GB2163174A - Monoazo disperse dyes from substituted 5-nitrobenzothiazoles - Google Patents

Abstract

Disperse dyes of formula (I) are, with certain exclusions, novel: <IMAGE> wherein R represents one, two or three substituents, which may be the same or different, and Z represents the residue of an azo dye coupler, R and Z being such that the dye is water-insoluble. The dyes give red to blue shades on acetate, polyester and polyamide fibres, and have good light- and sublimation-fastness on polyester fibres and good wet-fastness on polyester and polyester-cotton fibres.

Description

SPECIFICATION Azo dyes from substituted 5-nitrobenzothiazoles This invention relates to azo dyes made from benzothiazoles having a 5-nitro and at least one other substituent on the fused benzene ring and conventional couplers.

Numerous azo dyes made by reacting couplers with diazotised amino heterocyclic compounds have been proposed see, for example, U.K. Patent Application 2 036 775A. In U.K. Patent Application 8320878 filed before, but published after, the priority date ofthe present application and also in European PatentApplication 0 087 037A1, such-dyes prepared from 2 - amino - 5-nitrobenzothiazole are described.

We have discovered that dyes having improved performance in one or otherofthefollowing properties, namely light-fastness, wet-fastness, sublimation fastness, energy of application and exhaustion of the dye bath, when used with acetate, polyamide or polyesterfibres can be obtained by using a 2 - amino 5- nitrobenzothiazolewhich has at least one other substituent on the carbocyclic ring of the benzothiazole nucleus.

According to the present invention there are provided azo dyes of the general formula:

wherein R represents one, two orthree substituents, which may be the same or different, on the fused benzene ring and Z represents the residue of an azo dye coupler, Rand Z being such thatthe dye is a water insoluble disperse dye, providedthatR isotherthan 6-chloro when R represents one su bstituent and Z has the formula

wherein:RY iS hydrogen oroneortwosubstituents selected independently from fluorine, chlorine, bromine, alkyl, alkoxy, and phenoxy; R'O and R11 are selected independently from hydrogen, phenyl, cycloalkyl, alkyl, and alkyl substituted with 1-3 substituents independently selected from chloro, hydroxy, cyano, succinimido, phthalimido, alkoxy, phenoxy, alkoxyalkoxy, phenyl, alkoxycarbonyl, alkanoyloxy, acyloxy, alkylcarbamoyl, sulfamoyl, alkylsulfamoyl, and aryloxy.

Possible values for each substituent Rare acyl, (including formyl), acylamido, acyloxy, alkenyl, alkenylthio; alkenylsuiphonyl, alkyl, alkanesulphonamido, alkylsulphonyl, alkylsulphonyloxy, alkylthio, alkoxy, alkoxycarbonyl, alkoxycarbonylamino, amino, aryl, aryloxy, aryloxycarbonyl, arylsulphonamido, arylsulphonyl, arylsul phonyloxy, arylth io, carbamoyl, carbamoyloxy, carboxyl, cyano, cycloalkyl, cycloalkenyl, cycloalkoxy, cycloalkylsulphonyl, cycloalkylthio, halogen, hydroxyl, nitro, sulphamoyl, sulphonic acid halide, sulphonic acid amide or thiocyanato.Any substituent R (otherthan cyano, thiocyanato, halogen, hydroxyl, nitro or sulphonic acid halide) may itself be substituted, any substituent being a su bstituent selected from thosejust listed for R. or a heterocyclic group.

The residue Z can be derived from any azo dye coupler. Preferred couplers are of the general formula:

wherein each of R1 and R2 is hydrogen, an alkyl group, preferably lower alkyl i.e. having 1 to 4 carbon atoms, or such an alkyl group substituted with a substituent as defined for R of Formula (I) or heterocyclic group. Very suitable substituentsfor R1 andlor R2 are chloro, cyano, hydroxyl, phenyl, phthalimido, succinimido, acyloxy of formula -OCOR5 and groups of formula -OC2H4OR5;where R5 R5 is hydrogen, lower alkyl, lower alkenyl or aryl. Alternatively, R1 and R2 may complete a heterocyclic ring such as a morpholine ring. Each of R3 and R4 is hydrogen, or a substituent as defined for R of Formula (I).Very suitable substituents for R3 and/or R4 are lower alkyl, lower alkoxy, and chloro. A group offormula NHCoR5 is also preferred for R4, R5 being as defined above.

Any cycloalkyl or cycloalkenyl moiety constituting, or forming part of, a substituent R to R4 preferably has 3 to6carbon atoms.

Instead of being separate, R1 and R3 may together complete a 5- or 6-membered heterocyclic ring, possibly containing a sulphur or oxygen atom as a second heteroatom. Particularly preferred couplers wherein this is the case are tetrahydroquinoline and benzomorpholine couplers respectively of the for muiae:

wherein each of R6 and R7 is hydrogen or a su bstituent selected form those listed above for R, R8 is a substituentas defined for RI, and R' indicates the possible presence of one or more substituents, each of which is a substituent selected from those listed above for R.

