Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
HOE 76/F 159 K
1~91 b;~
The pre~ent invention relates to azamethine-Cu complex
compounds, to a proces3 for preparing them and their use as
pigments.
The present in~ention provides azamethine-Cu complex
compounds of the formula I
X~O--Cu--O ~
in which X represents hydrogen, chlorine, bromine, alkyl or
alkoxy having 1 to 4 carbon atoms each, nitro, trifluoromethyl
or a group of the formula -COOY, in which Y stands for ~ydro-
gen or alkyl having 1 to 5 carbon atoms, and R1 and R2 are
hydrogen, or one of the radicals R and R2 is hydrogen and the
other represents -COOY, with the pro~iso that at lc~st one of
the radicals X, Rl and R stands for -COOY.
If Y represents alkyl, it stands for example ror ethyl,
n-propyl, isopropyl, n-butyl, i~obutyl, n-amyl or i~oamyl,
however, preferably for methyl.
Thc invention also provides a proces~ for the preparation
of the compounds of the formula I, which comprises metallizing
an azamethine of the formula II
R~
N = CH ~ (II)
OR HO
R 1
wherein R i~ hydrogen or a methyl group, with a copper-ylel-
ding compound, i.e. an inorganic or organic, preferably bi-
valent copper salt, as well a~ their use a~ pigments.
HOE ~6 ~ 1~2 X
As oopper salts, there are ~uitable, for example,
copper(II)-chloride, copper(II)Yulfate, copper formate,
copper(II)acetate or copper ~tearate.
The coppering of the compound II 9 in which R stand~ for
hydrogen, may be carried out in water or organic solvents or
aqueou~-organic ~olvent~ at a temperature in the range Or from
20 to 180C, preferably from 20 to 150C, e~pecially from 80
to 110C. As ~ol~ents for the coppering there are suitable,
for e~ample, alcohol~, espeeially lower alkanol~, such a~ me-
thanol~ ethanol, n-propanol, isopropanol, n-butanol or i~o-
butanol; glycol-monomethylether; glacial acetic acid; form-
amide or dipolar aprotic sol~ents, ~uch as dimethylformamide,
N-methylpyrrolidone or tetramethylene-sulfone. For the coppe-
ring reaction, use is made preferably of the same ~olvent,
in which the copper salt has previously been di~sol~ed. The
coppering m~y be effected in the presence Or a basic compound,
such as sodium acetata.
The coppering of the ani~o~ derivati~ea (R=CH3) is carrisd `~
out in the prssence of a coppering agent in an inert organic
solvent at a temperature in *he ranga of from 120 to 180C
with desalkylation, to give the azamethine compound of the
formula I.
The azamethine compound of the formula II i3 prepared
either separately , or the azamethine-Cu complex of the form-
ula I is synthesized in a single reaction without isolating
intermediate product~.
m e compound~ of the formula II are prepared by a con-
densation of the correspondi~g 2-~minophenol or -anl~o~ or
29 their hydrochloride~ with th0 Z-hydroxynaphthaldehyde-(l)
~ IOE ~ 1 ~9 ~
~ optionally sub~tituted in the 3- or 6-position by the group
-COOY9 Y optionally also being a cation, for example an al-
kali metal, in which process equivalent amount~ of the two
starting compounds are reacted in water, organic sol~ents or
aqueous-organic sol~ents at a temperature in the range of
from 20 to 150C, preferably fro~ 80 to 110C.
The reactivn may al80 be effected under an inert gas
cover, such as in a nitrogen atmo~phere. If the reaction i8
carried out in water, the addition of surface-active agents,
such as cationic, anionic or non-ionogenic compou~ds, is re-
commended. If the hydrochloride of the 4-carbomethoxy-2-amino-
phenol or -ani~ol~ is used, a basic compound, for example,
sodium acetate, sodium hydrogencarbonate or pota~sium carbon-
ate, should be added. As organic 601vents there are mentioned,
for example: lower alcohols having 1 to 6 carbon atoms, gla-
cial acetic acid, dimethylformamide or glycol-monomethylether.
