Anionic azo dyes having a 3-dibenzofuranyl diazo component radical optionally having a 2- or 8-sulfo group

Disclosed are azo dyes containing, a diazo component radical of the formula ##STR1## wherein each of Z and Z.sub.1 is independently hydrogen or sulfo, with the proviso that at least one of Z and Z.sub.1 is hydrogen, for example monoazo and disazo dyes of the formula ##STR2## and salts thereof, wherein K is a coupling component radical of the aromatic carbocyclic, active methylene group-containing aliphatic or aromatic heterocyclic series, and PA1 Z and Z.sub.1 are as defined above, with the proviso that the dyes contain one or two sulfo groups, and the use thereof for the dyeing and printing of anionic dyeable substrates, particularly polyamide substrates.

The invention relates to sulfo group containing azo compounds. 
The invention provides azoic dyestuffs containing, as radical derived from 
a diazo component, a 3-dibenzofuranyl radical, which radical is 
unsubstituted or substituted in only one of the 2- and 8-positions thereof 
by a sulpho group, such compounds containing a total of 1 or 2 sulpho 
groups. 
The compounds of the invention may be monoazo or polyazo, preferably 
monoazo or disazo. They are preferably free from fibre-reactive groups. 
In the compounds of the invention, the radical derived from the coupling 
component may be any conventional in the azo dyestuff art. For example it 
may be a radical derived from a coupling component of the aromatic 
carbocyclic type, e.g. of the aminobenzene, hydroxybenzene, 
aminonaphthalene and hydroxynaphthalene series, of the aromatic 
heterocyclic type, e.g. of the pyrazolone, aminopyrazole, indole or 
carbazole series such as 1-phenyl or 1-naphthylpyrazolone-5, 1-phenyl- or 
1-naphthyl-5-aminopyrazole or indole series or of the active methylene 
group-containing aliphatic type, e.g. of the N-alkyl or 
N-arylacetoacetamide series, particularly the latter. 
Of the monoazo dyes provided by the invention, those containing, as the 
radical derived from the coupling component, a radical of one of the 
formulae (a) to (i') are preferred: 
##STR3## 
in which 
R.sub.1 is hydrogen, C.sub.1-4 alkyl (preferably methyl), phenyl or 
--CO--R.sub.2 ; preferably C.sub.1-4 alkyl, more preferably methyl, where 
R.sub.2 is --OH, --OR.sub.3 or --NH--R.sub.4, where 
R.sub.3 is C.sub.1-4 alkyl, and 
R.sub.4 is hydrogen, C.sub.1-4 alkyl or phenyl, 
R.sub.11 is --OH or --NHR.sub.12, where 
R.sub.12 is hydrogen or --SO.sub.2 R.sub.13 ; preferably hydrogen, 
R.sub.13 is C.sub.1-4 alkyl, phenyl or phenyl substituted by 1 to 3 
C.sub.1-4 alkyls, and 
R.sub.5 is hydrogen or one of the radicals of formulae (i) to (iv) 
##STR4## 
where 
R.sub.6 is hydrogen, halogen (preferably chlorine), C.sub.1-4 alkyl 
(preferably methyl), C.sub.1-4 alkoxy (preferably methoxy), --CN, 
--CF.sub.3, --OH or --SO.sub.2 NR.sub.10 R.sub.10 '; preferably hydrogen, 
chlorine, methyl, methoxy, --CN, --CF.sub.3 or --SO.sub.2 NR.sub.10 
R.sub.10 '; more preferably hydrogen, chlorine, methyl or methoxy; most 
preferably hydrogen or chlorine; 
R.sub.10 is hydrogen, C.sub.1-4 alkyl, C.sub.1-4 (preferably C.sub.2) 
hydroxyalkyl or phenyl; preferably hydrogen or 2-hydroxyethyl, and 
R.sub.10 ' is hydrogen or C.sub.1-4 alkyl; preferably hydrogen, 
