Patent Application
20230277427
This invention is concerned with compositions, and especially solutions comprising at least one cooling compound as further defined herein and a solvent, and the use of said composition in a flavour or fragrance composition.
Compounds providing a cooling sensation have for a long time played an important role in the flavor and fragrance industry in order to produce an association with freshness and cleanliness. Cooling compounds are widely used in a variety of products such as foodstuffs, tobacco products, beverages, dentifrices, mouthwashes, toothpastes, and toiletries. The cooling sensation provided contributed to the appeal and acceptability of consumer products. In particular, oral care products, such as dentifrices and mouthwashes are formulated with coolants because they provide breath freshening effects and a clean, cool, fresh feeling in the mouth.
The newest generation of synthetic cooling compounds is very potent at low concentrations, but unfortunately a lot of them are at room temperature crystalline solids and the use is not without problems. Firstly, it is not always convenient or easy to mix solids into consumer products, which may be in a liquid or a paste-like form. Secondly, powder-like ingredients must be handled with caution to avoid dust hazards associated therewith.
Accordingly, there remains a need to provide cooling compounds in a form that is essay to use in further formulation operations and which remains stable in that form for a long period of storage.
In accordance with a first aspect of the present invention there is provided a composition comprising
In certain embodiments the solvent is lactic acid.
In accordance with a second aspect of the present invention there is provided a fragrance or flavour composition comprising a composition of the first aspect of the present invention and at least one active selected from the group consisting of flavour and fragrance, and optionally comprising sweetening agent.
In certain embodiments, the at least one flavour/fragrance is selected from a list of ingredients providing additional cooling effect on the skin and/or mucosa, including menthol, mint oil, N-ethyl-p-menthan-3-carboxamide (WS-3), N-(4-(cyanomethyl)phenyl)-2-isopropyl-5-methylcyclohexane-1-carboxamide (Evercool 180), 2-isopropyl-5-methyl-N-(2-(pyridin-2-yl)ethyl)cyclohexane-1-carboxamide (Evercool 190), and menthyl lactate.
In accordance with a third aspect of the present invention there is provided a fragranced or flavoured product comprising a composition of the first aspect of the present invention or a composition of the second aspect of the present invention, and a product base.
In certain embodiments, the product is selected from consumer products which get into contact with the human skin and/or mucosa, including food products, beverages, chewing gum, tobacco and tobacco replacement products, dental care products, personal care products, including lip care products, sexual health and intimate care products.
In certain embodiments, the product is selected from air care products, such as an air freshener or a “ready to use” powdered air freshener which can be used in the home space (rooms, refrigerators, cupboards, shoes or car) and/or in a public space (halls, hotels, malls, etc.).
As cooling compounds are mainly used in the flavour and fragrance industry, in particular in consumer product which get into contact with the human skin and/or mucosa, solvents which are authorized for the use in such products are particular preferred.
The details, examples and preferences provided in relation to any particular one or more of the stated aspects of the present invention will be further described herein and apply equally to all aspects of the present invention. Any combination of the embodiments, examples and preferences described herein in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein, or otherwise clearly contradicted by context.
The present invention is based, at least in part, on the surprising finding that the cooling compounds of formula (I)
Non-limiting examples are compounds of formula (I) wherein R1 is phenyl substituted with one substituent selected from the group consisting of CH3, F and Cl in para position, and optionally substituted by one further substituent selected from the group consisting of Et, vinyl, CN, NO2, methoxy and CF3.
In one particular embodiment the compound of formula (I) are represented by the formula (II)
Thus there is provided in a first aspect a composition comprising a compound of formula (I) and at least one solvent selected from butyl lactate, ethanol, ethyl lactate, isopropyl alcohol, isopropylidene glycerol, and lactic acid, or a mixture thereof.
The compounds of formula (I) as herein defined have been developed by the applicant as new cooling compounds (which are described in more details in PCT/CN2019/111690 patent application of the applicant—the contents of which are incorporated herein by references). Said compounds are capable to activate the TRPM8 (transient receptor potential melastatin member 8, also known as Trp-p8 or MCR1) ion channels, inducing a sensation of coldness.
The compounds of formula (I) as herein defined are at room temperature crystalline solids, which are relatively insoluble in the common solvents suitable to be used in the flavour and fragrance industry.
Applicant surprisingly found that synthetic cooling compounds, in particular cooling compounds as defined by formula (I), are particular well soluble in a solvent selected from butyl lactate, ethanol, ethyl lactate, isopropyl alcohol, isopropylidene glycerol, and lactic acid, or a mixture thereof.
By “particular well soluble” it is meant within the context of the invention that a stable solution comprising up to 50 weight % of a compound of formula (I) can be prepared.
An advantage of such highly concentrated solutions is that the contribution of an intrinsic odour of the used solvent can be minimised. This is particularly important when such cooling compositions are used in combination with flavour and fragrance formulations. It is also worthwhile to note that the admixture of liquids, e.g., to a flavour/fragrance formulation could be regarded more sustainable than admixing a solid, which would require more energy.
By “stable” it is meant within the context of the invention that no precipitation was observed when stored for up to four weeks at a temperature of at least room temperature (i.e. about 22° C.).
Thus there is provided in a further aspect of the present invention a liquid comprising
Non-limiting examples are compounds of formula (I) wherein R1 is phenyl substituted with one substituent selected from the group consisting of CH3, F and Cl in para position, and optionally substituted by one further substituent selected from the group consisting of Et, vinyl, CN, NO2, methoxy and CF3.
