WO2002055488A1

WO2002055488A1 - Asymmetric divinylstilbene-sulphonic acids

Info

Publication number: WO2002055488A1
Application number: PCT/EP2002/000069
Authority: WO
Inventors: Victor Paul Eliu; Peter Rohringer; Julia Hauser
Original assignee: Ciba Specialty Chemicals Holdings Inc.
Priority date: 2001-01-12
Filing date: 2002-01-07
Publication date: 2002-07-18

Abstract

The present invention relates to novel asymmetric divinylstilbene-sulphonic acids represented by the formula (I) in which X and Y are different and each represents COOR1, -CONR2R3 wherein R1, R2 and R3 each, independently, represent hydrogen, a C1-C18alkyl or a C2-C18alkenyl residue, which is unsubstituted or substituted by one or more hydroxy, thiol, amino, cyano, C1-C4alkoxy, -COOC1-C4alkyl or sulphone groups;-CNm, phenyl, which is unsubstituted or substituted by one or more C1-C4alkyl or C1-C4alkoxy groups, halogen, SO3M or CN; SO3M or PO3M2 and M represents H, Na, Li, K, Ca, Mg, ammonium, or ammonium that is mono-, di, tri, or tetrasubstituted by C1-C4alkyl, C2-C4hydroxyalkyl or a mixture thereof, a process for their preparation and their use as fluorescent whitening agents (FWA's) for synthetic or natural organic materials.

Description

Asymmetric Divinylstilbene-sulphonic Acids

The present invention relates to novel asymmetric divinylstilbene-sulphonic acids, a process for their preparation and their use as fluorescent whitening agents (FWA's).

The novel compounds are represented by the formula

in which

X and Y are different and each represents -COOR₁₍ -CONR₂R₃, wherein

R₁, R₂ and R₃ each, independently, represent hydrogen, a Cι-C₁₈alkyl or a C₂-C₁₈alkenyl residue, which is unsubstituted or substituted by one or more hydroxy, thiol, amino, cyano,

C C alkoxy, -COOC_rC₄alkyl or sulphone groups; -CN, phenyl, which is unsubstituted or substituted by one or more C-ι-C₄alkyl or C C₄alkoxy groups, halogen, SO₃M or -CN; SO₃M or PO₃M₂ and represents H, Na, Li, K, Ca, g, ammonium, or ammonium that is mono-, di-, tri- or tetrasubstituted by C C₄alkyl, C₂-C₄hydroxyalkyl or a mixture thereof.

Preferred compounds of formula (1) are those in which X and Y are different and X represents -COOR^ -CONR₂R₃, wherein R_{1 (} R₂ and R₃ each, independently, represent hydrogen, a C C₁₈alkyl or a C₂-C₁₈alkenyl residue, which is unsubstituted or substituted by one or more hydroxy, thiol, amino, cyano, CrC₄alkoxy, -COOC*-C alkyl or sulphone groups; -CN, phenyl, which is unsubstituted or substituted by one or more C C₄alkyl or CrC₄alkoxy groups, halogen, SO₃M or -CN; -SO₃M or -PO₃M₂ and Y represents -COOR,, -CONR₂R₃, wherein

R-i, R₂ and R₃ each, independently, represent hydrogen, a C C₁₈alkyl or a C₂-Cι₈alkenyl residue, which is unsubstituted or substituted by one or more hydroxy, thiol, amino, cyano, C C₄alkoxy, -COOCrC₄alkyl or sulphone groups; SO₃M or PO₃M₂, M being as defined previously.

Particularly preferred compounds of formula (1) are those in which X and Y are different and X represents -COOH, -COOCι-C₄alkyl, -CONH₂, -CON(CrC₄alkyl)₂, -CN, phenyl, which is unsubstituted or substituted by d-C₄alkyl or Cι-C₄alkoxy groups or by halogen; -SO₃M or - PO₃M₂ and Y represents -COOH, -COOC_rC₄alkyl, -CONH₂, -CON(C C₄alkyl)₂ or SO₃M, M being as previously defined.

Compounds of formula (1), which are of especial interest are those in which X and Y are different and

X represents -COOH, -COOC_rC₄alkyl, -CONH₂, -CON(C_rC₄alkyl)₂, -CN, phenyl, -SO₃M or -

PO-3M₂, Y represents -COOH, -COOC_rC₄alkyl, -CONH₂, -CON(CrC₄alkyl)₂ or SO₃M and

M is hydrogen, K or Na, whilst those compounds in which

X represents -COOH, -COOCH₃, -COOC₂H₅, -CONH₂, -CON(CH₃)₂, -CN, phenyl, -SO₃M or -

PO₃M₂, Y represents -CONH₂, -CON(CH₃)₂ or SO₃M and is hydrogen, K or Na are most especially preferred.

Within the scope of the definitions of substituents X and/or Y, Cι-Cι₈alkyl groups may be branched or unbranched such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, t-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1 ,3-dimethylbutyi, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1 ,1 ,3,3-tetramethylbutyl, 1 -methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl, 1 ,1 ,3-trimethylhexyl, 1 ,1 ,3,3-tetramethylpentyf, n-nonyl, n-decyl, n- undecyl, 1 -methylundecyl, n-dodecyl, 1 ,1 ,3,3,5,5-hexamethylhexyl, n-tridecyl, n-tetradecyl, n- pentadecyl, n-hexadecyl, n-heptadecyl and n-octadecyl.

