Filed of the invention

The present invention relates to a malodor or off-taste counteracting composition. In particular the invention relates to an attenuator or suppressor earthy, musty and/or moldy malodors or off- tastes. The invention also relates to the use of said composition and attenuator or suppressor, for attenuating or suppressing malodors or off-tastes, in particular earthy, musty and/or moldy malodors and off-tastes.

Background of the invention

The olfactory earthy note is described as the smell of a freshly plunged soil. Although it may be a component of some smells usually considered as pleasant, such as petrichor (the typical smell that accompanies the first rain after a spell of warm weather), it is also constitutive of mildew or moldy or musty odors that are rather quoted as unpleasant.

The earthy note can be elicited by different chemicals, among which geosmin ((4S,4aS,8aR)- 4,8a-Dimethyl-1 ,2,3,4,5,6,7,-octahydnonaphthalen-4a-ol, C H O, CAS 19700-21-1 ) is probably the most typical. Other naturally occurring molecules, such as, but not limited to, 2- methylisoborneol, 2-ethylfenchol, huminol, ambrinol or synthetic compounds such, as but not limited to, terranol also possess the typical earthy note. Likewise, more complex mixtures, such patchouli oil disclose an earthy aspect. These different compounds and mixtures may possess additional olfactory notes described either as camphoraceous, terpenic, woody, amberry, musky, with respect to the considered compound or mixture.

They earthy note elicited by natural or synthetic products may correspond to a problem in different contexts. Two compounds, geosmin and 2-methylisoborneol, are often reported as the main culprits of mildew malodor or off-taste. The human nose is particularly sensitive to these compounds, with a detection threshold as low as 10 ng/L and 25 ng/L for geosmin and 2- methylisoborneol respectively. They occur as metabolites of Streptomycetes, cyanobacteria or molds that grow in damp environments or directly in water. Both compounds are not considered as toxic by themselves, but their presence is interpreted as a clue of contamination. They are responsible of the typical musty/moldy odor found in dank cellars or in buildings that present a problem of humidity and are therefore considered as an olfactory nuisance.

Both molecules may also be responsible of an off-taste in drinking water contained in reservoir or ducts. Even after a water cleaning step that would have removed biological contaminants, the remaining geosmin and/or 2-methylisoborneol could still have a repulsive effect on human consumers. Contaminations with these earthy smelling molecules may also occur during the fabrication process of other beverages such as wine or beer, conferring to the product an unpleasant off-taste. Likewise, geosmin and 2-methylisoborneol may accumulate in the flesh of fishes raised in pond, giving a taint that makes the fish meat unacceptable for consumers, although it represents a valuable food source.

Other compounds that are used in perfumery also possess the typical earthy odorant note along with other hues that are more interesting for perfume compositions. The earthy note can therefore constitute a limitation for their use in fragrance creation.

It is therefore of interest to identify means to counteract the unpleasant odorant character elicited by earthy olfactory note.

Summary of the invention

The present inventors have surprisingly found that a compound previously described as a potent analgesic (Cohen and Hernandez, J. Int Med Res, 1976, 4, pp 138-143) namely nefopam can be used as a malodor counteracting agent, in particular for counteracting earthy, musty and/or moldy malodors, or earthy, musty and/or moldy off-tastes.

In a first aspect, the present invention relates to a malodor and/or off-taste counteracting composition comprising nefopam, or a salt, a polymorph, a hydrate or a solvate thereof, preferably comprising nefopam, or a polymorph, a hydrate or a solvate thereof, wherein nefopam is selected from (RS)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)- 5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

In a second aspect, the present invention relates to the use of nefopam, or a salt, a polymorph, a hydrate or a solvate thereof, or of a composition according to the first aspect of the invention as a malodor and/or off taste counteracting agent. Preferably, the present invention relates to the use of nefopam, or a polymorph, a hydrate or a solvate thereof, or of a composition according to the first aspect of the invention as a malodor counteracting agent, wherein nefopam is selected from (RS)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 - phenyl-1 ,3,4,6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

In a third aspect, the present invention also relates to a method of counteracting malodors and/or off-tastes comprising: contacting a situs comprising a malodor and/or an off-taste or a situs that will become malodorous or develop an off-taste with a counteracting effective amount of nefopam, or a salt, a polymorph, a hydrate or a solvate thereof, or of a composition according to the first aspect of the invention. Preferably, the present invention provides a method of counteracting malodors comprising: contacting a situs comprising a malodor or a situs that will become malodorous with nefopam, or a polymorph, a hydrate or a solvate thereof, or contacting a situs comprising a malodor or a situs that will become malodorous with a composition according to the first aspect of the invention, wherein nefopam is selected from (RS)-5-methyl-1 - phenyl-1 ,3,4,6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 ,3,4,6- tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

In a fourth aspect, the present invention also relates to a consumer, industrial or textile product comprising nefopam, or a salt, a polymorph, a hydrate or a solvate thereof, or a composition according to the first aspect of the invention, as malodor counteracting agent and/or as an off- taste counteracting agent. Preferably, the present invention relates to the use of a consumer, industrial or textile product comprising nefopam, or a polymorph, a hydrate or a solvate thereof, or a composition according to the first aspect of the invention, as malodor counteracting agent, wherein nefopam is selected from (RS )-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

The independent and dependent claims set out particular and preferred features of the invention. Features from the dependent claims may be combined with features of the independent or other dependent claims as appropriate.

The present invention will now be further described. In the following passages, different aspects of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

Detailed description of the invention

Before the present invention is described, it is to be understood that this invention is not limited to particular compositions, compounds, uses, and methods described herein, as such compositions, compounds, uses, and methods may, of course, vary.

When describing the compounds and processes of the invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.

As used in the specification and the appended claims, the singular forms "a", "an," and "the" include both singular and plural referents unless the context clearly dictates otherwise. By way of example, "a compound" means one compound or more than one compound. The terms "comprising", "comprises" and "comprised of as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. The terms "comprising", "comprises" and "comprised of" also include the term“consisting of.

The term "about" as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/-10% or less, preferably +1-5% or less, more preferably +/- 1 % or less, and still more preferably +/-0.1 % or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier "about" refers is itself also specifically, and preferably, disclosed.

As used herein, the term "and/or," when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a list is described as comprising group A, B, and/or C, the list can comprise A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.

The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1 , 2, 3, 4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of end points also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

Reference throughout this specification to“one embodiment” or“an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims and statements, any of the embodiments can be used in any combination. Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, definitions for the terms used in the description are included to better appreciate the teaching of the present invention.

Preferred statements (features) and embodiments of the compositions, compounds, uses, and methods of this invention are set herein below. Each statements and embodiments of the invention so defined may be combined with any other statement and/or embodiments unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features or statements indicated as being preferred or advantageous. Hereto, the present invention is in particular captured by any one or any combination of one or more of the below numbered aspects and embodiments 1 to 34, with any other statement and/or embodiments.

