Fluorescent whitening agents and uses thereof

Abstract

The present invention provides a fluorescent whitening agent or optical brightener of formula (I) wherein: A is C(R1R2)(CH2)n or an optionally substituted aromatic or heteroaromatic ring fused with N and X wherein N and X are respectively bound to adjacent carbon atoms on the ring; X is O, S, or NR3; B is an optionally substituted heterocycle; and wherein: when A is C(R1R2)(CH2)n, R1 is H, CH2OH, COY, or an optionally substituted heterocycle, R2 is H, or CH2OH and wherein n is 1 or 2; Y (when present) is independently OM, OR3, O(CH2)qSO3M, NHOH, NHR3, or NR3 2, wherein, M is selected from an alkali metal or an alkaline earth metal, and q is 1 to 5; and the or each R3 is independently hydrogen, a linear or branched alkyl, a linear or branched alkenyl, an aryl, a heterocycle, an alkaryl, an aralkyl, a linear or branched alkyl carboxylic acid, a linear or branched alkyl carboxylate, a linear or branched alkyl nitrile, a linear or branched alkyl alcohol, a linear or branched alkyl alcohol polyol, an acyl, a hydroxyalkylamine, a linear or branched alkylamine, a polyhydric alcohol, a sugar, a linear or branched alkyl ether, a linear or branched polyether, a polyester having from 2 to 1000 repeat units, or a polyoxyalkylene chain having from 2 to 1000 repeating units, and alternatively, NR3 2 represents a heterocyclic ring, e.g. morpholine. Also provided are formulations, compositions and uses thereof.

Description

[0001] TSW-GFI 0368 P13584WO

[0002] FLUORESCENT WHITENING AGENTS AND USES THEREOF

[0003] TECHNICAL FIELD

[0004] The present invention concerns fluorescent whitening agents (FWAs) or optical brighteners comprising a pendant heterocycle, and the uses thereof.

[0005] BACKGROUND

[0006] Fluorescent whitening agents (FWAs) or optical brighteners are chemical compounds that absorb light in the ultraviolet and violet region of the electromagnetic spectrum and re-emit light in the blue region. FWAs or optical brighteners are used to enhance the appearance of different materials, by causing a "whitening" effect, making materials appear a brighter white colour by increasing the overall amount of blue light emitted. Although expensive, FWAs or optical brighteners can be used at low cost due to their effectiveness at low loading levels.

[0007] Current industry standard FWAs or optical brighteners, include DSPB (CAS 27344-41-8) and derivatives of the bis-benzoxazole type, such as the bis-benzoxazolyl-stilbene, OBI (CAS 1533-45-5) and the bis- benzoxazolyl-thiophene, OB (CAS 7128-64-5). In the laundry detergent industry, industry standard FWAs or optical brighteners include DAS-1 (CAS 16090-02-1), DAS-2 (CAS 16470-24-9), DSPB (CAS 27344-41-8), and FB28 (CAS 4404-43-7). These molecules have large conjugated aromatic systems of a high molecular mass, which have limited capability to be oxidised or hydrolysed, making them less biodegradable.

[0008] Conventional FWAs or optical brighteners have several disadvantages, including that they are conventionally manufactured from fossil fuel derived sources, they are typically non-biodegradable, and they are typically toxic to the aquatic environment.

[0009] There has therefore been a move to develop FWAs or optical brighteners that are biodegradable and produced from renewable sources. Examples of conventional FWAs or optical brighteners known in the art include:

[0010] CN114507230 describes a bicyclic pyridone derivative, as well as a synthesis method and application thereof. The bicyclic pyridone compounds can be synthesized through cheap and TSW-GFI 0368 P13584WO low-toxicity citric acid, the production cost is low, and the synthesis. The compounds have good antibacterial activity and fluorescence characteristics.

[0011] RSC Adv., 2015, 5, 34795, discloses 4-oxo-l-thia-3a-aza-6-indancarboxylic and 5-oxo-2,3- dihydro-5H-[l,3]oxazolo[3,2-o]pyridine-7-carboxylic acid via condensation of citric acid with amino acids or derivatives thereof, but with no suggestion of any potential application. The first mentioned compound is also disclosed in CN108101929 and in CN104530089 in the context of fluorescent imaging agents for medical use.

[0012] Conventional FWAs or optical brighteners have several disadvantages, which include that they are conventionally manufactured from fossil fuels; they are typically non-biodegradable; and that they are typically toxic in the aquatic environment.

[0013] The present invention seeks to overcome the aforementioned disadvantages and provide improved FWAs or optical brighteners, with comparable functionality and fewer environmental drawbacks.

[0014] SUMMARY OF THE INVENTION

[0015] According to a first aspect of the invention there is provided a fluorescent whitening agent or optical brightener of formula (I) having the structure: wherein:

[0016] A is C(R1R2)(CH2)n / or an optionally substituted aromatic or heteroaromatic ring fused with N and X wherein N and X are respectively bound to adjacent carbon atoms on the ring;

[0017] X is O, S, or NR3;

[0018] B is an optionally substituted heterocycle; and wherein: when A is C(R1R2)(CH2)n, R1is H, CH2OH, COY, or an optionally substituted heterocycle, R2is H or CH2OH and wherein n is 1 or 2; TSW-GFI 0368 P13584WO

[0019] Y (when present) is independently OM, OR3, O CF JqSOaM, NHOH, NHR3, or NR wherein, M is selected from an alkali metal or an alkaline earth metal, and q is 1 to 5; and the or each R3is independently hydrogen, a linear or branched alkyl, a linear or branched alkenyl, an aryl, a heterocycle, an alkaryl, an aralkyl, a linear or branched alkyl carboxylic acid, a linear or branched alkyl carboxylate, a linear or branched alkyl nitrile, a linear or branched alkyl alcohol, a linear or branched alkyl alcohol polyol, an acyl, a hydroxyalkylamine, a linear or branched alkylamine, a polyhydric alcohol, a sugar, a linear or branched alkyl ether, a linear or branched polyether, a polyester having from 2 to 1000 repeat units, or a polyoxyalkylene chain having from 2 to 1000 repeating units, and alternatively, NR32 represents a heterocyclic ring.

[0020] In particular embodiments, the FWA or optical brightener of formula (I) may be selected from, any one of, formula (la), formula (lb), or formula (Ic): wherein

[0021] B is an optionally substituted heterocycle;

[0022] X may be S, O, or -NR3; and the or each R1may be independently H, -C(O)ZR3, or an optionally substituted heterocycle, wherein Z may be selected from O, S, NH, or NR3, and the or each R3is independently hydrogen, a linear or branched alkyl, a linear or branched alkenyl, an aryl, a heterocycle, an alkaryl, an aralkyl, a linear or branched alkyl carboxylic acid, a linear or branched alkyl carboxylate, a linear or branched alkyl nitrile, a linear or branched alkyl alcohol, a linear or branched alkyl alcohol polyol, an acyl, a hydroxyalkylamine, a linear or branched alkylamine, a polyhydric alcohol, a sugar, a linear or branched alkyl ether, a linear or branched polyether, a polyester having from 2 to 1000 repeat units, or a polyoxyalkylene chain having from 2 to 1000 repeating units, and alternatively, NR32 represents a heterocyclic ring.

[0023] According a second aspect of the invention there is provided a composition comprising the FWA or optical brightener according to the first aspect of the invention, for use in a laundry application. TSW-GFI 0368 P13584WO

[0024] The composition may comprise a multiplicity of different FWA or optical brightener compounds. For example, the composition may comprise at least one, at least two, at least three or at least four different FWA or optical brightener compounds according to the invention.

[0025] The composition may comprise additional adjuvants or components.

[0026] The addition of further adjuvants or components may be necessary to further compatibilise the FWA or optical brightener with the composition, or to modify the final composition's properties for a particular application.

[0027] According to a third aspect of the invention there is provided a fluorescent whitening or optical brightening formulation of the composition according to the second aspect of the invention, for use in a laundry application.

[0028] The FWA or optical brightener may be formulated in combination with further adjuvants, additives, and / or components to alter and / or control the properties of the formulation or composition.

[0029] Typically, such formulation involves the provision of the active ingredient (FWA or optical brightener) in conjunction with at least one ancillary compound typically present in fluorescent whitening or optical brightening formulations. Such ancillary compounds may be selected from, for example, one or more of detergent(s), bleach(es), carrier compound(s), stabilizer(s), and / or dispersant(s).

[0030] According to a fourth aspect of the invention there is provided the use of the compounds according to the first aspect of the invention as FWAs or optical brighteners.

[0031] According to a fifth aspect of the invention there is provided a method for providing fluorescent whitening or optical brightening to a laundry substrate comprising contacting the substrate with the FWA or optical brightener according to the first aspect of the invention, or the fluorescent whitening or optical brightening formulation according to the third aspect of the invention, under conditions effective to allow chemical and / or physical bonding of the one or more compounds onto or into the substrate. TSW-GFI 0368 P13584WO

[0032] Any feature discussed in reference to one of the aspects of the present invention applies equally to all of the other aspects discussed herein.

