GB1583377A

GB1583377A - Disperse azo dyestuffs derived from a 2-aminothiophene-5-aldehyde

Info

Publication number: GB1583377A
Application number: GB17133/77A
Authority: GB
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1977-04-25
Filing date: 1977-04-25
Publication date: 1981-01-28
Also published as: CH631197A5; FR2388860B1; DE2818101A1; ES469122A1; IT7822675A0; FR2388860A1; JPS53146731A; IT1094933B

Abstract

The novel dispersion dyes of formula I are prepared using 2-aminothiophen-5-aldehydes substituted in the 3-position. <IMAGE>

Description

(54) DISPERSE AZO DYESTUFFS DERIVED FROM A 2-AMINOTHIOPHENE-5-ALDEHYDE (71) We, IMPERIAL CHEMICAL INDUSTRIES LIMITED, Imperial Chemical House, Millbank, London SWlP 3JF a British Company do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to disperse monoazo dyestuffs which are valuable for colouring synthetic textile materials.

According to the invention there are provided the disperse monoazo dyestuffs, free from sulphonic acid groups, which are of the formula:-

wherein X is nitro, cyano, optionally substituted phenyl, COOR, CONHR', CORl or SO2R2; Y is hydrogen, optionally substituted alkyl or optionally substituted phenyl; R is hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl or optionally substituted phenyl; Rt is hydrogen, optionally substituted alkyl or optionally substituted phenyl; R2 is optionally substituted alkyl, optionally substituted phenyl or optionally substituted amino; and E is the radical of a coupling component.

Throughout this Specification the terms "lower alkyl" and "lower alkoxy" are used to denote alkyl and alkoxy radicals respectively containing from 1 to 4 carbon atoms.

As examples of the substituted phenyl radicals represented by R, Rl, R2, X and Y there may be mentioned lower alkylphenyl such as tolyl and xylyl, lower alkoxyphenyl such as anisyl, halophenyl such as chlorophenyl and bromophenyl, lower alkoxycarbonylphenyl such as methoxycarbonyiphenyl and ethoxycarbonylphenyl, and nitrophenyl. It is preferred that when R, Rl, R2, X and Y are phenyl radicals they are unsubstituted phenyl radicals.

The optionally substituted alkyl radicals represented by R, Rl, R2 and Y, are, for example, alkyl radicals containing from 1 to 18 carbon atoms which may be substituted by halogen, cyano, hydroxy, carboxyl or lower alkoxy groups. It is preferred however, that the alkyl radicals represented by R R1, R2 and Y are optionally substituted lower alkyl radicals. As examples of such unsubstituted radicals there may be mentioned methyl, ethyl, n-propyl, iso-propyl, ti-butyl, sec-butyl and iso-butyl.As examples of substituted lower alkyl represented by R and R1 there may be mentioned hydroxy lower alkyl such as 3-hydroxyethyl, cc-methyl-(3-hydroxyethyl, B-methoxyethyl, ss-ethoxyethyl and amethoxypropyl. lower alkoxycarbonyl lower alkyl such as P-ethoxycarbonylethyl, carboxy lower alkyl such as P-carboxymethyl, cyano lower alkyl such as (3-cyanoethyl, halogeno lower alkyl such as ss-chloro- and ss-bromoethyl and phenyl lower alkyl such as benzyl and P-phenylethyl. Unsubstituted lower alkyl radicals are especially preferred. As examples of cycloalkyl radicals represented by R there may be mentioned cyclopentyl and cyclohexyl.

As specific examples of the COR1 and SO2R2 radicals represented by X there may be mentioned for example acetyl, propionyl, benzoyl, methylsulphonyl, ethylsulphonyl, phenylsulphonyl and p-tolylsulphonyl. Examples of the CONHR1 radicals represented by X are carbamoyl, N-methylcarbamoyl, N-ethylcarbamoyl and N-phenylcarbamoyl, and examples of the COOR radicals represented by X are carboxy, methoxycarbonyl, ethoxycarbonyl, n-butoxycarbonyl, B-hydroxyethoxycarbonyl, B-methoxyethoxycarbonyl, ss-(ss'-methoxyethoxy)ethoxycarbonyl, phenoxycarbonyl and cyclohexyloxycarbonyl. It is however preferred that X is nitro, cyano or lower alkoxycarbonyl.