1. A malodor counteracting composition comprising nefopam, a polymorph, a hydrate, or a solvate thereof, preferably wherein nefopam is selected from (RS)-5-methyl-1 -phenyl- 1 , 3,4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 , 3,4, 6-tetrahydro- 2,5-benzoxazocine free base, or a mixture thereof.

2. The composition according to statement 1 , wherein nefopam is the malodor counteracting compound.

3. The composition according to any one of statements 1 or 2, wherein nefopam is selected from the free base of (RS)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine (CAS registry number 13669-70-0) (racemic nefopam), or the free base of (S)-5-methyl-1 -phenyl- 1 , 3,4, 6-tetrahydro-2,5-benzoxazocine ((+)-nefopam) (CAS registry number 1 1001 1-82-0), or the free base of (R)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine (CAS registry number 91463-82-0) ((-)-nefopam), or a mixture thereof.

4. The composition according to any one of statements 1 to 3, wherein nefopam is selected from the free base of (RS)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine, (CAS registry number 13669-70-0), or the free base of (R)-5-methyl-1 -phenyl-1 , 3,4, 6-tetrahydro- 2,5-benzoxazocine (CAS registry number 91463-82-0), or a mixture thereof.

5. The composition according to any one of statement 1 to 4, wherein nefopam is selected from (R)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base ((-)-nefopam free base). to any one of statements 1 to 5, as a malodor counteracting agent, preferably wherein nefopam is selected from (RS)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

7. Use of nefopam, or a polymorph, a hydrate or a solvate thereof, or of a composition according to any one of statements 1 to 5, as a malodor counteracting agent wherein nefopam is selected from (RS)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

8. Use of nefopam, or a polymorph, a hydrate or a solvate thereof, to modify, suppress, reduce, decrease, mask and/or block the sensory perception of malodors wherein nefopam is selected from (RS)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

9. The use according to any one of statements 6 to 8, wherein said malodor is earthy, musty and/or moldy malodor.

10. The use according to any one of statements 6 to 9, wherein said malodor is earthy malodor.

1 1. The use according to any one of statements 6 to 10, wherein nefopam is ( R )-5-methyl-1 - phenyl-1 ,3,4,6-tetrahydro-2,5-benzoxazocine free base.

12. The use according to any one of statements 6 to 1 1 , wherein the malodor causing agent comprises geosmin.

13. The use according to any one of statements 6 to 12, wherein the malodor causing agent comprises 2-methylisoborneol.

14. A method of counteracting malodors comprising: contacting a situs comprising a malodor or a situs that will become malodorous with a counteracting effective amount of nefopam, or a polymorph, a hydrate or a solvate thereof, or contacting a situs comprising a malodor or a situs that will become malodorous with a composition according to any one of statements 1 to 5, preferably wherein nefopam is selected from (RS )-5-methyl-1 -phenyl-1 ,3,4,6- tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 ,3,4, 6-tetrahydro-2, 5- benzoxazocine free base, or a mixture thereof. 15. A method to modify, suppress, reduce, decrease, mask and/or block the sensory perception of malodors, which comprise the step of contacting a situs with nefopam, or a polymorph, a hydrate or a solvate thereof, or with a composition according to any one of statements 1 to 5, preferably wherein nefopam is selected from (RS )-5-methyl-1 -phenyl-1 ,3,4, 6-tetrahydro-2, 5- benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

16. The method according to any one of statements 14 to 15, wherein said situs is selected from air, a surface, a liquid, or a source of malodors, preferably said situs is air.

17. The method according to any one of statements 14 to 16, wherein said malodor is earthy, musty and/or moldy malodor.

18. A method for counteracting earthy, musty and/or moldy malodors comprising the use of nefopam, or a polymorph, a hydrate or a solvate thereof, or of a composition according to any one of statements 1 to 5 as a malodor counteracting agent, preferably wherein nefopam is selected from (RS)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

19. The method according to any one of statements 14 to 18, wherein said malodor is earthy malodor.

20. The method according to any one of statements 14 to 19, wherein nefopam is selected from the free base of (RS)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine (CAS registry number 13669-70-0), or the free base of (S)-5-methyl-1 -phenyl-1 ,3,4, 6-tetrahydro-2, 5- benzoxazocine (CAS registry number 1 1001 1 -82-0), or the free base of (R)-5-methyl-1 - phenyl-1 ,3,4,6-tetrahydro-2,5-benzoxazocine (CAS registry number 91463-82-0), or a mixture thereof.

21. The method according to any one of statements 14 to 20, wherein nefopam is selected from the free base of (RS)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine (CAS registry number 13669-70-0), or the free base of (R)-5-methyl-1 -phenyl-1 ,3,4, 6-tetrahydro-2, 5- benzoxazocine (CAS registry number 91463-82-0), or a mixture thereof.

22. The method according to any one of statements 14 to 21 , wherein nefopam is ( R )-5-methyl- 1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base.

23. The method according to any one of statements 14 to 22, wherein the malodor causing agent comprises geosmin 24. The method according to any one of statements 14 to 23, wherein the malodor causing agent comprises 2-methylisoborneol.

25. A consumer, industrial or textile product comprising nefopam, or a polymorph, a hydrate or a solvate thereof, or a composition according to any one of statements 1 to 5, preferably wherein nefopam is selected from (RS )-5-methyl-1 -phenyl-1 ,3,4, 6-tetrahydro-2, 5- benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine free base, or a mixture thereof.

26. The product according to statement 25, wherein nefopam acts as malodor counteracting agent counteracting agent.

27. The product according to any one of statements 25 to 26, wherein nefopam is selected from the free base of (RS)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine (CAS registry number 13669-70-0), or the free base of (S)-5-methyl-1 -phenyl-1 ,3,4, 6-tetrahydro-2, 5- benzoxazocine (CAS registry number 1 1001 1 -82-0), or the free base of (R)-5-methyl-1 - phenyl-1 ,3,4,6-tetrahydro-2,5-benzoxazocine (CAS registry number 91463-82-0), or a mixture thereof.

28. The product according to any one of statements 25 to 27, wherein nefopam is selected from the free base of (RS)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine (CAS registry number 13669-70-0), or the free base of (R)-5-methyl-1 -phenyl-1 ,3,4, 6-tetrahydro-2, 5- benzoxazocine (CAS registry number 91463-82-0), or a mixture thereof.

29. The product according to any one of statements 25 to 28, wherein nefopam is ( R )-5-methyl- 1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine free base.

30. The product according to any one of statements 25 to 29, for use as an air-freshener.

31. The product according to any one of statements 25 to 29, for use on a skin.

32. Use of a product according to any one of statements 25 to 31 , in a method according to any one of statements 14 to 24.

