WO2015082380A1

WO2015082380A1 - Deodorant compositions comprising hydrophilic cinnamic acid derivatives

Info

Publication number: WO2015082380A1
Application number: PCT/EP2014/076058
Authority: WO
Inventors: David William Thornthwaite
Original assignee: Unilever Plc; Unilever N.V.; Conopco, Inc., D/B/A Unilever
Priority date: 2013-12-03
Filing date: 2014-12-01
Publication date: 2015-06-11

Abstract

A non-therapeutic method of reducing malodour or a cosmetic composition for said use comprising a cosmetically acceptable carrier material and an ester or amide of an aromatic carboxylic acid of formula Ar-CH=CH-CO₂H, wherein Ar is an optionally substituted phenyl group and wherein the ester or amide is hydrophilic in nature.

Description

DEODORANT COMPOSITIONS COMPRISING HYDROPHILIC CINNAMIC ACID DERIVATIVES

Field of Invention The present invention is concerned with non-therapeutic methods of deodorising the surface of the human body. The method chosen involves the application of a cosmetic composition to the surface of the human body.

Background

Numerous methods for reducing the odour or malodour of the human body exist. Simple washing procedures do help to reduce malodour, but the problem is that malodour tends to return with time and often prior to the next opportunity to wash. Fragrances have been used to reduce malodour from ancient times, by masking malodours on the surface of the body. Fragrance technology has progressed greatly in recent years, making malodour control by this method extremely effective; however, simple fragrances do not actually remove the malodourous materials from the surface of the human body.

Another approach to malodour control has been to target the microbes on the skin that are responsible for converting odourless secretions from the eccrine and apocrine glands into malodours. The microbes responsible can be targeted with selected anti-microbials and this can also be an effective approach, although it does not in itself remove malodourous materials already present on the surface of the human body

Other approaches to malodour reduction have involved absorption or adsorption of malodours using a variety of substrates. As a particular type of malodour absorption, malodour molecules have been trapped or captured using chemical reaction. This method is particularly effective against thiol malodours, which are common in the underarm regions of the body and are particularly noxious.

US 5,601 ,809 discloses diethyl fumerate, di-n-butyl maleate, and N- ethylmaleinimide as reagent suitable for chemical reaction with thiol malodours.

WO 05/021051 (Givaudan, 2005) discloses the use as malodour neutraliser of an aminoalkyl substituted fumerate. WO 02/051788 (Givaudan, 2002) discloses malodour capture ingredients including numerous aromatic α,β-unsaturated esters of medium to long chain alcohols.

EP 2,524,704 A2 (IFF Inc., 2012) discloses reactive malodour counter-actives of low volatility. Particular counter-actives disclosed include PEG diacrylates.

Summary of Invention

It is an object of the present invention to provide a composition and method for reducing malodour on the surface of the human body, in particular malodour arising from the underarm regions of the human body.

It is an object of the present invention to provide a highly effective method of achieving a deodorancy benefit upon the surface of the human body.

The invention is particularly concerned with the removal of malodour molecules from the surface of the human body and especially their removal by chemical reaction with particular odour neutralisers. In a first aspect of the present invention there is provided a non-therapeutic method of reducing malodour comprising the application to the surface of the human body of a composition comprising a cosmetically acceptable carrier material and an ester or amide of an aromatic carboxylic acid of formula I, characterised in that the ester or amide is hydrophilic in nature

Formula I: Ar-CH=CH-CO₂H wherein Ar is an optionally substituted phenyl group, including the possibility of multiple substitution.

In a second aspect of the present invention there is provided a cosmetic composition comprising a cosmetically acceptable carrier material and an ester or amide of an aromatic carboxylic acid of formula I, characterised in that the ester or amide is hydrophilic in nature

In a third aspect of the present invention there is provided a process for capturing or trapping malodour molecules comprising the use of a method according to the first aspect of the invention or a composition according to the second aspect of the invention. The use of such molecules to capture malodours in this way is not something contemplated in the prior art.

It will be recognised that an ester or amide of an aromatic carboxylic acid of formula I is an ester or amide of cinnamic acid or an analogue thereof. Such acids or amides are of an unsaturated, conjugated, aromatic carboxylic acid and this is a key feature of their selection for use in the present invention.