The radical of the coupling component represented by E may be the radical of any of the series of coupling components which couple with diazo compounds, such as the radical of a coupling component of the acylacetarylamide, pyrazolone, aminopyrazole, phenol, naphthol, 2,6-diaminopyridine or 2,6-dihydroxypyridine series. More especially E is the radical of a coupling component of the aromatic series which couple by virtue of the presence of an optionally substituted amino group, such as the radical of a coupling component of the 1-naphthylamine series, and, especially, the radical of a coupling component of the aniline series which couple in para position to an optionally substituted amino group.

The radical of the coupling component represented by E is preferably of the formula:

wherein Zi and Z2 each independently represent hydrogen or an optionally substituted hydrocarbon radical, and the benzene ring B may contain additional substituents or form part of an optionally further substituted naphthalene or quinoline ring. It is preferred that Zi and Z2 are optionally substituted lower alkyl radicals.

E especially represents a radical of the formula:

wherein W is hydrogen, lower alkyl or lower alkoxy V is hydrogen, lower alkyl, lower alkoxy, chlorine, bromine or acylamino, in particular an acylamino group of the formula NHCOT2 or NHSO2T3, wherein T2 is hydrogen, alkyl (especially lower alkyl), aryl, amino or aminoalkyl. T3 is optionally substituted lower alkyl or optionally substituted aryl, Z is hydrogen or optionally substituted alkyl, especially optionally substituted lower alkyl, and Z is hydrogen or optionally substituted alkyl, especially optionally substituted lower alkyl, or optionally substituted aryl or optionally substituted cycloalkyl, As examples of the optionally substituted lower alkyl radicals represented by Z3 and Z4 there may be mentioned hydroxy lower alkyl such as (3-hydroxyethyl, ce-methyl-[3- hydroxyethyl. ss- or -hydroxypropyl. and 6-hydroxybutyl, lower alkoxy lower alkyl such as ss-(methoxy or ethoxy)ethyl and γ;-methoxypropyl, cyano lower alkyl such as ss-cyanoethyl, phenyl lower alkyl such as benzyl and ss-phenylethyl, acyloxy lower alky such as ss-acetoxyethyl and 1-acetoxy-2-propyl, carboxy lower alkyl such as (3-carboxyethyl and 6-carboxybutyl . lower alkoxy carbonyl lower alkyl such as (3-methoxycarbonylethyl, hydroxy lower alkoxy lower alkyl such as ss-(ss'-hydroxyethoxy)ethyl, lower alkoxy lower alkoxy lower alkyl such as ss-(ss'-methoxyethoxy)ethyl, lower alkoxy lower alkoxy carbonyl lower alkyt such as ss-(ss-methoxyethoxycarbonyl)ethyl, acyloxy lower alkyl in particular lower alkylcarbonyloxy lower alkyl such as ss-acetoxyethyl and #-acetoxybutyl, chloro lower alkyl such as γ ;-chloropropyl, and lower alkoxycarbonyloxy lower alkyl such as ssethoxycarbonyloxyethyl.

According to a further feature of the invention there is provided a process for the manufacture of the azo dyestuffs as hereinbefore dcfined which comprises diazotising an amine of the formula:

and coupling the resulting diazo compound with a coupling component of the formula: E-H, wherein E, X and Y have the meanings stated, the amine and coupling component being free from sulphonic acid groups.

The process of the invention may be conveniently carried out by adding sodium nitrite to a solution or dispersion of the amine in a strong inorganic acid or an aqueous solution thereof, or by stirring the amine with nitrosylsulphuric acid, and adding the resulting solution or dispersion of the diazo component to a solution of the coupling component in water or in a mixture of water and a water-miscible organic liquid, if necessary adjusting the pH of the mixture to facilitate the coupling reaction, and finally isolating the resulting dyestuff by conventional methods.