33. Use of a consumer, industrial or textile product comprising nefopam, or a polymorph, a hydrate or a solvate thereof, or a composition according to any one of statements 1 to 5, as malodor counteracting agent, wherein nefopam is selected from (RS)-5-methyl-1 -phenyl- 1 , 3,4, 6-tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 , 3,4, 6-tetrahydro- 2,5-benzoxazocine free base, or a mixture thereof. 34. Use of a consumer, industrial or textile product according to statement 33 as an air- freshener.

In a first aspect, the invention provides a malodor and/or off-taste counteracting composition comprising nefopam, or a salt, a polymorph, a hydrate or a solvate thereof, preferably the invention provides a malodor counteracting composition comprising nefopam, or a polymorph, a hydrate or a solvate thereof, wherein nefopam is selected from (RS )-5-methyl-1 -phenyl-1 ,3,4,6- tetrahydro-2,5-benzoxazocine free base, or (R)-5-methyl-1 -phenyl-1 ,3,4, 6-tetrahydro-2, 5- benzoxazocine free base, or a mixture thereof.

Nefopam is a known non-opioid, non-steroidal, centrally acting analgesic drug that is derivative of the non-sedative benzoxazocine, developed and known in 1960s as Fenazocine (Bassett JR, Cairncross KD, Hacket NB, Story M.; Br J Pharmacol. 1969; 37:69-78). In the early 1970s, nefopam was developed as an antidepressant and was also used as a myorelaxant for the treatment of spasticity. The additional analgesic property was soon recognized, and although the mechanism of analgesia is not completely understood, it appears that nefopam is a centrally acting, non-opioid analgesic that inhibits reuptake of serotonin, norepinephrine, and dopamine. As a consequence, nefopam has been used extensively in many countries for the treatment of acute and chronic malignant and non-malignant pain. In addition, nefopam is generally considered to be safe and well tolerated.

The present composition comprising nefopam, or a salt, a polymorph or a crystal habit thereof, a hydrate or a solvate thereof, is a malodor and/or off-taste counteracting composition and is therefore non-therapeutic. The present composition comprising nefopam free base as described herein above, or a polymorph or a crystal habit thereof, a hydrate or a solvate thereof, is a malodor counteracting composition and is therefore non-therapeutic.

The term "free base" herein to refer to nefopam as distinct from any salt thereof, i.e. devoid, or essentially devoid, of addition salts of nefopam.

Racemic nefopam can be used (compound of formula (I): ((RS)-5-methyl-1 -phenyl-1 ,3,4,6- tetrahydro-2,5-benzoxazocine, CAS registry number 13669-70-0), preferably its free base, as well as its individual enantiomers shown below and mixture thereof. Nefopam may therefore be used as a mixture of its two enantiomers: (+)-nefopam and (-)- nefopam shown below under formula (II) and (III) respectively:

(S)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine ((+)-nefopam: CAS registry number

1 1001 1-82-0), preferably its free base, and

(R)-5-methyl-1 -phenyl-1 ,3, 4, 6-tetrahydro-2,5-benzoxazocine ((-)-nefopam: CAS registry number 91463-82-0), preferably its free base.

It must be understood that any ratio of both enantiomers of (+)-nefopam and (-)-nefopam, including the racemic mixture (i.e. a ratio 1 :1 of both enantiomers) or each isomer taken separately can be used to fulfill the purposes of the invention.

The invention also concerns the use of the above defined composition and compounds as malodor and/or off-taste counteracting ingredients, preferably as malodor counteracting ingredients, e.g. to modify, suppress, reduce, decrease, mask or block the sensory perception of malodors and/or off-tastes, preferably malodors.

“Malodor” or“undesirable odor” refers to compounds generally offensive or unpleasant to most people. “Off-taste”, as defined herein, shall be given its ordinary meaning and shall include tastes that are undesired or unpleasant to most people.

“Odor blocking” refers to the ability of a compound to dull the human sense of smell.

“Odor masking” refers to the ability of a compound with a non-offensive or pleasant smell that is dosed such that it limits the ability to sense a malodorous compound.

Those of skill in the art will also recognize that nefopam may exist in many different protonation states, depending on, among other things, the pH of its environment. The invention is not limited to any particular protonation state - any and all protonated forms of nefopam are intended to fall within the scope of the invention; preferably the free base form of nefopam is used.

The term“solvate” is used herein to describe a molecular complex comprising nefopam and one or more solvent molecules such as alcohols (for example, ethanol), ketones, esters, ethers, nitriles and the like. The term“hydrate” is employed when said solvent is water.

The term "polymorph" refers to the ability of nefopam or a salt, or solvate thereof to exist in more than one form or crystal structure.

The term "salts" as used herein means the salt forms which nefopam is able to form. Salts may be formed from acid addition of certain organic and inorganic acids to basic centers, typically amine. Examples of such appropriate acids include, for instance, inorganic acids such as hydrohalogen acids, e.g. hydrochloric or hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like; or organic acids such as, for example, acetic, propanoic, hydroxyacetic, 2- hydroxypropanoic, 2-oxopropanoic, lactic, pyruvic, oxalic (i.e. ethanedioic), malonic, succinic (i.e. butanedioic acid), maleic, fumaric, malic, tartaric, citric, methanesulfonic, ethanesulfonic, benzenesulfonic, p-toluenesulfonic, cyclohexanesulfamic, salicylic (i.e. 2-hydroxybenzoic), p- aminosalicylic and the like. Salts of an hydrogen atom or an amino group include salts of organic carboxylic acids such as acetic, benzoic, lactic, fumaric, tartaric, maleic, malonic, malic, isethionic, lactobionic and succinic acids; organic sulfonic acids, such as methanesulfonic, ethanesulfonic, benzenesulfonic and p-toluenesulfonic acids; and inorganic acids, such as hydrochloric, sulfuric, phosphoric and sulfamic acids. It is to be understood that the compositions herein also comprise nefopam and combinations with stoichiometric amounts of water as in hydrates. Preferable anions to form acid addition salts are acetate, benzenesulfonate , benzoate, bicarbonate, bitartrate, bromide, calcium edetate, camsyiate, carbonate, chloride, citrate, dihydrochloride, edetate, edisylate, estolate, esylate, fumarate, gluceptate, gluconate, glutamate, glycollylarsanilate, hexylresorcinate, hydrabamine, hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isethionate, lactate, lactobionate, malate, maleate, mandelate, mesylate, methylbromide, methylnitrate, methylsulfate, mucate, napsylate, nitrate, palmoate (embonate), pantothenate, phosphate/diphosphate, polygalacturonate, salicylate, stearate, subacetate, succinate, sulfate, tannate, tartrate, teoclate, triethiodide, and the like. Preferably, nefopam free base devoid of any salt thereof is used.