In one particular embodiment the compound of formula (I) are represented by the formula (II)
In one particular embodiment the liquid comprises at least 3 weight % (e.g. 3-50 weight % (e.g., 4-45, 5-40, 15-35, or about 20 weight %) of a compound of formula (I) (which encompasses the compound of formula (II)).
In a further particular embodiment there is provided a liquid composition comprising (a) a compound of formula (I) (which encompasses the compound of formula (II)), and (b) a solvent selected from butyl lactate, ethanol, ethyl lactate, isopropyl alcohol, isopropylidene glycerol, and lactic acid, or a mixture thereof, wherein the weight ratio of ingredient (a) to the solvent (b) to is 1:20 to 1:1 (including 1:18 to 1:2, such as 1:4, 1:3, or 1:5).
In one particular embodiment lactic acid (2-hydroxypropanoic acid) is used as the sole solvent.
Lactic acid is chiral, consisting of two enantiomers. One is known as l-(+)-lactic acid or (S)-lactic acid and the other, its mirror image, is d-(−)-lactic acid or (R)-lactic acid. A mixture of the two in equal amounts is called dl-lactic acid, or racemic lactic acid. dl-Lactic acid is miscible with water and with ethanol above its melting point, which is around 17° C. Lactic acid is hygroscopic and thus in the food and beverage industry quite often used with a purity of about 85-90 weight %. L-Lactic acid is supplemented into foods and beverages (E270), and is widely used as a non-volatile acidulant. The use of the term “lactic acid” in this description encompasses not only the individual enantiomers and the racemate in their pure forms, but also the commercially-available forms of lactic acid, which are generally 85-90 wt % pure.
Even though 50 weight % or even more of a compound of formula (I) (which encompasses the compound of formula (II)) as hereinabove defined are soluble in lactic acid, compositions comprising lower concentrations (e.g. 30 weight % or less, such as 25-15 weight %) are preferred due to the viscosity of the resulting mixture. The more viscous a liquid is, the more difficult it is to dose. Instead of reducing the concentration of the compound of formula (I) (which encompasses the compound of formula (II)), healable mixing facilities could be used.
Lactic acid is commercially available, e.g., from PURAC Biochem BV (The Netherlands), and Prinova Europe LTD.
In another particular embodiment lactates (e.g., butyl lactate or ethyl lactate, or a mixture thereof) are used as the solvent.
In another particular embodiment the solvent (b) is selected from butyl lactate, isopropyl alcohol, and isopropylidene glycerol, or a mixture thereof.
The compounds of formula (I) (which encompasses the compound of formula (II)) comprise several chiral centers and as such exist as a mixture of stereoisomers, or they may be resolved as isomerically pure forms. Resolving stereoisomers adds to the complexity of manufacture and purification of these compounds and so it is preferred to use the compounds as mixtures of their stereoisomers simply for economic reasons. However, if it is desired to prepare individual stereoisomers, this may be achieved according to methods known in the art, e.g. preparative HPLC and GC, crystallization or stereoselective synthesis. The compounds as defined by formula (I) (which encompasses the compound of formula (II)) may exist in its tautomeric forms 1H-Imidazole-3H-Imidazole form. Accordingly, the chemical structures depicted herein encompass all possible sterioisomers and tautomeric forms of the illustrated compounds.
In one particular embodiment there is provided a liquid composition comprising or consisting of 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one (which includes (2S)-2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one) and least one solvent selected from the butyl lactate, ethanol, ethyl lactate, isopropyl alcohol, isopropylidene glycerol, and lactic acid, or a mixture thereof.
In a further embodiment there is provided a liquid composition comprising or consisting of 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one (which includes (2S)-2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one) and one solvent selected from the butyl lactate, ethanol, ethyl lactate, isopropyl alcohol, isopropylidene glycerol, and lactic acid, or a mixture thereof.
In another particular embodiment there is provided a composition comprising or consisting of 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one (which includes (2S)-2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one) and lactic acid.
The compositions as defined hereinabove may be added to any products in which a cooling effect on the skin or mucous membrane is desired. It may be employed in the product simply by directly mixing the composition with the product, or it may, in an earlier step, be entrapped in a suitable entrapment material. Alternatively the composition as hereinabove defined may be admixed with other actives, such as, flavours, fragrances, and sweetening agents, and mixtures thereof, before employing it into the product.
Thus there is provided in a further embodiment a flavour or fragrance formulation comprising
In one particular embodiment there is provided a flavour or fragrance formulation comprising
In a further particular embodiment there is provided a flavour or fragrance formulation wherein the compound of formula (I) are represented by a compound of formula (II)
Examples of flavour ingredients include natural flavors, artificial flavors, spices, seasonings, and the like. Exemplary flavor ingredients include synthetic flavor oils and flavoring aromatics and/or oils, oleoresins, essences, and distillates, and a combination comprising at least one of the foregoing.
Flavor oils include spearmint oil, cinnamon oil, oil of wintergreen (methyl salicylate), peppermint oil, Japanese mint oil, clove oil, bay oil, anise oil, eucalyptus oil, thyme oil, cedar leaf oil, oil of nutmeg, allspice, oil of sage, mace, oil of bitter almonds, and cassia oil; useful flavoring agents include artificial, natural and synthetic fruit flavors such as vanilla, and citrus oils including lemon, orange, lime, grapefruit, yuzu, sudachi, and fruit essences including apple, pear, peach, grape, raspberry, blackberry, gooseberry, blueberry, strawberry, cherry, plum, prune, raisin, cola, guarana, neroli, pineapple, apricot, banana, melon, apricot, cherry, tropical fruit, mango, mangosteen, pomegranate, papaya, and so forth.
