Fragrance precursor conjugates

Abstract

The invention relates to perfume precursor conjugates. The present invention relates to perfume precursor compounds and their preparation. Delivery systems and consumer products containing these perfume precursor compounds are also disclosed.

Description

[0001] This application is a divisional application of the parent application No. 202180039566.3. The application date of the parent application is June 3, 2021; the name of the invention is "Fragrance Precursor Conjugate". Technical Field

[0002] The present invention relates to profragrance compounds for the controlled release of fragrance molecules in consumer products. Background Art

[0003] Pro-fragrances have been used in the fragrance industry to provide protection to labile fragrance molecules and enhance delivery in a controlled manner.

[0004] Conjugated compounds have been used as fragrance precursors. WO 2003 / 049666 A2 describes sulfur-containing conjugated compounds for controlled release of fragrance ingredients. US2016 / 0222327 A1 discloses thioether conjugates as fragrance precursors. Upon exposure to triggering conditions such as light, water, heat or pH changes, these conjugates decompose and release fragrance molecules and thiol compounds. See also WO 2002 / 038120A1. However, due to incomplete release, fragrance precursors often have a weak perceived fragrance intensity. Many by-product thiol compounds have a strong unpleasant odor, which needs to be suppressed by additives.

[0005] There is a need to develop pro-fragrances that have high release rates but do not have an unpleasant odor. Summary of the invention

[0006] The present invention provides novel pro-fragrance compounds and their unexpectedly advantageous delivery of fragrance molecules at high perceived fragrance intensity when used in consumer products such as fabric care products, personal care products, home care products, and the like.

[0007] One aspect of the present invention relates to a pro-fragrance compound which is a Michael addition product of one or two fragrance molecules and 3,6-dioxa-1,8-octane-dithiol, wherein each of the one or two fragrance molecules has an α,β-unsaturated carbonyl group. When the pro-fragrance compound is a Michael addition product of two fragrance molecules and 3,6-dioxa-1,8-octane-dithiol, the two fragrance molecules may be different or the same.

[0008] Preferably, the one or two fragrance molecules are selected from the group consisting of coumarin, isojasmone, 1-(5,5-dimethyl-1-cyclohexenyl)pent-4-en-1-one, 2-(4-methylbenzylidene)heptanal, damascone, 2-methylpent-3-yl but-2-enoate, and 4-methyldec-3-en-5-one.

[0009] Another aspect of the present invention relates to a delivery system containing the above-mentioned pro-fragrance compounds. Also within the scope of the present invention are consumer products containing one or more of these pro-fragrance compounds. Also included within the scope of the present invention are fragrance compositions containing one or more of these pro-fragrance compounds, and methods of improving, enhancing or modifying fragrance formulations by adding olfactory acceptable amounts of one or more of these pro-fragrance compounds. DETAILED DESCRIPTION

[0010] It has been surprisingly and unexpectedly discovered that the pro-fragrance compounds of the present invention can effectively deliver fragrance molecules having high fragrance properties.

[0011] These pro-fragrance compounds have the following general structure:

[0012]

[0013] Where R 1 and R 2 Each of which may be H or a fragrance moiety, provided that R 1 and R 2 At least one of them is a flavoring component. 1 and R 2 When they are all flavor moieties, they may be the same or different. Each flavor moiety is derived from a compound having an α,β-unsaturated carbonyl group ( wherein the wavy borders represent covalent bonds). This α,β-unsaturated perfume molecule can react with 3,6-dioxa-1,8-octane-dithiol to form a Michael addition product of a compound having formula A.

[0014] Exemplary compounds having Formula A include those shown in Scheme 1 below:

[0015] Suitable α,β-unsaturated flavor molecules include:

[0016]

[0017] Other suitable α,β-unsaturated fragrance molecules include (E)-2-(4-methylbenzylidene)heptanal (Acalea TM ), allyl cinnamate, ethyl cinnamate, (Z)-3-phenylacrylonitrile (Cinnamalva TM), 3-phenylpropenal (cinnamaldehyde), (E)-2-methylbut-2-enoic acid ethyl ester (tiglic acid ethyl ester), 2-benzylideneoctanal (hexylcinnamaldehyde), 3-methyl-2-pentylcyclopent-2-en-1-one (dihydrojasmone), (Z)-3-methyl-2-(pent-2-en-1-yl)cyclopent-2-en-1-one (cis-jasmone), 2-methyl-4-oxo-4H-pyran-3-yl isobutyrate (maltol isobutyrate), (E)-2-methyl-3-phenylpropenal (methylcinnamaldehyde), and 1-(3,6,8,8-tetramethyl-2,3,4,7,8,8a-hexahydro-1H-3a,7-oxomethylazulen-5-yl)ethan-1-one The preferred α,β-unsaturated fragrance molecule is (E)-2-(4-methylbenzylidene)heptanal (Acalea TM ), allyl cinnamate, ethyl cinnamate, 3-phenyl-acrolein (cinnamaldehyde), ethyl tiglate, 3-methyl-2-pentylcyclopent-2-en-1-one (dihydrojasmone), and (Z)-3-methyl-2-(pent-2-en-1-yl)cyclopent-2-en-1-one (cis-jasmone).