R.sub.7 is hydrogen, halogen (preferably chlorine), C.sub.1-4 alkyl 
(preferably methyl), C.sub.1-4 alkyl (preferably methoxy), sulpho or 
carboxyl; preferably hydrogen, chlorine, methyl, methoxy or sulpho; more 
preferably hydrogen, chlorine or sulpho, and most preferably hydrogen or 
sulpho, 
R.sub.8 is hydrogen, halogen (preferably chlorine) or C.sub.1-4 alkyl 
(preferably methyl); preferably hydrogen or chlorine, and more preferably 
hydrogen, and 
R.sub.9 is hydrogen or sulpho, preferably hydrogen: 
where the phenyl group (i) is monosubstituted by sulpho, such sulpho 
preferably being in the 4-position and where monosubstituted by another 
substituent, e.g. chlorine, such preferably being in the 2- or 4-position, 
more preferably the latter: 
where the phenyl group (i) is disubstituted, such substituents being 
preferably in the 2,4-, 3,4- or 2,5- positions, more preferably the 
latter; any disubstituted phenyl group (i) preferably being 
2-chloro-5-sulphophenyl: 
where the phenyl group (i) is trisubstituted, such substituents being 
preferably in the 2,3,4-, 2,3,5-, 2,4,5- or 2,4,6- positions, one of the 
substituents preferably being sulpho in the 4- or 5-position; any 
trisubstituted phenyl group (i) preferably being 
2,5-dichloro-4-sulfophenyl: 
the most preferred phenyl group (i) being unsubstituted: 
##STR5## 
where the R.sub.29 's, independently, are hydrogen or sulpho, at least one 
preferably being sulpho: 
where radical (ii) is a 1-naphthyl group, such preferably being substituted 
by two sulpho groups in positions 2,5, 2,8 or 2,6, particularly the 
latter: 
where radical (ii) is a 2-naphthyl group monosubstituted by sulpho, such 
sulpho preferably being in position 1, 5, 6, 7 or 8, preferably 6; 
where radical (ii) is a 2-naphthyl group disubstituted by sulpho such 
sulpho groups preferably being in positions 4,8, 6,8 or 1,5, particularly 
the latter: 
the preferred radicals (ii) being 6-sulphonaphthyl-2 and 
1,5-disulphonaphthyl-2: 
##STR6## 
where R.sub.9a is hydrogen or sulpho, preferably sulpho in position 4, 
##STR7## 
where R.sub.49 is hydrogen or sulpho, and X is --CH.sub.2 -- or --O--, 
##STR8## 
where R.sub.14 is C.sub.1-12 alkyl, unsubstituted or monosubstituted by 
halogen, hydroxy, phenyl, sulphophenyl or naphthyl; cyclohexyl; cyclohexyl 
substituted by up to 3 C.sub.1-4 alkyls; or, preferably, a radical of 
formula (v) or (vi), 
##STR9## 
in which 
R.sub.9 is as defined above, preferably hydrogen, 
R.sub.15 is hydrogen, halogen (preferably chlorine), sulpho, C.sub.1-4 
(preferably C.sub.1-2) alkyl or alkoxy or --CF.sub.3 ; preferably 
hydrogen, chlorine, C.sub.1-2 -alkyl or alkoxy or sulpho, more preferably 
hydrogen, methyl, C.sub.1-2 - alkoxy or sulpho and, 
R.sub.16 is hydrogen, halogen (preferably chlorine), C.sub.1-4 (preferably 
C.sub.1-2) alkyl or alkoxy or phenoxy, preferably hydrogen, chlorine or 
C.sub.1-2 alkyl or alkoxy, more preferably hydrogen, methyl or methoxy; 
where the phenyl group (v) is monosubstituted, such substituent being 
preferably in position 2, except when sulpho where such is preferably in 
position 4, 
where the phenyl group (v) is disubstituted, such substituents preferably 
being in positions 2,5, 
##STR10## 
wherein m is 0, 1 or 2, preferably 1 or 2: 