Additional exemplary flavors imparted by a flavoring composition include a milk flavor, a butter flavor, a cheese flavor, a cream flavor, and a yogurt flavor; a vanilla flavor; tea or coffee flavors, such as a green tea flavor, an oolong tea flavor, a tea flavor, a cocoa flavor, a chocolate flavor, and a coffee flavor; mint flavors, such as a peppermint flavor, a spearmint flavor, and a Japanese mint flavor; spicy flavors, such as an asafetida flavor, an ajowan flavor, an anise flavor, an angelica flavor, a fennel flavor, an allspice flavor, a cinnamon flavor, a chamomile flavor, a mustard flavor, a cardamom flavor, a caraway flavor, a cumin flavor, a clove flavor, a pepper flavor, a coriander flavor, a sassafras flavor, a savory flavor, a Zanthoxyli Fructus flavor, a perilla flavor, a juniper berry flavor, a ginger flavor, a star anise flavor, a horseradish flavor, a thyme flavor, a tarragon flavor, a dill flavor, a capsicum flavor, a nutmeg flavor, a basil flavor, a marjoram flavor, a rosemary flavor, a bayleaf flavor, and a wasabi (Japanese horseradish) flavor; a nut flavor such as an almond flavor, a hazelnut flavor, a macadamia nut flavor, a peanut flavor, a pecan flavor, a pistachio flavor, and a walnut flavor; alcoholic flavors, such as a wine flavor, a whisky flavor, a brandy flavor, a rum flavor, a gin flavor, and a liqueur flavor; floral flavors; and vegetable flavors, such as an onion flavor, a garlic flavor, a cabbage flavor, a carrot flavor, a celery flavor, mushroom flavor, and a tomato flavor.
Generally any flavoring or food additive (including food colors) such as those described in “Essential guide to food additives”, Third edition 2008, page 101-321 (ISBN: 978-1-905224-50-0) by Leatherhead Food International Ltd., can be used. The publication is incorporated herein by reference.
In one particular embodiment the at least one active (c) may be selected from anethole, menthol laevo, carvone laevo, ethyl maltol, vanillin, eucalyptol, eugenol, menthol racemic, cis-3-hexenol, linalol, mint oil (e.g. peppermint arvensis oil, peppermint piperita oil, spearmint native oil, spearmint scotch oil), corylone, ethyl butyrate, cis-3-hexenyl acetate, citral, eucalyptus oil, ethyl-vanillin, methyl salicylate, 2′-hydroxypropiophenone, ethyl acetate, methyl dihydro jasmonate, geraniol, lemon oil, iso amyl acetate, thymol, ionone beta, linalyl acetate, decanal, cis jasmone, ethyl hexanoate, melonal (2,6-dimethylhept-5-enal), citronellol, ethyl aceto acetate, nutmeg oil and clove oil, or mixtures thereof.
In another particular embodiment the at least one active (c) may be selected from menthol (e.g., in form of peppermint oil), menthone, p-menthanecarboxamides, N-2,3-trimethyl-2-isopropyl-butanamide (WS-23), menthyl lactate (Frescolat® ML), menthone glycerol acetal (Frescolat® MGA), 3-(1-menthoxy)-propane-1,2-diol (TK-10), p-menthane-3,8-diol (known as Coolact 38D), isopulegol (known as Coolact P), monomenthyl succinate (Physcool®), monomenthyl glutarate, o-menthylglycerol, menthyl N,N-dimethylsuccinamate, 2-(sec-butyl)cyclohexan-1-one (Freskomenthe), N-(pyrazol-3-yl)-N-(thiophen-2-ylmethyl)-2-(p-tolyloxy)acetamide, 2-(4-ethylphenoxy)-N-(pyrazol-3-yl)-N-(thiophen-2-ylmethyl)acetamide, 3-(benzo[d][1,3]dioxol-5-yl)-N,N-diphenylacrylamide, 4-(2-(4-allyl-2,6-dimethoxyphenoxy)-1-ethoxypropyl)-2-methoxyphenol, 4-(2-(4-allyl-2,6-dimethoxyphenoxy)-1-((2-isopropyl-5-methylcyclohexyl)oxy)propyl)-2-methoxyphenol (including 4-(2-(4-allyl-2,6-dimethoxyphenoxy)-1-(((1S,2R,5S)-2-isopropyl-5-methylcyclohexyl)oxy)propyl)-2-methoxyphenol) and 4-(2-(4-allyl-2,6-dimethoxyphenoxy)-1-(((1R,25,5R)-2-isopropyl-5-methylcyclohexyl)oxy)propyl)-2-methoxyphenol), N-(2-Hydroxy-2-phenylethyl)-2-isopropyl-5,5-dimethylcyclohexane-1-carboxamide, N-(4-(Cyanomethyl)phenyl)-2-isopropyl-5,5-dimethylcyclohexanecarboxamide and N-(3-Hydroxy-4-methoxyphenyl)-2-isopropyl-5,5-dimethylcyclohexanecarboxamide.