The present invention also concerns methods to modify, suppress, reduce, decrease, mask and/or block the sensory perception of malodors or off-tastes, which comprise the step of contacting a situs such as air, a surface or the malodor source, with an effective amount of nefopam or of a composition according to the invention.

According to any embodiment of the invention, the malodor or off-taste counteracted by nefopam or a composition as described herein is of earthy, moldy and/or musty type. A non-exhaustive list of compounds presenting an earthy, moldy and/or musty note is shown in Table 1 .

Table 1

The present invention also encompasses a consumer, industrial or textile product comprising nefopam as described herein or a composition as described herein.

Nefopam can be incorporated into all manners of composition and consumer, industrial or textile products that are designed to freshen, reduce, suppress or eliminate malodors and/or off-tastes and more particularly malodors containing an earthy or moldy and/or musty note.

Malodor or off-taste counteracting effective amount is understood to mean the amount of the nefopam employed in a functional product that is organoleptically effective to abate a given malodor or off-taste while reducing the combined intensity of the odor or taste level, wherein the given malodor is present in air space or has deposited on a substrate or is present in a substance.

Typically, nefopam may be employed in these compositions and products in varying amounts that will depend on the nature of the composition and consumer, industrial, or textile product and the particular end use application. Typically, however, one might expect to employ nefopam in amounts ranging from 0.001 % to 10% by weight, preferably 0.005% to 5.0% by weight, more preferably 0.01 % to 2.0% by weight of the total composition, or consumer, industrial, or textile product.

In the preparation of a composition or product according to the present invention, the nefopam may be combined with other ingredients typically employed. For example, in an air freshener, an additional malodor-counteracting active agent may be desirable. This might be, for example a perfume, a humidity absorber, or an anti-microbial active.

Typical anti-microbial actives include quaternary ammonium compounds (like cetyltrimethylammonium salts), chlorhexidine and salts thereof; diglycerol monocaprate, diglycerol monolaurate, glycerol monolaurate, polyhexamethylene biguanide salts (also known as polyaminopropyl biguanide salts-, an example being Cosmocil CQ available from Arch chemicals), 2,4,4'-trichloro, 2'-hydroxy-diphenyl ether (triclosan), and 3,7,1 1 -trimethyldodeca- 2,6,10-trienol (farnesol). Levels of incorporation may be from 0.01 % to 1.0% by weight of the composition. In addition, the composition or product may contain one or more excipients or adjuvants, which are typically included in such composition or products in order to aid in their manufacture, storage, application or performance.

In particular, said composition or product may contain a carrier material that may be hydrophobic or hydrophilic, solid or liquid depending on the nature of the composition or product and the use for which it is intended.

Hydrophobic carrier materials include silicones, that is, 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. Alternatively, or additionally, non-silicone hydrophobic materials 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 C ₈ to Ci ₈ alkyl benzoates), and polyglycol ethers, for example polyglycol butanol ethers.

Hydrophilic carrier materials, for example water, may also be employed. Water can be distilled, deionized, or tap water. Water, containing a small amount of low molecular weight monohydric alcohols, e.g., ethanol, methanol, and isopropanol, or polyols, such as ethylene glycol and propylene glycol, can also be useful.

Organic solvents might also be employed. They include organic solvents that are aliphatic alcohols, for example monohydric or polyhydric alcohols having 2 to 8 carbon atoms, and polyglycol ethers, such as oligoglycol ethers having 2 to 5 repeat units. Examples include dipropylene glycol, glycerol, propylene glycol, butylene glycol, ethanol, propanol, isopropanol, and industrial methylated spirits.

Mixtures of carrier materials may also be used. The amount of carrier material employed is dependent on the nature of the product and can range from 1-99%, more typically 10-95%, by weight of a consumer product composition.

Structurants and emulsifiers may also be employed in the composition and consumer, industrial, or textile product of the invention. They may be present at levels from 0.01-50%, more typically 0.1-10% by weight of the composition or product.

Suitable structurants include cellulosic thickeners such as hydroxy propyl cellulose and hydroxy ethyl cellulose, and dibenzylidene sorbitol. Other suitable 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. Suitable emulsifiers include steareth-2, steareth-20, steareth-21 , ceteareth-20, glyceryl stearate, cetyl alcohol, cetearyl alcohol, PEG-20 stearate, dimethicone copolyol, and poloxamines.

Further emulsifiers/surfactants are perfume solubilizes and wash-off agents. Examples of the former include PEG-hydrogenated castor oil, available from BASF in the Cremaphor RH and CO ranges. Examples of the latter include poly(oxyethylene) ethers. Certain sensory modifiers are further desirable components in the compositions of the invention. 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 trimethicone, dioctyl adipate, and hexamethyl disiloxane.

The compositions, consumer, industrial, or textile products according to the invention may contain solubilizing aids for one or more other ingredients contained in said composition or product, including compounds according to formula (I) if needed. A suitable solubilizing aid is surfactant, preferably no-foaming or low-foaming surfactant. Suitable surfactants are nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, zwitterionic surfactants, and mixtures thereof, preferably nonionic surfactants and cationic surfactants, and mixtures thereof. Suitable solvents and diluents may be selected from compounds well known to the fragrance art for such purposes, typical non-limiting examples including propylene glycol, dipropylene glycol, isopropyl myristate, and the like.

Compositions and products according to the invention may contain preservatives, pH control agents (such as buffers), chelating agents, defoaming agents, antifoaming agents, antistatic agents, colorants, antioxidants, aesthetic agents such as opacifiers, perlizers, dyes and mixtures thereof.

If the composition or the product is in the form of an aerosol composition, a volatile propellant is typically employed. The level of incorporation of the volatile propellant is typically from 40-99% parts by weight.

Non-chlorinated volatile propellants 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 degrees Centigrade and especially those with a boiling point below zero degrees Centigrade. It is especially preferred to employ liquefied hydrocarbon gases, and especially C ₃ to C ₆ 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 gasses such air, nitrogen or carbon dioxide.

Fragrance can be also a desirable additional component in the composition and/or consumer product of the invention. Suitable materials include conventional perfumes, such as perfume oils and also include so-called deo-perfumes, as described in EP 545,556 patent and other publications. These latter materials may also qualify as additional organic anti-microbial agents. Levels of incorporation are preferably up to 20%, more typically up to 2% by weight. The fragrance ingredients may be selected for their odor characteristics, which are preferred in order to provide a fresh impression on the substrate to which the composition is directed.