where radical (vi) is a 1-naphthyl monosubstituted by sulpho, such sulpho 
being, for example, in position 4, 5, 6 or 7, preferably in position 4, 6 
or 7, and where disubstituted by sulpho, such preferably being in 
positions 3,6 or 4,6; 
where radical (vi) is a 2-naphthyl monosubstituted by sulpho, such sulpho 
being, for example, in position 1, 5 or 6, preferably in position 1 or 5, 
and where disubstituted by sulpho, such preferably being in positions 4,8 
or 5,7, 
##STR11## 
wherein 
R.sub.17 is hydrogen, halogen (preferably chlorine), C.sub.1-4 alkyl 
(preferably methyl) or C.sub.1-4 (preferably C.sub.1-2)alkoxy; preferably 
hydrogen, chlorine, methyl, methoxy or ethoxy; more preferably hydrogen, 
methyl or methoxy, 
R.sub.18 is hydrogen, C.sub.1-4 alkyl (preferably methyl), C.sub.1-4 
(preferably C.sub.1-2)alkoxy, --NH--CONHR.sub.22 or --NH--CO--R.sub.22 ', 
preferably hydrogen, methyl, methoxy or ethoxy, more preferably methyl or 
methoxy, 
R.sub.22 is hydrogen, C.sub.1-4 alkyl or phenyl, 
R.sub.22 ' is C.sub.1-4 alkyl or phenyl, either 
R.sub.19 is hydrogen and 
R.sub.20 is hydrogen; unsubstituted C.sub.1-4 alkyl; C.sub.1-4 -alkyl 
monosubstituted by halogen, phenyl, --CN or--OH (preferably --C.sub.2 
H.sub.4 Cl, --C.sub.2 H.sub.4 CN, --C.sub.2 H.sub.4 OH or benzyl); benzyl 
substituted by a sulpho group; or phenyl; preferably hydrogen, methyl, 
ethyl, propyl, butyl, -C.sub.2 H.sub.4 Cl, --C.sub.2 H.sub.4 CN, --C.sub.2 
H.sub.4 OH, benzyl, monosulfobenzyl or phenyl, more preferably hydrogen, 
methyl, ethyl, --C.sub.2 H.sub.4 CN or --C.sub.2 H.sub.4 OH, or 
R.sub.19 and R.sub.20, together form an ethylene or 1,3-propylene radical, 
and 
R.sub.21 is hydrogen, unsubstituted C.sub.1-4 alkyl or C.sub.1-4 alkyl 
monosubstituted by halogen, phenyl, --CN or --OH (preferably --C.sub.2 
H.sub.4 Cl, --C.sub.2 H.sub.4 CN or -C.sub.2 H.sub.4 OH ); preferably 
hydrogen, methyl, ethyl, propyl, butyl, --C.sub.2 H.sub.4 Cl, --C.sub.2 
H.sub.4 CN or --C.sub.2 H.sub.4 OH, more preferably hydrogen, methyl, 
ethyl, --C.sub.2 H.sub.4 CN or --C.sub.2 H.sub.4 OH, or 
R.sub.20 and R.sub.21, together with the nitrogen atom, form a saturated 5 
or 6 membered heterocyclic ring, e.g. morpholine, piperidine or 
pyrrolidine, the free bond in the radical (c) preferably being in 
p-position to the amino group; 
##STR12## 
where 
m is as defined above, 
R.sub.23 is --OH or --NH--R.sub.24, 
R.sub.24 is C.sub.1-4 alkyl; unsubstituted cyclohexyl; cyclohexyl 
substituted by up to 3 C.sub.1-4 alkyls; or, preferably, hydrogen or a 
radical of formula (vii) 
##STR13## 
where 
R.sub.25 is hydrogen, C.sub.1-4 alkyl (preferably methyl), C.sub.1-4 
(preferably C.sub.1-2)alkoxy, halogen (preferably chlorine), --CF.sub.3 or 
sulpho, preferably hydrogen, chlorine, methyl, methoxy, ethoxy or sulpho, 
R.sub.26 is hydrogen, C.sub.1-4 alkyl (preferably methyl) or C.sub.1-4 
(preferably C.sub.1-2)alkoxy, preferably hydrogen, methyl, methoxy or 
ethoxy, and 
R.sub.27 is hydrogen or C.sub.1-4 alkyl, preferably hydrogen or methyl, 
where, in the radical of formula (d), R.sub.23 is in the 1-position, any 
single sulpho group is preferably in position 3, 4 or 5, and any two 
sulpho groups are preferably in the 3,6 or 3,8 positions; 
where, in the radical of formula (d), R.sub.23 is in the 2-position, any 
