl-
2-phenylindole and 1-ethyl-2-phenylindole.
. ,-. ~ , . .. .. .. ...
",~, - - , ; ~ .
. ~ , . . .. ,,, . .. . - .
. ~ . ,
;: - . . .
. . .
.
... . .
~ ~ 6~ 7 ~
Possible cllkylating agents R-X are, or exarnple,
the unsubstituted or substituted alkyl esters or aralkyl
esters of a hydrogen halide, for example the methyl, ethyl,
n-propyl, n-butyl, ~-cyanoethyl, ~-methoxycarbonylethyl,
~-carbamoylethyl or benzyl esters of hydrochloric, hydro-
bromic or hydroiodic acid; the dialkylsulphates, for example
dimethyl or diethyl sulphatei the alkyl esters of an organic
sulphonic acid, for example the methyl, ~-chloroethyl, ethyl
and butyl esters of benzenesulphonic acid or of p-toluene-
sulphonic acid; and also the bromoacetic or chloroacetic
alkyl esters (containing one alkyl radical of preferably
l to 4 carbon atoms). Instead of certain substituted alkanol
esters, it is also possible to use their primary products,
for example instead of ~-cyanoethyl or ~-carbamoylethyl
chloride or bromide to use acrylonitrile or acrylic amide,
as well as alkylene oxides, for example propylene oxide,
epichlorohydrin in the presence of hydrochloric or hydro-
bromic acid or glacial acetic acid. The preferred quaternising
agent, however, is dimethyl sulphate or diethyl sulphate.
The quaternisation of the aminopyridines of
formula (2) or of the azo compounds of formulae (4a) or (4b)
with the above reactive esters to give the cycloammonium
compounds is advantageously carried out by heating both ~ -
substances in an organic solvent that does not participate in
- 7 - : -
- . . -. -., , . , . - . - . .
. ~ . , . . . . ., . - .
- , . , : :
- . . . - .
~ 7~(~
the reaction. Suitable solve~ts are, for example, optionally
halogenated or nitrated arornatic hydrocarbons, for exaople
toluene, xylene, halo- or nitrobenzene, optionally halogenated
aliphatic hydrocarbons, for example chloroform, trichloro-
ethylene, tetrachloroethylene, tetrachloroethane or trichloro- -
ethane, or water-miscible organic solvents, especially ali-
phatic or cycloaliphatic ketones, for example acetone,
methyl ethyl ketone or methyl isobutyl ketone or cyclohexanonei
medium alkanols, for example propanol, isopropanol, butanols
or amyl alcohols; and also dioxan, dimethyl sulphoxide,
tetrahydrofuran, methylpyrrolidone and dimethyl ~ormamide.
It is advantageous to carry out the process in the presence
of acid acceptors, for example sodium or potassium acetate,
calcium, sodium or potassium carbonate or magnesium oxide.
The cationic dyes o formula (1) are obtained in the
form of salts of the acids of the alkanol or aralkanol esters
used for their manufacture, that is to say of salts of
inorganic or organic acids. These are primarily halides,
such as chlorides, bromides or iodides, alkylsulphates, for
instance methosulphates and ethosulphates, benzenesulphonates
or p-toluenesulphonates. If desired, it is also possible to
obtain salts of other acids by double reaction in a sùitable
polar solvent, for example oxalates by addition of oxalic
acid. Double salts can also be obtained, for example with the
- ! ~
, , , , ~: .
.. . . .
~ 7~
dyestuff halides and corresponding ~inc halides,
The precipitation of the dye salts obtained is
brough~ to completion advantageously by adding sodium chloride
and/or zinc chloride in aqueous acid solution and they ar~
then isolated by filtration
The cationic azo dyes of formula (1) are readily
soluble in water. From an aqueous, neutral or weakly acid
solution, optionally in the presence of wetting agents with
dispersant action, for example in the presence of condensation
products of alkylene oxides with soluble alkanols, they
exhaust onto synthetic acid-modified ~ibrous material
substantially to completely, with heating in an open or
closed vessel under pressure, and produce on this material
bright, yellow to scarlet, level dyeings which are fast to
washing, decatising and light The cationic azo dyes, togeth-
er with known cationic dyes, are also suitable for producing
useful combination dyeings. They also have a good pH stability,
Surprisingly, the quaternised dyes of formula ..