Herein, "hydrophilic nature", with reference to the ester or amide of an aromatic carboxylic acid of formula I, means an ester of amide that has a water solubility of at least 1 g/l at 25°C or is a water-insoluble solid having a hydrophilic surface such that water has a contact angle with it of 60° or less.

In most aspects of the present invention the composition comprises, or the method comprises the use of, an ester or amide of formula II or III, respectively:

Formula II: Ar-CH=CH-CO.O-X

Formula III: Ar-CH=CH-CO.NH-X wherein X is a hydrophilic group. In preferred embodiments X is a water insoluble hydrophilic solid such that water has a contact angle with it of 60° or less or comprises sufficient ethyleneoxy (EO) and/or propyleneoxy (PO) groups to give the ester or amide a water solubility of at least 1 g/l.

Detailed Description of the Invention

In the course of their research, the present inventors became aware that one of the most odiferous molecules present in the underarm regions of the body is a thiol or mercaptan of the following structure:

HS-CH(CH₃)-CH(CH₃)-CH₂-OH

This molecule, 3-mercapto-2-methylbutanol is referred to as "3M2M" herein and is an extremely odiferous molecule. Its significance in human axillary odour is reported in "Microbiological and biochemical origins of human axillary odour", Gordon James, Corrine Austin, Diana Cox, David Taylor and Ralph Calvert, FEMS Microbiol. Ecol. 83 (2013) 527-540. 3M2M has not previously been extensively studied. The present inventors focussed their attentions on materials that would counteract this particular molecule, in particular materials that would capture it by chemical reaction.

Michael addition of thiols to α,β-unsaturated esters and similar materials are known from the prior art (vide supra). The present inventors have found that particular Michael acceptors have a surprisingly high affinity for 3M2M and are therefore particularly effective at countering this malodour. The materials identified, herein "odour capture agent(s)", were all found to be hydrophilic esters or amides of cinnamic acid or an analogue thereof as represented by formula I:

Formula I: Ar-CH=CH-CO₂H

Herein and throughout all formulae, Ar is an optionally substituted phenyl group, this including multiply substituted phenyl groups.

Herein and throughout all formulae, optionally substituted phenyl groups ("Ar") typically have the structure R-C₆H₄, wherein C₆H₄ represents a doubly substituted benzene ring and R is H, CH₃, HO or CH₃O. When a substituent is present, it is typically a para-substituent. Ar is most preferably a phenyl group ("Ph").

Herein and throughout all formulae, EO is an ethyleneoxy unit having the structure CH₂CH₂O, the repeat number of such units "n" typically being between 30 and 60 and preferably between 40 and 50. Herein and throughout all formulae, PO is a propyleneoxy unit having the structure CH₂CH(CH₃)O or CH(CH₃)CH₂O, the repeat number of such units "m" typically being from 3 to 10 and preferably from 5 to 8, most preferably about 6. Herein and throughout all formulae, carbon-carbon double bonds should be understood to be typically trans unless otherwise indicated.

Herein and throughout all formulae, the stereochemistry of any chiral centres is undefined and should be understood to be typically racemic, unless otherwise indicated.

Herein, "hydrophilic" esters or amides comprising sufficient EO and/or PO groups to give the ester or amide a water solubility of at least 1 g/l, preferably give the ester or amide a water solubility of at least 10 g/l and more preferably at least 100 g/l at 25°C. Esters or amides having such preferred or more preferred water solubilities may be used as alternatives to esters or amides that are water- insoluble solids having a hydrophilic surface such its contact angle with water is 60° or less. Herein, "water soluble" refers to materials having a solubility in water of at least 1 g/l at 25°C and "water insoluble" refers to materials having a solubility in water of less than 1 g/l at 25°C.

In preferred aspects of the present invention the composition comprises, or the method comprises the use of, an ester or amide of formula II or III, respectively:

Formula II: Ar-CH=CH-CO.O-X'

Formula III: Ar-CH=CH-CO.NH-X' wherein X' is a hydrophilic group comprising sufficient EO and/or PO groups to give the ester or amide a water solubility of at least 1 g/l.

In certain preferred embodiments, X in formula I or X' in formula II or III comprises EO and/or PO groups and a terminating group on the O atom most distant from the ester or amide link that is C1 -C4 alkyl or CO.CH=CH-Ar, in particular -CH₃ or CO.CH=CH-Ar.