Similarly, C₂-Cι₈alkenyl groups may be branched or unbranched such as ethenyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, 2-ethylbutenyl, n-pentenyl, isopentenyl, 1-methylpentenyl, 1,3-dimethylbutenyl, n-hexenyl, 1-methylhexenyl, n-heptenyl, isoheptenyl, 1,1 ,3,3- tetramethylbutenyl, 1-methylheptenyl, 3-methylheptenyl, n-octenyl, 2-ethylhexenyl, 1 ,1 ,3- trimethylhexenyl, 1 ,1 ,3,3-tetramethylpentenyl, n-nonenyl, n-decenyl, n-undecenyl, 1- methylundecenyl, n-dodecenyl, 1 ,1 ,3,3,5,5-hexamethylhexenyl, n-tridecenyl, n-tetradecenyl, n-pentadecenyl, n-hexadecenyl, n-heptadecenyl and n-octadecenyl.

d-C₄alkoxy groups may be branched or unbranched such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy or t-butoxy groups.

Halogen may be bromine, fluorine, iodine or, especially, chlorine. When M represents a cation formed from an amine these may be NH₄, mono-, di-, tri- or tetramethylammonium, mono-, di-, tri- or tetraethylammonium, mono, di-, tri- or tetra-n- or isopropylarnmonium, mono, di-, tri- or tetra-n-, sec- or t-butylammonium, mono-, di- or triethanolammonium, mono-, di- or tri- n- or isopropanolammonium, mono-, di- or tri-n- sec- or t-butanolammonium, morpholinium, piperidinium or pyrrolidinium.

A further aspect of the present invention is a process for the preparation of a compound of formula (1) characterized by the following reaction sequence:

a) Treatment of 4-amino 4'-nitrostilbene-2,2'-disulphonic acid or salts thereof with an acylating agent; b) reduction of the nitro group to an amino group; c) diazotisation of the resulting aminostilbene compound; d) reacting the resulting diazonium salt with a compound of formula

Y-CH=CH₂ (2)

in a solvent and in the presence of a palladium catalyst and an inorganic salt, resulting in the introduction of the group Y; e) hydrolysis of the acyl protecting group; f) diazotisation of the resulting aminostilbene compound and g) reacting the resulting diazonium salt with a compound of formula

X-CH=CH₂ (3)

in a solvent and in the presence of a palladium catalyst and an inorganic salt, resulting in the introduction of the group X, X and Y being as previously defined.

Step a) of the above reaction sequence is carried out in a suitable solvent such as water, in the presence of a base such as an alkaline or alkaline earth metal salt such as Li-, K-, Na-, Ca-, or Mg- acetate, bicarbonate, carbonate, hydroxide etc., sodium carbonate being particularly suitable. As acylating agent, appropriate derivatives of the corresponding mono- or dibasic carboxylic acids, such as anhydrides or halogenides, particularly acid chlorides, may be employed. Examples of such acylating agents are acetic or propionic anhydride, acetyl or propionyl chloride, optionally substituted benzoic acid anhydrides or benzoyl chlorides, mono-, di- or trichloro or fluoro acetic anhydrides or acetyl chlorides, optionally substituted phthalic anhydrides, succinic anhydride or optionally substituted benzene sulphonyl halides, particularly chlorides, such as benzene sulphonyl chloride or p-toluene sulphonyl chloride, acetic anhydride being most preferred.

For the reduction step b), any suitable process for the reduction of an aromatic nitro- compound to the corresponding aromatic amine is suitable as described, for example, in Houben and Weyl, providing further reduction of either the olefinic double bond or the aromatic rings does not occur. Particularly suitable, in this case, is reduction by metals such as iron or tin in the presence of mineral acids such as hydrochloric or acetic acid, the so- called Bechamp Reduction with iron and acetic acid being most preferred.

The diazotisation steps c) and f) of the process are carried out in the presence of a strong mineral acid and a diazotising reagent. Suitable strong mineral acids are, for example, hydrochloric acid, sulphuric acid, methane sulphonic acid or tetrafluoroboric acid, sulphuric acid being particularly preferred, whilst suitable diazotising reagents are, for example, sodium nitrite, C_'-Cs-alkyl nitrites or nitrosyl sulphuric acid, sodium nitrite being especially suitable. The temperature at which the diazotisation reaction is carried out is dependent on the structure of the amine, but, in general, lies within the range of between -10 and 30°C, -5 to 25°C or 10 to 15°C being preferred.

The palladium (II) compound used as a catalyst in steps d) and g) of the process is PdCI₂, PdBr₂, Pd(NO₃)₂, H₂PdCl₄, Pd(OOCCH₃)₂, [PdCl₄]Na₂, [PdCI₄]Li₂, [PdCI₄]K₂, palladium(ll)acetylacetonate, palladium(ll)dibenzylideneacetone (dba) or solvates thereof, dichloro-(1,5-cyclooctadiene)palladium(ll), dichlorobis-(acetonitrile)palladium(ll), dichlorobis- (benzonitrile)palladium(ll), π-allylpalladium(ll)chloride dimer, bis-(π-methallyl palladium(ll)chloride) or π-allylpalladium(ll)acetylacetonate, PdCl₂, Pd(dba)₂, or Pd(OCOCH₃)₂.or PdCl₂ being preferred.