single sulpho is preferably in position 4,6 or 8, particularly the latter, 
and any two sulpho groups are preferably in positions 3,6 or 6,8, 
##STR14## 
in which R.sub.23 is as defined above, 
##STR15## 
in which 
m is as defined above, and 
R.sub.28 is --SO.sub.2 --R.sub.29 ', (where R.sub.29 ' is C.sub.1-12 
alkyl); unsubstituted cyclohexyl; cyclohexyl substituted by up to 3 
C.sub.1-4 alkyls; or, preferably, hydrogen; C.sub.1-4 (preferably straight 
chain) alkyl (preferably methyl); or a radical of formula (viii), (ix), 
(x), (xi) or (xii), 
##STR16## 
in which R.sub.25, R.sub.26 and R.sub.27 and the preferred significances 
thereof are as defined above, 
##STR17## 
where R.sub.30 is hydrogen or C.sub.1-4 alkyl; preferably hydrogen or 
methyl, 
##STR18## 
where 
R.sub.31 is hydrogen, nitro, C.sub.1-4 alkyl or alkoxy (preferably methyl 
or methoxy) or --NHR.sub.34 ; preferably hydrogen, methyl or methoxy, 
R.sub.34 is hydrogen or C.sub.1-4 alkyl, 
R.sub.32 is hydrogen or C.sub.1-4 alkyl; preferably hydrogen or methyl, 
EQU --OC--R.sub.33 (xi) 
where R.sub.33 is C.sub.1-12 alkyl; preferably C.sub.1-4 alkyl; more 
preferably methyl or ethyl, 
EQU --O--CO--R.sub.33 ' (xii) 
where R.sub.33 ' is C.sub.1-18 alkyl, phenyl, unsubstituted cyclohexyl or 
cyclohexyl substituted by up to 3 C.sub.1-4 alkyls; preferably phenyl, in 
the radical (f) m preferably being 1 or 2, the preferred positioning of 
substituents and the free bond (coupling position) being according to the 
following table 
______________________________________ 
NH-R.sub.28 
OH sulpho(s) free bond 
______________________________________ 
2 8 6 1 
8 1 3,5, 3,6 or 5,7 
2 
5 1 3 2 
6 1 3 2 
7 1 3,4, 3,6 or 5,6 
2 
______________________________________ 
the positioning as shown the first two rows of the table being particularly 
preferred; 
##STR19## 
in which R.sub.36 is hydrogen, hydroxy, C.sub.1-8 (preferably C.sub.1-4) 
alkyl (preferably methyl, ethyl or tert.butyl), C.sub.1-4 (preferably 
C.sub.1-2)alkoxy, --NH.sub.2, --COOH, --COOR.sub.3, --CONH.sub.2, 
--CONHR.sub.38 or --NH-CO-R.sub.38, preferably methyl, ethyl, tert.butyl, 
methoxy or ethoxy, 
R.sub.3 is as defined above, 
R.sub.38 is C.sub.1-4 alkyl or a radical (xiii) 
##STR20## 
R.sub.39 is hydrogen, halogen (preferably chlorine), C.sub.1-4 alkyl or 
alkoxy, -CF.sub.3 or sulpho, 
R.sub.40 is hydrogen, C.sub.1-4 alkyl or sulpho, either 
R.sub.41 is hydrogen or C.sub.1-4 alkyl, or, where 
R.sub.36 is other than hydrogen, R.sub.41 is a radical 
--CH.dbd.CH--CR.sub.9 .dbd.CH--, thus forming a naphthyl radical, 
R.sub.9 is as defined above, 
##STR21## 
where 
R.sub.35 is C.sub.1-4 alkyl (preferably methyl, ethyl or propyl), 
--SO.sub.2 R.sub.29 ' or a radical (ix) above, (preferably where R.sub.30 
is hydrogen or methyl); preferably methyl, ethyl or propyl or a radical 
(ix); more preferably methyl; the group --OR.sub.35 preferably being para 
to the azo linkage, 
R.sub.37 is hydrogen or C.sub.1-4 (preferably C.sub.1-2) alkyl or alkoxy, 
preferably hydrogen, methyl, ethyl, methoxy or ethoxy, 
##STR22## 
where 
R.sub.42 is C.sub.1-4 alkyl, phenyl or benzyl; preferably phenyl, 
R.sub.43 is hydrogen, C.sub.1-4 alkyl or benzyl; preferably hydrogen, and 
R.sub.44 is hydrogen, halogen, sulpho or C.sub.1-4 alkyl or alkoxy; 
preferably hydrogen. 