[0033] DETAILED DESCRIPTION

[0034] Fluorescent whitening agents (also referred to as FWAs) and optical brighteners, are additives widely used in the laundry industry to enhance the whiteness, brightness, and visual appeal of various products, and / or the appearance of the surface to which they are applied. FWAs are compounds that absorb invisible ultraviolet (UV) light and re-emit it as visible blue light (wavelength 400 - 500 nm), making textiles look whiter and brighter.

[0035] Current industry standard FWAs and optical brighteners, including OB and OB-1, have large conjugated aromatic systems of high molecular mass, which have limited capability to be oxidised or hydrolysed, making them less biodegradable. As a result, current industry standard FWAs are raising environmental concern as they are not only detected as pollutants in urban wastewaters (Marine Pollution Bulletin, 2022, 178, 113559) but also in indoor environments (Environ. Sci. Technol., 2022, 56, 10131-10140). In the personal care industry, where products often either end up in wastewater or in landfill, it is key that FWAs and optical brighteners are environmentally friendly.

[0036] Pyridone and citrazinic acid derivatives are known to achieve similar n-electron counts to the large conjugated aromatic systems of industry standards and also emit visible blue light in the 420 - 470 nm range, whilst also being bio-derivable. These derivatives, which have substantially lower molecular weights, achieve this effect through the incorporation of heteroatoms, such as nitrogen and oxygen. Therefore, the pyridone and citrazinic acid derivatives of the invention can be synthesized through cheap and low toxicity starting materials, meaning that the production cost is low, and the synthesis process is simple.

[0037] Properties of Fluorescent Whitening Agents

[0038] According to the invention there is provided a compound of formula (I) as a fluorescent whitening agent or optical brightener.

[0039] The excitation and de-excitation properties of the FWAs or optical brighteners in accordance with the invention may be mechanistically understood with reference to prior art studies, such as Sci. Adv., TSW-GFI 0368 P13584WO

[0040] 2015, 5, 34795, which attributes the fluorescence in the 420 - 470 nm range of similar compounds to JI*- n transitions in the same carbon-oxygen double bond, as is found in scaffolds based on pyridone and citrazinic acid. The carboxyl groups, particularly the carboxylic acid groups, present in the structures of the present invention are believed to contribute to the required number of n-electrons associated with fluorescence in the desired range.

[0041] The FWA or optical brightener compounds of the invention are advantageous over current industry standards as they provide comparable fluorescence using a smaller compound, with a lower molecular weight. Additionally, further functionalisation of the compound formulae to modulate end-application performance may be readily achieved, with little effect on the overall fluorescent behaviour of the FWA or optical brightener.

[0042] Additionally, the smaller molecular weight, can lead to a lower loading of the FWA or optical brightener in the final formulation or composition. Lower loadings can mitigate any potential adverse effects associated with the compound.

[0043] The FWAs or optical brighteners of the invention have smaller fluorescent cores and are thus more biodegradable as they are more prone to biological attacks, whilst still providing enough stability to oxidation and hydrolysis to be of use in the intended applications.

[0044] In embodiments of the invention, the molecular weight of the FWA or optical brightener compounds may be below about 1400 Da, below about 1200 Da, below about 1000 Da, below about 750 Da, below about 500 Da, below about 400 Da, below about 300 Da, or below about 200 Da. In embodiments of the invention, the molecular weight of the FWA and optical brightener compounds may be from about 200 Da to about 1400 Da, from about 200 Da to about 1200 Da, from about 200 Da to about 1000 Da, from about 200 Da to about 750 Da, from about 200 Da to about 500 Da, from about 200 Da to about 400 Da, or from about 200 Da to about 300 Da. In preferred embodiments, the molecular weight of the FWA and optical brightener compounds is below about 500 Da.

[0045] In embodiments of the invention, the quantum yield of the FWA or optical brightener may be at least about 25%, may be at least about 30%, at least about 40%, at least about 50%, at least about 60%, or at least about 70%. In embodiments of the invention, the quantum yield of the FWA and optical brightener compounds may be from about 25% to about 100%, from about 30% to about 80%, from about 40% to about 80%, from about 50% to about 80%, from about 60% to about 80%, or from about TSW-GFI 0368 P13584WO

[0046] 70% to about 80%. In preferred embodiments, the quantum yield of the FWA and optical brightener compounds is at least about 60%.

[0047] As used herein, the term "quantum yield" will be understood to mean the ratio of the number of photons emitted to the number of photons absorbed. Therefore, the quantum yield is a dimensionless quantity representing the efficiency of a light-induced process, such as fluorescence.

[0048] Advantageously, the FWAs or optical brighteners of the present invention exhibit much higher relative quantum yields than current industry standards. For example, only DSPB gives a comparable value of greater than 70%.

[0049] As a result, the FWAs or optical brighteners contained within the formulations or compositions of the invention are advantageous over current industry standards as they provide comparable fluorescence whilst using a smaller compound, with a lower molecular weight. Additionally, further functionalisation of the structures of the invention to modulate application performance may be readily achieved, with little effect on the fluorescent behaviour of the FWA or optical brightener.

[0050] The FWA or optical brightener compounds, according to the present invention, have excellent chemical stability at relatively high pH, for example the typical pH of a laundry detergent formulation. They also have very suitable thermal stability in such applications, being preparable (see below) by synthetic methods involving temperatures of up to 130°C.

[0051] The FWA or optical brightener compounds may be stable at a relatively high pH, for example from about pH 7 to about pH 10, or about pH 7.5 to about pH 9.5, typical conditions in a laundry wash.

[0052] Advantageously, these pHs are within the typical conditions in a laundry wash and are a pH range where typical enzymes work to remove stains. Further advantageously, the FWAs are typically stable at temperatures used for the manufacture of detergents (e.g. slurry process for powders involving spray-drying with hot air) or a laundry wash itself.

[0053] Chemical Structure of Fluorescent Whitening Agents

[0054] According to the invention, the FWA or optical brightener is of formula (I): TSW-GFI 0368 P13584WO wherein:

[0055] A is C(R1R2)(CH2)n / or an optionally substituted aromatic or heteroaromatic ring fused with N and X wherein N and X are respectively bound to adjacent carbon atoms on the ring;

[0056] X is O, S, or NR3;

[0057] B is an optionally substituted heterocycle; and wherein: when A is C(R1R2)(CH2)n, R1is H, CH2OH, COY, or an optionally substituted heterocycle, R2is H, or CH2OH and wherein n is 1 or 2;

[0058] Y (when present) is independently OM, OR3, O(CH2)qSO3M, NHOH, NHR3, or NR32, wherein, M is selected from an alkali metal or an alkaline earth metal, and q is 1 to 5; and the or each R3is independently hydrogen, a linear or branched alkyl, a linear or branched alkenyl, an aryl, a heterocycle, an alkaryl, an aralkyl, a linear or branched alkyl carboxylic acid, a linear or branched alkyl carboxylate, a linear or branched alkyl nitrile, a linear or branched alkyl alcohol, a linear or branched alkyl alcohol polyol, an acyl, a hydroxyalkylamine, a linear or branched alkylamine, a polyhydric alcohol, a sugar, a linear or branched alkyl ether, a linear or branched polyether, a polyester having from 2 to 1000 repeat units, or a polyoxyalkylene chain having from 2 to 1000 repeating units, and alternatively, NR32 represents a heterocyclic ring, e.g. morpholine.

[0059] By "aromatic" compound, we mean a compound of the class of cyclic (ring-shaped) organic molecules characterised by a specific arrangement of alternating single and double bonds within the ring, leading to a stable, planar structure, and with a "delocalised" n-electron system, where electrons are not confined to specific bonds but rather spread out over the entire ring, contributing to the compound's stability through conjugation. These compounds typically comprise an aryl group. An aryl group is a monocyclic or polycyclic ring system having from 5 to 20 carbon atoms. The aryl group is preferably a "Cs-12 aryl group" and is an aryl group constituted by 6, 7, 8, 9, 10, 11 or 12 carbon atoms and includes condensed ring groups such as monocyclic ring group, or bicyclic ring group and the like. Specifically, examples of "Cg-io aryl group" include phenyl group, biphenyl group, indenyl group, naphthyl group or azulenyl group and the like. It should be noted that condensed rings such as indan and tetrahydro naphthalene are also included in the aryl group. TSW-GFI 0368 P13584WO

[0060] By "heteroaromatic" compound, we mean an aromatic compound which contains heteroatoms (e.g. O, N, S) as part of the cyclic conjugated n-system. These compounds typically comprise a heteroaryl group. A heteroaryl group is an aryl group having, in addition to carbon atoms, from one to four ring heteroatoms which are preferably selected from O, S, N, P and Si. A heteroaryl group preferably has from 5 to 20, more preferably from 5 to 14 ring atoms. Specifically, examples of a heteroaryl group include pyridine, imidazole, methylimidazole and dimethylaminopyridine.