The said amines can themselves be obtained by conventional methods for example, by Vilsmeier (see "Name Reactions in Organic Chemistry", by A.R. Surrey, 2nd Edition, published 1961 by Academic Press, page 113). formylation of 2-acetylaminothiophene followed by nitration (the nitro group enters the 3-position) and hydrolysis to give 2-amino-3-nitrothiophene-5-aldehyde. In some cases the Vilsmeier reaction conditions can be used to effect other desirable modifications to the 2-aminothiophene-5-aldehyde structure. For example, if 2-acetylamino-3-aminocarbonylthiophene is heated with phosphorous oxychloride in dimethylformamide the 5-aldehyde group is introduced, but in addition the aminocarbonyl group is dehydrated to give the cyano group and the acetylamino group is converted into the readily hydrolysable dimethylformamidino group.

The said amines may also be prepared, from the corresponding 5-methyl, 5-chloromethyl or 5-hydroxymethyl compounds by oxidation, the amino group being previously protected if necessary.

As specific examples of the said amines there may be mentioned 2-amino-3-nitro-4methylthiophene-5-aldehyde, 2-amino-3-(methoxy, carbonyl, ethoxycarbonyl, acetyl, benzoyl, methylsulphonyl or N-methylcarbamoyl)thiophene-5-aldehyde, and preferably 2amino-3-nitrothiophene-5-aldehyde or 2-amino-3-cyanothiophene-5-aldehyde.

As examples of the said coupling components there may be mentioned acylacetarylamides such as acetoacetanilide and acetoacet-2,5-dimethoxyanilide; aminopyrazoles such as 1-phenyl-3-methyl-5-aminopyrazole; pyrazolones such as 1 ,3-dimethyl-5-pyrazolone but more particularly 1-phenyl-3-(methyl, carbonamido or carbomethoxy)-5-pyrazolones in which the phenyl radical is optionally substituted by methyl, methoxy, ethoxy, chlorine, bromine, nitro, sulphonamido or acetylamino; 2,6-dihydroxypyridines such as 3-cyano-4methyl-2,6-dihydroxypyridine and 1-ethyl-3-cyano-4-methyl-6-hydroxypyrid-2-one; 2,6diaminopyridines such as 3-cyano-4-methyl-2,6-di(N-2-methoxyethylamino)pyridine; phenols such as o-cresol, resorcinol and 3-acetylaminophenol; naphthols such as P-naphthol; but more especially arylamines of the naphthylamine series such as 1-naphthylamine, and more particularly of the aniline series such as 2,5-dimethoxyaniline, N,N-diethylaniline, N,N-di(ss-hydroxyethyl)-m-toluidine,N,N-di(ss-cyanoethyl)aniline, N-ethyl-N-(ss- ethoxyethyl)aniline, N,N-di(B-carbomethoxyethyl)-m-toluidine, 2-methoxy-5-methyl-N-(ss- acetoxy-a-methylethyl)aniline, N-[ss-(ss'-methoxyethoxycarbonyl)ethylaniline, N,N-di(P- acetoxyethyl)-m-toluidine, N-ethyl-N-(ss-cyanoethylaniline, N-ethyl-N-(6- acetoxybutyl)aniline, N-ethyl-N-benzyl-m-toluidine and N,N-diethyl-m-acetamidoaniline.

The azo dyestuffs of the invention are valuable for colouring synthetic textile materials in particular secondary cellulose acetate and cellulose triacetate textile materials, polyamide textile materials such as polyhexamethylene adipamide textile materials, and, especially, aromatic polyester textile materials such as polyethylene terephthalate textile materials.

Such materials can be in the form of filaments, fibres or woven or knitted materials.

The said azo dyestuffs can be applied to the synthetic textile materials by methods which are conventionally employed in applying disperse dyestuffs to such textile materials. Thus the dyestuffs in the form of aqueous dispersions can be applied by dyeing, padding or printing processes using the conditions and other additives which are conventionally used in carrying out such processes. Alternatively the said dyestuffs can be applied to synthetic textile materials by solvent methods of dyeing, for example, by applying a solution or dispersion of the dyestuff in perchloroethylene optionally containing a minor amount of water to the textile material, preferably at elevated temperature.

When applied to synthetic textile materials the azo dyestuffs of the invention give colourations ranging from yellow to green which have excellent fastness to light and to wet and to dry treatments. The shade obtained is relatively unaffected by dyebath conditions such as pH. The said dyestuffs also have excellent build-up properties on synthetic textile materials, particularly aromatic polyester textile materials, thus enabling heavy depths of shade to be readily obtained, and in this respect they are superior to the corresponding known dyestuffs containing an acetyl group (instead of an aldehyde group) in the 5- position of the thiophene nucleus. Alternatively the said dyestuffs can be used for the mass colouration of synthetic polymers which are subsequently to be converted into fibres or filaments.The said dyestuffs can also be applied to synthetic textile materials by the process of transfer colour printing optionally at reduced air pressure or under wet or humid conditions.

The invention is illustrated but not limited by the following Examples in which the parts and percentages are by weight.

Example 1 1.72 Parts of 2-amino-3-nitrothiophene-5-aldehyde are added to a solution of nitrosysulphuric acid (which had been prepared by dissolving 0.75 part of sodium nitrite in 24.5 parts of sulphuric acid at 70"C, cooling and diluting with 30 parts of acetic acid and 5 parts of propionic acid) the temperature being maintained at --5" to OOC by external cooling. The temperatures of the mixture is raised to 0 C and stirring continued for 45 minutes. The resulting solution of the diazo compound is then added to a mixture of 3.5 parts of N,N-di(P-acetoxyethyl)-m-toluidine, 1 part of sulphamic acid, 20 parts of a 1% aqueous solution of sulphuric acid and 500 parts of ice/water, and the pH of the mixture is then raised to 4 by the addition of sodium acetate.The mixture is stirred for 1 hour and the precipitated dyestuff is filtered off, washed with water, and dried.

When dispersed in aqueous medium the dyestuff dyes aromatic polyester textile materials in bluish-violet shades.

The 2-amino-3-nitrothiophene-5-aldehyde used in the above Example was itself obtained as follows: 180 Parts of a nitration mixture, which had been obtained by mixing together 66.3 parts of nitric acid (sp.gr. 1.50), 120 parts of 20% oleum and 713 parts of sulphuric acid, were slowly added to a solution of 33.8 parts of 2-acetylaminothiophene-5-aldehyde (which had been prepared as described in the Journal of the American Chemical Society, 1953, Volume 75, page 989), in 310 parts of sulphuric acid, the temperature of the mixture being maintained at -100C to -50C. The mixture was then stirred for a further 5 minutes and poured into an ice/water mixture containing 5 parts of sulphamic acid. The precipitated 2-acetylamino-3-nitrothiophene-5-aldehyde was then filtered off, washed with water and dried.The N-acetyl group was then removed by stirring the solid in a 4% aqueous solution of sodium hydroxide at 40"-50"C, and filtering off the resulting 2-amino-3-nitrothiophene-5aldehyde.

The following Table gives further examples of the dyestuffs of the invention which are obtained when the 3.5 parts of N,N-di(P-acetoxyethyl)-m-toluidine used in Example 1 are replaced by equivalent amounts of the coupling components listed in the second column of the following Table; the shades obtained from the said dyestuffs being given in the third column of the Table.

Example Coupling Component Shade 2 3-acetylamino-N,N-diethylaniline Greenish-blue 3 3-methyl-N,N-diethylaniline Blue Example 4 2-acetylamino-3-aminocarbonylthiophene, m.p. 220-222"C, was prepared by treatment of 2-amino-3-aminocarbonylthiophene (preparation described in Bull. Soc. Chim. France, 1974, page 2869) with acetic anhydride. 36.8 parts of the acetylamino compound were added to 280 parts of dimethylformamide and 55.6 parts of phosphorus oxychloride were added dropwise to the mixture, the temperature being maintained below 60"C by means of external cooling. The mixture was then stirred at 60"C for 75 minutes, cooled and poured into an ice/water mixture.

2-(N ,N-dimethylformamidino)-3-cyano-5-formylthiophene crystallised slowly from the aqueous mixture and was collected and recrystallised from a 20:10:1 by volume propanol/methyl Cellosolve/water mixture to give orange needles, m.p. 192-193"C.

("Cellosolve" is a Registered Trade Mark).

This compound (20 parts) was mixed with methyl Cellosolve (100 parts) and cold 2N sodium hydroxide solution (100 parts) and the mixture was heated for 5 minutes at 60"C.

The resulting solution was filtered and acidified with 120 parts of 2N acetic acid. The precipitated 2-amino-3-cyano-5-formylthiophene was filtered off. The infra-red spectrum of the compound (Nujol mull) had peaks at 3390, 3295, 3150, 2210, 1695 and 1650.

2-Amino-3-cyano-5-formylthiophene (15.2 parts) was added to a mixture of acetic acid (220 parts), propionic acid (40 parts) and nitrosylsulphuric acid solution (160 parts) containing 13 parts of nitrosylsulphuric acid) at a temperature below 0 C. After stirring the mixture at OOC for 90 minutes it was poured into a mixture of ice and water (2000 parts), 2N-sulphuric acid (100 parts), N,N-diethyl-m-aminoacetanilide (20.6 parts) and 1M sulphamic acid (50 parts). The pH was adjusted to 3-4 by addition of sodium acetate and the precipitated dyestuff was filtered off after 30 minutes stirring of the mixture.

When applied from an aqueous dispersion to an aromatic polyester textile material the dyestuff gave reddish-blue shades having good fastness properties.

Example 5 2-Acetylamino-3-cyano-4-methylthiophene (3.6 parts) was added to a previously prepared mixture of dimethylformamide (14 parts) and phosphorus oxychloride (5.5 parts) at approximately 10 C. A slow exotherm caused the temperature to rise to approximately 35"C. After 2 hours the mixture was poured into ice and water. Yellow crystals 2-(N,N-dimethylformamidino)-3-cyano-4-methyl-5-formylthiophene precipitated slowly and were filtered off. This compound was hydrolysed by the method described in Example 4 to give 2-amino-3-cyano-4-methyl-5-formylthiophene.The latter compound was diazotised and coupled with N,N-diethyl-m-aminoacetanilide was described in Example 4 to give a dyestuff which imparts bright blue-violet shades to aromatic polyester textile material when applied by conventional exhaust dyeing methods.

Examples 6 to 18 Further Examples of dyestuffs according to the present invention are given in the following Table, in which the column headings X, Y, V, W, Zl and Z2 refer to the formula below. The final column of the Table gives the shade obtained when an aqueous dispersion of the appropriate dyestuff is applied to an aromatic polyester textile material.