After isolation and washing, the compound o~ the formula II
obtained may then be coppered as ha~ been described above.
According to another process the azamethine copper comple~ of
the formula I can be prepared directly in a grinding device,
in which the ~tarting compounds, for example, 4-carbometho~y-
2-aminophenol and 2-hydroxynaphthaldehyde-(1), are ground in
water together with a coppering agent, for example, copper(II)-
sulfate, in the presence of an acid buffer, such as sodium
acetate. As grinding de~ices there are suitable, for example,
ball mills, bead mills or sand mill~. The grinding may also
be carried out in the pre~ence o~ a salt and/or a surface-
acti~e agent.
Z9 The azamethine-copper complex compounds of the formula I
HOE 76~F 159 K
hava ~aluable properties as pigments.
In order to obtain optimum coloristic properties of the
pigm~nts of the invention, it is sometimes advantageous to
convert ~he ready pigment into a finely divided form by heating
it in a solYent, optionally in the presence of water or ~alt
solutions.
A~ solvents suitable for this purpose there may be men-
tioned those in which the pigment is insoluble, however, which
promote und~r the finishing conditions a certain superficial
dissol~ing action, for example, aliphatic alcohols, especially
lower alkanols, such as ethanol, isopropanol, i80- or n-butanol,
: chloro aromatic compounds, ~uch as chlorobenzene and -toluene,
or dichlorobenzenes, as well as dipolar aprotic solvents, for
axample, dimethylformamide, dimethylacetamide, dimethylsulfo~i-
de, N-methyl-pyrrolidone, polyalkyl-ureas, such as tetramethyl-
urea, and phosphoric acid amides, such a8 hexamethyl-phospho-
ric acid-trisamide.
Also a fine division by grinding with salts or solvents
may be advantageous, in which process in ths former case a dry
grinding in vibration grinding mills is preferably effected
and the salt is subsequently extracted with water, whereupon
a wet grinding or a temperature treatment with solvents may
optionally follow~
As salts there may be mentioned essentially alkali metal
and alkaline earth metal salts of hydrohalic acids or of sul-
furic acid, for example, ~odium or potassium chloride, as well
as sodium or magnesium sulfate.
The sol~ents which may be used for the wet grinding pro-
29 cess are essentially those mentioned above, for example,
HOE 76/F 159 K
alcohols, acid amides or dimethyl sulfoxide.
The novel compounds represent valuable pigments which are
used in printing inks, disper~ion dye~, varnishes, and which
are suitable for pigm0nting high-molecular-weight organic
material, for example, cellulose ethers and esters, polyamides,
polyurethanes or polyesters, acetyl cellulose, nitrocellulose,
natural resin~ or plastics, ~or example, aminoplasts, es-
pecially urea and melamine formaldehyde resins~ alkyd resins,
phenoplasts, polycarbonates, polyolefins, such a~ polyethylene
or polypropylene, polystyrene, polyvinylchloride, polyacrylo-
nitrile, polyacrylic acid esters, rubber, casein, siliconss
and silicone resins. It is unimportant whether the above-men-
tioned high-molecular-weight compounds are present as plaRtic
masses, melts, or in the form of spinning solutions~ lacquers
or printing paxtes. Depending on the application, it may be
advantageous to use the novel pigments as toners or in the form
of preparations.
The pigments of the invention have a high color intensity
(tinctorial strength), a pure color shade, a good fastness to
high temperatures in stove enamels and plastics, however,
particularly an excellent fastness to overlacquering, to light
and to weather, an extremely high fastness to light and to
weathering, especially under the extreme conditions of an alu-
minum metallic lacquering.
Z5 The following Examples ~erve to illu~trate the in~ention,
the percentages being by weight, unless otherwise stated.