[0061] By "optionally substituted," we mean that a compound which can be substituted may be optionally substituted; that is, we do not mean that only the first species mentioned in the list may be optionally substituted. The term optionally substituted when used herein means unsubstituted or substituted with a suitable group. Suitable groups will be known to the skilled person. Generally, such groups would not significantly detrimentally affect the function of the substituted group or of a larger moiety to which the substituted group is attached. In some cases, the skilled person would expect the substituent to improve the function of the substituted group.

[0062] As used herein, the term "alkali metal" refers to a Group 1 metal, which may be selected from lithium (K), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), or francium (Fr).

[0063] As used herein, the term "alkaline earth metal" refers to a Group 2 metal, which may be selected from beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), or radium (Ra).

[0064] As used herein, the term "alkyl" refers to a linear or branched hydrocarbon chain group consisting solely of carbon and hydrogen atoms, containing no unsaturation, and having the specified number of carbon atoms, which is attached to the rest of the molecule by a single bond. In embodiments of the invention, an alkyl group is preferably a "C1-34 alkyl group", that is an alkyl group that is a linear or branched chain with 1 to 34 carbons. The alkyl group therefore has 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 , 28, 29, 30, 31, 32, 33, or 34 carbon atoms. Preferably, when a linear alkyl, it is a C7-C34 alkyl, a C8-C34 alkyl, or a C9-C34 alkyl, and when a branched alkyl, it is a C1-C34 alkyl. Specifically, examples of "C1-34 alkyl group" include, but are not limited to, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl TSW-GFI 0368 P13584WO group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, n-hexyl group, l-ethyl-2-methylpropyl group, 1,1,2-trimethylpropyl group, 1-ethylbutyl group, 1-methylbutyl group, 2-methylbutyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 2,2- dimethylbutyl group, 1,3-dimethylbutyl group, 2,3-dimethylbutyl group, 2-ethylbutyl group, 2- methylpentyl group, 3-methylpentyl group, 3,5-dimethylhexyl group, 2-ethylhexyl group, 8- methylnonyl group, 4-methyldecyl group, 2,4,7-trimethyloctyl group, 4,6-dimethylnonyl group, and the like.

[0065] As used herein, the term "alkenyl" refers to a linear or branched hydrocarbon chain group consisting solely of carbon and hydrogen atoms, containing one or more carbon-carbon double bonds, and having the specified number of carbon atoms, which is attached to the rest of the molecule by a single bond. Alkenyl groups are preferably "C2-30 alkenyl", more preferably "C2-20 alkenyl", even more preferably "C2-15 alkenyl", even more preferably "C2-10 alkenyl", even more preferably "C2-8 alkenyl", most preferably "C2-6 alkenyl" groups, respectively.

[0066] As used herein, the term "alicyclic" refers to a saturated or partially unsaturated cyclic aliphatic monocyclic or polycyclic (including fused, bridging and spiro-fused) ring system which has from 3 to 20 carbon atoms, that is an alicyclic group with 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms. Preferably, an alicyclic group has from 3 to 15, more preferably from 3 to 12, even more preferably from 3 to 10, even more preferably from 3 to 8 carbon atoms, even more preferably from 3 to 6 carbons atoms. The term "alicyclic" encompasses cycloalkyl, cycloalkenyl and cycloalkynyl groups. It will be appreciated that the alicyclic group may comprise an alicyclic ring bearing one or more linking or non-linking alkyl substituents, such as -Cl- -cyclohexyl. Specifically, examples of the C3-20 cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl and cyclooctyl.

[0067] As used herein, the term "heterocyclic" refers to an alicyclic group as defined above which has, in addition to carbon atoms, one or more ring heteroatoms, which are preferably selected from O, S, N, P and Si. Heteroalicyclic groups preferably contain from one to four heteroatoms, which may be the same or different. Heteroalicyclic groups preferably contain from 5 to 20 atoms, more preferably from 5 to 14 atoms, even more preferably from 5 to 12 atoms. Specifically, an example of a heterocyclic group is a morpholine or piperidine group. TSW-GFI 0368 P13584WO

[0068] As used herein, the term "aryl" refers to a monocyclic or polycyclic ring system having from 5 to 20 carbon atoms. An aryl group is preferably a "Ce-iz aryl group" and is an aryl group constituted by 6, 7 , 8, 9, 10, 11 or 12 carbon atoms and includes condensed ring groups such as monocyclic ring group, or bicyclic ring group and the like. Specifically, examples of "Cg-io aryl group" include phenyl group, biphenyl group, indenyl group, naphthyl group or azulenyl group and the like. It should be noted that condensed rings such as indan and tetrahydro naphthalene are also included in the aryl group.

[0069] As used herein, the term "alkaryl" (or "alkylaryl") refers to an aryl group as defined above bonded at any position to an alkyl group as defined above. The point of attachment of the alkylaryl group to a molecule may be via the alkyl portion and thus, preferably, the alkylaryl group is -CHj-Ph or -CH2CH2- Ph. An alkylaryl group can also be referred to as "aralkyl."

[0070] As used herein, the term "alkyl amine" refers to an alkyl group as defined above bonded at any position to an amine group. Specifically, examples of "alkyl amine" include, but are not limited to, aminomethyl, l-(dimethylamino)methyl, 2-(dimethylamino)ethyl, or 5-aminopentyl.

[0071] As used herein, the term "alkyl alcohol" refers to refers to an alkyl group as defined above bonded at any position to a hydroxyl group. As used herein, the term "alcohol polyol" refers to an organic group, such as an alkyl or alkenyl as defined above, containing multiple hydroxyl groups, for example, at least two, at least three, at least four, or at least five hydroxyl groups.

[0072] As used herein, the term "alkyl ether" refers to an -O-alkyl group or -alkyl-O-alkyl group, where alkyl is as defined above. As used herein, the term "polyether" refers to a group comprising repeating chemical units linked together by ether groups (C-O-C). As used herein, the term "polyester" refers to a group comprising repeating chemical units linked together by ester groups (C(O)-O-C).

[0073] As used herein, the term "sugar" refers to a chemical carbohydrate group, which comprises monosaccharides (such as glucose), and complex sugars (such as di-saccharides and polysaccharides). The general formula of simple sugars is CnH2nOn, where n is typically between 3 and 7, for example glucose, whose formula is CgH^Og.

[0074] As used herein, the term "polyoxyalkylene" refers to a polymer chain composed of repeating oxyalkylene (ether) units. Each of the alkylene units may be as defined above. The polyoxyalkylenes may be terminated with a hydrogen, a hydroxyl, an alkyl, an alkoxy, or an alkenyl group as described TSW-GFI 0368 P13584WO above. For example, when terminated by a hydroxyl, the polyoxyalkylene may by selected from polyethylene glycol (PEG), polypropylene glycol, and the like. As used herein, the term "PEG" refers to polyethylene glycol, a polymer formed of repeating units of ethylene glycol. The structure of PEG is commonly expressed as -(O-CHj-CHjJn-OH, where n is the number of repeating units. PEG groups can vary in size and molecular weight, resulting in different physical properties. For example, when terminated by an alkoxy group, the polyoxyalkylene may by selected from methyloxy-polyethylene glycol (MeO-PEG), ethoxy-polyethylene glycol (EtO-PEG), and the like. As used herein, the term "MeO- PEG" refers to a polyethylene glycol that is terminated with a methyl group. The structure of MeO- PEG is expressed as H-(O-CH2-CH2)n-OMe, where n is the number of repeating units.

[0075] In embodiments of the invention, the compound may be a betaine. As used herein, the term "betaine" refers to a compound with a positively charged cationic functional group that bears no hydrogen atom, such as a quaternary ammonium or phosphonium cation (generally: onium ions), and with a negatively charged functional group, such as a carboxylate group that may not be adjacent to the cationic site.

[0076] Thus, in embodiments of the invention when the compound is a betaine, any basic group, such as an amine, may be protonated as a quaternary ammonium cation, and any acidic group, such as a hydroxyl, may be deprotonated as an oxide.

[0077] The side groups may be selected to compatibilise the FWA or optical brighteners for a target formulation. The core is the component that predominantly provides the fluorescence properties, and the side groups, which may be saturated (i.e. comprise no double bonds) or unsaturated (i.e. comprise double bonds), or linear or branched, are selected to compatibilise the compound with a particular formulation and / or application.

[0078] Particular embodiments of the FWAs or optical brighteners will now be described.

[0079] In embodiments where A is an optionally substituted aromatic or heteroaromatic ring, A is preferably a benzene or pyridine ring. The ring may particularly be substituted with an acid, amide or an alkyl group, or a further aromatic or heteroaromatic ring system.