Fragrance ingredients may be selected from the group consisting of aromatic and aliphatic esters having molecular weights from about 130 to about 250; aliphatic and aromatic alcohols having molecular weights from about 90 to about 240; aliphatic ketones having molecular weights from about 150 to about 260; aromatic ketones having molecular weights from about 150 to about 270; aromatic and aliphatic lactones having molecular weights from about 130 to about 290; aliphatic aldehydes having molecular weights from about 140 to about 200; aromatic aldehydes having molecular weights from about 90 to about 230; aliphatic and aromatic ethers having molecular weights from about 150 to about 270; and condensation products of aldehydes and amines having molecular weights from about 180 to about 320; and essentially free from nitromusks and halogenated fragrance materials.

Representative fragrance ingredients include: adoxal aliphatic aldehyde 2,6, 10-trimethyl-9- undecen-1 -al, allyl amyl glycolate, allyl amyl glycolate, allyl cyclohexane propionate, allyl-3- cyclohexyl propionate, amyl acetate, 3-methyl-1 -butanol acetate, amyl salicylate, amyl salicylate, anisic aldehyde, 4-methoxy benzaldehyde, aurantiol, bacdanol, 2-ethyl-4-(2,2,3-trimethyl-3- cyclopenten-1-yl)-2-buten-1 -ol, benzaldehyde, benzophenone, benzophenone, benzyl acetate, benzyl acetate, benzyl salicylate, benzyl salicylate, beta damascene, 1 -(2,6,6-trimethyl-1-cyclo- hexen-1-yl)-2-buten-1 -one, beta gamma hexanol, 3-hexen-1-ol, buccoxime, 1 ,5-dimethyl-oxime bicyclo[3,2,1] octan-8-one, cedrol, octahydro-3,6,8,8-tetramethyl-1 H-3A,7-methanoazulen-6-ol, cetalox, dodecahydro-3A,6,6,9A- tetramethylnaphtho[2,1 B]-furan, cis-3-hexenyl acetate, cis-3- hexenyl acetate, cis-3-hexenyl salicylate, beta, gamma-hexenyl salicylate, citronellol, 3,7- dimethyl-6-octenol, citronellyl nitrile, geranyl nitrile, clove stem oil, coumarin, cyclohexyl salicylate, cyclohexyl salicylate, cymal, 2-methyl-3-(para iso propylphenyl)propionaldehyde, decyl aldehyde, decyl aldehyde, delta damascene, 1 -(2,6,6-trimethyl-3-cyclo-hexen- 1 -yl)-2- buten-1-one, dihydromyrcenol, 3-methylene-7 -methyl octan-7-ol, dimethyl benzyl carbinyl ester, dimethyl benzyl carbinyl acetate, ethyl vanillin, ethyl-2-methyl butyrate, ethyl-2-methyl butyrate, ethylene brassylate, ethylene tridecan-1 ,13-dioate, eucalyptol, 1 ,8-epoxy-para-menthane, eugenol alcohol 4-allyl-2-methoxy phenol, exaltolide, cyclopentadecanolide, flor acetate, dihydro-nor-yclopentadienyl acetate, florhydral, 3-(3-isopropylphenyl) butanal, frutene, dihydro- nor-yclopentadienyl propionate, galaxolide, 1 ,3,4,6,7,8-hexahydro-4,6,6,7,8,8- hexamethylcyclopenta-gamma-2-benzopyrane, gamma decalactone, 4-N-hepty-4- hydroxybutanoic acid, gamma dodecalactone, 4-N-octyl-4-hydroxy-butanoic acid, geraniol, 3,7- dimethyl-2,6-octadien-1 -ol, geranyl acetate, 3,7-dimethyl-2,6-octadien-1-yl acetate, geranyl nitrile, 3,7-diemthyl-2,6-octadienenitrile, helional, alpha-methyl-3,4, (methylenedioxy) hydrocinnamaldehyde, heliotropin, heliotropin hexyl acetate, hexyl acetate, hexyl cinnamic aldehyde, alpha-n-hexyl cinnamic aldehyde, hexyl salicylate, hexyl salicylate, hydroxyambran, 2- cyclododecyl-propanol, hydroxycitronellal, hydroxycitronellal, ionone alpha, 4-(2,6,6-trimethyl-1 - cyclohexenyl-1 -yl)-3-buten-2-one, ionone beta aliphatic ketone 4-(2,6,6-trimethyl-1-cyclohexen- 1-yl)-3-butene-2-one, ionone gamma methyl 4-(2, 6, 6-trimethyl-2 -cyclohexyl-1 -yl)-3-methyl-3- buten-2-one, iso E super 7-acetyl-1 ,2,3,4,5,6,7,8-octahydro-1 ,1 ,6,7,tetramethyl naphthalene, iso eugenol ether 2-methoxy-4-(1-propenyl) phenol, iso jasmone aliphatic ketone 2-methyl-3-(2- pentenyl)-2-cyclopenten-1-one, koavone, acetyl di-isoamylene, lauric aldehyde, lavandin natural, lavender natural, lemon CP, d-limonene, d-limonene/orange terpenes alkene 1 -methyl-4-iso- propenyl-1 -cyclohexene, linalool, 3-hydroxy-3,7-dimethyl-1 ,6-octadiene, linalyl acetate ester 3- hydroxy-3,7-dimethyl-1 ,6 octadiene acetate, 2, 4-di hydroxy-3, 6-dimethyl benzoic acid methyl ester, lyral, 4-(4-hydroxy-4-methyl-pentyl) 3-cylcohexene-1 -carboxaldehyde, majantol, 2,2- dimethyl-3-(3-methylphenyl)-propanol, mayol, 4-(1 -methylethyl) cyclohexane methanol, methyl anthranilate, methyl-2-aminobenzoate, methyl beta naphthyl ketone, methyl beta naphthyl ketone, methyl cedrylone, methyl cedrenyl ketone, methyl chavicol, 1-methyloxy-4,2-propen-1 -yl benzene, methyl dihydro jasmonate, methyl dihydrojasmonate, methyl nonyl acetaldehyde, methyl nonyl acetaldehyde, musk indanone, 4-acetyl-6-tert butyl-1 , 1 -dimethyl indane, nerol, 2- cis-3,7-dimethyl-2,6-octadien-1 -ol, nonalactone, 4-hydroxynonanoic acid, norlimbanol, 1 -(2,2,6- trimethyl-cyclohexyl)-3-hexanol, orange CP, P.T. bucinal, 2-methyl-3(para tert butylphenyl)propionaldehyde, para hydroxy phenyl butanone, para hydroxy phenyl butanone patchouli, phenyl acetaldehyde, 1-oxo-2-phenylethane phenyl acetaldehyde dimethyl, phenyl acetaldehyde dimethyl acetal phenyl ethyl acetate, phenyl ethyl acetate phenyl ethyl alcohol, phenyl ethyl alcohol, phenyl ethyl phenyl acetate, 2-phenylethyl phenyl acetate, phenyl hexanol/phenoxanol, 3-methyl-5-phenylpentanol, polysantol, 3,3-dimethyl-5-(2,2,3-trimethyl-3- cyclopenten-1-yl)-4-penten-2-ol, prenyl acetate, 2-methylbuten-2-ol-4-acetate, rosaphen, 2- methyl-5-phenyl pentanol, sandalwood, alpha-terpinene aliphatic alkane 1 -methyl-4-iso- propylcyclohexadiene-1 ,3-terpineol (alpha terpineol and alcohol para-menth-1-en-8-ol, para-beta terpineol) menth-1-en-1-ol, terpinyl acetate ester para-menth-1 -en-8-yl acetate, tetra hydro linalool, 3,7-dimethyl-3-octanol, tetrahydromyrcenol, 2,6-dimethyl-2-octanol, tonalid, 7-acetyl- 1 ,1 ,3,4,4,6-hexamethyl, tetralin, undecalactone lactone 4-N-heptyl-4-hydroxybutanoic acid, undecavertol, 4-methyl-3-decen-5-ol, undecyl aldehyde, undecanal, undecylenic aldehyde, undecylenic aldehyde, vanillin aromatic aldehyde 4-hydroxy-3-methoxybenzaldehyde, verdox, 2- tert-butyl cyclohexyl acetate, vertenex, 4-tert-butyl cyclohexyl acetate and mixtures thereof.