The quantity of palladium catalyst used is in an amount of 0.01 to 5 mole %, based on the diazonium salt, preferrably 0.1 to 1 mole %. Steps d) and g) of the process may be effected in water as solvent or may be conducted in a two-phase solvent system comprising water and a water-immiscible organic solvent such as halogenated hydrocarbons in the presence of a phase transfer catalyst. Alternatively, an organic solvent may be employed, whereby the organic solvent is one or more of an alcohol; ketone; carboxylic acid; carboxylic acid anhydride; sulfone; sulfoxide; N,N-tetrasubstituted urea; N-alkylated lactam or N-dialkylated acid amide; ether; aliphatic carboxylic acid ester or lactone; nitrile; and a gfyme, mixtures of acetic acid and acetic anhydride being especially suitable.

The inorganic salt used in steps d) and g) of the process is a Li-, Na-, K-, NH -, Mg- or Ca~ salt of a carboxylic acid, preferably lithium-, potassium- or sodium acetate, bicarbonate or carbonate, whereby sodium or potassium acetate, or sodium or potassium bicarbonate are especially suitable, the inorganic salt being used in excess.

The reaction steps d) and g) of the process is carried out at a temperature of between 10 and 100°C, preferably at between 10 and 80°C and most preferably at between 30 and 60°C.

The hydrolysis step e) is preferably carried out in aqueous medium in the presence of an inorganic base. As inorganic base, hydroxides of Li, K, or, especially, Na may be used. Alternatively, hydrolysis may be performed in the presence of strong mineral acid such as hydrochloric or sulphuric acid.

In dissolved or finely divided states, the compounds of formula (1) display a more or less pronounced fluorescence. They are therefore used, according to the invention, for optically brightening synthetic or natural organic materials.

Examples of such materials which may be mentioned, without the review given below being intended to express any limitation thereto, are textile fibres from the following groups of organic materials, insofar as optical brightening thereof enters into consideration:

(a) Polyamides which are obtainable as polymerisation products by ring opening, for example those of the polycaprolactam type,

(b) polyamides which are obtainable as polycondensation products based on bifunctional or polyfunctional compounds capable of undergoing a condensation reaction, such as hexamethylenediamine adipate and (c) natural textile organic materials of animal or vegetable origin, for example based on cellulose or proteins, such as cotton or wool, linen or silk.

The organic materials to be optically brightened can be in diverse stages of processing and are preferably finished textile products. They can, for example be in the form of hank goods, textile filaments, yarns, twisted yams, nonwovens, felts, textile fabrics, textile composites or knitted fabrics.

The brighteners defined above are of particular importance for the treatment of textile fabrics. The treatment of textile substrates is advantageously carried out in an aqueous medium in which the particular optical brighteners are present in a finely divided form (suspensions, so-called microdispersions and in some cases solutions). Dispersing agents, stabilisers, wetting agents and further auxiliaries can optionally be added during the treatment.

The treatment is usually carried out at temperatures of from about 20° to 140°C, for example at the boiling point of the bath, or in the region thereof (about 90°C). For the finishing, according to the invention, of textile substrates it is also possible to use solutions or emulsions in organic solvents, as are used in dyeing practice in so-called solvent dyeing (pad-thermofix method and the exhaustion dyeing process in dyeing machines).

The optical brighteners, which can be used according to the present invention, can also be employed, for example, in the following use forms:

(a) In mixtures with so-called "carriers", wetting agents, softeners, swelling agents, antioxidants, light stabilisers, heat stabilisers and chemical bleaching agents (chlorite bleach and bleaching bath additives).

(b) In mixtures with crosslinking agents and finishing agents (for example starch or synthetic finishing agents) and also in combination with very diverse textile finishing processes, especially synthetic resin finishes (for example crease resistant finishes such as "wash-and- wear", "permanent press" and "no-iron"), and also flame resistant finishes, soft handle finishes, anti-soiling finshes or anti-static finishes or antimicrobial finishes.

(c) As additives to various soaps and washing agents.

(d) In combination with other substances having an optical brightening action. If the brightening process is combined with textile treatment or finishing methods, the combined treatment can in many cases advantageously be effected with the aid of corresponding stable formulations, which contain the compounds having an optical brightening action in a concentration such that the desired brightening effect is obtained.

In certain cases, the full effect of the brightener is achieved by an after-treatment. This can be, for example, a chemical treatment (for example acid treatment), a thermal treatment (for example heat) or a combined chemical/heat treatment.

The amount of the optical brighteners to be used according to the invention, relative to the material to be optically brightened, can vary within wide limits. A distinct and durable effect can already be achieved with vary small amounts and in certain cases, for example, with amounts of 0.03% by weight. However amounts of up to about 0.5% by weight can also be used. For most cases of interest in practice, amounts of between 0.05 and 0.5% by weight relative to the material to be brightened are preferably of interest.

The optical brighteners are also especially suitable as additives for washing baths or to industrial and household washing agents and they can be added in various ways. They are appropriately added to washing baths in the form of their solutions in water or organic solvents or also in a state of fine division as aqueous dispersions or slurries. They, or their components, are advantageously added to household or industrial washing agents at any phase of the manufacturing process of the washing agent, for example to the so-called "slurry" prior to spray-drying of the washing powder or during the preparation of liquid washing agent combinations. The compounds can be added both in the form of a solution or dispersion in water or other solvents and also without auxiliaries in the form of a dry brightener powder. However, they can also be sprayed, in the dissolved or pre-dispersed form, onto the finished washing agent.