Examples of p-methanecarboxamides include compounds such as N-ethyl-p-menthan-3-carboxamide (known commercially as WS-3), N-ethoxycarbonylmethyl-p-menthan-3-carboxamide (WS-5), N-(4-methoxyphenyl)-p-menthan-3-carboxamide (WS-12) and N-tert-butyl-p-menthan-3-carboxamide (WS-14), N-(4-(cyanomethyl)phenyl)-2-isopropyl-5-methylcyclohexane-1-carboxamide (known commercially as Evercool 180), 2-isopropyl-5-methyl-N-(2-(pyridin-2-yl)ethyl)cyclohexane-1-carboxamide (known commercially as Evercool 190), and (1R,2S,5R)-N-((S)-2-((R)-2-aminopropanamido)-2-phenylethyl)-2-isopropyl-5-methylcyclohexane-1-carboxamide.
In one specific embodiment the at least one active (c) is selected from menthol, mint oil, N-ethyl-p-menthan-3-carboxamide (WS-3), N-(4-(cyanomethyl)phenyl)-2-isopropyl-5-methylcyclohexane-1-carboxamide (Evercool 180), 2-isopropyl-5-methyl-N-(2-(pyridin-2-yl)ethyl)cyclohexane-1-carboxamide (Evercool 190), and menthyl lactate.
Examples of sweetening agents include, but are not limited to, sucrose, fructose, glucose, high fructose corn syrup, corn syrup, xylose, arabinose, rhamnose, erythritol, xylitol, mannitol, sorbitol, inositol, acesulfame potassium, aspartame, neotame, sucralose, and saccharine, and mixtures thereof; trilobatin, hesperetin dihydrochalcone glucoside, naringin dihydrochalcone, mogroside V, Luo Han Guo extract, rubusoside, rubus extract, glycyphyllin, isomogroside V, mogroside IV, siamenoside I, neomogroside, mukurozioside IIb, (+)-hernandulcin, 4β-hydroxyhernandulcin, baiyunoside, phlomisoside I, bryodulcoside, bryoside bryonoside, abrusosides A-E, cyclocarioside A, cyclocaryoside I, albiziasaponins A-E, glycyrrhizin, araboglycyrrhizin, periandrins I-V, pterocaryosides A and B, osladin, polypodosides A and B, telosmoside A8-18, phyllodulcin, huangqioside E neoastilbin, monatin, 3-acetoxy-5,7-dihydroxy-4′-methoxyflavanone, 2R,3R-(+)-3-Acetoxy-5,7,4′-trihydroxyflavanone, (2R,3R)-dihydroquercetin 3-O-acetate, dihydroquercetin 3-O-acetate 4′-methyl ether, brazzein, curculin, mabinlin, monellin, neoculin, pentadin, thaumatin, and combinations thereof. Some of the compounds listed above are known sweetness enhancers as well as sweeteners. When used as sweetness enhancers they are normally used below their sweetness detection thresholds.
In a further aspect there is provided a flavoured or perfumed product comprising a flavour or fragrance composition and a product base, e.g., an orally acceptable carrier for products which are taken into the mouth, and skin tolerable carriers for products which get into contact with the skin.
In some aspects, the product base may comprise salts (e.g., sodium hydrogen carbonate, sodium carbonate, calcium carbonate, trisodium phosphate, and/or disodium hydrogen phosphate), which may act as a buffer when lactic acid is used as the solvent for the imidazole cooling compound of formula (I) (which encompasses the compound of formula (II)).
In some aspects, the orally acceptable carrier may comprise one or more compatible solid or liquid excipients or diluents which are suitable for topical oral administration. By “compatible,” as used herein, is meant that the components of the composition are capable of being commingled without interaction in a manner which would substantially reduce stability and/or efficacy. The carriers can include the usual and conventional components of dentifrices, non-abrasive gels, subgingival gels, mouthwashes or rinses, mouth sprays, chewing gums, lozenges and breath mints. The choice of a carrier to be used is basically determined by the way the composition is to be introduced into the oral cavity. Carrier materials for toothpaste, tooth gel or the like include abrasive materials, sudsing agents, binders, humectants, flavoring and sweetening agents, etc. as disclosed in e.g., U.S. Pat. No. 3,988,433, to Benedict. Carrier materials for biphasic dentifrice formulations are disclosed in U.S. Pat. Nos. 5,213,790; 5,145,666 and 5,281,410 all to Lukacovic et al., and in U.S. Pat. Nos. 4,849,213 and 4,528,180 to Schaeffer. Mouthwash, rinse or mouth spray carrier materials typically include water, flavoring and sweetening agents, etc., as disclosed in, e.g., U.S. Pat. No. 3,988,433 to Benedict. Lozenge carrier materials typically include a candy base; chewing gum carrier materials include a gum base, flavoring and sweetening agents, as in, e.g., U.S. Pat. No. 4,083,955, to Grabenstetter et al. Sachet carrier materials typically include a sachet bag, flavoring and sweetening agents. For subgingival gels used for delivery of actives into the periodontal pockets or around the periodontal pockets, a “subgingival gel carrier” is chosen as disclosed in, e.g. U.S. Pat. Nos. 5,198,220 and 5,242,910 both to Damani. Carriers suitable for the preparation of compositions of the present disclosure are well known in the art. Their selection will depend on secondary considerations like taste, cost, and shelf stability, and the like.
Further suitable types of orally acceptable carrier materials or excipients are listed in WO2010/059289, in particular on page 17-31, which is incorporated by reference.