Preferred odour capture agents have formula ll(A) or lll(A): Formula ll(A): Ar-CH=CH-CO.O-(PO)_m-(EO)_n-R'

Formula lll(A): Ar-CH=CH-CO.NH-Y-(PO)_m(EO)_n-R' wherein R' is H, C1 -C4 alkyl, or CO.CH=CH-Ar, Y is an optionally present linking group preferably of structure CH₂CO.O, the methylene unit (CH₂) being linked to the N atom indicated in formula lll(A) and m is from 0 to 20 and n is from 0 to 200, with the proviso that m + n is at least 4 and is sufficient to give the ester or amide a water solubility of at least 1 g/l. When both EO and PO groups are present, their position may be reversed or randomised. In particularly preferred odour capture agents, R' is -CH₃ or CO.CH=CH-Ar and m + n is 4 to 100.

Especially preferred esters and amides for use in accordance with the present are selected from:

Ar-CH=CH-CO.O-(EO)_n-CH₃

Ar-CH=CH-CO.O-(EO)_n-CO.CH=CH-Ar

Ar-CH=CH-CO.NH-(EO)_n-CH₃ and

Ar-CH=CH-CO.NH-CH₂CO.O-(EO)_n-CH₃ wherein, n is 2 to 200, preferably 4 to 100 and more preferably 5 to 50 and Ar is preferably Ph for whichever level of ethoxylation is present. The esters or amide odour capture agents for use in accordance with any aspect of the invention are preferably of molecular weight greater than 1000 and preferably greater than 2000. Such odour capture agents may give performance benefits as a result of stability and/or ease of formulation and/or reduced skin penetration.

The odour capture agent(s) may be used at a level typically in the range from 0.01 to 10% by weight, based upon the total composition in which it is present excluding any volatile propellant present therein. The level of incorporation is preferably from 0.05 to 5% and more preferably 0.1 to 3% by weight, based upon the total composition in which it is present excluding any volatile propellant present therein. The cosmetically acceptable carrier material(s) used in accordance with the present invention may any of those commonly used in the art. The carrier material(s) may be hydrophobic or hydrophilic, solid or liquid. Preferred carrier materials are liquids, meaning that they are in neither a solid nor a gaseous state and are able to flow under gravity at ambient temperature and pressure (by which is meant 25°C and 1 atmosphere pressure). Preferred liquid carriers materials are selected from the group consisting of liquid silicones and short chain (C2-C6) alcohols, such as ethanol, and water.

The total amount of carrier material(s) is typically at least 5% by weight and more typically in the range from 40 to 99.99% by weight, based upon the total composition excluding any volatile propellant present therein. The level of incorporation is preferably from 50 to 99% and more preferably 60 to 98% by weight, based upon the total composition excluding any volatile propellant present therein. Liquid silicones are hydrophobic in nature and are frequently known as liquid polyorganosiloxanes. Such materials may be cyclic or linear, examples include Dow Corning silicone fluids 344, 345, 244, 245, 246, 556, and the 200 series; Union Carbide Corporation Silicones 7207 and 7158; and General Electric silicone SF1202.

Short chain (C2-C6) alcohols, as well as water, are often able to dissolve the odour capture agent(s) and it is common for said agents to be present in solution when the carrier material comprises such an alcohol or water. Preferred short chain (C2-C6) alcohols are dipropylene glycol, glycerol propylene glycol, butylene glycol, ethanol, propanol, isopropanol, and industrial methylated spirits.

Particularly preferred are ethanol and isopropanol, ethanol being the most preferred. Alternatively or in addition to a short chain (C2-C6) alcohol, another organic solvent may be used as a carrier material, examples including polyglycol ethers; for example, oligoglycol ethers having only 2 to 5 repeat units.

Alternatively or in addition to a silicone oil, a carrier material that is a non-silicone hydrophobic liquids may be used. Such materials include mineral oils,

hydrogenated polyisobutene, polydecene, paraffins, isoparaffins of at least 10 carbon atoms, aliphatic or aromatic ester oils (eg. isopropyl myristate, lauryl myristate, isopropyl palmitate, diisopropyl sebecate, diisopropyl adipate, or C₈ to Ci8 alkyl benzoates), and polyglycol ethers, for example polyglycol butanol ethers.