Washing agents which can be used are the known mixtures of detergent substances, such as, for example, soap in the form of chips and powders, synthetic products, soluble salts of sulphonic acid half-esters of higher fatty alcohols, arylsulphonic acids, which are substituted by higher alkyl and /or polysubstituted by alkyl, carboxylic acid esters with alcohols of medium to higher molecular weight, fatty acid acylaminoalkyl- or aminoaryl-glycerol- sulphonates, phosphoric acid esters of fatty alcohols and the like. So-called "builders" which can be used are, for example, alkali metal polyphosphates and alkali metal polymeta- phosphates, alkali metal pyrophosphates, alkali metal salts of carboxyethylcellulose and other "soil redeposition inhibitors", and also alkali metal silicates, alkali metal carbonates, alkali metal borates, alkali metal perborates, nitrilotriacetic acid, ethylenediamine-tetraacetic acid and foam stabilisers, such as alkanolamides of higher fatty acids. Furthermore, the washing agents can contain, for example: antistatic agents, superfatting skin protection agents, such as lanolin, enzymes, antimicrobial agents, perfumes and dyestuffs.

The brighteners have the particular advantage that they are also effective in the presence of active chlorine donors, such as, for example, hypochlorite and can be used without substantial loss of the effects in washing baths with non-ionic washing agents, for example alkylphenol polyglycol ethers. Also in the presence of perborate or peracids and activators, for example tetraacetylglycoluril or ethylenediamine-tetraacetic acid, the new brighteners are very stable both in pulverulent washing agent and in washing baths.

The brighteners according to the invention are added in amounts of 0.005 to 2% or more and preferably of 0.03 to 0.5%, relative to the weight of the liquid or pulverulent ready-to-use. washing agent. When they are used to wash textiles made of cellulose fibres, polyamide fibres, cellulose fibres with a high grade finish, wool and the like, wash liquors which contain the indicated amounts of the optical brighteners according to the invention impart a brilliant appearance in daylight.

The washing treatment is carried out, for example, as follows:

The indicated textiles are treated for 1 to 30 minutes at 5° to 100°C and preferably at 25° to 100°C in a wash bath which contains 1 to 10 g/kg of a composite washing agent containing builders and 0.05 to 1 % relative to the weight of the washing agent, of the brighteners claimed. The liquor ratio can be 1 :3 to 1 :50. After washing, the textiles are rinsed and dried in the customary manner. The wash bath can contain, as a bleach additive, 0.2 g/l of active chlorine (for example in the form of hypochlorite) or 0.1 to 2 g/l of sodium perborate.

The brighteners according to the invention can also be applied from a rinsing bath with a "carrier". For this purpose the brightener is incorporated in a soft rinsing agent or in another rinsing agent, which contains, as the "carrier", for example, polyvinyl alcohol, starch, copolymers on an acrylic basis or formaldehyde/urea or ethylene-urea or propylene-urea derivatives, in amounts of 0.005 to 5% or more and preferably of 0.2 to 2%, relative to the rinsing agent. When used in amounts of 1 to 100 ml, and, preferably of 2 to 25 ml, per litre of rinsing bath, rinsing agents of this type, which contain the brighteners according to the invention, impart brilliant brightening effects to very diverse types of treated textiles.

A further application of the compounds of the invention is for the brightening of paper, either in the pulp mass during paper manufacture or in the size-press, which has been described in British Patent Specification 1 ,247,934, or, preferably, in coating compositions. When brighteners of the present invention are employed in such formulations papers brightened with them exhibit a very high degree of whiteness.

The compounds obtained by the process of the present invention are particularly advantageous in that they exhibit not only extremely high whitening ability, but, in addition, in many cases highly desirable water solubilities and also possess excellent white aspects in the solid state.

The following Examples serve to illustrate the invention without intending to be restrictive in nature; parts and percentages are by weight, unless otherwise stated.

Example 1

Step a): Acetylation of 4-amino-4'-nitrostilbene-2,2'-disulphonic acid

41 g of 4-amino-4'-nitrostilbene-2,2'-disulphonic acid monosodium salt are added to 100ml of water resulting in an orange-brown suspension of pH 2.1. The pH of the stirred suspension is then adjusted to 7.0 by careful addition of 50g of sodium carbonate, excess foaming being avoided. 10.6g of acetic anhydride are then added dropwise at room temperature over 20 minutes, whereby the temperature rises to 28°C and the pH drops to 3.8-4.0. After stirring for 1 hour, there are obtained approximately 200ml of a yellowish brown suspension of the acetylated compound, which is used directly for the following step.

Step b): Reduction of the nitro-compound.

24g of iron filings are stirred into 40ml of water, heated to 80°C, 0.5ml of 80% acetic acid added to etch the iron and the mixture stirred for a further 15 minutes. The temperature is then raised to 100°C and the suspension obtained in the previous step a) added. The redox potential rises from an initial value of 145mV to 160mV. After the addition, stirring is continued for a further 10 minutes, the mixture cooled to 60°C and the pH adjusted to 8-8.5 by the addition of 4.5g of 50% aqueous sodium hydroxide solution. The mixture is then clarified through a pre-heated suction filter and the residues washed with a little water. There are obtained 280ml of a brownish solution with a nitrite value of 15%, which is used directly for the following step.

Step c): Diazotisation of 4-amino-4'acetylaminostilbene-2,2'-disulphonic acid.

To 20g of water and 150g of ice, 20g of 96% sulphuric acid are added with stirring. The solution obtained from the previous step b), to which 20.2g of 37% aqueous sodium nitrite solution is added, is then added gradually over 1.5 hours with external cooling to maintain the temperature below 15°C. After the addition, the nitrite excess is checked and, if necessary, neutralized by the addition of a little sulphamic acid. The suspension is filtered, the filter cake washed with 50ml of water and the resulting 118g of moist filter cake used immediately in the next step.