~z
g
. .
.,, . , ~ . .. ; ,. . .. .. .... . . .. .
. . .
.... .. . ... .... . .. ...
~ 7 ~()
yield brilliant yellow shades, although in ormula (S) the
positive charge at the pyridine nitrogen atom cannot be
delocalised to the indole nitrogen, as is the case with
dyes derived from the 2- and 4-aminopyridines. Despite
delocalisation not being possible, surprisingly productive
dyes are also obtained with 3-aminopyridine. This fact is
especially worthy of note, because the dyes of formula (5)
are more easily obtainable than the products derived from
4-aminopyridine and, in particular, 2-aminopyridine.
Examples of suitable synthetic acid-modified fibrous
material with which the cationic dyes of the present invention
can be dyed or printed are acid-modified polyamides, for
example polycondensation products of 4,4'-diamino-2,2'-
diphenyldisulphonic acids or 4,4'-diamino-2,2'-diphenyl-
alkanedisulphonic acids and polyamide-forming starting materials,
polycondensation products of monoaminocarboxylic acids or
their amide-forming derivatives or dibasic carboxylic acids
and diamines with aromatic dicarboxysulphonic acids, for
example polycondensation products of caprolactam or hexamethyl-
enediammonium adipate with potassium-3,5-dicarboxybenzene-
sulphonate, or acid-modified polyester fibres, for example poly-
condensation products of aromatic polycarboxylic acids, for
example terephthalic acid or isophthalic acid, with polyhydric
alcohols, for example ethylene glycol and 1,2- or 1,3-dihydroxy-
-- 10 -
~' ' ' '' , '~ '`, ' ,'''"'. ~ ' ' ;'
,~,: ' ,, ' ~ ' ' ' ' ' ,
- , : .
.
. ' , ' . , .
~ 7 ~
3-(3-sodium sulphopropoxy)propane, 2,2-dimethylol-1-(3-
sodium sulphopropoxy)butane, or 3,5-dicarboxyben~enesulph-
onic acid or sulphonated terephthalic acid or sulphonated
diphenyl-4,4'-dicarboxylic acid. Preferred fibrous material
S is that from polyacrylonitrile or from polyacrylonitrile
copolymers, in which latter case the copolymer contains
preferably at least 80 percent by weight of acrylonitrile.
Besides the acrylonitrile, other vinyl compounds are nor-
mally used as comonomers, for example vinylidene chloride,
vinylidene cyanide, vinyl chloride, methacrylates, methyl
vinyl pyridine, N-vinylpyrrolidone, vinyl acetate, vinyl
alcohol or styrenesulphonic acids.
The invention is illustrated by the following
Examples, in which the parts are by weight unless otherwise
stated. The relationship between parts by weight and parts
by volume is the same as that between the gram and the
cubic centimetre.
. , . .... . .. , ,.. .. ,... . ~... , . ., . ,,. . .. ;, .. ~,
. . - , . . .-: . - ~ . ,
xample 1
4.72 parts of the dye of formula
ï
~1
are suspended at 100C in 100 parts by volume of chloro-
benzene, Then 0~5 part of magnesium oxide is added and 5
parts of dimethyl sulphate are added dropwise in the course
of 5 minutes. The reaction mixture is kept for 30 minutes
at 100C and the dye salt of formula
CH3
_ ' _ . '
precipitates in crystalline form. The dye is filtered off
and dried at 70C in vacuum. It dyes polyacrylonitrile, acid- -
modified polyamide and acid-modified polyester fibres in
yellow shades from an acetic acid bath.