Of the disazo dyes provided by the invention, those having as the radical 
bound to the azo group in the 3-position of the dibenzofuranyl radical a 
radical of formula (j) are preferred, 
EQU --Y--N.dbd.N--K.sub.1 (j) 
in which Y is a radical of formula (xv), (xvi), (xvii) or (xviii); 
preferably of formula (xv) or (xvi), 
##STR23## 
where R.sub.17 and R.sub.18 and the preferred significances thereof are as 
defined above, 
##STR24## 
where m is as defined above, 
##STR25## 
where the R.sub.9 's and the preferred significances thereof, 
independently, are as defined above, and K.sub.1 is the radical of a 
coupling component of formula (a), (b), (c), (d), (e), (f), (g), (h) or 
(i'), preferably such radicals having preferred substituents as above: 
where the radical (xv) is a monosubstituted 1,4-phenylene, the substituent 
preferably being in meta-position to the group --N.dbd.N--K.sub.1 : 
where the radical (xv) is disubstituted 1,4-phenylene, the two substituents 
preferably being in para-position relative to each other: 
where, in the radical (xvi), m is 1, the sulpho group cannot, of course, be 
in the 3-or 5 position relative to the --N.dbd.N--K.sub.1 group, 
preferred radicals of formula (xvi) being unsubstituted or monosubstituted 
by sulpho, the sulpho being in the 6;7 or 8 position relative to the 
--N.dbd.N--K.sub.1 group. 
Particularly preferred compounds of the invention are the compounds which 
contain one or two sulpho groups and which are of the formula 
##STR26## 
where each of 
Z and Z.sub.1, independently, signifies hydrogen or sulpho, with the 
proviso that both do not simultaneously signify sulpho, 
K.sub.2 is a radical of formula (aa), (ab), (ba), (ca), (da), (db), (fa), 
(ga), (gb), (ha) or (ja), 
##STR27## 
where 
R.sub.1 ' is C.sub.1-4 alkyl; preferably methyl, 
R.sub.11 ' is --OH or --NH.sub.2, 
R.sub.9 and the preferred significance thereof is as defined above, 
R.sub.6 ' is hydrogen, chlorine, methyl, methoxy, --CN or --SO.sub.2 
NR.sub.10 R.sub.10 ' (where R.sub.10 and R.sub.10 ' and the preferred 
significances thereof are as defined above); preferably hydrogen, 
chlorine, methyl or methoxy; more preferably hydrogen or chlorine, 
R.sub.7 ' is hydrogen, chlorine, methyl, methoxy or sulpho; preferably 
hydrogen, chlorine or sulpho; more preferably hydrogen or sulpho, 
R.sub.8 ' is hydrogen, chlorine or methyl; preferably hydrogen or chlorine; 
more preferably hydrogen, and the preferred positioning of substituents is 
as defined above the formula (a), 
##STR28## 
in which R.sub.1 ' and the R.sub.29 's are as defined above, and the 
preferred positions of substitution are as defined above, for formula (a); 
##STR29## 
where R.sub.14 ' is a radical of formula (vi), above, or a radical of 
formula (v') 
##STR30## 
where 
R.sub.15 ' is hydrogen, chlorine, C.sub.1-2 alkyl or alkoxy or sulpho; 
preferably hydrogen, methyl, C.sub.1-2 -alkoxy or sulpho, and 
R.sub.16 ' is hydrogen, chlorine or C.sub.1-2 alkyl or alkoxy; preferably 