[0080] In some embodiments in accordance with the above, the further aromatic or heteroaromatic ring system may have the general formula of: TSW-GFI 0368 P13584WO wherein A and X may be as defined above.

[0081] In some embodiments in accordance with the above, the further aromatic or heteroaromatic ring system may be preferably selected from:

[0082] In preferred embodiments B may be an optionally substituted single-ring heterocycle or a fused heterocycle. The heterocycle may comprise heteroatoms, including, but not limited to O, S or N.

[0083] In most preferred embodiments, B may be selected from the following:

[0084] The inventors have surprisingly found that FWA or optical brightener compounds with an increased number of aromatic rings provides a flatter structure overall and consequently an improved adsorption onto fabrics, such as cotton, for example, which is useful during laundry processes. TSW-GFI 0368 P13584WO

[0085] Additionally, the use of heteroatoms provides increased electron density, and improved biodegradability versus carbon-based cores.

[0086] In embodiments when R3is alkyl, it may be a linear or branched alkyl.

[0087] In embodiments when R3represents a linear or branched alkyl, R3is preferably selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 1,1-dimethylpropyl, 1,3,3- trimethylpropyl, 2,5-dimethylhexyl, isopropyl, 3-methylpentan-2-yl, 3-methylpentan-3-yl, or tertbutyl. In some particular embodiments R3may be a C1-C34 alkyl.

[0088] In embodiments when R3represents an alkyl alcohol, R3is preferably selected from methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, dodecanol, or stearyl or oleyl alcohol.

[0089] In embodiments when R3represents an aryl, a heterocycle, or an alkaryl, the respective ring may be optionally substituted.

[0090] In embodiments when R3represents an aryl, R3is preferably phenyl, and in embodiments where R3represents alkaryl, R3is preferably selected from benzyl, or ethyl phenyl.

[0091] In embodiments when R3represents a heterocycle, meaning a ring system comprising at least one atom that is not carbon, it is preferably a heteroaryl. Preferably, the at least one atom that is not carbon in the heterocycle is selected from O, N or S. In most preferred embodiments, R3is preferably selected from a triazole, an imidazole, a pyrazole, or an imidazoline.

[0092] In embodiments when R3represents a linear or branched alkyl alcohol, R3is preferably selected from 2-hydroxyethyl, 4-hydroxybutyl, l-hydroxyprop-2-yl, or 2-hydroxyprop-l-yl.

[0093] In embodiments when R3represents a linear or branched alcohol polyol, R3is preferably a diol or triol. In most preferable instances, R3may be selected from 2,3-dihydroxypropyl, or 2-hydroxy-l- (hydroxymethyl)ethyl. In particular embodiments where R3is a branched alkyl alcohol polyol, it may be preferably selected from polyglycerol, polyglycerol derivatives.

[0094] In embodiments when R3is a polyoxyalkylene, it may be selected from PEG or MeO-PEG. In embodiments where R3is PEG, it may have from 2 to 1000 repeat units. More preferably, it has 2 to TSW-GFI 0368 P13584WO

[0095] 20 repeat units. In embodiments where R3is MeO-PEG, it may have from 2 to 1000 repeat units. More preferably, it has 2 to 20 repeat units.

[0096] In embodiments when R3represents a hydroxyalkylamine, R3is preferably selected from triethanolamine, / V-methyldiethanolamine or triisopropanolamine.

[0097] In embodiments where R3represents a polyhydric alcohol, R3is preferably glycerol.

[0098] In embodiments where R3represents a sugar, R3is preferably selected from dextrose, fructose, galactose, glucose, lactose, maltose, or sucrose.

[0099] In embodiments where R3represents a linear or branched alkyl ether, R3is preferably selected from 2-(2-hydroxyethoxy)ethyl, 2-(2-hydroxy-l-methylethoxy)-l-methylethyl, 2-[2-(2-hydroxy-l- methylethoxy)-l-methylethoxy]-l-methylethyl, 3-(3-hydroxypropoxy)propyl, 3-[3-(3- hydroxypropoxy)propoxy]propyl, 4-(4-hydroxybutoxy)butyl, 4-[4-(4-hydroxybutoxy)butoxy]butyl, 2- (2-methoxyethoxy)ethyl, or 2-[2-(2-methoxyethoxy)ethoxy]ethyl.

[0100] In embodiments where R3represents a polyester or a polyoxyalkylene having from 2 to 1000 repeat units, it may be a homopolymer or a copolymer.

[0101] In particular embodiments, when X is NR3, the R3group may function as a linker group between at least two compounds of formula (I). Thus, a group in position R3, may be shared between at least two compounds of formula (I).

[0102] In such an embodiment, for example where R3functions as a linker group between two compounds of formula (I) where X is NR3, the FWA or optical brightener may be of the formula (Ila) or (lib): TSW-GFI 0368 P13584WO

[0103] In exemplary embodiments, the FWA or optical brightener compounds may be selected from: TSW-GFI 0368 P13584WO

[0104] The FWA or optical brightener may be biodegradable.

[0105] The FWA or optical brightener compounds in accordance with the invention are preferably UV stable.

[0106] Synthesis of Fluorescent Whitening Agents

[0107] The FWAs and optical brighteners in accordance with the invention may be synthesised from readily available and bio-renewable starting materials, such as for example, citrazinic acid or citric acid. In some embodiments, the method of synthesis may be water-based or use green chemistry methods.

[0108] As used herein, the term "bio-renewable" refers to materials and resources derived from natural sources, such as plants or animals, i.e. recently living organisms (biomass), that can be replenished at a rate that makes them available for future use. Examples of bio-renewable materials include, but are not limited to, algae, sugars, starches, corns, natural fibres, sugarcanes, beets, citrus fruits, woody plants, cellulosics, lignocelluosics, hemicelluloses, potatoes, plant oils, other polysaccharides such as pectin, chitin, levan, and pullulan, and a combination thereof.

[0109] As used herein, the term "green chemistry" means the design of products and associated processes that reduce or eliminate the use of hazardous substances throughout the entire life cycle of a chemical product. The approach aims to prevent pollution at its source by developing chemicals and processes that are inherently safer for human health and the environment, promoting efficiency in resource and energy use. TSW-GFI 0368 P13584WO

[0110] A general synthesis of the compounds of structure (I) from citric acid is shown below in Scheme 1, where X, A, and Y are as defined above.

[0111] Scheme 1

[0112] As detailed above, in exemplary embodiments of structure (I), the compounds may be selected from, any one of, formula (la), formula (lb) or formula (Ic). A general synthesis for these compounds is shown below in Scheme 2, where Ri, R3, X, A, and Z are as defined above:

[0113] Scheme 2 TSW-GFI 0368 P13584WO

[0114] As shown above, the compounds may be synthesised by conventional methods such as heating citric acid with a second amine building block in the presence of water, with water itself as the major byproduct. Advantageously, water-based synthesis is safer, cleaner, more environmentally friendly, and highly scalable industrially. The skilled person would be able to readily adapt the above to access a range of chemical structures in accordance with formula (I).

[0115] Further synthetic functionalisation of the core units to modify and / or improve substantivity of the resultant FWA or optical brightener compound in the desired formulation or composition or desired application may be readily achieved by a second, facile reaction with either an ethanolamine, ethylene diamine, 2-aminophenol, o-Phenylenediamine. Suitable groups will be known to the skilled person. Generally, such groups would not significantly detrimentally affect the function of the substituted group or of a larger moiety to which the substituted group is attached. In some cases, the skilled person would expect the substituent to improve the function of the substituted group.

[0116] Advantageously, the synthesis of the compounds is highly tuneable, and enables easy alteration of the side groups, increasing the adaptability of compounds to different personal care applications by matching the side groups accordingly.

[0117] In comparison, preparation of existing optical brighteners, such as benchmarks DAS 1, DAS 2 and FB28, require complex synthetic methods comprising 5 synthetic steps, as well as the use of environmentally undesirable materials, such as precious metal catalysts and hazardous materials such as cyanuric chloride. Similarly, the preparation of the optical brightener DSPB requires complex synthetic steps involving environmentally undesirable and / or hazardous materials, such as trimethyl phosphite and dimethylformamide (DMF). Both families of molecules use petrochemical-derived raw materials.

[0118] Uses and Applications

[0119] According to the invention there is provided the use of the compounds of the invention as fluorescent whitening agents or optical brighteners.

[0120] The FWA or optical brightener compounds in accordance with the invention are preferably oxidatively stable in a conventional wash cycle. TSW-GFI 0368 P13584WO

[0121] The FWAs or optical brighteners according to the present invention may be used in a range of applications including, but not limited to, laundry, dishwashing, paper manufacturing, personal care (cosmetics, hair care, etc.), inks, coatings, and adhesives. In these applications, the FWA or optical brightener is able to make materials, for example cotton, appear whiter, whilst also masking yellowing on aging.