[0018] The fragrance precursor compounds of the present invention can be used as independent free ingredients in any fragrance composition and consumer products. They can also be incorporated into delivery systems, including microcapsule delivery systems (WO 2015 / 023961A1), polymer-assisted delivery systems (polymer particles, see US 8,187,580), fiber-assisted delivery systems (US2010 / 0305021), cyclodextrin complexes (US 6,287,603 and US2002 / 0019369), coacervate complexes (WO 2019 / 179939 A1 and US10,092,023B2), and any combination thereof. Preferably, the delivery system is sustainable or biodegradable.

[0019] As used herein, "biodegradable" with respect to a material (such as a microcapsule as a whole and / or a biopolymer of a microcapsule shell) has no actual or perceived health and / or environmental issues and is capable of and / or does undergo physical, chemical, thermal, microbial and / or biological degradation. Ideally, the microcapsules and / or biopolymers are considered "biodegradable" when they pass one or more of the Organization for Economic Co-operation and Development (OECD) tests, including but not limited to OECD 301 / 310 (rapid biodegradation), OECD 302 (intrinsic biodegradation), ISO 17556 (solid stimulation study), ISO 14851 (fresh water stimulation study), ISO 18830 (marine sediment stimulation study), OECD 307 (soil stimulation study), OECD 308 (sediment stimulation study), and OECD 309 (water stimulation study). In a particular embodiment, the microcapsules are readily biodegradable as determined using the OECD 310 test. The passing level for rapid biodegradability according to OECD 310 is 60% ThC02 production within a 10-day window within a 28-day test period, where the 10-day window begins when the extent of biodegradation reaches 10%.

[0020] Suitable microcapsule delivery systems each contain a plurality of microcapsules dispersed in an aqueous phase, wherein each of these microcapsules has a core-shell structure having a single microcapsule core and a microcapsule shell encapsulating the microcapsule core. The microcapsule core has active materials such as fragrance precursors, spices, flavors, malodor-removing active substances, cosmetic active substances, nutrients, etc. The microcapsule wall is formed by an encapsulating polymer, which can be selected from the group consisting of: sol-gel polymers (e.g., silica), polyacrylates, polyacrylamides, poly(acrylate-co-acrylamide), polyureas, polyurethanes, starches, gelatin and gum arabic, coacervate complexes, poly(melamine-formaldehyde), poly(urea-formaldehyde), proteins, polysaccharides, polyphenols, and combinations thereof.

[0021] The compounds of the present invention are widely used in perfumed products, including the preparation of perfumes and colognes, personal care products (such as soaps, shower gels, and hair care products), fabric care products, air fresheners, and perfumed cosmetic preparations. The present invention can also be used for perfumed cleaning agents, such as detergents, dishwashing materials, scrubbing compositions, window cleaning materials, etc.

[0022] In these preparations, the fragrance precursor compounds of the present invention can be used alone or in combination with other fragrance compositions, solvents, adjuvants, etc. The properties and types of other ingredients that can also be used are known to those skilled in the art. Many types of fragrance ingredients can be used in the present invention, the only limitation being the compatibility with the other components used. Suitable fragrance ingredients include, but are not limited to, fruits such as almonds, apples, cherries, grapes, pears, pineapples, oranges, strawberries, raspberries; musk; floral scents such as lavender, roses, irises, and carnations. Other pleasant smells include herbal and woodland smells derived from pine, spruce and other forest smells. Fragrance ingredients can also be derived from various oils (such as essential oils) or derived from plant materials (such as mint, spearmint, etc.).