Step d): 4-Styryi-4'-acetylaminostilbene-2,2'-disulphonic acid di-sodium salt.

The 118g of moist filter cake obtained in the previous step c) are slurried in 200g of glacial acetic acid and the suspension cooled to 5°C. 300g of acetic anhydride are then added dropwise over 2 hours with stirring, followed by 29g of sodium bicarbonate in portions, foaming being kept under control. To the reaction mixture 0.2g of Pd(dba)₂ and 14g of styrene are then added, whereby strong gas evolution immediately commences and the temperature rises. Gas evolution continues for 1 -2 hours and the temperature is maintained at 40°C. Stirring is then continued for a further 2 hours, after which time no further diazonium salt can be detected by reaction with alkaline H-acid. The yellowish suspension is cooled, filtered, washed with glacial acetic acid and dried. Recrystallization from water/salt yields 37g of the required product, characterized by the following ¹H-NMR spectrum recorded in D₆- DMSO:

2.10 3H, s amide methyl group

7.26 1 H, t, j = 8Hz aromatic proton

7.26 2H, q, j = 17Hz vinyl protons (overlapping)

7.35 2H, t, j = 8Hz aromatic protons

7.60 5H, m, aromatic protons (overlapping)

7.70 1 H, d, j = 8Hz aromatic proton

7.97 1 H, s, aromatic proton adjacent to sulphonic acid group

8.03 1 H, s aromatic proton adjacent to sulphonic acid group

8.08 2H, q, j = 17Hz vinyl protons between sulphonic acid groups

10.9 1 H, s, N-H Step e): Hydrolysis of the amide.

The moist or dried product obtained from the previous step d) is slurried in 250ml of 20% aqueous sodium hydroxide solution and heated to 120°C with stirring. After stirring at this temperature for 3 hours, the mixture is cooled to 60°C, the pH adjusted to 7 by the addition of 60% sulphuric acid and filtered. After drying, there are obtained 36g of 4-amino-4'- styrylstilbene-2,2'-disulphonic acid salt as a yellowish green solid with an active content of 90%.

Step f): Diazotisation of 4-amino-4'-styrylstilbene-2,2'-disulphonic acid.

The product obtained in the previous reaction step is suspended in 100ml of water at 40°C and treated with 20g of 35% aqueous sodium nitrite solution. The resulting solution is then added over 1 hour with external cooling at 10-15°C to a solution of 41 g of 60% sulphuric acid and 50ml of water. After stirring for a further 30 minutes at this temperature, the excess nitrite is checked and, if necessary, neutralized by the addition of a little sulphamic acid. The suspension is then filtered to yield approximately 156g of red filter cake, which is used immediately for the next reaction step.

Step g): Preparation of compound (101).

The 156g of filter cake obtained in the previous step f) are slurried in 50ml of glacial acetic acid and cooled to 20°C. 522g of acetic anhydride are then added dropwise over 2 hours, followed by the careful addition of 16.8g of sodium bicarbonate, in portions, to keep foaming under control. To the reaction mixture are then added 0.1 g of Pd(dba)₂ and 9.5g of methyl acrylate, whereupon gas evolution commences immediately and the temperature rises. Gas evolution continues for approximately 5 hours, the temperature being maintained at 35°C during this time. After no further diazonium salt can be detected by testing with alkaline H- acid solution, the yellow suspension is cooled, filtered with suction, washed with glacial acetic acid and dried to yield 50.6g of product. Purification by recrystallization from water/salt, yields 32g of the compound of formula (101), characterized by the following ¹H- NMR spectral data recorded in D₆-DMSO: 4.20 3H, s methyl group

6.60 1 H, d, j = 16Hz vinyl proton

6.30 2H, q, j = 16Hz vinyl protons

7.30 1 H, t, j = 8Hz aromatic proton

7.40 2H, t, j = 16Hz aromatic protons

7.60 6H, m, j = 8Hz aromatic protons

7.80 1 H, d, j = 8Hz aromatic proton

7.95 1 H, s aromatic proton adjacent to sulphonic acid group

8.03 1 H, s aromatic proton adjacent to sulphonic acid group

8.22 2H, q, j = 17Hz vinyl proton between sulphonic acid groups.

Example 2

The 156g of filter cake obtained as described in Example 1 , steps a) to f) are slurried in 50ml of glacial acetic acid and cooled to 20°C. 522g of acetic anhydride are then added dropwise over 2 hours, followed by the careful addition of 16.8g of sodium bicarbonate, in portions, to keep foaming under control. To the reaction mixture are then added 0.1g of palladium acetate and 44g of 30% vinyl sulphonic acid dissolved in 176g of acetic anhydride, whereupon gas evolution commences immediately and the temperature rises. Gas evolution continues for approximately 4 hours, the temperature being maintained at 45°C during this time. After no further diazonium salt can be detected by testing with alkaline H-acid solution, the yellow solution is evaporated to dryness. After purification by recrystallization from methanol/ethanol, there are obtained approximately 40g of the compound of formula (102), characterized by the following ¹H-NMR spectral data recorded in D₆-DMSO:

6.90 2H, q, j = 16Hz vinyl protons

7.30 1H, t, aromatic proton

7.30 2H, d, j = 16Hz vinyl protons

7.40 2H, t, j = 8Hz aromatic protons 7.60 6H, m, aromatic protons

7.85 1H, s, aromatic proton adjacent to sulphonic acid group

8.05 1 H, s aromatic proton adjacent to sulphonic acid group

8.20 2H, q, j = 16Hz vinyl proton between sulphonic acid groups.