The dyeings have very good fastness to light and decatising.
- 12 - ~
. : . . , j . .
.- . ., . . ~ ,, ... . - , ~ .. -- :
.. : . . . . .:
... ,, . : - ~ . .:
. . . . . . . . . . .. . .
, : : , ~ ~ - ., .
, ,. ; . . ~ : ". .: :
~0 ~ 1 7 ~
The azo compound used in this Example as starting material
is obtained by diazotising 3-aminopyridine in conventional
manner and coupling it with 2-methylindole,
Example 2
5.96 parts of the dye of formula
N
H
are suspended at 100C in 100 parts by volume of chlorobenzene.
Then 0.5 part of magnesium oxide is added followed by the
dropwise addition of 5 parts of dimethyl sulphate in the
course of 5 minutes. The reaction mixture is kept for 1
hour at 110C and the dye salt of formula . -
1H3 ~ f3 CH3504
'
precipitates in crystalline form. The precipitate is filtered
- 13 -
~ .
171~(~
off at 40C,washed with a sm~ll amount of chlorobenzene
and dried in vacuo at 70C, The resultant dye dyes poly-
acrylonitrile, acid-modified polyamide and acid-modified
polyester fibres in golden yellow shades. The dyeings have
excellent fastness to light and decatising,
The azo compound used in this Example as starting material
is obtained by diazotising 3-aminopyridine and coupling
it to 2-phenylindole in the conventional way.
Example 3
2.98 parts of the dye of formula
are dissolved in 4.5 parts by volume of glacial acetic at
20C. Then 4 parts of ethylene oxide are passed in over
the course of 2 hours. The reaction solution is then diluted
with 200 parts of water and sodium chloride is added, where-
upon the dye salt of formula
- 14 -
.
-' . i . , ': , . : : -
'
10~1780
L ~ ~
Cl~3
C~12
H . _
precipitates in crystalline form. The dye is filtered off
and dried at 70C in vacuo. It dyes polyacrylonitrile, acid-
modified polyamide and acid-modified polyester fibres from
an acetic acid bath in golden yellow shades which have very
good fastness to light and decatising.
The dyes listed in the following table are obtained in
analogous manner:
- 15 -
. j,, , . ::
~ - -
~ ~ o
o-,la~
~s~ ~ ~
u a
o-~
o .,l - - ~ - - - - - - - - -
a~
a~ ~
J ~ o
~ ~oo ~o
X
~ ~ o ~ o ~
a~ t~ ~rl ~ I
rl O~ ~ O ~ C~l
~ ~ ~ ~ x o s ~
,1 tn o u~ O ~ o
~n ~ ~
,~ ~ .~ ~ a~ o ~q~ ~ 5~ ~ X O
~ ~ ~ ~ ~ ~ o o o ~ ~ o s~ ~
:~ ~ ~ o ~ o a~
J ~ N O :~. e ~ ~ ~ , t, ~ ~ ~ x
~ ~ ~ a ~ o ~ o e
~ ~ ~ ~ a~ ~
~ _ _ . .
~ ~ O ~
.Q~ ~ ~ ~ ~ O
~dO
E~~ .,1 ,_1 .,~ ,1 ,c ,~ ,~ ~ p~
o :~ ~ a ~ ~ X~ X
~ ~ ~ O ~ ~ ~ O ~ O ~
oD ~ , 1 ~ ~ ~ 1 ,, , .~ ~ .~ ,,,
~ ~
I a)
o ~ al ~ ~ .C
, ~ e e~
O
C~ ~ ~ ~ ~-~, ~ ~ ~
C ~ :
O .~1
N t~ .
~ l
~)
~, ~ U~ ~ CS` O ~ C~
.
.. __._ . ._.
- 16 -
.
;, . . . ~ , .