[0023] A list of suitable perfume ingredients is provided in U.S. Patent No. 4,534,891, the contents of which are incorporated by reference in their entirety as set forth. Another source of suitable perfume ingredients is found in Perfumes, Cosmetics and Soaps, 2nd edition, edited by W.A. Pocket in 1959. Among the perfume ingredients provided in this monograph are acacia, acacia, chypre, cyclamen, fern, gardenia, hawthorn, heliotrope, honeysuckle, hyacinth, jasmine, clove, lily, magnolia, mimosa, narcissus, fresh cut hay, orange blossom, orchid, mignonette, sweet pea, clover, tuberose, vanilla, violet, bamboo, and the like.

[0024] The pro-fragrance compounds of the present invention can be used in combination with complementary fragrance compounds. As used herein, the term "complementary fragrance compound" is defined as a fragrance compound selected from the group consisting of: 2-[(4-methylphenyl)methylene]-heptanal (Acalea), allyl isopentyloxyacetate (allylpentyl glycolate), (3,3-dimethylcyclohexyl)ethylethylpropane-1,3-dioate (Applelide), (E / Z)-1-ethoxy-1-decene (Arctical), 2-ethyl-4-(2,2,3-trimethyl-3-cyclo-penten-1-yl)-2-buten-1-ol (Bacdanol), 2-methyl-3-[(1,7,7-trimethylbicyclo[2.2.1]hept-2-yl)oxy]exo-1-propanol (Bornafix), 1,2,3,5,6,7-hexahydro-1,1,2,3,3-pentamethyl-4H-inden-4-one (Cash meran), trimethylcyclopentenylmethyloxabicyclooctane (Cassiffix), 1,1-dimethoxy-3,7-dimethyl-2,6-octadiene (Citral DMA), 3,7-dimethyl-6-octen-1-ol (Citronellol), 3A,4,5,6,7,7A-hexahydro-4,7-methano-1H-inden-5 / 6-yl acetate (Cyclac et), 3A,4,5,6,7,7A-hexahydro-4,7-methano-1H-inden-5 / 6-yl propionate (Cyclaprop), 3A,4,5,6,7,7A-hexahydro-4,7-methano-1G-inden-5 / 6-yl butyrate (Cyclobutanate), 1-(2,6,6-trimethyl-3-cyclohexen-1-yl)-2-buten-1-one (Delta Damascone), 3-(4-ethylphenyl)-2,2-dimethylpropionitrile (Fleuranil), 3-(O / P-ethylphenyl)-2,2-dimethylpropionaldehyde (Floralozone), tetrahydro-4-methyl-2-(2-methylpropyl)-2H-pyran-4-ol (Floriffol), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-γ-2-benzopyran (Galaxolide), 1-(5,5-dimethyl-1-cyclohexen-1-yl)pent-4-en-1-one (Galbascone), E / Z-3,7-dimethyl-2,6-octadien-1-yl acetate (Geranyl acetate Acetate), α-methyl-1,3-benzodioxole-5-propionaldehyde (Helional), 1-(2,6,6-trimethyl-2-cyclohexene-1-yl)-1,6-heptadien-3-one (Hexalon), (Z)-3-hexenyl-2-hydroxybenzoate (cis-3-hexenyl salicylate (CIS-3)), 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one (α-ionone (Iononeα)), 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthyl)-ethan-1-one (Iso E Super), 3-oxo-2-pentylcyclopentaneacetate (Kharismal), 2,2,4-trimethyl-4-phenyl-butyronitrile (Khusinil), 3,4,5,6,6-pentamethylhept-3-en-2-one (Koavone), 3 / 4-(4-hydroxy-4-methyl-pentyl)cyclohexene-1-carbaldehyde (Lyral), 3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-butene-2-one (γ-methylionone (Methyl Iononeγ)), 1-(2,6,6-trimethyl-2-cyclohexen-1-yl)pent-1-en-3-one (α-methylionone extra (Methyl IononeαExtra), methylionone N (Methyl Ionone N)), 3-methyl-4-phenylbutan-2-ol (Muguesia), cyclopentadecan-4-en-1-one (Musk Z4), 3,3,4,5,5-pentamethyl-11,13-dioxatricyclo[7.4.0.0<2,6>]tridec-2(6)-ene (Nebulone), 3,7-dimethyl-2,6-octadien-1-yl acetate (Neryl Acetate), 3,7-dimethyl-1,3,6-octatriene (Ocimene), o-tolylethanol (Peomosa), 3-methyl-5-phenylpentanol (Phenoxanol), 1-methyl-4-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde (Precyclemone B), 4-methyl-8-methylene-2-adamantanol (Prismantol), 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol (Sanjinol), 2-methyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol (Santaliff), terpineol, 2,4-dimethyl-3-cyclohexene-1-carbaldehyde (Triplal), decahydro-2,6,6,7,8,8-hexamethyl-2H-indeno[4,5-B]furan (Trisamber), 2-tert-butylcyclohexyl acetate (Verdox), 4-tert-butylcyclohexyl acetate (Vertenex), acetyl cedrene (Vertofix), 3,6 / 4,6-dimethylcyclohex-3-ene-1-carbaldehyde (Vertoliff) and (3Z)-1-[(2-methyl-2-propenyl)oxy]-3-hexene (Vivaldie).