Example 3

Step d): 4-Acetylamino-4'-vinylsulphonylstilbene-2,2'-disulphonic acid sodium salt

47.7g of 30% vinyl sulphonic acid are added dropwise at room temperature to 189g of acetic anhydride and the resulting solution mixed with the 118g of red filter cake obtained as described in Example 1 , steps a) to c). To the resulting mixture 433g of acetic anhydride are then added dropwise over 2 hours, followed by 10Og of glacial acetic acid and then by the careful addition of 16.8g of sodium bicarbonate, in portions, to keep foaming under control. 0.1g of Pd(dba)₂ is then added, whereupon, from the reddish brown suspension, vigorous gas evolution immediately commences and the temperature rises. Gas evolution continues for approximately 5 hours, during which time the temperature is maintained at 50°C. After no further diazonium salt can be detected by testing with alkaline H-acid solution, the green suspension is cooled, filtered with suction and the resulting filter cake washed with glacial acetic acid, dried and used directly for the next reaction step.

Step e): Hydrolysis of the amide.

The moist or dried product obtained from the previous step d) is slurried in 150ml of 20% aqueous sodium hydroxide solution and heated to 120°C with stirring. After stirring at this temperature for 3 hours, the mixture is cooled to 60°C, the pH adjusted to 7 by the addition of 60% sulphuric acid, clarified and the resulting yellowish brown solution evaporated to dryness. Step f): Diazotisation of 4-amino-4'-vinylsulphonylstilbene-2,2'disulphonic acid.

The product obtained in the previous reaction step is dissolved in 100ml of water and treated with 20g of 35% aqueous sodium nitrite solution. The resulting solution is then added over 1 hour with external cooling at 10-15°C to a solution of 41 g of 60% sulphuric acid and 50ml of water. After stirring for a further 30 minutes at this temperature, the excess nitrite is checked and, if necessary, neutralized by the addition of a little sulphamic acid. The suspension is then filtered to yield approximately 85g of red filter cake, which is used immediately for the next reaction step.

Step q): Preparation of compound (103).

The 85g of filter cake obtained in the previous step f) are slurried in 50ml of glacial acetic acid and cooled to 20°C. 178g of acetic anhydride are then added dropwise over 2 hours, followed by the careful addition of 16.8g of sodium bicarbonate, in portions, to keep foaming under control. To the reaction mixture are then added 0.1 g of Pd(dba)₂ and 8g of acrylamide, whereupon gas evolution commences immediately and the temperature rises. Gas evolution continues for approximately 5 hours, the temperature being maintained at 35°C during this time. After no further diazonium salt can be detected by testing with alkaline H-acid solution, the yellow suspension is cooled, filtered with suction, washed with glacial acetic acid and dried to yield 46g of product. Purification by recrystallization from water/methanol yields the compound of formula (103), characterized by the following ¹H-NMR spectral data recorded in D₆-DMSO:

6.65 1 H, d, j = 16Hz vinyl proton

6.88 2H, q, j = 16Hz vinyl protons

7.10 1 H, s, amide proton

7.40 1 H, d, j = 16Hz vinyl proton

7.55 2H, t, j = 8Hz aromatic protons

7.63 3H, m, aromatic protons and amide proton

7.85 1 H, s aromatic proton adjacent to sulphonic acid group

8.05 1 H, s aromatic proton adjacent to sulphonic acid group

8,20 2H, q, j = 17Hz vinyl proton between sulphonic acid groups. Example 4

Following the procedure described in Example 3, but replacing the 8g of acrylamide by 9.4g of methyl acrylate in step g), there are obtained, after recrystallization from water/methanol, 50g of the compound of formula (104), characterized by the following ¹H-NMR spectral data recorded in D₆-DMSO:

3.75 3H,s methyl group

6.55 1 H, d, j = 16Hz vinyl proton

6.88 2H, q, j = 16Hz vinyl protons

7.55 1H, d, j = 8Hz aromatic proton

7.65 1 H, d, j = 16Hz vinyl proton

7.65 2H, m, j = 8Hz aromatic protons

7.75 1 H, d, j = 8Hz aromatic proton

7.82 1 H, s aromatic proton adjacent to sulphonic acid group

8.00 1 H, s aromatic proton adjacent to sulphonic acid group

8.20 2H, q, j = 16Hz vinyl protons between sulphonic acid groups.

Example 5

Step d): 4-Acrylic acid 4'-acetylaminostilbene-2,2'-disulphonic acid sodium salt.

The 118g of filter cake obtained from step c) of Example 1 are slurried in 50g of glacial acetic acid and the suspension cooled to 20°C. 408g of acetic anhydride are then added dropwise over 2 hours with stirring, followed by 16.8g of sodium bicarbonate in portions, foaming being kept under control. To the reaction mixture 0.1 g of Pd(dba)₂ and 7.9g of acrylic acid are then added, whereby vigorous gas evolution immediately commences and the temperature rises. Gas evolution continues for approximately 5 hours, during which time the temperature is maintained at 50°C. After no further diazonium salt can be detected by reaction with alkaline H-acid, the greenish yellow suspension is cooled, filtered, washed with glacial acetic acid and dried.

Step e : Hydrolysis of the amide.

The moist or dried product obtained from the previous step d) is slurried in 150ml of 20% aqueous sodium hydroxide solution and heated to 120°C with stirring. After stirring at this temperature for 3 hours, the mixture is cooled to 60°C, the pH adjusted to 7 by the addition of 60% sulphuric acid and the resulting suspension filtered and dried to yield approximately 41 g of greenish yellow solid.