The composition of the invention may be added to and incorporated into a product base by known methods. Sufficient may be added to provide a cooling effect. The necessary proportion to provide such an effect will naturally depend on the desired cooling effect, but typical weight proportions being from 0.01 to 0.5%. For examples in an oral application of a compound of the present invention, such as dentifrice, floss, chewing gum, or white strip, the levels of use may be from about 0.00001% (0.01 ppm) to about 0.1% (1000 ppm); from about 0.00005% (0.5 ppm) to about 0.1% (1000 ppm); from about 0.0001% (1 ppm) to about 0.05% (500 ppm); from about 0.005% (50 ppm) to about 0.03% (300 ppm); or from about 0.001% (10 ppm) to about 0.01% (100 ppm) by weight of the composition. When a compound of the present invention is used in a mouthwash, the level of use may be from about 0.000001% (10 ppb) to about 0.01% (100 ppm) or from about 0.0001% (1 ppm) to about 0.001% (10 ppm) by weight of the composition. When a compound of the present invention is delivered topically, for example in shampoos and lotions the levels may be from about 0.001% (10 ppm) to about 0.5% (5000 ppm) by weight of the composition or from about 0.01% (100 ppm) to about 0.4% (4000 ppm) by weight of the composition. These are general guidelines, not rigid boundaries, and formulators seeking particular effects may find it possible or even desirable to formulate outside them.
The composition and methods are now further described with reference to the following non-limiting examples, which describe particular embodiments.
Example 1a: tert-butyl-2-(1H-imidazol-2-yl)piperidine-1-carboxylate: To a solution of tert-butyl-2-formylpiperidine-1-carboxylate (9.5 g, 35.6 mmol) and glyoxal solution (40% in water, 25.9 g, 178 mmol) in methanol (100 mL) were added dropwise ammonia solution (25% in water, 17.0 g, 249 mmol) at 0° C. The solution was allowed to warm up to rt. (room temperature) and stirred at rt. for 16 h. Then the solution was concentrated under reduced pressure, and the result residue was extracted with ethyl acetate (100 mL*3). Any precipitate was removed by filtration, and the organic phase was washed with saturated aqueous NaHCO3 solution (100 mL) and brine (100 mL). The solution was then concentrated under reduced pressure to give tert-butyl-2-(1H-imidazol-2-yl)piperidine-1-carboxylate (5.2 g, yield: 58%) as white solid. GC/MS (El): m/z (%): 251 (3) [M+], 195 (4), 178 (10), 150 (20), 134 (13), 122 (5), 95 (100), 82 (10), 57 (21).
Example 1b: tert-butyl-2-(4,5-dibromo-1H-imidazol-2-yl)piperidine-1-carboxylate: N-bromosuccinimide (7.4 g, 41.8 mmol) was added portionwise to a solution of tert-butyl-2-(1H-imidazol-2-yl)piperidine-1-carboxylate (5.0 g, 19.9 mmol) in dichloromethane (100 mL) over 10 min at 0° C. The mixture was stirred at 0° C. for another 2 h and then concentrated by rotary evaporate. The residue was dissolved in ethyl acetate (250 mL), washed with water (100 mL*2) and brine (100 mL), dried with MgSO4, and concentrated to get a very brown residue. The residue was recrystallized by dichloromethane/hexanes (1:1) to get tert-butyl-2-(4,5-dibromo-1H-imidazol-2-yl)piperidine-1-carboxylate (6.0 g, yield: 74%) as white solid. GC/MS (El): m/z (%): 411 (2) [M+], 409 (4) [M+], 407 (2) [M+], 355 (6), 353 (12), 351 (6), 311 (11), 309 (22), 307 (11), 294 (11), 292 (22), 290 (11), 255 (50), 253 (100), 251 (50), 242 (12), 240 (24), 238 (12), 148 (9), 57 (50).
Example 1c: tert-butyl-2-(5-bromo-1H-imidazol-2-yl)piperidine-1-carboxylate: A suspension of the tert-butyl-2-(4,5-dibromo-1H-imidazol-2-yl)piperidine-1-carboxylate (34.0 g, 90%, 74.8 mmol) and Na2SO3 (94 g, 748 mmol) in ethanol (300 mL) and water (300 mL) was refluxed overnight. Then cool down and concentrated. The residue was partitioned between CH2Cl2 (200 mL) and H2O (200 mL). The aqueous layer was extracted with ethyl acetate (200 mL*3). The combined organic layers were washed with brine (200 mL), dried with Na2SO4, filtered and evaporated. The residue was purified by column chromatography on silica gel to give tert-butyl-2-(5-bromo-1H-imidazol-2-yl)piperidine-1-carboxylate (23.0 g, yield: 93%) as white solid. GC/MS (El): m/z (%): 329 (3) [M+], 331 (3) [M+], 275 (10), 273 (10), 258 (9), 256 (9), 230 (20), 228 (20), 214 (26), 212 (26). 175 (100), 173 (100), 162 (9), 160 (9), 93 (8), 57 (44).