[0025] The terms "fragrance formulation", "fragrance composition", and "perfuming composition" are synonymous and refer to a consumer composition comprising a mixture of fragrance ingredients such as alcohols, aldehydes, ketones, esters, ethers, lactones, nitriles, natural oils, synthetic oils, and thiols, which are mixed so that the combined odor of the individual components produces a pleasant or desirable aroma. The fragrance formulation of the present invention is a consumer composition comprising the compound of the present invention. The fragrance formulation of the present invention comprises the compound of the present invention and further comprises a complementary fragrance compound as defined above.

[0026] The term "fragrance molecule" refers to the final fragrance ingredient released from the pro-fragrance compound.

[0027] The term "fragrance product" means a consumer product containing a fragrance ingredient that increases fragrance or masks malodor. Fragrance products may include, for example, perfume; cologne; bar soap; liquid soap; shower gel; bubble bath (foambath); makeup; skin care products such as creams, lotions and shaving products; hair care products for shampooing, rinsing, conditioning, bleaching, coloring, dyeing and styling; deodorants and antiperspirants; feminine care products such as tampons and feminine hygiene products; baby care products such as diapers, bibs and wipes; home care products such as bath tissue, facial tissue, paper handkerchief or paper towels; towel); fabric products such as fabric softeners and fabric fresheners; air care products such as air fresheners and fragrance delivery systems; cosmetic preparations; cleaners and disinfectants such as detergents, dishwashing materials, scouring compositions, glass and metal cleaners (such as window cleaners), countertop cleaners, floor and carpet cleaners, toilet cleaners and bleach additives; cleaning agents such as general-purpose, heavy-duty, and hand or delicate fabric cleaners (including laundry detergents and rinse additives); dental and oral hygiene products such as toothpaste, tooth gel, dental floss, denture cleaners, denture adhesives, dentifrice, tooth whiteners and mouthwashes; health care and nutritional products and food products such as snacks and beverage products. The fragrance products of the present invention are consumer products containing the compounds of the present invention. The fragrance products of the present invention contain the compounds of the present invention and further contain complementary fragrance compounds as defined above.

[0028] The term "improving" in the phrase "improving, enhancing or modifying a fragrance formulation" is understood to mean raising a fragrance formulation to a more desirable characteristic. The term "enhancing" is understood to mean making a fragrance formulation more effective or providing improved characteristics to the fragrance formulation. The term "modifying" is understood to mean providing a change in the characteristics of a fragrance formulation.

[0029] The term "olfactory acceptable amount" is understood to mean the amount of a compound in a perfume formulation, wherein the compound will contribute its unique olfactory characteristics. However, the olfactory effect of a perfume formulation will be the sum of the effects of the individual perfume ingredients. Therefore, the compounds of the present invention can be used to improve or enhance the aromatic characteristics of a perfume formulation, or to modify the olfactory response contributed by other ingredients in the formulation. The olfactory acceptable amount can vary depending on many factors, including other ingredients, their relative amounts, and the desired olfactory effect.

[0030] The amount of the compound of the present invention used in the fragrance formulation varies from 0.0001 to 70 weight percent, preferably from 0.005 to 50 weight percent, more preferably from 0.5 to 25 weight percent, and even more preferably from 1 to 10 weight percent. Those skilled in the art will be able to use the desired amount to provide the desired fragrance effect and intensity. In addition to the compound of the present invention, other materials can also be used in conjunction with the fragrance formulation to encapsulate and / or deliver fragrance. Some well-known materials are, for example, but not limited to, polymers, oligomers, and other adjuvants such as surfactants, emulsifiers, lipids including fats, waxes and phospholipids, organic oils, mineral oils, petrolatum, natural oils, perfume fixatives, fibers, starches, sugars and solid surface materials such as zeolites and silica.

[0031] When used in fragrance formulations, these ingredients provide protection to vulnerable fragrance molecules and release them with additional notes when triggered to make the fragrance formulation more pleasant and attractive, and increase the perceived value. The odor qualities found in these fragrance molecules help to beautify and enhance the finished product consistency, as well as improve the performance of other materials in the fragrance composition.