[0122] The FWA or optical brightener may be used in all types of formulation, such as liquids, powders, sheets, or bars, in different ratios and loadings as appropriate.

[0123] Due to performance, health, and environmental concerns, fewer than 50 FWAs or optical brighteners are still in mass production for commercial uses. Those remaining have acceptable safety profiles in terms of their toxicity to the environment and human health. However, they remain of concern due to a variety of factors, including a lack of biodegradability, reproductive toxicity concerns, and potential irritation to sensitive skin.

[0124] Biodegradability remains one of the most significant areas of concern as once discharged as wastewater, the FWAs or optical brighteners are released from water treatment plants into open or underground water. The industry standards frequently biodegrade slowly and may end up accumulating in the marine ecosystem, as well as being acutely harmful to aquatic organisms.

[0125] The FWAs or optical brighteners, and compositions and formulations thereof, are derived from naturally derivable cores, such as citric acid and are therefore advantageously biodegradable.

[0126] Advantageously, the FWAs and optical brighteners in accordance with the invention are biodegradable, obviates problems associated with conventional FWAs used in laundry applications.

[0127] Preferably they contain at least one functional group which is not oxidised, or which is only partially oxidised, and thereby is oxidisable or further oxidisable. Preferably they contain at least one hydrolysable group.

[0128] Therefore, the FWA or optical brightener may comprise at least one labile group. Inherently biodegradable FWAs may be defined as > 20% but < 60% biodegradability in water as measured by standard OECD 301A-F testing. A readily biodegradable FWA or optical brightener may be characterised by the ability of the material to biodegrade quickly and completely in water (either > TSW-GFI 0368 P13584WO

[0129] 70% dissolved organic carbon removal, > 60% theoretical carbon dioxide or > 60% theoretical oxygen demand, depending on standard OECD 301A-F test methods) in a 10-day window within 28 days.

[0130] In embodiments according to the invention, the FWA or optical brightener, and compositions and formulations thereof, may be used in laundry applications, such as detergents, for example.

[0131] Fluorescent Whitening Agent Formulations

[0132] In some aspects of the invention, the FWA or optical brightener may be comprised in a laundry composition or laundry formulation.

[0133] For instance, in typical concentrated and granular detergent compositions, the compositions are typically provided to an end user for use as a diluted or dissolved solution. In such a solution, the pH that a FWA is exposed to, prior to use, can be particularly high, which can give rise to storage issues, in particular with regards to storage stability. Thus, there is a need for improved delivery compositions that are compatible with environmentally acceptable FWA or optical brightener compounds, particularly those agents defined according to the present invention.

[0134] Similarly, FWAs or optical brighteners may be incorporated into fabric washing detergent compositions. Mere incorporation does not guarantee that the compound will be able to absorb onto a fabric being washed. One of the functions of a detergent composition is to absorb onto the surfaces of fabric materials and preferentially adhere, such that oils and other residues are removed. Typically, this is achieved using surfactants, which may be classified as anionic, non-ionic, and cationic in nature. Thus, there is a need for a formulation of a fabric washing detergent composition incorporating an environmentally acceptable FWA or optical brightener, such that the compound can remain absorbed on a fabric material surface after a washing process, particularly where the washing process is followed by a rinsing process, and the compound remains in-situ on the material after such a process.

[0135] Particularly, there is a need for delivery compositions which enable environmentally acceptable FWA or optical brightener compounds, specifically those structures defined according to the present application, which provide delayed release of the FWA at a specific point of the washing process. Specifically, at a point in a washing process where the compound has the highest probability of adsorption onto a fabric. Alternatively, rapid release of the FWA or optical brightener may also be advantageous in certain circumstances, as this would enable the compound to adsorb onto one fabric TSW-GFI 0368 P13584WO before significant concentrations of the surfactant, for example, are present in a washing method, so as to compete with the FWA compound for adsorption onto a fabric.

[0136] The composition or formulation may comprise a multiplicity of different FWA or optical brightener compounds. For example, the composition or formulation may comprise at least one, at least two, at least three or at least four different FWA or optical brightener compounds according to the invention.

[0137] The composition or formulation may comprise additional adjuvants or components. The addition of further adjuvants or components may be necessary to further compatibilise the FWA or optical brightener with the composition or formulation, or to modify the final composition's properties for a particular application. Particularly, the FWA or optical brightener may be formulated in combination with further adjuvants, additives, and / or components to alter and / or control the properties of the formulation or composition.

[0138] Typically, such formulation involves the provision of the active ingredient (FWA or optical brightener) in conjunction with at least one ancillary compound typically present in fluorescent whitening or optical brightening formulations. Such ancillary compounds may be selected from, for example, one or more of detergent(s), bleach(es), carrier compound(s), stabilizer(s), and / or dispersant(s).

[0139] In a particular embodiment of the invention, fabric washing detergent compositions are provided.

[0140] The fabric washing detergent compositions may be in a number of different formats, such as compositions for hand washing, machine washing, uncoloured garments and coloured garments.

[0141] The composition or formulation may further comprise an oxidising agent. Compositions which provide an oxidising agent are widely used and these can also give rise to stability problems for environmentally acceptable FWAs, such as those structures defined in the present application. There is therefore a need for delivery compositions which mitigate or ameliorate issues caused by oxidising agents present in fabric washing detergent compositions.

[0142] The aforementioned problems are particularly relevant for environmentally acceptable FWAs due to the chemical complexity of such molecules, especially because these compounds are present in small amounts and therefore inherently of a higher surface area to volume ratio in a composition, and that compounds tailored to environmentally acceptable compositions frequently have labile groups that TSW-GFI 0368 P13584WO are intended to be degraded in order to have improved biodegradability. Notably, chemical groups designed to improve biodegradability are typically more labile in the presence of an oxidising agent or in high pH conditions, or combinations thereof.

[0143] Furthermore, FWA or optical brightener compounds used in detergent compositions are preferably present at low levels, for example levels as low as 0.01%. High concentrations, such as those caused by individual granules, are unfavourable as these can give rise to an uneven distribution of the agent on a fabric. This effect is particularly exacerbated due to settling of a granular mixture, for example, during transportation. Thus, there is also a need for delivery compositions which enable an even distribution throughout the composition, along with any other relevant detergent ingredients in the overall detergent composition, particularly a fabric washing detergent composition, and even more particularly a granular, solid fabric washing detergent composition.

[0144] In a particular embodiment of the present invention there is provided a solid carrier composition of a FWA composition comprising a carrier and a FWA or optical brightener compound of the invention, in accordance with the above.

[0145] In such an embodiment, the FWA or optical brightener compound may be absorbed into the structure of the carrier. The FWA or optical brightener compound may be present in the carrier composition at less than 50%, less than 40%, less than 30%, less than 20% or less than 10% by weight. In a particular embodiment the FWA or optical brightener may be present in the carrier composition at less than 34% by weight.

[0146] In another embodiment the FWA or optical brightener compound may be present in the carrier composition at between 1% and 34% by weight. In a preferable embodiment, the FWA or optical brightener compound may be present between 15 and 30% by weight. Advantageously this appears to result in less dusting and less wicking of any liquid out of the granule, particularly when the FWA is provided as a liquid.

[0147] The FWA or optical brightener compounds according to the present invention may be provided in solid or liquid form.

[0148] The FWA or optical brightener compounds may particularly be in liquid or low melting form, making them difficult to handle whilst incorporating them into products in which they may be present as an TSW-GFI 0368 P13584WO adjuvant. Examples of such products may include detergents, such as fabric washing detergents, cosmetics, such as sunscreens, paper manufacture, such as for paper finishing, and a variety of other applications in which FWAs are incorporated. In these applications the FWAs may be present in a small amount, typically less than 1% by weight, sometimes as low as 0.01% by weight.

[0149] In these applications, it is therefore more difficult to handle and incorporate such materials. To overcome this challenge, it is therefore advantageous to increase the weight and volume of the FWA or optical brightener by incorporating it into a carrier. However, it is important that, particularly when the fabric whitening agent is a liquid or a low melting solid, that it is fully incorporated into the carrier. In particular embodiments of the invention when such a level of incorporation is 34 wt.% or less, the FWA or optical brightener may be advantageously incorporated into interstices of an otherwise porous structure.

[0150] In embodiments of the present invention, the carrier may be selected from one or more of sodium carbonate, potassium carbonate, calcium carbonate, magnesium carbonate cellulose, carboxymethyl cellulose, polyvinyl alcohol of 100,000 or more repeat units, sodium silicate, polyvinylpyrrolidone of 50,000 or more repeat units, or a zeolite. Particularly, such materials are compatible with detergent compositions.

[0151] In preferred embodiments of the present invention, the carrier may be a water-soluble inorganic salt. These salts have been found to more rapidly disperse FWA compounds, particularly when incorporated into aqueous media.

[0152] In the present invention, the carrier composition may be prepared by drying the FWA compound and the carrier from a solution, as this enables a homogeneous mixture to be produced before the carrier composition is prepared in solid form by drying.