Example 1d: tert-butyl 2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidine-1-carboxylate: A pressure vessel was charged with tert-butyl 2-(5-bromoimidazol-2-yl)piperidine-1-carboxylate (400 mg, 1.211 mmol), p-tolylboronic acid (181 mg, 1.332 mmol, 1.1 equiv.), sodium carbonate (257 mg, 2.42 mmol, 2 equiv.), 1,1′-bis(diphenylphosphino)-ferrocene-palladium(II)dichloride dichloromethane complex (49 mg, 0.061 mmol, 0.05 equiv.), tetrahydrofuran (5 mL) and water (1 mL). The mixture was degassed by purging with nitrogen and the vessel was sealed. The mixture was stirred and heated to 100° C. overnight. The resulting mixture was cooled to 0° C., the vessel was opened and the contents poured into aq. sat. NaHCO3 solution (50 mL), extracted with EtOAc (2×50 mL), washed with water (50 mL) and brine (50 mL), dried over MgSO4 and concentrated under reduced pressure. The crude material was purified by silica gel flash column chromatography eluting with a gradient of EtOAc in Heptane to give tert-butyl 2-(5-(p-tolyl)imidazol-2-yl)piperidine-1-carboxylate (314 mg, 0.920 mmol, 76% yield) as a white solid. MS (El, 70 eV): 341 (4, [M]+•), 285 (11), 268 (3), 240 (30), 185 (100), 172 (16), 91 (6), 57 (99). 1H NMR (DMSO-d6, 400 MHz, mixture of rotamers and tautomers): δ 11.66-12.09 (m, 1H), 7.49-7.70 (m, 2H), 7.20-7.48 (m, 1H), 7.08-7.23 (m, 2H), 5.34-5.23 (m, 1H), 3.89 (br d, J=12.1 Hz, 1H), 3.05 (br t, J=10.9 Hz, 1H), 2.28 (s, 3H), 2.18-2.25 (m, 1H), 1.65-1.78 (m, 1H), 1.22-1.63 (m, 13H) ppm. 13C NMR (75 MHz, DMSO, mixture of tautomers) δ 155.1 (q), 147.5 (q), 140.2 (q), 135.3 (q), 132.7 (q), 129.4 (t), 124.6 (t), 112.5 (t), 79.3 (q), 63.3 (d), 49.7 (t), 41.2 (d), 28.5 (s), 28.4 (d), 26.8 (d), 25.3 (d), 21.2 (s), 19.9 (d) ppm.
Example 1e: 2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidine: A solution of tert-butyl 2-(5-(p-tolyl)imidazol-2-yl)piperidine-1-carboxylate (304 mg, 0.890 mmol) in dichloromethane (3 mL) was treated dropwise at 5° C. with trifluoroacetic acid (0.549 mL, 7.12 mmol, 8 equiv.) and the resulting mixture stirred at room temperature for 2 hours or until complete consumption of the starting material. The mixture was poured into iced water (30 mL) and the pH made basic by the addition of aqueous 1M NaOH solution. The mixture was then extracted with dichloromethane (3×20 mL), dried over MgSO4 and concentrated under reduced pressure to give 2-(5-(p-tolyl)imidazol-2-yl)piperidine (160 mg, 0.664 mmol, 74% yield) as a pale yellow oil which was used in the next step without further purification. MS (El, 70 eV): 241 (6, [M]+•), 185 (100), 172 (13), 158 (8), 91 (3), 84 (4). 1H NMR (CHLOROFORM-d, 400 MHz): δ 8.67-8.89 (br s, 1H), 7.50 (d, J=8.1 Hz, 2H), 7.19 (d, J=7.8 Hz, 2H), 7.13 (s, 1H), 4.14 (dd, J=12.3, 3.1 Hz, 1H), 3.30 (br d, J=12.7 Hz, 1H), 2.71-2.84 (m, 1H), 2.37 (s, 3H), 2.15-2.27 (m, 1H), 2.01 (br dd, J=14.4, 3.2 Hz, 1H), 1.90 (br d, J=13.4 Hz, 1H), 1.67-1.77 (m, 2H), 1.32-1.46 ppm (m, 1H).
Example 1f: 2-(methylthio)-1-(2-(5-(p-tolypimidazol-2-yl)piperidin-1-yl)propan-1-one: To a solution of 2-(5-(p-tolyl)imidazol-2-yl)piperidine (0.88 mmol) in Dichloromethane (DCM) (2 mL) was added Hydroxybenzotriazole (HOBt) (1.056 mmol, 1.2 equiv.) and 3-(((ethylimino)methylene)amino)-N,N-dimethylpropan-1-amine hydrochloride (EDCI) (1.056 mmol, 1.2 equiv.) at 0-5° C. and the mixture was stirred at room temperature for 0.5 h. The mixture was then treated with 2-(methylthio)propanoic acid (0.968 mmol, 1.1 equiv.) and N,N-diisopropylethylamine (DIPEA) (0.88 mmol, 1 equiv.) and the resulting mixture was stirred at rt. for 16 h. The mixture was filtered and solvent was removed and the crude purified by silica gel chromatography (gradient of EtOAc in Heptane) to furnish 2-(methylthio)-1-(2-(5-(p-tolyl)imidazol-2-yl)piperidin-1-yl)propan-1-one as a white solid.
MS (El, 70 eV): 343 (2, [M]+•), 241 (17), 240 (100), 213 (13), 185 (18), 184 (9), 75 (55), 56 (11), 55 (9), 47 (10), 41 (11). 1H NMR (400 MHz, DMSO-d6, mixture of stereoisomers and tautomers) δ 12.07, 11.99, 11.95, 11.76 (brs, 1H), 7.72-7.60(m, 2H), 7.59-7.42 (m, 1H), 7.26-7.08 (m, 2H), 5.75-5.39 (m, 1H), 4.49-3.00 (m, 3H), 2.71-2.15 (m, 1H), 2.30 (s, 3H), 2.07-1.96 (m, 3H), 1.94-1.48 (m, 5H), 1.43-1.34 (m, 3H) ppm. 13C NMR (101 MHz, DMSO-d6, mixture of stereoisomers and tautomers) δ 170.2 (q), 170.2 (q), 170.0 (q), 147.0 (q), 146.8 (q), 146.7 (q), 140.4 (q), 140.3 (q), 139.9 (q), 135.3 (q), 135.2 (q), 135.1 (q), 132.7 (q), 132.6 (q), 132.6 (q), 129.7 (t), 129.3 (t), 124.6 (t), 113.0 (t), 112.6 (t), 112.5 (t), 51.5 (t), 47.3 (t), 47.0 (t), 43.1 (d), 43.0 (d), 38.8 (d), 38.0 (t), 37.6 (t), 37.3 (t), 28.8 (d), 28.6 (d), 28.1 (d), 27.9 (d), 26.1 (d), 25.7 (d), 25.4 (d), 21.2 (s), 20.3 (d), 20.1 (d), 18.3 (s), 18.0 (s), 17.8 (s), 11.9 (s), 11.7 (s), 11.6 (s) ppm.