It is preferred for any alkyl, cycloalkyl or alkenyl grouporresidueforming, orforming part of, a substituent R, R', R' to R4and R6to R8to have a maximum of 6 carbon atoms, and for any aryl group or residue to be a phenyl or naphthyl group or residue.

Azo dye couplers are described in numerous specifications, including,for instance, U.K. Specifications 1,298,450, 1,419,999 and 1,425,426.

Particular examples of substituents R forthe azo dyes ofthe invention are methyl, methoxy,trifluoromethyl, fluorine, chlorine, bromine, iodine, cyano,thiocyanato, chlorosulphonyl,fluorosulphonyl, methanesulphonyl and nitro.

The substituted 5-nitrobenzothiazole dyes ofthe invention are made by diazotising the appropriate substituted 2 - amino -5 - nitrobenzothiazole and then reacting the productwith the chosen coupling compound. The necessary substituted 2 -amino - 5 - fnitrobenzothiazoles can be prepared by various methods,thatchosen depending upon the required substitution. Possible methods are asfollows.

a) Electrophilicsubstitution of2 - amino - 5 - nitrobenzothiazole.

This method is suitable forthe introduction a second nitro group orofathiocyanato group or of one ortwo halogen atoms.

b) Nitration ofthe approptiate 2-aminobenzothiazole.

Avariety ofsubstituents may be present in the 2-aminobenzothiazole including,forexample, halogen, alkyl, haloalkyl, alkoxy and thiocyanato.

c) Cyclisation of the appropriately substituted dinitrophenyl thiocyanate.

Thefusedthiazole ring can be formed on an appropriately substituted benzene ring buy a method analogous to that described in East German Patent 150895.

Clearly, some substituents in the desired 2 - amino 5 - nitrobenzothiazole are more readily obtained by initially introducing some other substituent chosen for its ready conversion to the desired su bstituent, and then carrying outthatconversion. Thus a 6-SO2CH3 derivative is readily produced from the corresponding 6-SCN compound, and a 6-cyano derivative is readily produced from the corresponding 6-formyl compound.

The dyes ofthe invention can be used for producing red to blue shades on acetate, polyester and polyamidefibres. The dyeing is appropriately carried out using an aqueous suspension of the dye. If a carrier is present a temperature in the range 80-1 000C is often suitable whereas in the absence of a carrier a temperature in the range 100-140"C is likelyto be required. Ifthe so-called thermofixing process is used, a temperature of 180-230"C is usually necessary.

Ifthe dyes are used for printing textiles woven from polyester or polyamidefibres, the textiles can be steamed at80 to 110"C in the presence of a carrier and at 110 to 1400C in its absence. When goods printed with the new dyes are to be treated bythethermofixing process, the 180-230"C range already quoted is suitable.

The dyes ofthe invention havegood light-fastness and sublimation fastness on polyesterfibres, and good wet-fastness on polyester and polyester-cotton fibres.

The invention is illustrated bythefollowing Examples.

Example 1 i) 2-Amino -5,6-dinitrobenzothiazole (by method (a) above) To a solution of 2- amino - 5 - nitro benzothiazole (1.95 g) in concentrated sulphuric acid (20 ml) was added a mixture of fuming nitric acid (3 ml) and concentrated sulphuric acid (3 ml). Afterstirring at 200Cfor 16 rs. the solution was drowned into iced water (200 ml) then filtered and water washed to yield 2 - amino - 5,6- dinitro benzothiazole (2.4 g).

ii} Dye from 2 - amino - 5,6 - dinitrobenzothiazole andS - acetamido - N,N - diethylaniline coupler To 20% nitrosyl sulphuric acid (9.5 g) was added at < 5'C acetic-propionic acid (5: 1) (1 Oml). To the stirred mixture at < 50C was added the substituted 2 - amino 5 -nitrobenzothiazole (0.01 moles) followed by a further5ml portion of acetic-propionic acid (1 :5) and orthophosphoric acid (5 ml). The mixture was stirred for 2 hours at 0-5"C. It was added to the coupler (0.01 moles) dissolved in dilute sulphuric acid-ice (100 ml).

The mixture was stirred at 5-1 5'Cfor 1 hour, the dye productfiltered off, washed with water, and dried.

This dye gave a reddish-blue shade.

Example 2 i) 2 - Amino - 4,6 - dichloro - 5 - nitrobenzothiazole (bymethod(b) above) To a solution of 2 - amino -4,6 - dichloro benzothiazole (4.4 g) in concentrated sulphuric acid (20 ml) was added at < 5 C a mixture offuming nitric acid (1.49) and concentrated sulphuric acid (5 ml).

The mixture was stirred at 15"C for 30 minutes, added to ice water and pH adjusted to 5 with 0.88 ammonia.