'7~
?~ ~
P< s~ ,,
~ ~
O a~ ~
~a
~, ~ o
U~ ~ ~ oo
.
~o ~
.,, ~q
.~ -
.~, ~ ~
J __
g ~
. a~ .- - .
. .
'Pll ~ ~0 ~ . '~.
~ ~ ~ ~ -
O E3 ~
':'
, . '
Q.c~ ~ ~ ~ ~ ~ ~,:
~O h O ~ .
O t: 'I ~ t:
~I E~ I E3 I E3
~ , ~
.,
Q. . ' '
l~i . .. _~ '' '~ '
- 17 -
. . .
.. . . ... . - - - - - ., `. . _.. ....... . .. .. .
,1 . , ' , , ' ' ;' ~ ' . , . , . ! . . .
~ 3
Example 21
5.46 parts of the dye of formula
~ N ~
are suspended together with 0.5 g of magnesium oxide in
50 parts by volume of tetrachloroethane. Then 5 parts of
dimethyl sulphate are added dropwise and the mixture is
heated, with good stirring, to 100C. After 1 hour the
solvent is removed by steam distillation. To the residual
aqueous solution are added, 5 parts of zinc chloride and
50 parts of sodium chloride, whereupon the dye salt of
formula -
-
[ H3C-N ~ --N ~ ~ znC ~
precipitates. It dyes polyacrylonitrile fibres from an
acetic acid bath in scarlet shades of outstanding fastness to
- 18 -
light and decatising. The water-insoluble dye used as
starting material in this Example is obtained in conventional
manner by diazotising, 4-aminopyridine and subsequently
coupling it to 2-phenylindole.
The following dyes can be obtained in analogous manner.
- 19 -
, . .. . ; , .. .. :~.... . :,
- -~ -
o
u~ ~ ~o - - -
- - -
J~
Cd ~ C ro
-
~1 ~ ~ . .,
~- Q~ c~
l ~ l ~': o~ ~
N . ~ .
Cd ~ ~ ~ U~
~ C`l C~ l
- 20 -
,, `', . ' " .. ' . ' .' :' ; ' ' ' . ~ ,, ' .
- . ' ' ' . . , ' ' ',, ' '' . ' ~ '
,- .' ' . . '. . ' ' "' ,' . .' ' ': . ' . '
l()~ O
Example 26
4.4 parts of 1-methyl-2-amino-pyridinium-methosulphate
are dissolved in a mixture of 10 parts by volume o glacial
acetic acid and 10 parts by volume of propionic acid. To
this solution is added dropwise 3.5 parts by volume of
nitrosylsulphuric acid (corresponding to 1.38 parts of
sodium nitrite) in the course of 15 minutes at -15 to
-10C. The resultant diazo solution is subsequently treated
with a solution of 3,8 parts of 2-phenylindole in 30 parts
by volume of glacial acetic acid. After it has been stirred
briefly at -10C, the reaction mixture is poured onto
500 parts of ice and the pH is adjusted to 4 with sodium
acetate. The dye of formula
is precipitated by adding zinc chloride and sodium chloride. -
It is filtered off, washed with sodium chloride solution
and dried. This dye dyes polyacrylonitrile fibres from an
acetic acid bath in scarlet shades. The dyeings have out-
- 21 -
` ' ' '' : " '' ', ' .'. ' ' ' ,,' ' ' .' ' " .' ~' "' . " ;',; '' "' ''.' " ' ''; '', ': '
0
standing fastness to, light, decatisi.ng and washing, Dyes
which yield scarlet dyeings with a similar deg~ee of
fastness are obtained by using instead of 2-phenylindole
equimolar amounts of l-methyl-2-phenylindole or l-(~-hydroxy-
ethyl~-2-phenylindole.
- 22 -'
' - : ' ' ' ' ' , ' ' ' .' :
.''. . ~' ". ' '; , : ' ' ,. ' ' :.. : ; ' . " ' ~ .:
