GB2058115A

GB2058115A - Disperse azo dyestuffs

Info

Publication number: GB2058115A
Application number: GB8015889A
Authority: GB
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1979-08-16
Filing date: 1980-05-13
Publication date: 1981-04-08
Also published as: GB2058115B

Abstract

Disperse o-hydroxyazo dyestuffs of the formula: <IMAGE> wherein R and R' each independently represent an optionally substituted alkyl, aryl or aralkyl radical; Z is a hydrogen atom, an alkyl radical or an alkoxy radical; W is an acyl radical, and the ring A may carry additional substituents are prepared by reacting the corresponding o-halogenoazo dyestuff in a dipolar solvent with a copper salt and a salt of a carboxylic acid to give a copper complex, from which the o-hydroxyazo dyestuff is liberated by acidification. The use of the dyestuffs for the colouration of synthetic textile materials is described.

Description

SPECIFICATION Disperse azo dyestuffs This invention relates to disperse azo dyestuffs useful for the colouration of synthetic textile materials.

According to the present invention there are provided disperse azo dyestuffs of the formula:

wherein R and R' each independently represent an optionally substituted alkyl, aryl or aralkyl radical; Z is a hydrogen atom, an alkyl radical or an alkoxy radical, W is an acyl radical, and the ring A may carry additional substituents.

The alkyl radicals represented by R, R1 and Z are preferably lower alkyl radicals, for example, methyl, ethyl, n-propyl, isopropyl and n-butyl.

The substituted alkyl radicals represented by R and R' are preferably substituted lower alkyl radicals, for example, hydroxy lower alkyl such as p-hydroxyethyl, y-hydroxypropyl and 8-hydroxybutyl; halogeno lower alkyl such as p-chloroethyl and ,B-bromoethyl; cyano lower alkyl such as p-cyanoethyl; lower alkoxy lower alkyl such as ,B-methoxyethyl and P-ethoxyethyl; lower alkoxy lower alkoxy lower alkyl such as methoxyethoxyethyl and ethoxyethoxyethyl; lower alkoxycarbonyl lower alkyl such as methoxycarbonylethyl, ethoxycarbonylethyl and butoxycarbonylethyl,; acyloxy lower alkyl such as acetoxyethyl and optionally N-substituted alkylaminocarbonyl lower alkyl such as p-carbamoylethyl and ,3-(N-methylaminocarbonyl)ethyl.

The optionally substituted aryl radicals represented by R and R1 are preferably optionally substituted phenyl radicals, for example, lower alkyl phenyl such as tolyl; lower alkoxy phenyl such as methoxyphenyl; halogenophenyl such as chlorophenyl and bromophenyl; The alkoxy radicals represented by Z are preferably lower alkoxy radicals, for example, methoxy and ethoxy.

Examples of the optionally substituted aralkyl radicals represented by R and R1 are benzyl, chlorobenzyl and p-phenylethyl.

The acyl radicals represented by Ware preferably radicals of the formula -CO.T or -SO2.T wherein T is an alkyl radical, preferably a lower alkyl radical, or an aryl radical, preferably a monocyclic aryl radical. Examples of the acyl radicals represented by W are acetyl, propionyl, benzoyl, methylsulphonyl, ethylsulphonyl and phenylsulphonyl.

Examples of the additional substituents which may be carried by ring A are lower alkyl, lower alkoxy, halogen, nitro, cyano, alkoxycarbonyl, alkylsulphonyl, optionally substituted sulphamoyl and optionally substituted carbamoyl. Halogen may be, for example, chlorine or bromine.

Throughout this specification the terms "lower alkyl" and "lower alkoxy" are used to mean alkyl and alkoxy radicals respectively which contain from 1 to 4 carbon atoms.

According to a further feature of the invention there is provided a process for the preparation of the disperse azo dyestuffs having the above formula (I) which comprises reacting together in a dipolar solvent (a) an azo compound of the formula:

wherein Visa halogen atom and R, R1,W and Z have the meanings defined above and the ring A may carry additional substituents, (b) at least one mole per mole of the azo compound of a copper salt and (c) at least one mole per mole of the azo compound of a salt of a carboxylic acid, R2.COOM, wherein R2 is an alkyl or aryl radical and M is a metal, followed by acidification of the copper complex so obtained with a strong organic or inorganic acid.

Examples of the dipolar solvents which may be used in the above process are dimethylformamide, dimethylacetamide, dimethylsulphoxide, N-methylpyrrolidone, pyridine and hexamethylphosphoramide.

Examples of the copper salts which may be used are copper(ll) chloride, copper(ll) bromide, copper(ll) sulphate, copper(ll) acetate and copper (I) iodide.

The alkyl radicals represented by R2 are preferably lower alkyl radicals, and the aryl radical represented by R2 is preferably the phenyl radical.

The salt of a carboxylic acid R2 COOM which is used in the process is preferably an alkali metal salt, and especially a sodium or potassium salt. Examples of such salts are sodium and potassium acetate, and sodium and potassium benzoate.

Examples of strong organic or inorganic acids which can be used in the final acidification stage of the process are p-toluenesulphonic acid, hydrochloric acid, sulphuric acid or phosphoric acid.

Examples of the halogen atoms represented by V are chlorine. bromine and iodine.

It is preferred that ring A carries a substituent in the ortho position to the azo linkage.

The process of the invention is carried out by stirring together the azo compound of formula (II), the copper salt and the salt of a carboxylic acid in the dipolar solvent. The reaction period may vary widely, from one minute to several hours, for example, from 5 minutes to 48 hours, depending upon the reactivity of the reactants, the nature of the solvent and the temperature at which the reaction is carried out. The reaction may be conducted at normal room temperature or at an elevated temperature, for example, up to 1 000C, until formation of the intermediate copper complex is substantially complete.

The free o-hydroxyazo dyestuff is then liberated from the copper complex by treatment with a strong acid.

The initial product of the reaction is an azo compound which is believed to have the structure:

wherein R, R1, R2, W and Z have the previously defined meanings and ring A may carry additional substituents. This intermediate, which can be isolated in some cases, passes with relative ease into the copper complex of the azo dyestuff of formula (I), which copper complex is believed to have the structure:

The copper complex~(lV) is isolated from the reaction mixture, for example, by addition of a liquid which is miscible with the dipolar reaction solvent but in which the copper complex is insoluble.

Suitable liquids for this purpose are, for example, lower alkanols such as methanol and ethanol. The copper complex is then stirred in an aqueous solution of a strong organic or inorganic acid as hereinbefore defined, whereupon the azo dyestuff of formula (I) is liberated and is then collected, washed with water and dried.

In general, reaction proceeds more rapidly in dimethylsulphoxide as solvent than in dimethylformamide, and also proceeds more rapidly when ring A carries a bulky substituent, for example, nitro, bromo or methyl, ortho to the azo linkage than when there is no such substituent. The use of copper(l) iodide as the copper salt has a tendency to give an Ullman-type product resulting from the linking together of two molecules of azo compound (II) by splitting out of the halogen atom V, in addition to the desired azo dyestuff of formula (I), and for this reason it is preferred not to use copper(l) iodide as the copper salt.

When the group V in the azo compound of formula (II) is bromine, and the ring A carries a nitro group para to the azo linkage and a second bromine atom ortho to the azo linkage, it is possible under certain conditions for both bromine atoms to be replaced by the acyloxy group R2C00-- derived from the salt of a carboxylic acid R2COOM, so that the copper complex which is obtained has the structure (IV) in which there is a group R2C0O- ortho to the azo linkage. This variant of the reaction may occur when dimethylsulphoxide is being used as the dipolar solvent. It has not been observed when the solvent is dimethylformamide.

The process of the present invention enables azo dyestuffs to be prepared which are not readily accessible by other means.

The dyestuffs are useful for the colouration of synthetic textile materials, for example, cellulose triacetate, polyamide and especially aromatic polyester textile materials, using methods which are well known in the art. For example, the dyestuff, in the form of an aqueous dispersion, may be incorporated into a dyebath, padding liquor or print paste which may be used for the colouration of synthetic textile materials by conventional dyeing, padding or printing processes respectively. The synthetic textile materials are coloured in yellow to blue shades which have good fastness to the tests conventionally applied to such coloured textile materials.

The invention is illustrated by the following Examples in which parts and percentages are by weight.

EXAMPLE 1 Potassium acetate (3 parts) was added to a stirred mixture of dimethylformamide (130 parts), copper(ll) acetate (2 parts) and 3-acetylamino-4-(2'-bromo-4',6'-dinitrophenylazo)-N,N-diethylaniline (4.8 parts) at room temperature. After 1 8 hours the mixture was filtered to remove excess potassium acetate, and methanol (350 parts) was added to the filtrate. The copper complex of 3-acetylamino-4 (2'-hydroxy-4',6'-dinitrophenylazo)-N,N-diethylaniline, which separated as fine hairs, was filtered off, washed with methanol and dried (3.5 parts). Found: C, 45.5; H, 3.7; Cu, 13.0; N, 17.2. C,8Ha8CuN606 requires C, 45.25; H, 3.8: Cu. 13.3; N,1 7.5%.

The copper complex (2.5 parts) was stirred with hydrochloric acid (125 parts of 2N) at room temperature for 1 5 hours. The produce was then filtered off, washed with water and crystallised from methanol to obtain 3-acetylamino-4-(2'-hydroxy-4',6'-dinitrophenylazo)-N,N-diethylaniline as fine hairs (2 parts). Found: C, 51.9; H, 4.8; N, 18.4%. C,8H20N606 requires C, 51.9; H, 4.85; N, 18.5%. When this dyestuff is applied in the form of an aqueous dispersion to aromatic polyester textile material, violet shades are obtained.

EXAMPLE 2 When the dimethylformamide in Example 1 was replaced by dimethylsulphoxide (130 parts) reaction was effectively complete in 5 minutes at room temperature. The product, the copper complex of 3-acetylamino-4-(2'-hydroxy-4',6'-dinitrophenylazo)-N,N-diethylaniline, was isolated by a similar method (3.7 parts). found: C, 45.1; H, 3.6; Cu, 13.0; N, 17.3%. Conversion of the copper complex into the metal-free azo dyestuff was effected by the method employed in Example 1. Found: C, 51.8; H, 4.7; N, 19.0%.

EXAMPLE 3 Potassium acetate (3 parts) was added to a stirred mixture of dimethylformamide (100 parts), copper(ll) acetate (2 parts) and 3-acetylamino-4-(2',4'-dibromo-6'-nitrophenylazo)-N,N-diethylaniline (5.1 parts ) at room temperature. The temperature was raised to 500C for 3 hours when the mixture was filtered to remove excess potassium acetate, and methanol (300 parts) was added to the filtrate.

The copper complex of 3-acetylamino-4-(2'-hydroxy-4'-bromo-6'-nitrophenylazo)-N,N-diethylaniline which separated as rr,)icroneedles, was filtered off, washed with methanol and dried (4 parts). Found: C, 42.4; H, 3.4, Br, 15.5; Cu, 11.9; N, 13.5%. C8Ha8BrCuN504 requires C, 42.2; H, 3.55; Br, 15.6; Cu, 12.4; N, 13.7%. The copper complex was converted into the metalfree azo dyestuff by the method employed in Example 1. Found: C, 48.2; H, 4.4; Br, 17.7; N, 15.4%. C,8H20BrNso4 requires C, 48.0; H, 4.45; Br, 17.75; N, 15.55%. When this dyestuff is applied in the form of an aqueous dispersion to aromatic polyester textile material, red shades are obtained.

EXAMPLE 4 Sodium benzoate (4.3 parts) was added to a stirred mixture of dimethylformamide (130 parts), copper(ll) acetate and 3-acetylamino-4-(2'-bromo-4',6'-dinitrophenylazo)-N,N-diethylaniline (4.8 parts) and the temperature was raised to 550C. After 8 hours the mixture was filtered and methanol was added to the filtrate. The precipitated copper complex was filtered off, washed with methanol and dried (5.0 parts). Found: C, 45.0; H, 3.9; Cu, 13.1; N, 17.6%. The copper complex was converted into the metal-free azo dyestuff by the method employed in Example 1 The infra-red spectrum of the product was identical with that of the product obtained as described in Example 1.

EXAMPLE 5 Potassium acetate (3.0 parts) was added to a stirred mixture of dimethylsulphoxide (130 parts), copper(ll) acetate (2 parts) and 3-acetyla mino-6-methoxy-4-(2'-bromo-4' ,6'-dinitrophenylazo)-N,N- di(P-methoxycarbonylethyl)aniline (6.3 parts) at room temperature. After 5 minutes the mixture was filtered to remove excess potassium acetate, and methanol (300 ports) was added to the filtrate. The precipitated copper complex of 3-acetylamino-6-methoxy-4-(2'-hydroxy-4' ,6'-dinitrophenylazo)-N,N- di(P-methoxycarbonylethyl)aniline was filtered off, washed with methanol and dried (5.6 parts). Found: C, 44.0; H, 3.9; Cu, 10.1; N, 13.2%. C23H24CuN8O requires C, 44.25; H, 3.85; Cu, 10.2; N, 13.45%.

EXAMPLES 6-17 Further examples of o-hydroxyazo dyestuffs of formula (I) are obtained by replacing the o-halogen atom V by hydroxyl in the o-halogenoazo compounds of formula (II) which are given in the following table, in which R, Rr, V, W and Z have the previously defined meanings and A refers to the substituents which are present on the benzene ring identified as A in formulae (I) and (II). The dyestuffs are prepared by the method in Example 1. The shades obtained when the derived o-hydroxyazo dyestuffs are applied to aromatic polyester textile material are given in the final column of the table.

Shade of derived Ex. A V W Z R R1 o-hydroxyazo dyestuff 6 6-bromo-4-nitro Br COCH3 H ethyl ethyl Bright bordeaux 7 4-bromo-6-cyano " " " methyl methyl Red 8 4-nitro " COC2H5 " n-propyl n-propyl Bluish Red 9 4-bromo-6-methyl " COCH3 " ethyl ethyl Orange 10 4-bromo-6-nitro " COC6H5 " " " Red 11 4,6-dinitro " COCH3 OCH3 " " Blue 12 4-bromo l " H ss-cyano- " Orange ethyl 13 4-methyl Br COC2H3 " ss-acetoxy- ss-acetoxy- " ethyl ethyl 14 4,6-dinitro " COCH3 OCH3 ss-methoxy- ss-methoxy- Blue carbonyl- carbonylethyl ethyl 15 4-nitro-6- " " H ethyl ethyl Rubine sulphamoyl 16 4-bromo-6- " " " " " Scarlet carbamoyl 17 3-chloro-4-nitro Cl " " " " Bluish-red

Claims

1. Disperse azo dyestuffs of the formula:

wherein R and R1 each independently represent an optionally substituted alkyl, aryl or aralkyl radical; Z is a hydrogen atom, an acyl radical or an alkoxy radical; W is an acyl radical, and the ring A may carry additional substituents.

2. Dyestuffs as claimed in claim 1 wherein the optionally substituted alkyl radicals represented by R and R1 are optionally substituted lower alkyl radicals.

3. Dyestuffs as claimed in claim 1 or claim 2 wherein the alkyl radicals represented by Z are lower alkyl radicals.

4. Dyestuffs as claimed in any one of claims 1 to 3 wherein the optionally substituted aryl radicals represented by R and R1 are optionally substituted phenyl radicals.

5. Dyestuffs as claimed in any one of claims 1 to 4 wherein the alkoxy radicals represented by Z are lower alkoxy radicals.

6. Dyestuffs as claimed in any one of claims 1 to 5 wherein the acyl radicals represented by W are radicals of the formula --CO.T or --SO,.T wherein T is an alkyl or an aryl radical.

7. Dyestuffs as claimed in claim 6 wherein the alkyl radicals represented by Tare monocyclic aryl radicals.

8. Dyestuffs as claimed in claim 6 or claim 7 wherein the aryl radicals represented by T are monocyclic aryl radicals.

9. Disperse monoazo dyestuffs substantially as hereinbefore described in any one of the foregoing Examples.

10. A process for the preparation of the dyestuffs claimed in claim 1 which comprises reacting together in a dipolar solvent (a) an azo compound of the formula:

wherein V is a halogen atom and R, Rt, W and Z have the meanings defined in claim 1 and the ring A may carry additional substituents, (b) at least one mole per mole of the azo compound of a copper salt and (c) at least one mole per mole of the azo compound of a salt of a carboxylic acid R2.COOM, wherein R2 is an alkyl or aryl radical and M is a metal, followed by acidification of the copper complex so obtained with a strong organic or inorganic acid.

11. A process as claimed in claim 10 wherein the alkyl radicals represented by R2 are lower alkyl radicals.

12. A process as claimed in claim 10 or claim 11 wherein the aryl radical represented by R2 is a phenyl radical.

1 3. A process as claimed in any one of claims 10 to 12 wherein the salt of a carboxylic acid R2.COOM is an alkali metal salt.

14. A process as claimed in claim 13 wherein the alkali metal salt is a sodium or potassium salt.

1 5. A process as claimed in any one of claims 10 to 14 wherein ring A carries a substituent in the ortho position to the azo linkage.

1 6. A process for the preparation 9f disperse azo dyestuffs substantially as hereinbefore described in any one of the foregoing Examples.

1 7. Disperse azo dyestuffs whenever obtained by a process as claimed in any one of claims 10 to 16.

18. A process for the colouration of synthetic textile material by a dyeing, padding or printing method an aqueous dispersion of a disperse azo dyestuff as claimed in claim 1.

1 9. A process as claimed in claim 18 wherein the synthetic textile material is an aromatic polyester textile material.

20. Synthetic textile materials whenever coloured by the use of a process as claimed in claim 18 or claim 19.