Step D: Diazotisation of 4-acrylic acid 4'-aminostilbene-2,2'-disulphonic acid.

The product obtained in the previous reaction step is slurried in a mixture of 100ml of water and 41 g of 60% sulphuric acid and cooled to 15°C. A solution of 20g of 35% aqueous sodium nitrite is then added over 1 hour with external cooling at 10-15°C. After stirring for a further 30 minutes at this temperature, the excess nitrite is checked and, if necessary, neutralized by the addition of a little sulphamic acid. The suspension is then filtered to yield approximately 128g of red filter cake, which is used immediately for the next reaction step.

Step q): Preparation of compound (105).

The 128g of filter cake obtained in the previous step f) are slurried in 50ml of glacial acetic acid and cooled to 20°C. 426g of acetic anhydride are then added dropwise over 2 hours, followed by the careful addition of 16.8g of sodium bicarbonate, in portions, to keep foaming under control. To the reaction mixture are then added 0.1 g of Pd(dba)₂ and 8g of acrylamide, whereupon gas evolution commences immediately and the temperature rises. Gas evolution continues for approximately 5 hours, the temperature being maintained at 45°C during this time. After no further diazonium salt can be detected by testing with alkaline H-acid solution, the yellow suspension is cooled, filtered with suction, washed with glacial acetic acid and dried to yield 41 g of product. Purification by recrystallization from water/methanol yields the compound of formula (105), characterized by the following ¹H-NMR spectral data recorded in D₆-DMSO:

6.50 1 H, d, j = 16Hz vinyl proton

6.65 1 H, d, j = 16Hz vinyl proton

7.10 1 H, s, amide proton

7.40 1 H, d, j = 16Hz vinyl proton

7.60 1 H, d, j = 16Hz vinyl proton

7.70 5H, m, aromatic protons and amide proton

7.95 1 H, s aromatic proton adjacent to sulphonic acid group

8.00 1 H, s aromatic proton adjacent to sulphonic acid group

8.20 2H, q, j = 17Hz vinyl protons between sulphonic acid groups.

Example 6

Following the procedure described in Example 5, but replacing the 8g of acrylamide by 11 g of dimethyl acrylamide in step g), there are obtained 63g of the compound of formula (106), which, after recrystallization from water/methanol, is characterized by the following ¹ H-NMR spectral data recorded in D₆-DMSO: 3.00 3H,s methyl group

3.20 3H,s methyl group

6.50 1 H, d, j ^•= 16Hz vinyl proton

7.10 1H, s, vinyl proton

7.45 1H, d, j = 16Hz vinyl proton

7.52 1 H, d, j = 16Hz vinyl proton

7.60 4H, m, aromatic protons

7.95 1 H, s aromatic proton adjacent to sulphonic acid group

8.00 1 H, s aromatic proton adjacent to sulphonic acid group

8.25 2H, q, j = 16Hz vinyl protons between sulphonic acid groups.

Example 7

Step d): 4-Vinylphosphonic acid 4'-acetylaminostilbene-2,2'-disulphonic acid sodium salt.

12g of vinylphosphonic acid are added dropwise to 190g of glacial acetic acid at room temperature, followed by the 118g of filter cake obtained from step c) of Example 1. 233g of acetic anhydride are then added dropwise over 2 hours with stirring, followed by a further 100g of glacial acetic acid and then by 16.8g of sodium bicarbonate, in portions, foaming being kept under control. To this reaction mixture, 0.1g of Pd(dba)₂ is then added, whereby vigorous gas evolution immediately commences and the temperature rises. Gas evolution continues for approximately 5 hours, during which time the temperature is maintained at 50°C. After no further diazonium salt can be detected by reaction with alkaline H-acid, the green suspension is cooled, filtered, washed with glacial acetic acid and dried. Step e): Hydrolysis of the amide.

The moist or dried product obtained from the previous step d) is slurried in 150ml of 20% aqueous sodium hydroxide solution and heated to 120°C with stirring. After stirring at this temperature for 3 hours, the mixture is cooled to 60°C, the pH adjusted to 7 by the addition of 60% sulphuric acid and the resulting yellowish brown solution evaporated to dryness.

Step f): Diazotisation of 4-vinylphosphonic acid 4'-aminostilbene-2,2'-disulphonic acid.

The product obtained in the previous reaction step is dissolved in 100ml of water and 20g of 35% aqueous sodium nitrite added. The resulting solution is then added to a mixture of 50ml of water and 41 g of 60% sulphuric acid over 1 hour with external cooling at 10-15°C. After stirring for a further 30 minutes at this temperature, the excess nitrite is checked and, if necessary, neutralized by the addition of a little sulphamic acid. The suspension is then filtered to yield approximately 85g of reddish brown filter cake, which is used immediately for the next reaction step.

Step g): Preparation of compound (107).