E X A M P L E 1:
17.2 Grams of 2-hydroxynaphthaldehyde-(1) are suspended
29 in 200 ml of ethanol, are heated to boiling temperature with
- 6 -
~ HOE 76~F 1~_K
21 . 5 g of the hydrochloride Or 4-carbomsthoxy-2-aminophenol
and 10 g of anhydrous Podium acetate in 200 ml of ethanol, and
the reaction mixture is maintained at this temperaturs for 1
hour. During the reaction time, nitrogen i6 led over the mix-
ture. The orange-red precipitate of the aza~ethine i~ suction-
filtered and washed with ethanol and w~ter. Yisld (after dry-
ing)s 29.4 g (91.6 ~ of the theory)O
16 Grams of the azamethine thuo obtained are dissol~d in
150 ml of di~eth~lformamide and are treated for 3 ho~r~ at
100 C with 10 g of copper(II)acetate. Ths mi~ture is cooled to
50C~ i~ suction-filtered, and the yellow pigment is washed
with ethanol and water. After drying7 17.8 g of the compound
of the formula - -
H3COCO ~ O-C~-
are obtained.
E X A M P L E 2-
--
16.7 Grams of 4-carbomethoxy-2-aminophenol and 17.2 g of
2-hydroxynaphthaldehyde-(1) are ~tirred for 5 minutes in 100
ml of water. Sub~equently 50 ml of 2N sodium hydro~ide solu-
tion and 30 ml of a 40 % sodium hydrogen~ulfite solution are
added, and the mixture ii stirred for 15 minutes at 95 C. The
precipitate is filtered off with auction and is wa~hed with
cold water. The press cake ia then stirred in 200 ml of water
with an impeller.
Subsequently a solution of 27.S g of copper(II)sulfate
pentahydrate in 100 ml of water and 50 g of concentrated
~ ~ ~ HOE 76/F ?~9 K
ammonia solution are added, the mixture i9 h0ated to 95 C and
i9 maintainad at this -temperature for 1 hour. The pigmsnt i~
filtered off with suction, while hot, is washed with hot water
and dried. 32.9 Grams of the compound Or Exampla 1 are ob-
tained,
A mixture of 16.7 g of 4-carbomethoxy-2-aminophenol,
17.2 g of 2-hydroxynaphthaldehyde-(1) and 200 ml of water is
ground in a ball mill with 200 g of ceramic balls (diame~er
of 10 mm) for 24 hours. Upon adding 25 g of 30dium acetate-
trihydrate, 26 g of copper(II)sulfate pentahydrate and 100 ml
of water, the mixture is continued to be ground for another
80 hDurs. The ground product obtained is wa~hed with water
and dried.
Yield: 35.7 g of the yellow pigment of Example 1.
E X A M P L E 4:
16.7 Gram~ of 4-carbomethoxy-2-aminophenol and 17.2 g of
2-hydroxynaphthaldehyde-(1) are dispersed with 400 ml of water
by means of an impeller, and the disp0rsion is heated to a
temperature in the range of from 95 to 98C and maintained at
this temperature for 4 hours.
The product is suction-filtered, washed with hot water,
and the moist press cake is stirred with 400 ml of water in
which 26 g of copper(II)sulfate pentahydrate and 25 g of so-
dium acetate are dissolved; thereafter the mixture is heatedto boiling temperature. After is has been heated to 100 C for
g hours, the product i8 filtered off with Yuction, while hot,
is washed with water and dried. 34.9 Grams of the yellow pig-
29 ment of Example 1 are obtained.
-- 8 --
HOE 76/F 1S9 X
~9~6~3~
E X_A M P L E 5:
18.1 Grams o~ 4-carbomethoxy-2-aminoaniso~ and 17.2 g of
2-hydroxynaphthaldehyde-(1) are heated i~ 400 ml of diethylene-
glycol-monomethylether to 100C and are maintained at this
temperature for 2 hours. During the reaction time, nitrogen is
led over the mixture. 10 Grams Or copper(II)acetate dissolved
in 100 ml of diglycol-monomethylether are added to the hot
reaction mixture. Said mixture is heated to 150C and is main-
tained at this temperature for 4 hours. After cooling, the
yellow pigment is filtered off with suction, i6 thoroughly
washed with ethanol and water and dried. 31.9 Grams of the
compound of Example 1 are obtained.