In compositions comprising water, the pH is preferably from 6 to 8 and more preferably from 7 to 8, such pH enhancing the in use deodorancy performance without causing the irritation that can result at more extreme pH values. It is highly preferred that compositions of the invention comprise a fragrance material. Suitable fragrance materials include conventional perfumes, such as perfume oils and also include so-called deo-perfumes, as described in EP

545,556 and other publications. These latter materials may also qualify as additional organic anti-microbial agents. Levels of incorporation are preferably up to 4% by weight, particularly from 0.1 % to 2% by weight, and especially from 0.7% to 1 .7% by weight of a composition. Synergies may exist between the odour capture agent(s) and the perfume - highly effective odour control being the result.

Particular compositions of the invention comprise a solution of the odour capture agent(s) in a organic solvent. Such solutions are preferably homogeneous, preferably having an absorbance, relative to the solvent, of less than 0.2, especially less than 0.1 (for a 1 cm pathlength at 600 nm) measured using a Pharmacia Biotech Ultrospec 200 Spectrophotometer or similar instrument.

Suitable solvents for use in this embodiment include the aforementioned short chain (C2-C6) alcohols.

When organic solvent is present in the composition, it is preferably present at from 30% to 98, more preferably at from 60% to 97% by weight of the composition, excluding any volatile propellant present.

In embodiments of the invention in which the odour capture agent(s) is suspended in the carrier material, the deodorant active of formula I may have superior chemical stability.

Deodorant actives other than the odour capture agent(s) may also be present in compositions according to the invention. Such materials may be organic antimicrobial agents. Levels of incorporation of such materials are typically from 0.01 % to 3%, in particular from 0.03% to 0.5% by weight of the composition, excluding any volatile propellant also present. Most of the classes of agents commonly used in the art can be utilised, for example quaternary ammonium compounds, like cetyltrimethylammonium salts; chlorhexidine and salts thereof; and diglycerol monocaprate, diglycerol monolaurate, glycerol monolaurate, and similar materials, as described in "Deodorant Ingredients", S.A.Makin and

M.R.Lowry, in "Antiperspirants and Deodorants", Ed. K. Laden (1999, Marcel Dekker, New York). More preferred additional deodorant actives are

polyhexamethylene biguanide salts; 2,4,4'-trichloro,2'-hydroxy-diphenyl ether (triclosan); and 3,7,1 1 -trimethyldodeca-2, 6,10-trienol (farnesol).

A particularly preferred additional deodorant active is a transition metal chelator, in particular a material having a high binding constant for iron (III); that is to say, a binding constant for iron (III) of greater than 10¹⁵, preferably greater than 10²⁰, and most preferably greater than 10²⁶, such materials being described in EP

1 ,248,520 B (Unilever). A particularly preferred material of this class is

diethylenetriaminepentaacetic acid (DTPA). Salts of such materials may also be employed. The total amount of transition metal chelator and/or salt thereof is preferably from 0.1 % to 5%, more preferably from 0.2% to 3%, and especially from 0.4% to 2% by weight of the composition. Inorganic anti-microbial agents may also be present as additional deodorant actives. Such materials may also function as antiperspirant actives. Typically, such materials are astringent metal salts, in particular, aluminium, zirconium and mixed aluminium/zirconium salts, including both inorganic salts, salts with organic anions and complexes. Examples of such astringent salts include aluminium, zirconium and aluminium/zirconium halides and halohydrate salts, such as chlorohydrates. When included, preferred levels of incorporation are from 0.5% to 60%, particularly from 5% to 30% or 40% and especially from 5% or 10% to 30% or 35% by weight of a composition. Structurants and emulsifiers are further carrier materials that may be employed. Structurants, when employed, are preferably present at from 1 % to 30% by weight of a composition, whilst emulsifiers are preferably present at from 0.1 % to 10% by weight of a composition. Structurants include cellulosic thickeners such as hydroxy propyl cellulose and hydroxy ethyl cellulose, and dibenzylidene sorbitol. Other structurants include sodium stearate, stearyl alcohol, cetyl alcohol, hydrogenated castor oil, synthetic waxes, paraffin waxes, hydroxystearic acid, dibutyl lauroyl glutamide, alkyl silicone waxes, quaternium-18 bentonite, quaternium-18 hectorite, silica, and propylene carbonate. Emulsifiers include steareth-2, steareth-20, steareth-21 , ceteareth-20, glyceryl stearate, cetyl alcohol, cetearyl alcohol, PEG-20 stearate, and dimethicone copolyol.