[0032] Additionally, the compounds of the present invention can be used to protect fragrance molecules in malodor counteracting applications such as human perspiration, environmental odors such as mold and mildew, bathrooms, etc. These fragrance molecules substantially eliminate the perception of malodors and / or prevent the formation of such malodors and can therefore be used with a wide variety of consumer products.

[0033] Examples of consumer products are provided herein to illustrate various aspects of the present invention. However, they are not intended to limit the scope of the present invention. Consumer products may include, for example, conventional room freshener (or deodorant) compositions, such as room freshener sprays, aerosols or other sprays; scent diffusers, wicks or other liquid systems, or solids, such as candles or wax bases in scent boxes and plastics, powders in sachets or dry sprays, or gels such as in solid gel sticks; deodorants for clothing such as those applied by washing machine applications, such as detergents, powders, liquids, whitening agents or fabric softeners, fabric fresheners, linen sprays, closet blocks, closet aerosol sprays. spray), or in clothing storage areas or during dry cleaning to overcome residual solvent notes on clothing; bathroom accessories such as paper towels, toilet paper, sanitary napkins, wet wipes, disposable wash cloths, disposable diapers and diaper pail deodorants; cleaning products such as disinfectants and toilet bowl cleaners; cosmetic products such as antiperspirants and deodorants; general body deodorants in powder, aerosol, liquid or solid form; or hair care products such as hair sprays, conditioners, rinses, hair colorants and dyes, perms, depilatories, straighteners; hair grooming applications (hair grooming applications) application) such as pomades, creams and lotions; medicated hair care products, or shampoos containing ingredients such as selenium sulfide, coal tar or salicylates; or foot care products such as foot powders, liquids or colognes; aftershaves and body lotions; or soaps and synthetic detergents such as bars, liquids, foams or powders; odor control such as during manufacturing processes (such as textile finishing and printing (ink and paper)); effluent control such as in processes involving pulping, livestock farming and meat processing; sewage treatment; garbage bags or garbage disposal; or in product odor control, such as in textile finished products, rubber finished products or car air fresheners; agricultural and pet care products, such as dog and chicken house effluents and livestock and pet care products such as deodorants, shampoos or detergents, or animal hygiene litter materials; and in large-scale closed air systems such as auditoriums, and subways and transportation systems.

[0034] Thus, it can be seen that the compositions of the present invention are typically compositions in which the malodor counteractant is present together with a carrier, by means of which or from which the malodor counteractant can be introduced into an air space in which the malodor is present, or into a substrate on which the malodor is deposited. For example, the carrier can be an aerosol propellant such as chlorofluoromethane, or a solid such as a wax, plastic material, rubber, inert powder or gel. In core-type air fresheners, the carrier is a low-volatility, substantially tasteless liquid. In several applications, the compositions of the present invention contain a surfactant or disinfectant, while in other applications, the malodor counteractant is present on a fibrous substrate. In many compositions of the present invention, there is also a fragrance component that imparts fragrance to the composition. All of the above fragrances can be used.

[0035] The malodor counteracting effective amount is understood to mean the sensory effective amount of the malodor counteracting agent of the present invention used in the functional product to reduce the combined intensity of the odor level while reducing the given malodor, wherein the given malodor is present in the air space or has been deposited on the substrate. The exact amount of the malodor counteracting agent used may vary depending on the type of malodor counteracting agent, the type of carrier used, and the desired level of malodor counteracting. In general, the amount of malodor counteracting agent present is the ordinary dose required to obtain the desired result. Such doses are known to those skilled in the art. In a preferred embodiment, when used in combination with malodorous solid or liquid functional products such as soaps and detergents, the compound of the present invention can be present in an amount ranging from 0.005 to 50 weight percent, preferably from 0.01 to 20 weight percent, and more preferably from 0.05 to 5 weight percent, and when used in combination with malodorous gaseous functional products, the compound of the present invention can be present in an amount ranging from 0.1 to 10 mg / cubic meter of air.

[0036] The following is provided as a specific embodiment of the present invention. Other modifications of the present invention will be apparent to those skilled in the art. Such modifications are understood to be within the scope of the present invention. Unless otherwise stated, all percentages as used herein are weight percentages, ppm is understood to represent parts per million, L is understood to be liters, mL is understood to be milliliters, g is understood to be grams, Kg is understood to be kilograms, mol is understood to be moles, psi is understood to be pounds per square inch, and mmHg is understood to be millimeters (mm) of mercury (Hg). IFF as used in the examples is understood to mean International Flavors & Fragrances Inc., New York City, New York, USA.