E X A M
17.2 Grams of 2-hydroxy-1-naphthaldeh~de are suspended
in 700 ml of n-propanol. Thereafter 24.3 g of the hydrochlori-
de of 3-amino-4-hydroxybenzoic acid-n-propylester and 10 g of
anhydrous sodium acatate are added. The mixture is rafluxed
for 2 hours under a nitrogen atmo3phere. The yellow a~amethine
of the formula
n-C3H700 ~ OH HO ~
is suction-filtered, while hot, is washed with n-propanol and
water and dried. Yield: 33 Grams.
17.45 Grams of the azamethine thus preparod are suspended
in 250 ml of n-propanol. Subsequently 12.5 g of copper(II)-
sulfate-pentahydrate dissolved in 30 ml of water are added
dropwise within 15 minute~. The pH value is maintained at 5
by adding about 25 ml of a 4N sodium acetate solution. The
~OE 76/F 159 K
9~ 3.~
mixture is then h~ated under reflux for 3 hours under a nitro-
gen atmosphere, ~ubsequently the product is suction-filtered,
while hot, is washed with n-propanol and water and dried. Z3.3
Grams of the green pigment of the formula
n-C3H700
are obtained.
L ~
17.2 Grams of 2-hydroxy-1-naphthaldahyde are su~pended
in 500 ml of ethanol. Subsequently 23 g Or the hydrochloride
of 3-amino-4-hydro~ybenzoic acid ethylaster and 10 g of an-
hydrouq sodium acetate are added. The mixture is boiled under
reflux for 2 hours in a nitrogen atmosphere. The precipitated
orange azamethine of the formula
C2H500C ~ OH HO ~
is filtered off with suction, while hot, is washed with etha-
nol and water and dried. Yield: 28.4 Grams.
16.75 Grams of the azamethine thus prepared are su pended-
in 250 ml of ethanol and are coppered, as has been described
in Example 6. 24 Grams of the green pigment of the formula
C2H500C ~ N ~ CH
Cu~
are obtained.
-- 10 -
~ 8~ HOE 76/F 159 K
E X A M P_L E 8:
17.2 Grams of 2-hydroxy-1-naphthaldehyde are ~uapended in
500 ml of n-butanol, thereafter 25.75 g of the hydrochloride
of 3-amino-4-hydroxybenzoic acid n-butyle~ter and 10 g of an-
hydrous sodium acetate are added. Ihe mixture i~ heat~d to 90Cand i8 maint~ined at thi~ temperature for 2 hour~. Subsequently
the product i9 filtered of~ with ~uction at about 70C, is
washed with n-butanol and water and dried. 26.55 Grams of the
ora~ge a~amethine of the ~ormuls
n-C4HgOOC ~ N = CH
ara obtained.
18.15 Grams of the azamethine thu~ obtained are su~pended
in 250 ml of n-butanol and are copp~red accordlng to the method
describ~d in Example 6. 19.9~ Grams of the yellowi~h-green pig_
ment of the formula
n-C4H900C ~ ~ Cu~
are obtained.
In a manner analogous to that described in Examples 6
through 8, the following pigments were obtained:
YOOC N = CH ~
Example Y Color Shade in book-prin-
~ tin~s
9 H greenish-yellow
H3C\
/ CH- greenish-yellow
H3C
~3c\
11 CH-CH - reddish-yellow
H3C
CH3
CH3-CH2-CH- browni3h-yellow
13 3 2 2 2 2 reddish-yellow
~H3
14 CH -CH -CH-CH brownish-yellow
21.6 Grams of 2-hydroxy-1-naphthaldehyde-3-carboxylic
acid ara re~luxed together with 11.4 g o~ Q-aminophenol in
300 ml of ethanol undar a nitrogen atmo~phere. Then the pre-
cipitate of the azamethine is suction-filtered~ while hot, i~
washed with ethanol and water and dried.