The 85g of filter cake obtained in the previous step f) are slurried in 50ml of glacial acetic acid and cooled to 20°C. 178g of acetic anhydride are then added dropwise over 2 hours, followed by the careful addition of 16.8g of sodium bicarbonate, in portions, to keep foaming under control. To the reaction mixture are then added 0.1 g of Pd(dba)₂ and 10g of dimethyl acrylamide, whereupon gas evolution commences immediately and the temperature rises. Gas evolution continues for approximately 5 hours, the temperature being maintained at 35°C during this time. After no further diazonium salt can be detected by testing with alkaline H-acid solution, the yellow suspension is cooled, filtered with suction, washed with glacial acetic acid and dried to yield 46g of product. Purification by recrystallization from water/methanol yields the compound of formula (107), characterized by the following ¹H- NMR spectral data recorded in D₆-DMSO:

3.00 3H,s methyl group

3.20 3H,s methyl group

6.50 1 H, d, j = 16Hz vinyl proton 6.80 2H, q, j = 16Hz vinyl protons

7.40 1 H, d, j = 16Hz vinyl proton

7.50 2H, t, j = 8Hz aromatic protons

7.60 2H, m, aromatic protons

7.80 1 H, s aromatic proton adjacent to sulphonic acid group

8.00 1 H, s aromatic proton adjacent to sulphonic acid group

8.20 2H, q, j = 16Hz vinyl protons between sulphonic acid groups.

Application Examples

A wood-free base paper containing neither fluorescent whitening agent nor dyestuff and having a brightness of 83.8 is used as test substrate.

To a coating colour containing 60 parts of calcium carbonate and 40 parts of china clay are added 9 parts of SBR-latex and 0.25 parts of polymeric acrylic acid, followed by 1 part of polyvinyl alcohol. The pH of the coating colour is then adjusted to 9.0 with sodium hydroxide solution and 0.2g of the appropriate compound of the invention are stirred in. With the aid of a laboratory hand-coater, sufficient coating is applied to the base paper in order that, after drying and climatizing, a coat weight of 12 g/m² results.

Whiteness and fluorescence are then measured according to CIE and ISO respectively. The results of the measurements are shown in the following Table 1 :

Table 1

Claims

1. A compound of the formula

in which

X and Y are different and each represents -COORT , -CONR₂R₃, wherein

R_L R₂ and R₃ each, independently, represent hydrogen, a Cι.-C₁₈alkyl or a C₂-C₁₈alkenyl residue, which is unsubstituted or substituted by one or more hydroxy, thiol, amino, cyano,

C_rC₄alkoxy, -COOC C₄alkyl or sulphone groups; -CN, phenyl, which is unsubstituted or substituted by one or more C C₄alkyl or CrC^alkoxy groups, halogen, SO₃M or -CN; SO₃M or PO₃M₂ and

M represents H, Na, Li, K, Ca, Mg, ammonium, or ammonium that is mono-, di-, tri- or tetrasubstituted by C C₄alkyl, C₂-C hydroxyalkyl or a mixture thereof.

2. A compound according to claim 1 , in which X represents -COOR-, -CONR₂R₃, wherein

R₁₍ R₂ and R₃ each, independently, represent hydrogen, a CrC₁₈alkyl or a C₂-C₁₈alkenyl residue, which is unsubstituted or substituted by one or more hydroxy, thiol, amino, cyano,

C_rC₄a!koxy, -COOC C₄a\kyl or sulphone groups; -CN, phenyl, which is unsubstituted or substituted by one or more C_rC₄alkyl or C C alkoxy groups, halogen, SO₃M or -CN; -SO₃M or -PO₃M₂ and

Y represents -COOR., -CONR₂R₃, wherein

R-i, R₂ and R₃ each, independently, represent hydrogen, a C_rC₁₈alkyl or a C₂-C₁₈alkenyl residue, which is unsubstituted or substituted by one or more hydroxy, thiol, amino, cyano,

C_rC₄alkoxy, -COOC C alkyl or sulphone groups; S0₃M or PO₃M₂,

M being as defined in claim 1.

3. A compound according to claims 1 or 2 in which X represents -COOH, -COOC C₄alkyl, -CONH₂, -CON(C C₄alkyl)₂, -CN, phenyl, which is unsubstituted or substituted by C_rC₄alkyl or C C₄alkoxy groups or by halogen; -SO₃M or - PO₃M₂ and

Y represents -COOH, -COOC_rC₄alkyl, -CONH₂, -CON(C_rC₄alkyl)₂ or SO₃M, M being as previously defined.

4. A compound according to any one of the preceding claims, in which

Y represents -COOH, -COOC_rC₄alkyl, -CONH₂, -CON(C_rC₄alkyl)₂ or SO₃M and M is hydrogen, K or Na.

5. A compound according to any one of the preceding claims, in which

X represents -COOH, -COOCH₃, -COOC₂H₅, -CONH₂, -CON(CH₃)₂, -CN, phenyl, -SO₃M or - PO₃M₂,

Y represents -CONH≥, -CON(CH₃)₂ or SO₃M and M is hydrogen, K or Na.

6. A process for the preparation of the compound of formula (1) characterized by the following reaction sequence: a) Treatment of 4-amino 4'-nitrostilbene-2,2'-disulphonic acid or salts thereof with an acylating agent; b) reduction of the nitro group to an amino group; c) diazotisation of the resulting aminostilbene compound; d) reacting the resulting diazonium salt with a compound of formula

Y-CH=CH₂ (2)

in a solvent and in the presence of a palladium catalyst and an inorganic salt, resulting in the introduction of the group Y; e) hydrolysis of the acyl protecting group; f) diazotisation of the resulting aminostilbene compound and g) reacting the resulting diazonium salt with a compound of formula X-CH=CH₂ (3)

7. Use of the compounds of formula (1) according to claim 1 as optical brightening agents for synthetic or natural organic materials.

8. Use of the compounds of formula (1) according to claim 1 as optical brightening agents for paper in pulp, size-press or coating applications.

9. Use of the compounds of formula (1) according to claim 1 as optical brightening agents for textile materials.

10. Use of the compounds of formula (1) according to claim 1 as optical brightening agents in detergent compositions.