[0153] In the present invention, the drying of the composition is preferably achieved using spray drying. Spray drying has been found to enable particularly relatively low solubility FWAs to be effectively combined with soluble components in the form of a carrier, in a substantially homogeneous manner. This is particularly useful where the FWA or optical brightener compound is a liquid or a low melting solid, as a homogeneous mixture with a solubilised carrier may be produced for spray drying providing a resultant 'dry' and low-dusting granule. TSW-GFI 0368 P13584WO

[0154] In the present invention, the carrier composition may be prepared by drying of the composition by a fluidised bed. Advantageously drying in this manner is effective where the FWAs are sensitive to high drying temperatures. This is particularly relevant as the compounds according to the invention are readily biodegradable and often have labile groups such as esters, which makes them temperature sensitive relative to conventional FWAs.

[0155] In the present invention, where the carrier composition comprises an insoluble carrier and a low solubility or solid FWA or optical brightener, it may be prepared by co-granulation of the carrier and the FWA with a binder. This process avoids high temperatures and is therefore advantageous given the aforementioned problems regarding the stability of the FWA compounds. The binder may be selected from sodium silicate, or an organic polymer. In most preferred embodiments the binder may be an organic polymer in particular a polyvinyl alcohol or a polyvinyl alcohol copolymer. The polar nature of these polymers advantageously provides more homogeneous compositions than those polymers with low polarities or hydrophilicities. Polycarboxylic acid may also be an example of a suitable binder material, especially where there is an amine or amide functionality in the FWA as it provides improved solubilisation of the FWA during preparation of the carrier composition.

[0156] In laundry applications, it has been shown that there is a synergistic effect between proteolytic enzymes and FWA or optical brightener compounds, and therefore in some further embodiments of the present invention, the carrier composition may further comprise a proteolytic enzyme. This is particularly the case where the FWA or optical brightener compound comprises an amide functionality. Additionally, there is synergistic effect between lipolytic enzymes and FWAs, and therefore the carrier composition may further comprise a lipolytic enzyme. This is particularly the case where the FWA comprises an ester functionality.

[0157] The FWA or optical brightener compound may be a liquid at ambient temperature.

[0158] The FWA or optical brightener compound may have a solubility of less than about 1 g / L in water at ambient temperature.

[0159] The carrier may be in the form of a polymer sheet, which may form a sachet or pouch for a detergent composition. TSW-GFI 0368 P13584WO

[0160] In accordance with the invention, there is also provided a detergent composition comprising the aforesaid FWA or optical brightener compound.

[0161] The detergent composition may comprise a detersive surfactant, for example an anionic, a cationic, a zwitterionic, a non-ionic, or a bio- surfactant.

[0162] In preferred embodiments the detergent composition comprises non-ionic surfactants.

[0163] Advantageously, it has been found that non-ionic surfactants provide a preferred base detergent composition for the deposition of FWAs or optical brighteners of the present invention.

[0164] In embodiments of the present invention where the detersive surfactant is a bio-surfactant, it may be selected from one or more glycolipids, such as for example a rhamnolipid or sophorolipid. Commercial examples of such surfactants include, but may not be limited to, BioLoop 56L, BioLoop 56L-PG, BioLoop 68L, BioLoop 68L-PG, BioLoop 84L and BioLoop 84L-PG.

[0165] Particularly, the FWA or optical brightener compounds of the invention preferably have a heterocyclic functionality.

[0166] It has been found that such FWA or optical brightener compounds provide better adsorption onto surfaces being cleaned by the detersive composition. Not wishing to be bound by theory, it is understood that some degree of positive charge on the amide can interact with negatively charged services. It is conventionally understood to be the case when articles are being washed.

[0167] It has been found that such compounds provide improved deposition onto a substrate when used in relevant detergent compositions. It is hypothesised that the FWA or optical brightener compound coadsorbs with the cationic surfactant onto surfaces being washed.

[0168] In compositions utilising a positively charged surfactant, such as a cationic or zwitterionic surfactant the FWA or optical brightener compound preferably has Y as OH or OM, M being Na or K. It has been found that these FWAs or optical brighteners provide improved deposition, possibly because of the combination of the negatively charged FWA or optical brightener and the positively charged surfactant, which together provide improved surface adsorption. This is particularly beneficial for detersive compositions such as fabric softeners. TSW-GFI 0368 P13584WO

[0169] In the present invention, the in-use pH of the detergent composition is preferably in the range from about pH 8 to about pH 10. A pH in this range is particularly beneficial for adsorption of ionisable FWA or optical brightener.

[0170] In the present invention, the detergent composition is preferably a laundry detergent composition, such as includes fabric softeners, whitening agents, pre-treatment agents as well as conventional solid, liquid, gel, pouch detergent compositions, as well as heavy duty, light duty 'whites' and 'colours' detergent compositions.

[0171] In the present invention, the detergent composition may preferably be a fabric washing detergent composition selected from one or more of a laundry detergent, a laundry fabric softener, a bleach, or a booster laundry aid (such as whitening agent).

[0172] In the present invention, the detergent composition preferably further comprises a proteolytic enzyme and the FWA or optical brightener compound comprises an amide linkage.

[0173] The detergent composition of the present invention may further comprise a lipolytic enzyme, especially in embodiments in the FWA or optical brightener comprises an ester linkage.

[0174] The detergent composition of the present invention may be in the physical form of the detergent composition is a powder (granulate), liquid, a gel, a pouch, a tablet, or a solid sheet.

[0175] Preferably the physical form is solid. This is particularly the case for FWA or optical brightener compounds where m is 3 or more and L is a polymer. Such embodiments provide an FWA or optical brightener compounds in a solid form which is compatible with other solids and not subject to hydrolysis in the undiluted state. When the solid is diluted, such as during washing, the detergent composition components, such as enzymes or pH agents can trigger hydrolysis, which releases the FWA or optical brightener into the washing composition.

[0176] The compounds according to the present invention may be capable of providing a fluorescent whitening or optical brightening effect, as well as being readily, ultimately, or inherently biodegradable. The compounds may all have a common renewable building block, which makes their production environmentally friendly. Additionally, the compounds may have one or more of the

[0177] T1 TSW-GFI 0368 P13584WO characteristics of: being substantive to fabric, such as natural materials including cotton and cellulose; being compatible with a synthetic fabric materials; providing peak fluorescent output in the blue (450 and 495nm) or green (495-570 nm) portions of the visible spectrum; providing high fluorescence in solid form and solution; providing high fluorescence when absorbed on a fabric and solution; and / or providing higher absorption onto cotton than 2,2'-Stilbenedisulphonic acid.

[0178] In addition to laundry applications, such as detergents, other applications of the FWAs as defined in the present invention, include, but are not limited to fabrics, paper, and cosmetics.

[0179] For example, FWAs or optical brighteners of the present invention may be used in fabric manufacturing, such as in finishing processes for cotton, which include the treatment of griege (loomstate) cloth into finished fabric. Alternatively, the compounds may be used in melt spinning thing synthetic fibres.

[0180] For example, FWAs or optical brighteners of the present invention may be used in paper manufacturing, such as, for example, during "wet" manufacturing processes. Alternatively, the compounds may be used in paper finishing, or in pre-treatment where they may be used to treat cellulose fibre before paper manufacture.

[0181] For example, FWAs or optical brighteners of the present invention may be used in conjunction with an emollient to provide cosmetics compositions, which may include sunscreen compositions, for example. The advantages of FWA or optical brightener cosmetics is that they provide an increase in the apparent lustre, shine or colour intensity of the cosmetics and do so in an environmentally acceptable format.

[0182] As an example, representative detergent compositions in accordance with the present invention are described in Tables 1, 2, 3 and 4 below: TSW-GFI 0368 P13584WO

[0183] Table 1: Representative Laundry Powder Compositions for Conventional and Compact Compositions

[0184] Table 2: Representative Detergent Tablet Compositions for Zeolite and Phosphate based Compositions TSW-GFI 0368 P13584WO

[0185] Table 3: Representative Laundry Powder Compositions for Homogeneous and Structured Compositions

[0186] Table 4: Representative Fabric Bleach Detergent Compositions for Solid and Liquid Forms

[0187] EXAMPLES

[0188] Example 1 - Synthesis of FWAs

[0189] General Synthesis of carboxylic acid precursor of Fluorescent Whitening Agent with formula I TSW-GFI 0368 P13584WO

[0190] A mixture of citric acid (1 eq.) and corresponding amine (1 eq.) were dissolved in water (1 vol). The reaction mixture was heated to 100 °C to allow all water to distil. The reaction temperature was then increased to 140 °C to melt the resulting residues, the molten mixture was then stirred for 16 h and the water of reaction allowed to distil. The resulting resinous material was cooled <100 °C before adding fresh water (1 vol.). The mixture was then cooled to ambient temperature with vigorous stirring to disperse the product before filtration. The isolated solids were washed with fresh water (0.5 vol.) before drying in a vacuum oven to give the final product.