[0037] The present invention is described in more detail by the non-limiting examples below. Without further elaboration, it is believed that those skilled in the art can utilize the present invention to its maximum extent based on the description herein. All publications cited herein are incorporated by reference in their entirety.

[0038] Example 1

[0039]

[0040] To a solution of 2H-chroman-2-one (II, 6 g, 41.1 mmol) and 1,8-diazabicyclo[5.4.0]undec-7-ene ("DBU", 0.625 g, 4.11 mmol) in tetrahydrofuran ("THF", 10 g) was added 2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-1-thiol) (I, 3.74 g, 20.5 mmol). The reaction mixture was stirred at room temperature for 5 hours. The solvent was removed under reduced pressure to afford a clear yellowish oil, which was purified by flash chromatography to give 0.83 g of 4-((2-(2-mercapto-ethoxy)ethoxy)ethyl)thio)chroman-2-one (IV, 12%) and 0.4 g of 4,4'-(((ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))bis(sulfanediyl))bis(chroman-2-one) (III, 4%).

[0041] Compound III 1 H NMR (400 MHz, CHLOROFORM-d) δ: 7.31 (m, 4H), 7.11 (m, 4H), 4.40 (t, J=4.14 Hz, 2H), 3.64 (m, 8H), 3.07 (m, 4H), 2.71 (m, 4H).

[0042] Compound IV 1 H NMR (400 MHz, CHLOROFORM-d) δ: 7.33 (m, 2H), 7.13 (m, 2H), 4.45 (t, J = 4.15 Hz, 1H), 3.65 (m, 8H), 3.10 (m, 2H), 2.71 (m, 4H), 1.58 (t, J = 8.19 Hz, 1H).

[0043] Example 2

[0044]

[0045] To a solution of (E)-2-methylpentan-3-yl ester of but-2-enoic acid (V, 6 g, 35.2 mmol) and DBU (0.537 g, 3.52 mmol) in THF (10 g) was added 2,2'-(ethane-1,2-diylbis(oxy))bis-(ethane-1-thiol) (I, 3.21 g, 17.6 mmol). The reaction mixture was stirred at room temperature for 6 hours. The solvent was removed under reduced pressure. The crude product was purified by flash chromatography to give 3.5 g of 3,14-dimethyl-7,10-dioxa-4,13-dithiahexadecandioic acid bis(2-methyl-pentan-3-yl) ester (VI, 38%) and 1.1 g of 3-((2-(2-(2-mercaptoethoxy)ethoxy)ethyl)thio)butanoic acid 2-methylpentan-3-yl ester (VII, 18%).

[0046] Compound VI 1 H NMR(500MHz, chloroform-d)δ:4.67(m,2H),3.60(m,8H),3.23(m,2H),2.73(m,4H),2.63(m, 2H), 2.43 (m, 2H), 1.81 (m, 2H), 1.53 (m, 4H), 1.31 (d, J = 6.60Hz, 6H), 0.86 (m, 18H).

[0047] Compound VII 1 H NMR (500 MHz, CHLOROFORM-d) δ: 4.69 (m, 1H), 3.63 (m, 8H), 3.26 (m, 1H), 2.61-2.80 (m, 5H), 2.44 (m, 1H), 1.82 (m, 1H), 1.57 (t, J = 8.23 ​​Hz, 1H), 1.53 (m, 2H), 1.33 (d, J = 6.88 Hz, 3H), 0.88 (m, 9H).

[0048] Example 3

[0049]

[0050] To a solution of 2-hexylcyclopent-2-en-1-one (VIII, 6 g, 36.1 mmol) and DBU (0.549 g, 3.61 mmol) in THF (10 g) was added 2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-1-thiol) (I, 3.29 g, 18.04 mmol). The reaction mixture was stirred at room temperature for 6 hours. The solvent was removed under reduced pressure to afford a slightly turbid oil, which was purified by flash chromatography to give 1.4 g of 3,3'-(((ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))bis(sulfane-diyl))bis(2-hexylcyclopentan-1-one) (IX, 15%) and 0.7 g of 2-hexyl-3-((2-(2-(2-mercaptoethoxy)-ethoxy)ethyl)thio)cyclo-pentan-1-one (X, 11%).

[0051] Compound IX 1 H NMR (500 MHz, CHLOROFORM-d) δ: 3.65 (m, 8H), 3.09 (m, 2H), 2.75 (m, 4H), 2.41 (m, 4H), 2.11 (m, 2H), 1.98 (m, 2H), 1.83 (m, 2H), 1.58 (m, 4H), 1.19-1.46 (m, 16H), 0.86 (m, 6H).