Further emulsifiers desirable in compositions of the invention comprising perfume are perfume solubilisers. Examples include PEG-hydrogenated castor oil, available from BASF in the Cremaphor RH and CO ranges, preferably present at up to 1 .5% by weight, more preferably 0.3 to 0.7% by weight.

Other emulsifiers desirable in compositions of the invention are wash-off agents, for example poly(oxyethylene) ethers.

Certain sensory modifiers are further desirable components in the compositions of the invention. Such materials are preferably used at a level of up to 20% by weight of a composition. Emollients, humectants, volatile oils, non-volatile oils, and particulate solids which impart lubricity are all suitable classes of sensory modifiers. Examples of such materials include cyclomethicone, dimethicone, dimethiconol, isopropyl myristate, isopropyl palmitate, talc, finely divided silica (eg. Aerosil 200), polyethylene (eg. Acumist B18), polysaccharides, corn starch, C12- C15 alcohol benzoate, PPG-3 myristyl ether, octyl dodecanol, C7-C14

isoparaffins, di-isopropyl adipate, isosorbide laurate, PPG-14 butyl ether, glycerol, hydrogenated polyisobutene, polydecene, titanium dioxide, phenyl t methicone, dioctyl adipate, and hexamethyl disiloxane.

It should be noted that certain components of compositions perform more than one function. Such components are particularly preferred additional ingredients, their use often saving both money and formulation space. Examples of such components include ethanol, isopropyl myristate, and silica.

Further additional components that may also be included are colourants and preservatives, for example C1 -C3 alkyl parabens.

Aerosol compositions for use according to the invention generally comprise a volatile propellant. The level of incorporation of the volatile propellant is typically from 30 to 99 parts by weight and particularly from 50 to 95 parts by weight. Non- chlorinated volatile propellant are preferred, in particular liquefied hydrocarbons or halogenated hydrocarbon gases (particularly fluorinated hydrocarbons such as 1 ,1 -difluoroethane and/or 1 -trifluoro-2-fluoroethane) that have a boiling point of below 10°C and especially those with a boiling point below 0°C. It is especially preferred to employ liquefied hydrocarbon gases, and especially C₃ to C₆ hydrocarbons, including propane, isopropane, butane, isobutane, pentane and isopentane and mixtures of two or more thereof. Preferred propellants are isobutane, isobutane/isopropane, isobutane/propane and mixtures of isopropane, isobutane and butane. Other propellants that can be contemplated include alkyl ethers, such as dimethyl ether or compressed non-reactive gases such as air, nitrogen or carbon dioxide.

Compositions according to the invention may be prepared by suspending or dissolving a odour capture agent in a cosmetically acceptable carrier material, preferably with sufficient agitation to achieve a homogeneous mixture. When the odour capture agent is suspended in the carrier material, it is preferred that it is first ground to a mean particle size of less 100 microns. Fragrance material is preferably added to the composition after the odour capture agent has been dissolved or suspended in the carrier.

Examples

The ester poly(ethylene glycol) methyl ether cinnamate (1) was prepared by reacting poly(ethylene glycol) methyl ether with cinnamoyi chloride by the method described below.

Poly(ethylene glycol) methyl ether (20.00 g, MW ca. 2000, 9.93 mmol) was added to a 2-neck round-bottomed flask (100 ml) and heated to 80°C until liquid.

Nitrogen was bubbled through the melt to maintain an anhydrous environment and aid later expulsion of gaseous HCI. An exhaust was fitted, and cinnamoyi chloride (2.07 g, 12.42 mmol) was added portion-wise and the resultant mixture stirred for 24 hours. The melt was cooled to room temperature and dissolved in methanol (100 ml). Precipitation from ether (800 ml), followed by filtration and drying in vacuo gave 9.94 g (4.64 mmol) of poly(ethylene glycol) methyl ether cinnamate (1 ) as a white powder. ¹H NMR (400 MHz, CDCI₃) δ_Η 3.38 (3H, s, OCH₃), 3.47- 3.82 (nH, m, OCH₂CH₂O), 4.36-4.38 (2H, m, CH₂OCO), 6.48 (1 H, d, J = 16 Hz, CH=CH), 7.30-7.51 (5H, m, ArH), 7.71 (1 H, d, J = 16 Hz, CH=CH) ppm; FTIR (ATR, diamond) v 2884, 1713, 1638, 1467, 1341 , 1097, 960, 842 cm^"1. NMR indicated 79 % conjugation.