[0191] General Synthesis of carboxylic acid precursor of Fluorescent Whitening Agent Containing an Aromatic or Heteroaromatic Ring

[0192] A mixture of citric acid (1.05 eq.) and corresponding aromatic amine (1 eq.) were dissolved / slurried in water (1 vol). The water was then removed in vacuo and the resulting residues heated to 180 °C for 1 h, allowing the water of reaction to distil. The reaction temperature was then decreased to 140 °C and xylene (3 vol.) and p-toluenesulphonic acid (0.05 eq.) were charged to resuspend the crude product. The slurry was then stirred for 16 h under reflux. The reaction mixture was then cooled <100 °C before adding fresh water (3 vol.) and cooling further to ambient temperature with vigorous stirring to disperse the product before filtration. The isolated solids were washed with 50:50 water / MeOH (2 x 1 vol.) before drying in a vacuum oven to give the final product.

[0193] General Procedure for functionalisation of Fluorescent Whitening Agent Core Unit with Subsequent Heterocyclic Group

[0194] A mixture of prepared FWA core (1.0 eq.) is suspended in xylene (10 vol.) with corresponding amine or aromatic amine (1.2 eq.) and ZnCL (0.01 eq.). The resulting mixture is heated to reflux and allowed to stir for 4h. Where the target compound is soluble in the reaction mixture the resulting residues are removed by hot filtration before cooling the organic liquors <100 °C and washing with 1 vol water. Xylene is then removed from the product in vacuo to give the target compound. For compounds that are insoluble in the final xylene mixture the reaction is instead cooled <100 °C before adding fresh water (3 vol.) and cooling further to ambient temperature with vigorous stirring to disperse the product before filtration. The isolated solids were washed with 50:50 water / MeOH (2 x 1 vol.) before drying in a vacuum oven to give the final product.

[0195] Synthesis of Carboxylic Acid Precursor to Fluorescent Whitening Agent Structure 7 TSW-GFI 0368 P13584WO

[0196] A mixture of citric acid (61.2 g, 1.05 eq.) and / V-methyl-l,2-phenylenediamine dihydrochloride (60 g, 1 eq.) were dissolved / slurried in water (60 mL, 1 vol.). The water was then removed in vacuo and the resulting residues heated to 180 °C for 1 h, allowing the water of reaction to distil. The reaction temperature was then decreased to 140°C. Xylene (180 mL, 3 vol.) and p-toluenesulphonic acid (2.9 g, 0.05 eq.) were charged to resuspend the crude product. The slurry was then stirred for 16 h under reflux. The reaction mixture was then cooled <100 °C before adding fresh water (180 mL, 3 vol.) and cooling further to ambient temperature with vigorous stirring to disperse the product before filtration. The isolated solids were washed with 50:50 water / MeOH (2 X 100 mL) before drying in a vacuum oven to give the final product as a yellow-green powder in 63 % yield.

[0197] LCMS m / z +1: 243.0;3H NMR (700 MHz, DMSO) 6 13.46 (s, 1H), 8.71 (dt, J = 8.1, 0.9 Hz, 1H), 7.66 (dt, J = 8.2, 0.8 Hz, 1H), 7.55 (ddd, J 8.3, 7.4, 1.2 Hz, 1H), 7.33 (ddd, J = 8.3, 7.4, 1.1 Hz, 1H), 6.68 (d, J = 1.5 Hz, 1H), 6.41 (d, J = 1.5 Hz, 1H), 3.81 (s, 3H);13C NMR (176 MHz, DMSO) 6 166.83, 158.89, 144.68, 140.52, 133.51, 126.90, 126.56, 121.52, 116.39, 109.15, 102.62, 82.35, 29.43.

[0198] Procedure for functionalisation of Carboxylic Acid Precursor to give FWA Structure 7

[0199] A mixture of prepared FWA precursor (36.33g, 1.0 eq.) is suspended in xylene (350ml, 10 vol.) with corresponding o-phenylenediamine (19.47, 1.2 eq.) and ZnCL (0.2g, 0.01 eq.). The resulting mixture was heated to reflux and allowed to stir for 4h. The reaction was then cooled <100 °C before adding fresh water (100ml, 3 vol.) then cooled further to ambient temperature with vigorous stirring to disperse the product before filtration. The isolated solids were washed with 50:50 water / MeOH (2 x 1 vol.) before drying in a vacuum oven to give the crude product, which was then purified by column chromatography to give the final product as a green-yellow powder.

[0200] LCMS m / z +1: 315.5;3H NMR (700 MHz, DMSO) 6 10.56 (br S, 1H), 8.11 (dd, 2H), 8.07 (dd, 2H), 7.55 (m, 2H), 7.22 (d, 1H), 7.09 (m, 1H), 6.69 (m, 1H), 6.59 (d, 1H), 2.21 (s, 3H);13C NMR (176 MHz, DMSO) 6 171.58, 158.16, 151.35, 150.07, 144.62, 135.62, 135.34, 130.58, 130.21, 129.87, 129.12, 121.45, 121.38, 111.75, 110.53, 106.83, 102.91, 99.10, 43.57.

[0201] Example 2 - Evaluation of Fluorescent Whitening Agents

[0202] Fluorescent whitening agents and optical brighteners of the present invention have been evaluated TSW-GFI 0368 P13584WO to determine their chemical stability, UV stability, quantum yield, fluorescence / whiteness effect, biodegradability, and substantivity onto cellulose, in comparison with commercially available benchmarks. Relative Quantum Yield

[0203] A solution of FWA was prepared in 0.1 M sodium carbonate. The solution was diluted down till a UV absorbance of 0.1 was measured (Agilent™ Cary UV-vis), this was then diluted further to obtain a range of UV absorbance readings. These solutions were then run to determine their fluorescence response (Agilent™ Cary Eclipse Fluorescence Spectrometer). The integrated area from the fluorescence measurements was plotted against the UV absorbance readings and compared to the gradient measure for a quinine sulphate in 0.1 M sulfuric acid standard to calculate the relative quantum yield for each compound. The results are provided below in Table 5, with comparison with benchmarks DAS-2 and DSBP.

[0204] Table 5: Relative quantum yield of FWA or optical brightener benchmarks or examples TSW-GFI 0368 P13584WO

[0205] Examples show similar blue fluorescence and quantum yield range as the commercial benchmarks, such as DAS-2.

[0206] Fluorescence / whiteness effect as measured on cotton swatch:

[0207] Colour measurement was made with a Lovibond* LC100 spectrocolorimeter. The surface colour of the cotton swatch was quantified using a series of values L*, a*, and b* from the colour model CIELAB defined by the International Commission on Illumination's (Commission Internationale de I'Eclairage). L* is a measure of the amount of white or black in a sample ; higher L* values indicate a lighter coloured sample. A measure of the amount of red or green in a sample was determined by "a*" values. A measure of the amount of blue or yellow in a sample was determined by "b*" values; lower (more negative) b* values indicate more blue on a sample.

[0208] Colour can also be measured using a different model, CIE L*C*h*, where C* represents chroma, and h* represents the hue angle. The cotton swatch (10 cm x 10 cm, Woven Cotton, Cretonne, bleached, without optical brightener, 155 g / m2, CN11 code from Center For Testmaterials B.V.) from each substantivity test was measured against a blanked washed cotton swatch.

[0209] The surface colour of the swatches was measured in duplicate, and the average values for the surface colour are provided below in below in Table 6. Visual inspection of the swatches was also carried out.

[0210] Table 6: Cotton Swatch Brightness Results for example compounds TSW-GFI 0368 P13584WO

[0211] Substantivity onto fabric:

[0212] A buffer stock solution was prepared using 0.1 g SDS, 1.0 g glycerol, 8.4 g sodium carbonate, 1.7 g sodium bicarbonate and 0.4 g EDTA in 2 L tap water. Wash solutions with either 20 ppm or 100 ppm of each FWA were prepared by solubilizing respectively 2 mg or 10 mg of material in 40 mL of buffer stock solution and made up to 100 mL using tap water. A volume of 15 mL of each wash solution was transferred to separate vials containing a cotton swatch (10 cm x 10 cm, Woven Cotton, Cretonne, bleached, without optical brightener, 155 g / m2, CN11 code from Center For Testmaterials B.V.). The vials were placed on a roller for 20 mins. A 100 pL sample from the initial 20 ppm wash solution was taken and diluted to 25 mL in a volumetric flask using water. Dry the cotton fabric. The same dilution method was applied to a 100 pL sample of the final wash solution after the roller mixing was complete.

[0213] The swatches are then compared under UV light at 254 and 365 nm by visual inspection against ones washed with the same quantity of the commercial benchmarks.

[0214] Results for the substantivity on cotton are provided below in Table 8, in comparison with benchmarks DAS-1, DAS-2, FB28 and DSBP.