[0052] Compound X 1H NMR (500 MHz, CHLOROFORM-d) δ: 3.62 (m, 8H), 3.12 (m, 1H), 2.78 (m, 2H), 2.67 (m, 2H), 2.41 (m, 2H), 2.14 (m, 1H), 1.98 (m, 1H), 1.85 (m, 1H), 1.57 (m, 3H), 1.19-1.45 (m, 8H), 0.86 (m, 3H).

[0053] Example 4

[0054]

[0055] To a solution of 1-(2,6,6-trimethylcyclohex-3-en-1-yl)but-2-en-1-one (XI, 6 g, 31.2 mmol) and DBU (0.475 g, 3.12 mmol) in THF (10 g) was added compound I (2.84 g, 15.6 mmol) The reaction mixture was stirred at room temperature for 6 hours. The solvent was removed under reduced pressure to afford a clear bright yellow oil, which was purified by flash chromatography to give 2.6 g of 3,14-dimethyl-1,16-bis(2,6,6-trimethylcyclohex-3-en-1-yl)-7,10-dioxa-4,13-dithiahexadecane-1,16-dione (XII, 29%) and 0.9 g of 3-((2-(2-(2-mercaptoethoxy)ethoxy)ethyl)thio)-1-(2,6,6-trimethylcyclohex-3-en-1-yl)butan-1-one (XIII, 15%).

[0056] Compound XII 1 H NMR (500 MHz, CHLOROFORM-d) δ: 5.52 (m, 2H), 5.45 (m, 2H), 3.62 (m, 8H), 3.33 (, 2H), 2.69 (m, 8H), 2.51 (m, 2), 2.19 (m, 2H), 1.96 (m, 2H), 1.68 (m, 2H), 1.29 (d, J = 6.92 Hz, 6H), 0.92 (m, 18H).

[0057] Compound XIII 1 H NMR(500MHz, chloroform-d)δ:5.52(m,1H),5.43(m,1H),3.62(m,8H),3.33(m,1H),2.47-2.92(m,2H),2.72(m,4H),2.51 (m,1H),2.20(m,1H),1.95(m,1H),1.68(m,1H),1.57(t,J=8.23Hz,1H),1.29(m,3H),0.95(m,6H),0.87(m,3H).

[0058] Example 5

[0059]

[0060] To a solution of 1-(5,5-dimethylcyclohex-1-en-1-yl)pent-4-en-1-one (XIV, 6 g, 31.2 mmol) and DBU (0.475 g, 3.12 mmol) in THF (10 g) was added 2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-1-thiol) (I, 2.84 g, 15.6 mmol). The reaction mixture was stirred at room temperature for 6 hours. The solvent was removed under reduced pressure to give a yellowish oil, which was purified by flash chromatography to yield 3.9 g of 1,1'-((((ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))bis(sulfanediyl))bis-(5,5-dimethyl-cyclohexane-2,1-diyl))bis(pent-4-en-1-one) (XV, 44%) and 0.6 g of 1-(2-((2-(2-mercaptoethoxy)ethoxy)ethyl)thio)-5,5-dimethylcyclohexyl)-pent-4-en-1-one (XVI, 11%).

[0061] Compound XV 1 H NMR(500MHz, chloroform-d)δ:5.80(m,2H),5.00(m,4H),3.54(m,8H),2.63(m,12H),2 .31(m,4H),1.95(m,2H),1.54(m,2H),1.40(m,4H),1.21(m,4H),0.9(m,12H).

[0062] Compound XVI 1 H NMR (400 MHz, chloroform-d) δ: 5.76-5.91 (m, 1H), 4.94-5.12 (m, 2H), 3.53-3.69 (m, 8H), 2.46-2.82 (m, 8H), 2.28-2.42 (m, 2H), 1.93-2.07 (m, 1H), 1.53-1.66 (m, 2H), 1.38-1.51 (m, 2H), 1.16-1.34 (m, 2H), 0.95 (s, 3H), 0.94 (s, 3H).