The di-ester poly(ethylene glycol) bis cinnamate (2) was prepared by reacting poly(ethylene glycol) with cinnamoyi chloride by the method described below.

Poly(ethylene glycol (32.00 g, MW: ca. 2000, 15.66 mmol) was added to a round bottomed flask (100 ml) and heated to 70°C until liquid. Nitrogen was bubbled through the melt to maintain an anhydrous environment and aid later expulsion of gaseous HCI. An exhaust was fitted and cinnamoyl chloride (6 g, 36.0 mmol) was added portion-wise and the resultant mixture stirred for 12 hours. The melt was cooled to room temperature and dissolved in methanol (100 ml). Precipitation from ether (800 ml), followed by filtration and drying in vacuo gave 27.98 g, 1 1 .90 mmol) of poly(ethylene glycol) bis cinnamate (2) as a white powder. ¹H NMR (400 MHz, CDCIs) δ_Η 3.46-3.80 (nH, m, OCH₂CH₂O), 4.36-4.38 (2H, m, CH₂OCO), 6.48 (1 H, d, J = 16 Hz, CH=CH), 7.38-7.52 (5H, m, ArH), 7.71 (1 H, d, J = 16 Hz, CH=CH) ppm; FTIR (ATR, diamond) v 2884, 1712, 1637, 1466, 1341 , 1 102, 958, 842 cm^"1. NMR indicated 98 % conjugation

The amide (3) of cinnamic acid and Jeffannine M2070^* (ex Huntsman) was prepared as follows. ^* Jeffamine M2070: CH₃O(CH₂CH₂O)6CH₂CH₂NH₂

Jeffannine M2070 (18.01 g, 9.00 mmol) was dissolved in water (100 ml) containing sodium hydrogen carbonate (0.832 g, 9.90 mmol) and cooled in an ice bath.

Cinnamoyl chloride (1 .5 g, 9.00 mmol) in THF (50 ml) was added portion-wise over 5-10 minutes and was allowed to warm to room temperature, with stirring, overnight. The reaction mixture was dialysed (SpectraPor 6, 1 KDa MWCO) for 12 hours and the resulting solution freeze-dried to afford amide 3 (18.81 g, 8.83 mmol) as a viscous oil. NMR indicated 76 % conjugation. The amide of the glycine methyl ester and cinnamic acid, i.e., methyl 2- cinnamamidoacetate (4i) was prepared as follows.

Methyl 2-aminoacetate hydrochloride (glycine methyl ester hydrochloride) (3.77 g, 30.0 mmol) was dissolved in water (20 ml) and sodium hydrogencarbonate (5.29 g, 63.0 mmol) added. Cinnamoyl chloride(3) (5 g, 30.0 mmol) dissolved in THF (10 ml) was added slowly and the mixture stirred vigorously. After 3 hours, ethyl acetate (50 ml) was added and the biphasic mixture separated. The organic layer was washed with 0.4 N HCI (25 ml), saturated aqueous sodium hydrogen carbonate (2 x 25 ml) and brine (25 ml), then dried over magnesium suphate, filtered and dried in vacuo. Methyl 2-cinnamamidoacetate (4i) (5.17 g, 23.6 mmol) was obtained as a white powder. ¹H NMR (400 MHz, CDCI₃) δ_Η 3.77 (3H, s, OCH₃), 4.19 (2H, d, J = 5.2 Hz, NCH₂), 6.50 (1 H, d, J = 16 Hz, CH=CH and 1 H, br s, NH), 7.34-7.47 (5H, m, ArH), 7.63 (1 H, d, J = 16 Hz, CH=CH) ppm. NMR indicated a high purity material (>98 % pure).

Methyl 2-cinnamamidoacetate (4i) as prepared above was transesterified with PEG45 methyl ether (4ii), by the method described below, to give the amide (4) indicated below. Ph-CH=CH-CO.NHCH₂CO.OMe + HO-(CH₂CH₂O)₄5CH3

(4i) (4ii)

Ph-CH=CH-CO.NHCH₂CO.O-(CH2CH₂O)₄5CH3

(4) PEG45 methyl ether (4ii) (16.71 g, 8.29 mmol) and methyl 2-cinnamamidoacetate (4i) (2 g, 9.12 mmol) were combined in a round bottomed flask and the mixture heated to 60-80 °C. A nitrogen line was fitted to bubble gas through mixture and vent methanol. Sulphuric acid (0.041 g, 0.415 mmol) was added and the mixture heated/stirred for 72 hours. The mixture was cooled to room temperature, dissolved in methanol (100 ml) then precipitated from diethyl ether (800 ml), filtered and dried in vacuo. The amide (4) (15.94 g, 7.24 mmol) was obtained as a pale orange crystalline solid. ¹H NMR (400 MHz, CDCI₃) δ_Η 3.38 (3H, s, OCH₃), 3.47-3.82 (nH, m, OCH₂CH₂O), 4.21 (2H, d, J = 5.3 Hz, NCH₂), 4.33 (2H, t, J = 4.8 Hz, CH₂OCO), 6.54 (1 H, d, J = 16 Hz, CH=CH), 6.63 (1 H, br s, NH), 7.36-7.51 (5H, m, ArH), 7.65 (1 H, d, J = 16 Hz, CH=CH) ppm. NMR indicated 80 % transesterifaction to the PEG45 ester.

3-mercapto-2-methylbutanol (3M2M) was prepared from 3-chloro-2-methylbutanol and thiourea via a two step process as described below.

3-chloro-2-methylbutan-1 -ol (0.5 g, 41 mmol) in absolute ethanol (30 ml) was treated with thiourea (3.1 g, 41 mmol) and heated at reflux for 4 days. After cooling, the solvent was evaporated, the remaining solid triturated with diethyl ether (3x50 ml) and dried in vacuo to yield 3.7 g of a crude thiourea salt of formula (H₂N)2C=S⁺CH(CH₃)CH(CH₃)CH₂OH.Cr, as a white solid.

A solution of the crude thiourea salt (2 g, 10 mmol) in 2M NaOH (20 ml) was heated at reflux for one hour. The cooled solution was acidified with 1 MHCI to pH1 and then extracted with diethyl ether (4x50 ml). The combined organic fractions were dried over anhydrous magnesium sulphate and evaporated to yield 0.9 g of the desired thiol.

3M2M is an extremely odiferous molecule. The neutralisation of its odour was assessed using the following protocol.

5 ml of an aqueous solution of each of the odour neutralisers indicated in Table 1 was prepared in 120 ml amber, screw cap, glass jar. To each solution was added 100 μΙ of a 0.01 % v/v solution of 3M2M in propylene glycol. The jars were sealed and the odour within assessed at 30 minute intervals by an expert panel of two assessors. Table 1 indicates the period required for complete odour neutralisation by each of the odour neutralisers. Table 1

The cinnamate esters (1) and (2) were prepared as described above. The acrylate esters (A) and (B) were obtained from Sigma Aldrich Co. The PEG chain lengths of acrylate esters (A) and (B) were the same as those of cinnamate esters (1) and (2): n = approximately 45.

The above results indicate that the cinnamate esters of the present invention are much more effective neutralisers of the 3M2M malodour than the acrylate esters as disclosed in EP 2,524,704 A2 (IFF Inc., 2012).

In a further experiment, neutralisation of 3M2M by the cinnamide of Jeffamine M2070 (3) and the cinnamide of glycine PEG45 ester (4), prepared as described above, were compared with that of poly(ethylene glycol) methyl ether cinnamate (1) using the test procedure detailed above, but with a single assessment of thiol odour being made after 30 minutes. The results are indicated in Table 2. Table 2

In a further series of experiments, roll-on compositions as indicated in Table 3 were prepared using methods known in the art. 0.3 g of each of these roll-on compositions was placed in a glass vial (10 ml) within a 120 ml amber, screw cap glass jar. To each of the vials was added 10 μΙ of 3M2M in propylene glycol. The jars were then sealed and the odour within assessed at time intervals indicated in Table 2 by an expert assessor on a 0 to 100 line scale.

With reference to Table 2, it may be noted that the molar concentration of poly(ethylene glycol) methyl ether cinnamate (1) in Composition 1 was 4.7 mmoldm^"3, whereas the molar concentration of 2-ethylhexyl 4-methoxycinnamate in Composition C was 5.1 mmoldm^"3.