10.2 Grams of the orange azamethine thus prepared are
suspend~d in 300 ml of ethanol and are then heated to boiling
temperature together with 7 g of copper acetate and maintained
at $he boil for 3 hours. The pE value i~ maintained at 6.5 by
adding 25 ml of 4N sodium acetat~ solution. The product is
suction-filtered, while hot, is washed with ethanol and watur
- 12 -
1~9iiL6&~
and dried. Yield: 11.7 Gram~ of the greenish-yellow pigment
of the formula Q
` Cu'O ~
COOH
~
21.6 Grams of Z-hydro~y-l-naphthaldehyde-6-carboxylic
acid are suspend~d together wi$h 11. 4 g Or o-aminophenol in
300 ml of glacial acetic acid. The suspension is heated to
the boiling point and is maintained at this temperature for
3 hours. The product is filtered off with suction, while hot,
and is wa~hed with ~thanol and water. After drying, 30.5 g of
the orange azamethine o~ the formula
COOH
N = CH
OH HO
are obtained.
15.35 Grams of $he azaQethine thu~ prepared are dis~olved
in 100 ml of dimathylformamid~ and are heated with 100 ml of
diethylene-glycol-dimethylether and 15 g of copper acet~te
to 100 C; then the mixture is maintained at thi~ temperature
for 3 hour~. 16.7 Gram~ of the greeni3h~yellow pigment of the
~ormula ~ COOH
~ N - CH
are obtained.
E X A M P L E 1l.
If the proces~ i8 carried out according to the method
- 13 _
described in Example 16, howevsr, while using 23.2 g Or the
correspondlng methylester instead of the 2-hydroxy-1-naphthal-
dehyde-6-carboxylic acid, 29.7 g of the orange azamethine of
the formula
N = CH ~ COOCH3
OH HO
are obtained.
20 Grams of the azamethine aro dissolved in a mixture o~
150 ml of dimethylformamide and 150 ml of diethylene-glycol-
dimethylether and are heated with 13.5 g of copper(II)sulfate
pentahydrate to 100C and maintained at this temperature for
3 hours. The product i9 then suction-filtered, while hot, is
washed with ethanol and water and dried.
12 Grams o~ this crude pigment are ground for 10 hour~ to-
gether with 50 g of sodium sulfate and 50 g of sodium acetate
in a porcelain ball mill with 800 g of porcelain balls ha~ing
a diameter of 10 m~. The contents of the mill are stirred in
hot water, the greenish-yellow pigment is isolatad which is
then washed until it is fres from Aalt and dried.
E X A_M P L E_ 18-
If the proce~s is carried out as has been described inExample 17, however, while replacing the 2-hydroxy-1-naphthal-
dehyde-6-carboxylic acid-methylester by 24.8 g Or 2-hydroxy-1-
naphthaldehyde-3-carboxylic acid-ethylester, 31.5 g of the
azamethine of the formula
H HO ~
COOC2H5
- ~4 _
:~"3~ 3 lL
are obtained.
15.4 Grams o~ the azamethine thus prepared are heated to 100C with
100 ml of dimethylformamide and 100 ml of diethylene-glycol-aimethylether and
9 g of copper acetate, and the mixture is maintained at this temperature for
3 hours. Subsequently the product is filtered off with suction, while hot,
is washed with dimethylformamide, methanol and water and dried. 16.3 Grams of
the yellowish-green azamethine-Cu complex compound of the formula
~ N--CH ~
COOC2H5
are obtained.
According to the method described in Examples 15 through 18, the
following further azamethine-Cu complex compounds are obtained:
~ 0~ 0 ~
- 15 -
Example Rl R2 Color Sh~de
19 COOCH3 H greenish-yellow
C00-nC3H7 H greenish-yellow
21 COO-n~C~Hg H greenish-yellow
22 COOCH / 3 H yellow
CH3 CEI3
23 COoCH-CH2CH3 H yellow
24 COO-n-C H H greenish-yellow
CO0-CH2CH-CH2CH3 H yellow
CH3
- 15a -
~.