[0063] Example 6

[0064]

[0065] To a solution of (E)-4-methyldec-3-en-5-one (XVII, 5 g, 29.7 mmol) and DBU (0.18 g, 1.19 mmol) in tetrahydrofuran ("THF", 5 g) was added 2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-1-thiol) (I, 2.17 g, 11.9 mmol). The reaction mixture was stirred at room temperature for 24 hours. The solvent was removed under reduced pressure to provide a yellow oil, which was purified by flash chromatography to give 6.17 g of 8,19-diethyl-7,20-dimethyl-12,15-dioxa-9,18-dithiacosaccharide-6,21-dione (XVIII, 73%) and 0.5 g of 3-((2-(2-mercaptoethoxy)ethoxy)ethyl)thio)-4-methyldec-5-one (XIX, 11%).

[0066] 1H NMR (400 MHz, chloroform-d) δ of compound XVIII: 3.51-3.71 (m, 8H), 2.79-2.90 (m, 2H), 2.60-2.78 (m, 6H), 2.38-2.58 (m, 4H), 1.39-1.74 (m, 8H), 1.22-1.38 (m, 8H), 1.19 (d, J = 7.0 Hz, 80% of 6H), 1.07 (d, J = 6.9 Hz, 20% of 6H), 0.98-1.04 (m, 6H), 0.89 (t, J = 7.1 Hz, 6H).

[0067] Comparative Compounds IV', IV", IX', and X'

[0068] Comparative Compound IV' was prepared following the same procedure as described in Example 1, except that 1,8-octanedithiol was used instead of 2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-1-thiol). 1-dodecanethiol (C 12 SH) to prepare comparative compound IV". Similarly, comparative compound IX' was prepared using 1,8-octanedithiol following the procedure in Example 3. Comparative compound X' was also prepared using 1-dodecanethiol.

[0069] The chemical structures of these comparative compounds are shown below.

[0070]

[0071] Study on the headspace release of fabric softener

[0072] Compound IV and comparative compounds IV' and IV" were evaluated in a fabric softener headspace study. Compound II was used as a control.

[0073] Sample preparation: Each compound was added at 1 wt% to a fabric softener base and allowed to macerate for 24 hours.

[0074] Cleaning process: Three 4 x 5 inch cotton samples were treated with fabric softener diluted 1000 times with water. After treatment, the excess water was spun out. The samples were dried at high heat for 30 minutes.

[0075] Headspace Collection: The dried samples were placed in the bottom of gallon size jars, capped and equilibrated at 40°C for 3 hours. After equilibration, 1 liter of headspace was collected from each jar while in a 40°C water bath. The collection was repeated three times at the initial time point (T=0), T=7 days and T=14 days after the cleaning process.

[0076] Headspace analysis: Headspace samples were run on an Agilent 7890 gas chromatograph with a quadrupole mass spectrometer. Peak areas were converted to vapor concentrations based on standard response factors and collected volumes.

[0077] Unexpectedly, Compound IV was released at the highest level in the GC headspace, up to 215.2 ng / L. In comparison, Compound II was released at 29.2 ng / L, Comparative Compound IV' was released at 65.8 ng / L, and Comparative Compound IV" was released at 53.1 ng / L. For these results, see Table 1 below.

[0078] Compounds IX and X were also evaluated along with comparative compounds IX' and X'. Compound VIII was used as a control.

[0079] Unexpectedly, Compound IX was released in the GC headspace at a level of 354.4 ng / L, and Compound X was released at a level of 478 ng / L, much higher than the comparative compound and the control. See Table 1 below.

[0080] Table 1.

[0081] Compound GC headspace release, ng / L IV 215.2 Contrast IV' 65.8 Contrast IV" 53.1 Control II 29.2 IX 354.4 Comparison IX' 86.9 X 478 Compare X' 167.5 Control VIII 19.2

Claims

1. A fragrance precursor compound, which is a Michael addition product of one or two fragrance molecules and 3,6-dioxa-1,8-octane-dithiol, wherein each of the one or two fragrance molecules has an α,β-unsaturated carbonyl group, wherein, The pro-fragrance compound is compound XVIII, 2. A delivery system comprising the pro-fragrance compound of claim 1.

3. The delivery system of claim 2, wherein: The delivery system is a microcapsule delivery system, a polymer particle delivery system, a fiber-assisted delivery system, a cyclodextrin complex, a coacervate complex, or any combination thereof.

4. The delivery system of claim 2, wherein: The delivery system is biodegradable.

5. A consumer product comprising the pro-fragrance compound of claim 1.

6. The consumer product of claim 5, wherein: The consumer product is a fabric softener.

7. A method for preparing a fragrance precursor compound as claimed in claim 1, comprising the step of reacting 3,6-dioxa-1,8-octane-dithiol with one or two fragrance molecules to form a Michael addition product, wherein each of the one or two fragrance molecules has an α,β-unsaturated carbonyl group.

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