Ex. X Y V W Z1 Z2 Shade 6 NO2 H CH3 H C2H4COOCH3 C2H4COOCH3 Blue 7 " " " OCH3 " " " 8 " " " C2H4COOC2H4OCH3 H " 9 NHCOCH3 H H H 10 " OCH3 C2H4COOCH3 C2H4COOCH3 Greenishblue 11 ' H C2H4CN C2H5 " 12 CN CH3 H C2H4COOCH3 C2H4COOCH3 Violet 13 " NHCOCH3 OCH3 C2H5 C2H5 Blue 14 ' H H C2H5 C6H5CH2 Violet 15 " ' NHCOCH3 H C2H5 CH2CH(CH3)2 Blue 16 " CH3 CH3 H C2H4COOC2H5 C2H4COOC2H5 Violet 17 COOC2H5 H " H C2H4COOCH3 C2H4COOCH3 Bluishred 18 " " H H C2H4CN C2H5 Red Ex X Y V W Z1 Z2 Shade 19 CN H CH3 H C2H5 C2H4COOCH3 Violet 20 " C6H5 CH3 H C2H5 C2H4OH " 21 m-ClC6H4 H H C2H5 C2H4NHCOCH3 " 22 H OCH3 H C2H5 C2H5 Blue 23 " H NHCOCH3 H H CH2CH(CH3)2 " 24 NO2 H " H H " Greenishblue 25 0-NO2C6H4 H CH3 H C2H4OCOCH3 C2H4OCOCH3 Red 26 COCH3 H CH3 H " " Violet 27 CONH2 H CH3 H C2H5 n-C4H9 " 28 SO2CH3 H NHCOCH3 H C2H5 " " 29 SO2C6H5 H CH3 H C2H4COOCH3 C2H4COOCH3 Red 30 SO2N(CH3)2 H H CH3 H CH(CH3)CH2- " COOCH3 31 CN H NHCOCH3 OCH3 H C2H4COOC2H4- Greenish OCH3 blue Examples 32-38 The following Table gives further examples of the dyestuffs of the invention which are obtained when the diazonium compound obtained by diazotisation of the amine given in the second column of the table is coupled with the coupling component given in the third column of the table. The shade obtained when an aqueous dispersion of the appropriate dyestuff is applied to aromatic polyester textile material is given in the fourth column of the table.

Ex. Amine Coupling Component Shade 32 2-amino-3-nitro-5-formyl N-phenylmorpholine Violet thiophene 33 " 1-phenyl-3-methyl-5- Red pyrazolone 34 2-amino-3-cyano-4-methyl- resorcinol 5-formylthiophene 35 " 1-ethyl-3-cyano-4-methyl 6-hydroxypyrid-2-one 36 " N-(p-hydroxyethyl)-1- Blue naphthylamine 37 2-amino-3-cyano-5-formyl P-naphthol Red thiophene 38 " acetoacetanilide Orange WHAT WE CLAIM IS 1.Disperse monoazo dyestuffs, free from sulphonic acid groups, which are of the formula:

wherein X is nitro, cyano, optionally substituted phenyl, COOR, CONHRt, COR1 or SO2R2; Y is hydrogen, optionally substituted alkyl or optionally substituted phenyl; R is hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl or optionally substituted phenyl; Rt is hydrogen, optionally substituted alkyl or optionally substituted phenyl; R2 is optionally substituted alkyl, optionally substituted phenyl or optionally substituted amino; and E is the radical of a coupling component.

2. Dyestuffs as claimed in claim 1 wherein the phenyl radicals represented by R, R', R2, X and Y are unsubstituted phenyl.

3. Dyestuffs as claimed in claim 1 wherein the alkyl represented by R, R', R2 and Y are lower alkyl.

4. Dyestuffs as claimed in claim 3 wherein R, R', R2 and Y are unsubstituted lower alkyl.

5. Dyestuffs as claimed in claim 1 wherein X represents nitro, cyano or lower alkoxycarbonyl.

6. Dyestuffs as claimed in any one of claims 1 to 5 wherein the radical of the coupling component represented by E has the formula:

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

Examples 32-38 The following Table gives further examples of the dyestuffs of the invention which are obtained when the diazonium compound obtained by diazotisation of the amine given in the second column of the table is coupled with the coupling component given in the third column of the table. The shade obtained when an aqueous dispersion of the appropriate dyestuff is applied to aromatic polyester textile material is given in the fourth column of the table.

Ex. Amine Coupling Component Shade 32 2-amino-3-nitro-5-formyl N-phenylmorpholine Violet thiophene 33 " 1-phenyl-3-methyl-5- Red pyrazolone 34 2-amino-3-cyano-4-methyl- resorcinol