Following the general procedure described in Example 1f: 2,2-dimethylbut-3-enoic acid (170 mg, 1.492 mmol), HOBt (228 mg, 1.492 mmol), 3-(((ethylimino)methylene)amino)-N,N-dimethylpropan-1-amine (232 mg, 1.492 mmol), 2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidine (300 mg, 1.243 mmol) and DIPEA (0.391 ml, 2.238 mmol) in dichloromethane (30 mL) were reacted to give the title product (255 mg, yield: 68%) as white solid.
GC/MS (El): m/z (%): 337 (1) [M+], 322 (3), 268 (10), 240 (89), 213 (6), 197 (6), 172 (100), 117 (8), 69 (8). 1H NMR (300 MHz, DMSO-d6, mixture of tautomers) δ 12.04-11.70 (m, 1H), 7.83-7.51 (m, 2H), 7.51-7.37 (m, 1H), 7.32-7.00 (m, 2H), 6.23-6.10 (m, 1H), 5.81-5.34 (m, 1H), 5.27-4.80 (m, 2H), 4.60-2.96 (m, 2H), 2.43-2.17 (m, 4H), 1.87-1.43 (m, 5H), 1.40-1.19 (m, 6H). 13C NMR (75 MHz, DMSO-d6, mixture of tautomers) δ 174.1 (q), 147.0 (q), 144.4 (t), 139.9 (q), 135.2 (q), 132.7 (q), 129.7 (t), 129.3 (t), 124.5 (t), 112.9 (t), 112.5 (d), 52.7 (t), 47.6 (t), 45.1 (s), 43.9 (d), 28.0 (d), 27.4 (s), 27.1 (s), 25.3 (d), 21.2 (s), 20.2 (d) ppm.
Example 3a: 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)but-3-en-1-one: To a solution of 2-methylbut-3-enoic acid (0.597 g, 5.97 mmol) in dichloromethane (100 mL) was added HOBt (0.914 g, 5.97 mmol) and 3-(((ethylimino)methylene)amino)-N,N-dimethylpropan-1-amine (0.926 g, 5.97 mmol) at 0˜5° C. and the mixture was stirred at room temperature for 0.5 h. Then 2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidine (1.2 g, 4.97 mmol) and DIPEA (1.563 ml, 8.95 mmol) was added and the mixture was stirred at rt. for 16 h. The suspension was filtered and solvent was removed and the crude product was purified by silica gel chromatography (hexane:MTBE=3:1) to give 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)but-3-en-1-one (808 mg, yield: 50%) as white solid.
GC/MS (El, mixture of stereoisomers, ratio 1:2): isomer 1: m/z (%):323 (2) [M+], 268 (5), 240 (100), 172 (95), 117 (7), 84 (3), 55 (11). isomer 2: m/z (%):323 (2) [M+], 268 (5), 240 (100), 211 (6), 172 (81), 117 (7), 84 (2), 55 (10). 1H NMR (300 MHz, DMSO-d6, mixture of stereoisomers and tautomers) δ 12.06, 11.81 (brs, 1H), 7.69-7.62 (m, 2H), 7.49 (s, 1H), 7.15 (d, J=7.3 Hz, 2H), 6.12-5.70 (m, 2H), 5.47-4.81 (m, 2H), 4.63-2.90 (m, 3H), 2.81-2.35 (m, 1H), 2.29 (s, 3H), 1.78-1.29 (m, 5H), 1.17 (t, J=5.6 Hz, 3H). 13C NMR (75 MHz, DMSO-d6, mixture of stereoisomers and tautomers) δ 172.7 (q), 172.5 (q), 172.3 (q), 147.1 (q), 146.7 (q), 140.3 (q), 139.8 (q), 139.6 (t), 139.1 (t), 135.3 (q), 132.7 (q), 129.4 (t), 124.6 (t), 115.4 (d), 115.3 (d), 113.0 (t), 112.6 (t), 51.7 (t), 51.3 (t), 47.0 (t), 46.8 (t), 42.8 (d), 42.6 (d), 40.2 (t), 39.3 (t), 38.6 (d), 28.4 (d), 28.1 (d), 26.1 (d), 25.8 (d), 25.3 (d), 21.2 (s), 20.3 (d), 20.1 (d), 18.4 (s), 18.2 (s), 18.0 (s) ppm.
Example 3b: 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one: 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)but-3-en-1-one (350 mg, 1.082 mmol) was hydrogenated, catalysed by 10% Pd/C (216 mg, 0.216 mmol) in ethyl acetate (20 ml) under hydrogen atmosphere overnight. The mixture was then purged with nitrogen, filtered over celite and evaporated to give a crude material which was purified by flash column chromatography (hexane:MTBE=3:1) to give the title product (290 mg, yield: 82%) as white solid.