hydrogen, methyl or methoxy, the preferred positions of substitution in 
radical (V') being as given above for radical (v); 
##STR31## 
where 
R.sub.17 ' is hydrogen, chlorine, methyl, or methoxy or ethoxy; preferably 
hydrogen, methyl or methoxy, 
R.sub.18 ' is hydrogen, methyl, methoxy or ethoxy; preferably methyl or 
methoxy, 
R.sub.20 ' is hydrogen, methyl, ethyl, propyl, butyl, --C.sub.2 H.sub.4 Cl, 
--C.sub.2 H.sub.4 CN, --C.sub.2 H.sub.4 OH, benzyl, monosulphobenzyl or 
phenyl; preferably hydrogen, methyl, ethyl, --C.sub.2 H.sub.4 CN or 
--C.sub.2 H.sub.4 OH, and 
R.sub.21 ' is hydrogen, methyl, ethyl, propyl, butyl, --C.sub.2 H.sub.4 Cl, 
--C.sub.2 H.sub.4 CN or --C.sub.2 H.sub.4 OH; preferably hydrogen, methyl, 
ethyl, --C.sub.2 H.sub.4 CN or --C.sub.2 H.sub.4 OH, 
the substituents R.sub.17 ' and R.sub.18 ', where both are other than 
hydrogen, preferably being in para position relative to each other, 
##STR32## 
where m is as defined above, 
##STR33## 
where R.sub.24 ' is hydrogen or a radical (vii') 
##STR34## 
where 
R.sub.25 ' is hydrogen, chlorine, methyl, methoxy, ethoxy or sulpho, 
R.sub.26 ' is hydrogen, methyl, methoxy or ethoxy, and R.sub.27 ' is 
hydrogen or methyl, the preferred positioning of any sulpho groups in 
radicals (da) and (db) being as given above for radical (d), 
##STR35## 
where m is as defined above, and 
R.sub.28 ' is hydrogen, methyl, ethyl, n-propyl, n-butyl, --CO--CH.sub.3, 
--CO--C.sub.2 H.sub.5 or --O--CO--C.sub.6 H.sub.5 or a radical (viii'), 
(ix') or (x') 
##STR36## 
where R.sub.25 ', R.sub.26 ' and R.sub.27 ' are as defined above, 
##STR37## 
where R.sub.30 ' is hydrogen or methyl, 
##STR38## 
where 
R.sub.31 ' is hydrogen, methyl or methoxy, and 
R.sub.32 ' is hydrogen or methyl, the preferred positioning of substituents 
and the free bond in formula (fa) being as given above for formula (f), 
##STR39## 
R.sub.36 ' is methyl, ethyl, tert.butyl, methoxy or ethoxy; 
##STR40## 
where R.sub.36 ' as defined above, of the radicals (ga) and (gb), (gb) 
being preferred; 
##STR41## 
where R.sub.35 ' is methyl, ethyl, propyl, 
##STR42## 
R.sub.37 ' is hydrogen, methyl, ethyl, methoxy or ethoxy; 
EQU --Y'--N.dbd.N--k.sub.1 ' (ja) 
where Y' is a radical (xv') or (xvi') 
##STR43## 
where R.sub.17 ' and R.sub.18 ' are as defined above and the preferred 
positioning thereof is as given for formula (xv), 
##STR44## 
where 
R.sub.9 is as defined above, and 
K.sub.1 ' signifies a radical of formula (aa), (ab), (ba), (ca), (da), 
(db), (fa), (ga), (gb) or (ha). 
Of the above preferred class of dyes, those monoazo dyes in which K.sub.2 
is a radical of formula (aa), (ab), (ba), (ca), (da) or (gd) are 
particularly preferred and those disazo dyes in which K.sub.1 ' is a 
radical of formula (ca), (da), (db), (fa) or (gb) are particularly 
preferred. 
Also particularly preferred are the monoazo compounds of the formula 
##STR45## 
wherein 
Z and Z.sub.1 are as defined above, and 
R.sub.36a is C.sub.1-8 alkyl. 