~3~
Example R1 R2 Color Shade
26 H COOC2H5 greenish-yellow
27 H COO-n-C3H7 greenish-yellow
28 H COO-n-C4Hg greenish-yellow
29 H COO-CH b H3 greenish-yellow
H3
H Coo-n-C5H11 greenish-yellow
I~I3
31 H COOCH-CH2-CH3 yellow
32 H COOCH2CH-CH2-CH3 greeni8h~yellow
CH3
E X A M P L E ~:
21.6 Gram~ of 2-hydroxy-1 naphthaldehyde-6-carboxylic
acid are suspsnded with 21.5 g of the hydrochloride of 3-
hydroxy-4-aminobenzoic acid-methylester in 300 ml of glacial
acetic acid. The mixture is heated to the boiling psint and is
maintained at this temperature for 3 hours. The product is
filtered off with suction, while hot, is washed with ethanol
and water. After drying, 35.Z g of the orange azamethine of
the formula
U3COOC ~ OH HO ~ CO~H
are obtained.
20 Grams of the azamethine are dissolved in a mixtura of
150 ml of dimethylformamide and 150 ml of diethylene-glycol-
dimethylether and are heated to 100C with 15 g of copper(II)-
sulfate pentahydrate, the mixture being maintained at this
- 16 _
~ ~ lg;~ OE ~6/F 159 X
temperature for 3 hours. Subseque~tly the product is sucti~n-
filtered, while hot, is washed with ethanol and water and
dried. Yield~ 23.5 Grams of the greenish-yellow pigment of the
formula
~ COOH
~ Cu '
12 Grams of this crude pigment are ground for 10 hours
togsther with 50 g of sodium sulfate and 50 g of sodium aceta-
te in a porcelain ball mill with 800 g of porcelain balls
ha~ing a diameter o~ 10 ~m. The contents of the mill are then
stirred in hot water, the greenish-yellow pigment is isolated,
washed until it is saltfree and dried.
If the proces~ i~ carried out as ha~ been described in
Example 33, however, while replaci~g the 2-hydroxy-1-naphthal-
dehyde-6-carboxylic acid by 2-hydroxy-1-naphthaldehyde-3-
carboxylic acid, 35.75 g of the a~amethine of the formula
COOH
are obtained.
18.3 Grams of the azamethine thus prepared are heated to
100C with 100 ml of dimethylformamide and 100 ml of diethy-
lene-glycol-dimethylether and 10 g of copper acetate, and the
mixture is maintained at thi~ temperature for 3 hour~. Subse-
quently the product is filtered off with suction, while hot,
~ HoE--~6/F 1~9 K
is wash~d with di~ethylfo~amide, ethanol and water and dried.
17.3 Grams of the yellowish-gr0en ~zamethine-Cu complex com-
pound of the for~ula
~ 0~ 0
COO~
are obtained.
In a manner analogoua to that de3crib~d in Examples 33
and 34, the ~ollowing further a~amethine-Cu complex co~pounds
are obtained~ .
~O Cu-O ~JR2
R1
Example X R1 R2 Color Shade
Cl COOH E reddish-brown
36 Cl H COOH yellow
37 NO2 COOH H reddish-yellow
38 NO2 H COOH reddish-yellow
39 Br COOH H greeni~h-yellow
Br H COOH brownish-yellow
41 COOC2H5 COOH H yellowish-green
42 COOC2H5 H COOH green
43 CoOC3H7(n) COOH H brownish-green
44 COOC3H7(n) H COOH yellowish-green
COOCH'' 3 COOH H brownish-green
~CH3
_ 18 -
1~91~ HOE 76~F 159 K
Example X R1 R2 Color Shade
46 C CH ~ 3 H COOH yellowi~h-green
c~3
47 COOC4Hg(n) COOH H yellowi~h green
48 COOC4Hg(~) H COOH bluish-green
49 CH3 COOH H reddi~h-yellow
C~3 ~ COOH reddi~h-yellow
51 CF3 COOH H yellowi~h-green
52 CF3 H COOH yellow
53 OCH3 COOH H brownish-yellow
54 OCH3 H COOH reddish-yellow
Cl COOCH3 H reddish-yellow
56 NO2 H COOCH3 reddish-yellow
57 CO2CH3 H COOCH3 yellow
58 COOH COOH H greenish-yellow
59 COOH H COOH greenish~yellow
- 19 _