Preferably, the compositions and products contain an effective amount of perfume to provide the freshening fragrance to surfaces when first applied and some lingering fragrance in-wear.

Nefopam and/or the compositions of the present invention may be in the form of liquids or solids and they may be simply admixed into consumer, industrial, or textile product bases in these neat forms. Alternatively, if solid forms are used it may be desirable to solubilize them in a suitable solvent before mixing into the consumer, industrial, or textile product base.

Still further, it may be desired to spray dry a liquid nefopam or the composition onto a solid support to form a powder, which can then be admixed with a consumer, industrial, or textile product base.

Still further, it may be desirable to present nefopam or the compositions comprising nefopam in a delivery vehicle. For example, it may be desirable to present nefopam or the compositions comprising nefopam on or in a solid support. Said vehicles may be in the form of a core-shell capsule, wherein the compound or composition is contained in a core and surrounded by a shell. Alternatively, it may be desired to absorb the nefopam or the composition comprising nefopam into a porous body such as a porous bead or the like. Further still, in may be desirable to dissolve or disperse nefopam or the composition comprising nefopam in a matrix material.

Such vehicles may be employed as a means of affecting the rate of release of nefopam into the vapor phase, or it may act as a means by which nefopam or a composition comprising nefopam can be incorporated into a consumer, industrial, or textile product base. Still further, it may be a means of stabilizing nefopam against an aggressive external environment.

Capsule shells may be formed from any of those materials conventionally known in the art and may include a naturally-derived material, such as gelatin or waxes; or a synthetic polymer, such as an aminoplast resin, an acrylic resin or a polyurea. Synthetic materials may include water- insoluble or water-soluble encapsulating materials such as polyethylenes, polyamides, polystyrenes, polyisoprenes, polycarbonates, polyesters, polyacrylates, vinyl polymers and polyurethanes and mixtures thereof.

Capsules may consist of a matrix of polysaccharide and polyhydroxy compounds, water-soluble or water-dispersible encapsulating materials comprising dextrins derived from ungelatinized starch acid-esters of substituted dicarboxylic acids; useful starches including, raw starch, pregelatinized starch, modified starch derived from tubers, legumes, cereal and grains, for example corn starch, wheat starch, rice starch, waxy corn starch, oat starch, cassava starch, waxy barley, waxy rice starch, sweet rice starch, amioca, potato starch, tapioca starch, oat starch, cassava starch, and mixtures thereof; modified starches including hydrolyzed starch, acid thinned starch, starch esters of long chain hydrocarbons, starch acetates, starch octenyl succinate, and mixtures thereof.

The term "hydrolyzed starch" refers to oligosaccharide-type materials that are typically obtained by acid and/or enzymatic hydrolysis of starches, preferably corn starch. Suitable hydrolyzed starches for inclusion in the present invention include maltodextrins and corn syrup solids. The hydrolyzed starches for inclusion with the mixture of starch esters have a Dextrose Equivalent (DE) values of from about 10 to about 36 DE. The DE value is a measure of the reducing equivalence of the hydrolyzed starch referenced to dextrose and expressed as a percent (on a dry basis). The higher the DE value, the more reducing sugars present. A method for determining DE values can be found in Standard Analytical Methods of the Member Companies of Corn Industries Research Foundation, 6th ed. Corn Refineries Association, Inc. Washington, DC 1980, D-52.

Starch esters having a degree of substitution in the range of from about 0.01 % to about 10.0% may be used to encapsulate nefopam or a composition comprising nefopam.

Modified starches having emulsifying and emulsion stabilizing capacity such as starch octenyl succinates can be used. Preferably, the encapsulating material is water-soluble modified starch solid matrix, preferably a starch raw material that has been modified by treating said starch raw material with octenyl-succinic acid anhydride. More preferably the said modified starch is mixed with a polyhydroxy compound before treatment with octenyl-succinic acid anhydride.

A particular example of a modified starch is a waxy, maize starch, pregelatinized, dextrinized is mixed with sorbitol or any other alcohol type and then treated with octenyl succinic anhydride.

The use of such starches is described in European Patent 0 965 326, the contents of which are included herein by reference.

Nefopam or composition comprising nefopam may be added to consumer, industrial or textile product bases as such, or they may be added to the bases as part of a mixture of ingredients. For example, nefopam may be mixed with fragrance ingredients to form a fragrance composition, which can then be added to a consumer, industrial or textile product base.

Nefopam is odorless. It can be added to a perfume composition without influencing or affecting the particular hedonic effect that a perfumer is attempting to create.

In a particular embodiment of the invention, nefopam can be used alone, in a composition as defined herein or in combination with other compounds, or added in a defined consumer, industrial, or textile product to counteract (i.e. modify, suppress, reduce, decrease, mask or block) a predominantly earthy, musty and/or moldy malodor present in closed environment such as a room, a cellar, a bathroom, a kitchen, a car interior where microorganisms develop due to the presence of water or to an elevated humidity level.

In another embodiment of the invention, nefopam or a composition comprising nefopam can be used alone or in combination with other compounds, or added in a defined consumer product as a food additive to modify, suppress, reduce, decrease, mask or block the earthy off note elicited by earthy tasting molecule such as geosmin or 2-methylisoborneol that can occur in food or beverages. For example, geosmin and 2-methylisoborneol accumulate in the flesh of fishes raised in pond or stagnant water, eliciting an unpleasant earthy or moldy off-taste. This off-taste can constitute a hurdle to the consumption of these fishes that otherwise represent a safe and valuable food source.