GC/MS (El): m/z (%): 325 (10) [M+], 268 (2), 240 (100), 224 (3), 185 (10), 159 (2), 142 (1), 84 (2), 57 (4). 1H NMR (300 MHz, DMSO-d6, mixture of stereoisomers and tautomers) δ 12.05-11.72 (m, 1H), 7.73-7.53 (m, 2H), 7.51-7.40 (m, 1H), 7.27-7.03 (m, 2H), 5.81-5.28 (m, 1H), 4.61-3.16 (m, 2H), 2.87-2.58 (m, 1H), 2.38-2.19 (m, 4H), 1.86-1.49 (m, 5H), 1.46-1.23 (m, 2H), 1.09-0.95 (m, 3H), 0.94-0.80 (m, 3H). 13C NMR (75 MHz, DMSO-d6, mixture of stereoisomers and tautomers) δ 175.4 (q), 175.2 (q), 147.3 (q), 147.2 (q), 140.5 (q), 140.1 (q), 135.2 (q), 132.7 (q), 129.7 (t), 129.3 (t), 124.6 (t), 112.9 (t), 112.6 (t), 51.5 (t), 46.9 (t), 46.8 (t), 42.6 (d), 38.6 (d), 36.8 (t), 36.5 (t), 36.1 (t), 29.2 (d), 28.9 (d), 28.4 (d), 27.2 (d), 26.9 (d), 26.2 (d), 25.4 (d), 25.2 (d), 21.2 (s), 20.3 (d), 18.4 (s), 17.7 (s), 17.3 (s), 12.2 (s), 12.0 (s), 11.9 (s) ppm.
Following the general procedure described in Example 1f: 2-methyl-2-(methylthio)propanoic acid (0.267 g, 1.989 mmol), HOBt (305 mg, 1.989 mmol), 3-(((ethylimino)methylene)amino)-N,N-dimethylpropan-1-amine (309 mg, 1.989 mmol), 2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidine (400 mg, 1.657 mmol) and DIPEA (0.521 ml, 2.980 mmol) in dichloromethane (30 mL) were reacted to give the title product (287 mg, yield: 48%) as white solid.
GC/MS (El): m/z (%): 357 (5) [M+], 342 (7), 268 (11), 240 (100), 185 (11), 159 (5), 117 (4), 89 (10). 1H NMR (300 MHz, DMSO-d6, mixture of tautomers) δ 12.06, 11.82 (brs, 1H), 7.80-7.54 (m, 2H), 7.50 (s, 1H), 7.33-7.08 (m, 2H), 6.15-5.89 (m, 1H), 4.92-2.73 (m, 2H), 2.47-2.23 (m, 4H), 2.19-2.03 (m, 3H), 1.86-1.35 (m, 11H). 13C NMR (75 MHz, DMSO-d6, mixture of tautomers) δ 171.1 (q), 170.8 (q), 148.3 (q), 146.8 (q), 140.1 (q), 136.1 (q), 135.2 (q), 132.6 (q), 131.6 (q), 129.7 (t), 129.7 (t), 129.3 (t), 124.6 (t), 112.8 (t), 53.5 (t), 48.4 (t), 47.6 (q), 44.4 (d), 29.3 (d), 28.6 (d), 27.6 (s), 25.8 (d), 21.2 (s), 20.2 (d), 12.9 (s) ppm.
Into a 20 ml vial 0.4 g of 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one (white solid) have been added followed by the addition of 1.6 g of the respective solvent as indicated in Table 1 below. The vial was warmed to about 50° C. with gentle agitation for 1 hour. If 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one hasn't dissolved, 2 g of the respective solvent was added (resulting in a composition comprising 10 weight % of a compound of formula (I)), and again gentle agitated for an additional hour at about 50° C. If 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one still hasn't dissolved, 4 g of the respective solvent was added (resulting in a composition comprising 5 weight % of a compound of formula (I)), and again gentle agitated for an additional hour at about 50° C.
If 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one has dissolved, the vial was removed from the heat and was allowed to cool to room temperature. If no precipitation was observed the vials haven been placed in the fridge (about 4° C.) over night.
If 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one still has not dissolved, the procedure above has been repeated, starting with 0.05 g of 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one and 0.95 g of the respective solvent as indicated in Table 1 below. If still not dissolved, 1 g of the respective solvent was added (resulting in a composition comprising 2.5 weight % of a compound of formula (I))). If still not dissolved further solvent was added. The results are shown in Table 1 below.
a)L-Lactic acid; purity: 86.7 weight %
b)dl-Lactic acid; purity: 88 weight %
c)same results have been observed for the solubility of (2S)-2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one
The compound of Formula 1 was 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one (hereinafter “the compound”). The testing procedure with a number of different solvents was as follows:
Any solvent in which the compound was not crystallising at a 20 weight % solution, the testing procedure was repeated with a higher concentration as follows:
Table 2 below shows the solvents in which at least 5 weight % of the compound was soluble (see Example A) and the weight proportions and conditions under which they were considered “good” over a range of weeks at room temperature.
d)L-Lactic acid; purity: 86.7 weight %
e)dl-Lactic acid; purity: 88 weight %
f)same results have been observed for the solubility of (2S)-2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one
The flavoring compositions were prepared by admixing the following ingredients:
The flavoring compositions may be added to an oral care product (e.g. mouth wash) or to confectionary (e.g. chewing gum).
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012170.3 | Aug 2020 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/071109 | 7/28/2021 | WO |