[0215] Table 8: Substantivity on cotton results for benchmark and example compounds TSW-GFI 0368 P13584WO

[0216] The carbonate-buffered wash solution forms in-situ the sodium salt of any FWA loaded as its carboxylic acid. The sodium salt of the above example shows comparable adsorption and dispersion onto the cotton fabric than the benchmarks.

[0217] Biodegradability Assessment using Biowin™

[0218] The chemical structures of the present invention are preferably, and advantageously, biodegradable.

[0219] For the purposes of the present invention, an inherently biodegradable FWA is defined as having > 20% but < 60% biodegradability in water as measured by OECD 301A-F testing. A readily biodegradable FWA is defined as having the ability to biodegrade quickly and completely in water (either > 70% dissolved organic carbon DOC removal, > 60% theoretical carbon dioxide or > 60% theoretical oxygen demand, depending on OECD 301A-F test methods) in a 10-day window within 28 days.

[0220] Biowin™ software was used to provide predictions of biodegradability. This method of prediction of biodegradability is available as part of the Estimation Program Interface (EPI) Suite™ of software provided by the United States Environmental Protection Agency (EPA). Environ. Sci. Technol., 1994, 28, 459-465, shows an example of the group contribution method for predicting probability and the rate of aerobic biodegradation. This is the type of method used by Biowin™.

[0221] Biowin 3 and Biowin 5 models are of particular relevance to the present invention. The predicted biodegradability of some of the compounds according to the present invention were assessed using these models. If the Biowin 3 (ultimate survey model) result is >= 2.75 (i.e. "weeks" or faster) and the TSW-GFI 0368 P13584WO

[0222] Biowin 5 (MITI linear model) probability is >= 0.5, then the prediction is YES (readily biodegradable). If this condition is not satisfied, the prediction is NO (not readily biodegradable).

[0223] The results of this biodegradability study are provided below in Table 9, in comparison with benchmarks DAS-1, DAS-2, FB28 and DSBP:

[0224] Table 9: Biowin predicted biodegradability score for the benchmark and example compounds TSW-GFI 0368 P13584WO TSW-GFI 0368 P13584WO TSW-GFI 0368 P13584WO

Claims

TSW-GFI 0368 P13584WOCLAIMS1. A fluorescent whitening agent or optical brightener of formula (I) having the structure:wherein:A is C(R1R2)(CH2)n / or an optionally substituted aromatic or heteroaromatic ring fused with N and X wherein N and X are respectively bound to adjacent carbon atoms on the ring;X is O, S, or NR3;B is an optionally substituted heterocycle; and wherein: when A is C(R1R2)(CH2)n, R1is H, CH2OH, COY, or an optionally substituted heterocycle, R2is H or CH2OH and wherein n is 1 or 2;Y (when present) is independently OM, OR3, O(CH2)qSO3M, NHOH, NHR3, or NR32, wherein, M is selected from an alkali metal or an alkaline earth metal, and q is 1 to 5; and the or each R3is independently hydrogen, a linear or branched alkyl, a linear or branched alkenyl, an aryl, a heterocycle, an alkaryl, an aralkyl, a linear or branched alkyl carboxylic acid, a linear or branched alkyl carboxylate, a linear or branched alkyl nitrile, a linear or branched alkyl alcohol, a linear or branched alkyl alcohol polyol, an acyl, a hydroxyalkylamine, a linear or branched alkylamine, a polyhydric alcohol, a sugar, a linear or branched alkyl ether, a linear or branched polyether, a polyester having from 2 to 1000 repeat units, or a polyoxyalkylene chain having from 2 to 1000 repeating units, and alternatively, NR32 represents a heterocyclic ring.

2. The fluorescent whitening agent or optical brightener according to Claim 1, wherein B is a single-ring heterocycle or a fused heterocycle.

3. The fluorescent whitening agent or optical brightener according to either Claim 1 or Claim 2, wherein B is selected from the following:TSW-GFI 0368 P13584WO4. The fluorescent whitening agent or optical brightener according to any one of Claims 1 to 3, wherein: a. when R3a linear or branched alkyl, R3is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 1,1-dimethylpropyl, 1,3,3-trimethylpropyl, 2,5-dimethylhexyl, isopropyl, 3-methylpentan-2-yl, 3-methylpentan-3-yl, or tertbutyl; when R3represents an alkyl alcohol, R3is selected from methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, dodecanol, or stearyl or oleyl alcohol; b. when R3represents an aryl, R3is phenyl; c. when R3represents alkaryl, R3is selected from benzyl, or ethyl phenyl; d. when R3represents a heterocycle, R3is a heteroaryl, optionally wherein R3is selected from a triazole, an imidazole, a pyrazole, or an imidazoline; e. when R3represents a linear or branched alkyl alcohol, R3is 2-hydroxyethyl, 4- hydroxybutyl, l-hydroxyprop-2-yl, or 2-hydroxyprop-l-yl; f. when R3represents a linear or branched alcohol polyol, R3is a diol or triol, optionally 2,3-dihydroxypropyl, or 2-hydroxy-l-(hydroxymethyl)ethyl; g. when R3is PEG, it has from 2 to 1000 repeat units; h. when R3is MeO-PEG, it has from 2 to 1000 repeat units; i. when R3represents a hydroxyalkylamine, R3is selected from triethanolamine, N- methyldiethanolamine or triisopropanolamine; j. when R3represents a polyhydric alcohol, R3is glycerol; k. when R3represents a sugar, R3is selected from dextrose, fructose, galactose, glucose, lactose, maltose, or sucrose; l. when R3represents a linear or branched alkyl ether, R3is selected from 2-(2- hydroxyethoxy)ethyl, 2-(2-hydroxy-l-methylethoxy)-l-methylethyl, 2-[2-(2-hydroxy-TSW-GFI 0368 P13584WO l-methylethoxy)-l-methylethoxy]-l-methylethyl, 3-(3-hydroxypropoxy)propyl, 3-[3- (3-hydroxypropoxy)propoxy]propyl, 4-(4-hydroxybutoxy)butyl, 4-[4-(4- hydroxybutoxy)butoxy] butyl, 2-(2-methoxyethoxy)ethyl, or 2-[2-(2- methoxyethoxy)ethoxy]ethyl; and / or m. when R3represents a polyester or a polyoxyalkylene having from 2 to 1000 repeat units, the chain is a homopolymer or a copolymer.

5. The fluorescent whitening agent or optical brightener according to Claim 1, wherein, the fluorescent whitening agent or optical brightener may be selected from, any one of, formula (la), formula (lb), or formula (Ic):whereinB is an optionally substituted heterocycle;X is S, O, or -NR3; and the or each R1may be independently H, -C(O)ZR3, or an optionally substituted heterocycle, wherein Z may be selected from O, S, NH, or NR3, and the or each R3is independently hydrogen, a linear or branched alkyl, a linear or branched alkenyl, an aryl, a heterocycle, an alkaryl, an aralkyl, a linear or branched alkyl carboxylic acid, a linear or branched alkyl carboxylate, a linear or branched alkyl nitrile, a linear or branched alkyl alcohol, a linear or branched alkyl alcohol polyol, an acyl, a hydroxyalkylamine, a linear or branched alkylamine, a polyhydric alcohol, a sugar, a linear or branched alkyl ether, a linear or branched polyether, a polyester having from 2 to 1000 repeat units, or a polyoxyalkylene chain having from 2 to 1000 repeating units, and alternatively, NR32 represents a heterocyclic ring.

6. The fluorescent whitening agent or optical brightener according to Claim 1, wherein, when X is NR3, the R3group functions as a linker group between at least two compounds of formula (I).

7. The fluorescent whitening agent or optical brightener according to Claim 6, wherein the fluorescent whitening agent or optical brightener is of the formula (Ila) or (lib):TSW-GFI 0368 P13584WO8. The fluorescent whitening agent or optical brightener according to any one of Claims 1 to 7 , wherein the fluorescent whitening agent or optical brightener is biodegradable.

9. A composition comprising the fluorescent whitening agent or optical brightener of any one of Claims 1 to 8, for use in a laundry application.

10. A fluorescent whitening or optical brightening formulation of the composition according to Claim 9, for use in a laundry application.

11. The formulation according to Claim 10, further comprising at least one ancillary compound, optionally selected from one or more of surfactant(s), detergent(s), bleach(es), carrier compound(s), stabilizer(s), and / or dispersant(s).

12. Use of the compounds of formula (I) according to any one of Claims 1 to 8, as fluorescent whitening agents or optical brighteners.

13. A method for providing fluorescent whitening or optical brightening to a laundry substrate comprising contacting the substrate with the fluorescent whitening agent or optical brightener according to any one of Claims 1 to 8, or the fluorescent whitening or optical brightening formulation of Claims 10 or 11, under conditions effective to allow chemical and / or physical bonding of the one or more compounds onto or into the substrate.

Images