With odour neutralisations via chemical reaction, it is of course the molar amounts of active that are of relevance. Hence, the above results indicate that the hydrophilic cinnamate esters of the present invention are much more effective neutralisers of the 3M2M malodour than the hydrophobic cinnamate esters such as2-ethylhexyl 4-methoxycinnamate disclosed in WO 02/051788 (Givaudan, Table 3

The compositions indicated in the following tables are examples according to the invention and may be prepared by methods known in the art. All amounts are percentages by weight of the total composition. Table 4: Squeeze Spray Compositions

Table 5: Solid Compositions

1 . C12-C15 alkyl benzoate, ex Finetex.

2. Poloxamine 1307, ex BASF. Table 6: Roll-on Compositions

Table 7: Aerosol Compositions

Cinnamide of Jeffannine M2070, prepared as described above.

Cinnamide of glycine PEG45 ester, prepared as described above.

Claims

1 . A non-therapeutic method of reducing malodour comprising the application to the surface of the human body of a composition comprising a

cosmetically acceptable carrier material and an ester or amide of an aromatic carboxylic acid of formula Ar-CH=CH-CO₂H, wherein Ar is an optionally substituted phenyl group, characterised in that the ester or amide is hydrophilic in nature.

2. A method according to claim 1 , wherein the ester or amide has a water solubility of at least 1 g/l at 25°C or is a water-insoluble solid having a hydrophilic surface such that water has a contact angle with it of 60° or less.

3. A method according to claim 2, wherein the ester or amide has a water solubility of at least 10 g/l at 25°C or is a water-insoluble solid having a hydrophilic surface such that water has a contact angle with it of 60° or less.

4. A method according to claim 3, wherein the ester or amide has a water solubility of at least 100 g/l at 25°C or is a water-insoluble solid having a hydrophilic surface such that water has a contact angle with it of 60° or less.

5. A method according to any of the preceding claims, wherein the ester or amide is of formula Ar-CH=CH-CO.O-X or Ar-CH=CH-CO.NH-X, respectively, wherein X is a water insoluble hydrophilic solid such that water has a contact angle with it of 60° or less or comprises sufficient ethyleneoxy (EO) and/or propyleneoxy (PO) groups to give the ester or amide a water solubility of at least 1 g/l.

6. A method according to any of the preceding claims, wherein the ester or amide is water soluble.

7. A method according to claim 6, wherein the ester or amide is of formula Ar- CH=CH-CO.O-(PO)_m-(EO)n-R' or Ar-CH=CH-CO.NH-Y-(PO)_m(EO)_n-R\ respectively, wherein R' is H, C1 -C4 alkyl, or CO.CH=CH-Ar, Y is an optionally present linking group, m is from 0 to 20 and n is from 0 to 200, with the proviso that m + n is at least 4.

8. A method according to claim 7, wherein the ester or amide is selected from the group consisting of:

Ar-CH=CH-CO.O-(EO)_n-CH₃

Ar-CH=CH-CO.O-(EO)_n-CO.CH=CH-Ar

Ar-CH=CH-CO.NH-(EO)_n-CH₃ and

Ar-CH=CH-CO.NH-CH₂CO.O-(EO)_n-CH₃

wherein, n is 2 to 200, preferably 4 to 100 and more preferably 5 to 50 and Ar is preferably Ph for whichever level of ethoxylation is present.

9. A method according to any of the preceding claims, wherein the

composition comprises a fragrance.

10. A method according to any of the preceding claims, wherein the ester is present in the composition at a level at least 0.1 % by weight of the total composition, excluding any volatile propellant that may be present.

1 1 . A method according to any of the preceding claims, wherein the

composition comprises humectant oil.

12. A process for capturing malodourous materials, utilising a method according to any of the preceding claims.

13. A cosmetic composition comprising a cosmetically acceptable carrier

material and an ester or amide of an aromatic carboxylic acid of formula

Ar-CH=CH-CO₂H, wherein Ar is an optionally substituted phenyl group, characterised in that the ester or amide has a water solubility of at least 1 g/l at 25°C or is a water-insoluble solid having a hydrophilic surface such that water has a contact angle with it of 60° or less.

14. A cosmetic composition according to claim 13 or claim 14 comprising

fragrance.

15. The use of a composition according to claim 13 or claim 14 for capturing malodour.