Preferably, 
(i) the hydroxy group is in the 4-position and the R.sub.36a group is in 
the 2-position or the 3-position or 
(ii) the hydroxy group is in the 2-position and the R.sub.36a group is in 
the 5-position. In either case, R.sub.36a is preferably C.sub.1-4 alkyl 
and more preferably is t-butyl. 
The compounds provided by the present invention may be obtained in 
conventional manner, for example the monoazo dyes may be obtained by 
coupling the diazo derivative of a 3-aminodibenzofuran, unsubstituted or 
substituted in only one of positions 2 and 8 thereof by a sulpho group, 
with a coupling component, the coupling component being so chosen so that 
the final azo dyestuff contains one or two sulpho groups. By choosing a 
coupling component having a diazotisable amino group, the resulting 
compound may be diazotised and coupled with a further coupling component 
to produce a disazo dye, again the coupling components being chosen so 
that the final disazo dye contains 1 or 2 sulpho groups. 
Such couplings may be carried out in conventional manner, e.g. in aqueous 
or aqueous/organic acid, neutral or alkaline medium at a temperature of 
from -10.degree. C. to room temperature, optionally in the presence of a 
coupling accelerator such as pyridine or urea. 
As will be appreciated, where, in the final azo dye, in the radical derived 
from the coupling compound, it is desired to have an alkoxy or acyl group, 
and such group would hinder or prevent coupling taking place if it were 
present in the "coupling" component (e.g. in the radical of formula (h), 
above), such dyes are prepared by employing the corresponding hydroxy 
substituted coupling component, followed by etherification or acylation in 
conventional manner. Such etherification is conveniently carried out, e.g. 
with dialkyl sulphates, in aqueous media at a pH of from 8 to 10, at a 
temperature of from 30.degree. to 80.degree. C., preferably from 
40.degree. to 60.degree. C. in the presence of, for example, sodium or 
potassium carbonate or bicarbonate. The acylation is suitably carried out 
in aqueous media at a pH of from 8 to 10, preferably about 9, at a 
temperature of 30.degree. to 80.degree. C., preferably at about 50.degree. 
C., the reaction advantageously being carried out in the presence of 
sodium carbonate or disodium phosphate. Inert solvents such as 
dichlorobenzene may also suitably be used. 
The azo dyes according to the invention may be in free acid or salt forms. 
In such salt forms, the cations may be any conventional in the anionic 
dyestuff art, their exact nature, provided they are non-chromophoric, not 
being critical. Particularly suitable cations ar the alkali metal cations, 
e.g. sodium and potassium and the ammonium, alkyl- and alkanolammonium 
cations, e.g. of the formula N.sym.RaRbRcRd, where Ra, Rb, Rc and Rd, 
independently, signify hydrogen, C.sub.1-3 alkyl or C.sub.2-4 hydroxyalkyl 
(where the hydroxy is separated from the nitrogen by at least 2 carbon 
atoms) with the proviso that where any of Ra, Rb, Rc and Rd signify 
hydroxyalkyl, at least one signifies hydrogen. Examples of such cations 
include mono-, di-, tri- and tetra-methylammonium and mono-, di- and 
tri-isopropanolammonium cations. The preferred cation is the sodium 
cation. 
The azo dyes of the invention may be used for the dyeing or printing of 
anionic dyeable substrates, e.g. natural and synthetic polyamides, such as 
wool, silk or nylon. 
On the above-mentioned substrates the compounds have notable fastness to 
light and notable general fastness properties, e.g. wet fastness, such as 
notable wash fastness, sweat fastness, resistance to action of acids and 
alkali; also they have notable dry cleaning fastness and dry rubbing 
fastness. 
However, the dyes are preferably used for the dyeing or printing of 
polyamides, in particular nylon. 
The dyes according to the invention were surprisingly found to have the 
combination of good affinity from a neutral bath and notable migration. 
These two properties are not usually found in combination in dyes of the 
present type. The dyes go on neutral and at the same time act as levelling 
dyes, a particularly sought-after combination of qualities.