5-formylthiophene 35 " 1-ethyl-3-cyano-4-methyl

6-hydroxypyrid-2-one 36 " N-(p-hydroxyethyl)-1- Blue naphthylamine 37 2-amino-3-cyano-5-formyl P-naphthol Red thiophene 38 " acetoacetanilide Orange WHAT WE CLAIM IS 1.Disperse monoazo dyestuffs, free from sulphonic acid groups, which are of the formula:

wherein X is nitro, cyano, optionally substituted phenyl, COOR, CONHRt, COR1 or SO2R2; Y is hydrogen, optionally substituted alkyl or optionally substituted phenyl; R is hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl or optionally substituted phenyl; Rt is hydrogen, optionally substituted alkyl or optionally substituted phenyl; R2 is optionally substituted alkyl, optionally substituted phenyl or optionally substituted amino; and E is the radical of a coupling component.
2. Dyestuffs as claimed in claim 1 wherein the phenyl radicals represented by R, R', R2, X and Y are unsubstituted phenyl.
3. Dyestuffs as claimed in claim 1 wherein the alkyl represented by R, R', R2 and Y are lower alkyl.
4. Dyestuffs as claimed in claim 3 wherein R, R', R2 and Y are unsubstituted lower alkyl.
5. Dyestuffs as claimed in claim 1 wherein X represents nitro, cyano or lower alkoxycarbonyl.
6. Dyestuffs as claimed in any one of claims 1 to 5 wherein the radical of the coupling component represented by E has the formula:

wherein Zt and Z2 each independently represent hydrogen or an optionally substituted hydrocarbon radical, and the benzene ring B may contain additional substituents or form part of an optionally further substituted naphthalene or quinoline ring.
7. Dyestuffs as claimed in claim 6 wherein the optionally substituted hydrocarbon radicals represented by Z1 and Z2 are optionally substituted lower alkyl radicals.
8. Dyestuffs as claimed in any one of claims 1 to 5 wherein the radical of the coupling component represented by E has the formula:

wherein W is hydrogen, lower alkyl or lower alkoxy, V is hydrogen, lower alkyl, lower alkoxy, chlorine, bromine or acylamino, Z3 is hydrogen or optionally substituted alkyl, and Z4 is hydrogen, optionally substituted alkyl, optionally substituted aryl, or optionally substituted cycloalkyl.
9. Dyestuffs as claimed in claim 8 wherein the acylamino group represented by V has the formula NHCOT2 or NHSo2T3 in which R2 is hydrogen, alkyl, aryl, amino or alkylamino and T3 is optionally substituted lower alkyl or optionally substituted aryl.
10. Dyestuffs as claimed in claim 9 wherein the alkyl radical represented by T2, and the optionally substituted alkyl radicals represented by Z and Z are lower alkyl and optionally substituted lower alkyl respectively.
11. Disperse monoazo dyestuffs, as claimed in claim 1, substantially as hereinbefore described in any one of the foregoing Examples 1 to 18.
12. Disperse monoazo dyestuffs, as claimed in claim 1, substantially as herinbefore described in any one of the foregoing Examples 19 to 38.
13. A process for the manufacture of the disperse monoazo dyestuffs claimed in claim 1 which comprises diazotising an amine of the formula:

and coupling the resulting diazo compound with a coupling component of the formula E-H, wherein E, X and Y are as defined in claim 1, the amine and coupling component being free from sulphonic acid groups.
14. A process as claimed in claim 13, for the manufacture of disperse monoazo dyestuffs, free from sulphonic acid groups, substantially as hereinbefore described in any one of the foregoing Examples 1 to 18.
15. A process as claimed in claim 13, for the manufacture of disperse monoazo dyestuffs, free from sulphonic acid groups, substantially as hereinbefore described in an; one of the foregoing Examples 19 to 38.
16. Disperse monoazo dyestuffs, free from sulphonic acid groups, whenever obtained by a process as claimed in claim 13 or claim 14.
17. Disperse monoazo dyestuffs, free from sulphonic acid groups, whenever obtained by a process as claimed in claim 15.
18. A method for the colouration of synthetic textile materials which comprises applying to the said synthetic textile material by a dyeing, padding or printing process an aqueous dispersion of a disperse monoazo dyestuff as claimed in claim 1.
19. A method as claimed in claim 18 wherein the synthetic textile material is an aromatic polyester textile material.