In another embodiment of the invention, nefopam or a composition comprising nefopam can be used alone in combination with other compounds, or added in a defined consumer or industrial product to modify, suppress, reduce, decrease or mask the malodor emanating from stagnant or waste waters such as water rejected by industries, water from sewage or in water treatment plants. According to this embodiment, nefopam or a composition comprising nefopam can be, alone or combination with other compounds or added to a consumer or industrial product, added to the waste water to be treated. Alternatively, it can be sprayed in the environment surrounding the said waste water.

In another aspect of the invention, nefopam or a composition comprising nefopam can be used alone or in combination with other compounds or added in a defined consumer, industrial or textile product to reduce the olfactory impact of earthy smelling compounds that are used for a particular purpose. More particularly, the earthy smelling compound can serve in integrated pest control. For example, earthy smelling compounds such, as but not restricted to, geosmin, an archetypal earthy smelling compound has been identified as a repellent for some insect pests (M.C. Stensmyr, in Cell, 151 , 1345-1357, December 7, 2012; A.K. Wallingford in Pest Management Science, Volume 72, Issue 4, 701-706, April 2016). Nefopam or a composition comprising nefopam may therefore be useful to reduce the olfactory impact of earthy smelling compound geosmin for residents dwelt in the vicinity of cultures where earthy smelling compound geosmin is used as an insect repellent.

In a particular embodiment of the invention, nefopam or a composition comprising nefopam can be used to modify the olfactory character of a compound or a brand, used for perfume, flavor or fragrance composition that possess an earthy note. Since it has no intrinsic odor, nefopam will not bring an additional note to the earthy compound or brand but will reveal or enhance the other olfactory notes owned by the compound or the brand to be modified. Nefopam can therefore be used to repurpose smelling materials used in flavors and perfume creation.

The invention will now be illustrated by the following, non-limiting illustrations of particular embodiments of the invention.

Examples

The following terms are used:

h hour

RT room temperature

HCI Hydrochloric acid

NaHC0 ₃ Sodium bicarbonate

LC-MS Liquid Chromatography - Mass Spectrometry

MS Mass Spectrometry

HPLC High Performance Liquid Chromatography

SOR Specific Optical Rotation

ESI Electrospray Ionisation

NH ₄ OAC Ammonium acetate

min minute

¹ H NMR Proton Nuclear Magnetic Resonance EtOAc Ethyl Acetate

DMSO Dimethylsulfoxide

DMSO-d6 Deuterated Dimethylsulfoxide

DEA Diethylamine

TFA trifluoroacetic acid

ACN Acetonitrile

aq aqueous

CDCI ₃ Deuterated Chloroform

s singleton

d doublet

t triplet

q quadruplet

m multiplet

mL Milliliters

Example 1 Isolation of (S)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine ((+)-

Nefopam):

Scheme 1

The isolation of (+)-nefopam was performed as shown in Scheme 1. A stirred solution of nefopam. HCI salt (250 g, 865.05 mmol; commercially available from ISOCHEM, Vert-le-petit, FRANCE) in water (250 mL) was basified with saturated aqueous NaHC0 ₃ solution (4 L) to a pH of about 7 and extracted with EtOAc (3 x 1 L). The combined organic extracts were dried over sodium sulfate, filtered and concentrated under reduced pressure to afford nefopam (200 g, 91 %) as colorless oil. To a stirred solution of nefopam (200 g, 790.51 mmol) in ethanol (200 mL) was added (-)-O,O'- dibenzoyl-L-tartaric acid (70.75 g, 197.63 mmol) in ethanol (200 mL) at RT and the mixture was stirred for 12 h. The obtained solid was collected by filtration, washed with ethanol (2 x 200 mL) and dried under vacuum to obtain 140 g of nefopam-L-tartaric acid salt as on off-white solid with 85.60% chiral HPLC purity.

The obtained Nefopam-L-tartaric acid salt was dissolved in ethanol (500 mL) and heated to 80 °C under stirring until dissolution of the solid (1 h). Then the mixture was gradually cooled to RT and allowed to stand for 5 h. The obtained crystals were collected by filtration, washed with ethyl acetate (2 x 250 mL) and dried under vacuum to afford nefopam-L-tartaric acid salt (160 g) as off white crystals with 91.16% chiral HPLC purity.

The above crystallization process was repeated twice to attain 100% chiral HPLC purity of Nefopam-L-tartaric acid salt (100 g, 21 %) as off white crystals.

To a stirred solution of the obtained nefopam-L-tartaric acid salt crystals (100 g, 163.67 mmol) in water (250 mL) was added a solution of NaOH solution (16.37 g, 409.16 mmol) in water (250 mL) at RT and the mixture was stirred for 10 min. Then the mixture was diluted with water (200 mL) and extracted with ethyl acetate (3 x 200 mL). The combined organic extracts were dried over sodium sulfate, filtered and concentrated under reduced pressure to afford (+)-nefopam free base (40 g, 97%) as pale yellow oil.

¹ H NMR (400 MHz, CDCI ₃ ): d 7.33-7.27 (m, 4H), 7.25-7.21 (m, 3H), 7.21-7.16 (m, 1 H), 6.99 (d, J = 7.4 Hz, 1 H), 5.80 (s, 1 H), 4.81 (d, J = 12.7 Hz, 1 H), 4.21 -4.15 (m, 1 H), 3.90-3.84 (m, 1 H), 3.70 (d, J = 12.8 Hz, 1 H), 2.86-2.80 (m, 1 H), 2.66-2.60 (m, 1 H), 2.46 (s, 3H);

LC-MS (Agilent 6310 Ion Trap): 99.07%; m/z 254.1 [M + H] ⁺ ; (column; Kinetex EVO C-18 (50 ^c 3.0 mm, 2.6 pm); RT 2.93 min. 2.5 mM Aq. NH ₄ OAc : ACN; 0.8 mL/min);

HPLC (purity): 99.58%; (column: X SELECT CSH C18 (150 x 4.6 mm, 3.5 pm); RT 5.63 min; 0.05% TFA + 5% ACN : ACN + 5% 0.05% TFA; 1.0 mL/min, Diluent: H ₂ 0 : ACN); Chiral HPLC: Rt = 5.09 min (99.20%); (Chiralpak-I F3, 150 x 4.6 mm, 3.0 pm); mobile phase (A) 0.1 % DEA in n-Hexane (B) CH ₂ CI ₂ : CH ₃ OH (50: 50) (A : B :: 95 : 05); flow Rate: 1.0 mL/min);

SOR: [a]20D +79.52 (c 0.25, CHCI ₃ ); [a]20D +68.57 (c 0.25, EtOH).