The title product was filtered off, washed with water and dried. The yield was 5.1 g.

ii) Dye from 2-amino -4,6- dichloro -5 nitrob enzothiazole an d N - e thyl - N - (2 -propiony- loxyethyl)aniline coupler.

The substituted benzothiazole was diazotised and coupled bythe procedure described in Example 1 (ii).

The dye gave a red shade.

Example 3 i) 2-Amino -6-bromo - 5 - nitrobenzothiazole (by method (a) above) A mixture of 2 - amino - 5 - nitrobenzothiazole (2 g), AcOH (50 ml), sodium acetate (5 g) and bromine (1.8 g) was stirred at 100 Cfor31/2 hours. The mixture was cooled, added to water, and the solid productfiltered off. The yield was 1.9 9.

ii) Dyefrom P-amino- 6-bromo -5- nitrobenzothiazole and N - ethyl - 2 - methoxy 5 -methylaniline coupler The diazotised substituted benzothiazole wascou- pled with the coupler bythe method described above in Example 1 (ii).

Example4 to 19 Further dyes ofthe invention as tabulated below, were prepared by methods analogous to those already described.

R R 1 Z Shade C3H7 ll 4 M do bur bkHCOcH3 BI*Red CsH,N/C1Hs T acS,wLO tCH3 BluishRed H=N,C2H5 6. :N 3tlNHCocHX Red C7fN/C2HsOCOCH, 7 Red c,11?N c3ii7 C3H7~No C3H7 ≈ S502CI gD CX Red a Z Shade CN3 9 SN02 H3 Blue C2H 10 ~ CH3O~ NEt2 Red U SOCH3 one2 Red Et 12 Wr SCI > \ Bbds?ed al,P R z Shade 13. 6-502CH3 c'1 BluiRed CH3 14 U CH) Cycl Red r t KI N Red 17 6-CF3 O NEt2 Bluish-Red

Claims (5)

1. An azo disperse dye of the general formula:

wherein R represents one, two orthree substituents, which may be the same or different, and Z represents the residue of an azo dye coupler, R and Z being such that the dye is water-insoluble, provided that R is otherthan 6-chloro when R represents one substi tuentand Zhas the formula

wherein: R9 is hydrogen or one ortwo substituents selected independently from fluorine, chlorine, bromine, alkyl, alkoxy, and phenoxy; R10 and R11 are selected independentlyfrom hydrogen, phenyl, cycloalkyl, alkyl, and alkyl substituted with 1-3 su bstituents independently selected from chloro, hydroxy, cyano, succinimido, phthalimido, alkoxy, phenoxy, alkoxyalkoxy, phenyl, alkoxycarbonyl, alkanoyloxy, acyloxy, alkylcarbamoyl sulfamoyl, alkylsulfamoyl, and aryloxy.

2. Adye according to claim 1 wherein each substituent R is selected from acyl (including formyl), acylamido, acyloxy, alkenyl, alkenylthio, alkenylsulphonyl, alkyl, alkanesulphonamido, aikylsulphonyl, alkysulphonloxy, alkylthio, alkoxy, alkoxycarbonyl, alkoxycarbonylamino, amino, aryl, aryloxy, aryloxycarbonyl, arylsulphonamido, arylsulphonyl, arylsulphonyloxy, arylthio, carbamoyl, carbamoyloxy, carboxyl, cyano, cycloalkyl, cycloalkenyl, cycloalkoxy, cycloalksulphonyl, cycloalkylthio, halogen, hydroxyl, nitro, sulphamoyl, sulphonic acid amide, sulphonic acid halide orthiocyanato, any substituent R, other than cyano, thiocyanato, halogen, hydroxyl, nitro oF sulphonic acid halide, possibly being itself substituted, any substituent being a substituent selected fromthoselistedforR our a heterocyclic group.

3. A dye according to claim 1 or 2 wherein Z is the residue of a coupler of the general formula:

wherein each of R1 and R2 is hydrogen, and alkyl group, or an alkyl group substituted with a substituent as defined for R ofthe Formula (I) of claim 1 or with a heterocyclic group and each of R3 and R4 is hydrogen or a substituent as defined for R of the Formula (I) of claim 1,orR1 and R3togethercomplete a 5- or 6-membered heterocyclic ring possibly containing asulphurofoxygen atom asa second heteroatom.

4. Adye according to claim 3whereinZisthe residue of a couplerofoneoftheformulae:

wherein each of R6 and R7 is hydrogen or a substituent selected from those possible for R in the Formula (I) of claim 1, R8 is a substituent as defined for R1 in the Formula (II) of claim 3 and R' indicates the possible presence of one or more substituents each ofwhich is a substituentselected from those possible for R in the Formula (I) of claim 1.

5. A dye according to claim 1 which is one of the dyes specified in the Examples 1 to 17 herein.