Absolute stereochemistry confirmation of (+)-nefopam:

As (-)-nefopam HCI salt absolute stereochemistry was reported (Acta Chem. Scand. B 38 (1984) No. 4, 327-329), the above obtained (+)-nefopam was converted into HCI salt. A mixture of (+)-Nefopam (50 mg, 0.19 mmol) free base in isopropyl alcohol (0.3 mL) under nitrogen atmosphere was heated to 50 °C and stirred for 30 min. To this solution was added concentrated HCI (0.03 mL) under the same temperature, and the mixture was stirred for 10 min. The mixture was cooled to 0 °C slowly. The precipitate obtained was filtered, washed with cold isopropyl alcohol (2 x 0.5 mL) and dried under vacuum to afford (+)-nefopam.HCI salt (7 mg, 12%) as an off-white solid.

¹ H NMR (400 MHz, D ₂ 0): d 7.55-7.40 (m, 6H), 7.39-7.34 (m, 2H), 7.29 (br d, J = 7.3 Hz, 1 H), 6.07 (s, 1 H), 5.62 (br s, 1 H), 4.53 - 4.44 (m, 1 H), 4.39 (br d, J = 13.1 Hz, 1 H), 4.21 (dt, J = 14.2, 3.5 Hz, 1 H), 3.50 - 3.39 (m, 1 H), 3.23 (dt, J = 14.6, 3.5 Hz, 1 H), 3.05 (br s, 3H).

LC-MS: 96.01 %; m/z 254.2 [M + H]+; (column; Ascentis Express C18, (50 ^c 3.0 mm, 2.7 pm); RT 1.79 min. 0.025% Aq. TFA + 5% ACN: ACN + 5% 0.025% Aq. TFA, 1.2 mL/min).

HPLC (purity): 98.70%; (column; X-Select CSH-C-18 (150 x 4.6 mm, 3.5 pm); RT 5.57 min. 0.05% TFA + 5% ACN: ACN + 5% 0.05% TFA; 1.0 mL/min, Diluent: ACN: H ₂ 0).

Chiral HPLC: Rt = 13.53 min (99.27%); (Chiralcel-OJ-H, 250 x 4.6 mm, 5.0 pm); mobile phase (A) 0.1 % DEA in n-Hexane (B) EtOH: MeOH (50: 50) (A : B :: 95 : 05); flow Rate: 1.0 mL/min);

Observed SOR for (+)-nefopam HCI salt: [a]20D +1 13.72 (c 0.1 , DMSO); [a]20D +96.44 (c 0.7, MeOH).

Reported SOR for (-)-nefopam HCI salt: (Acta Chem. Scand. B 38 (1984) No. 4, 327-329) [a ] ^22D -1 19 (c 1 , DMSO); [a]20D -100.4 (c 0.7, MeOH).

From this it was confirmed that (+)-nefopam is an (S)-3,4,5,6-tetrahydro-5-methyl-1 -phenyl-1 H- 2,5-benzoxazocine hydrochloride.

Example 2: Isolation of (f?)-5-methyl-1 -phenyl-1 , 3, 4, 6-tetrahydro-2,5-benzoxazocine ((-)- Nefopam) :

The isolation of (-)-nefopam was performed as shown in Scheme 2. A stirred solution of Nefopam. HCI salt (300 g, 1038.6 mmol) in water (1 L) was basified with saturated aqueous NaHC0 ₃ solution (6 L) to a pH of about 7 and extracted with ethyl acetate (3 x 500 ml_). The combined organic extracts were dried over sodium sulfate, filtered and concentrated under reduced pressure to afford Nefopam (260 g, 99%) as colorless oil.

To a stirred solution of Nefopam (260 g, 1027.67 mmol) in ethanol (1 L) was added (+)-0,0 - dibenzoyl-D-tartaric acid (91.98 g, 256.92 mmol) in ethanol (500 mL) drop wise over a period of 20 min at RT, and the mixture was stirred for 12 h. The obtained solid was collected by filtration, washed with ethanol (2 x 200 mL) and dried under vacuum to obtain 180 g of nefopam-D-tartaric acid salt as on off white solid with 74.53% chiral HPLC purity.

The obtained nefopam-D-tartaric acid salt was dissolved in ethanol (800 mL), heated to 75°C under stirring until dissolution of the solid (4 h). Then the mixture was gradually cooled to RT and allowed to stand for 2 h. The obtained crystals were collected by filtration, washed with ethyl acetate (2 x 100 mL) and dried under vacuum to afford nefopam-D-tartaric acid salt (130 g) as off white crystals with 96.18% chiral HPLC purity.

The above crystallization process was repeated thrice to attain 98.15% chiral HPLC purity of Nefopam-D-tartaric acid salt (82 g) as off white crystals.

To a stirred solution of above obtained nefopam-D-tartaric acid salt crystals (82 g, 134.21 mmol) in water (1 L) was added aqueous saturated NaHC0 ₃ solution (2 L) at RT and the mixture was stirred for 24 h. Then the mixture was extracted with ethyl acetate (3 x 600 ml_). The combined organic extracts were dried over sodium sulfate, filtered and concentrated under reduced pressure to afford (-)-nefopam free base (33 g, 97%) as pale yellow oil.

¹ H NMR (400 MHz, DMSO-d6): d 7.33-7.28 (m, 4H), 7.26-7.15 (m, 4H), 7.00-6.96 (m, 1 H), 5.84 (s, 1 H), 4.66 (d, J = 12.7 Hz, 1 H), 4.01 -3.95 (m, 1 H), 3.78-3.72 (m, 1 H), 3.68 (d, J = 12.7 Hz, 1 H), 2.71 -2.64 (m, 1 H), 2.48-2.46 (m, 1 H), 2.28 (s, 3H);

LC-MS (ESI): 99.66%; m/z 254.1 [M + H] ⁺ ; (column; Kinetex EVO C-18 (50 x 3.0 mm, 2.6 pm); RT 2.10 min. 2.5 mM NH ₄ OOCH in water + 5% ACN : ACN + 5% 2.5 mM NH ₄ OOCH in water; 0.8 mL/min);

HPLC (purity): 99.76%; (column: X SELECT CSH C18 (150 x 4.6 mm, 3.5 pm); RT 9.63 min; 5 mM NH ₄ OAC: ACN; 1.0 mL/min, Diluent: ACN: H20);

Chiral HPLC: Rt = 4.39 min (98.77%); (Chiralpak-I F3, 150 x 4.6 mm, 3.0 pm); mobile phase (A) 0.1 % DEA in n-Hexane (B) CH ₂ CI ₂ : CH ₃ OH (50: 50) (A : B :: 95 : 05); flow Rate: 1.0 mL/min);

SOR: [a]20D -85.04 (c 0.25, CHCI3); [a]20D -93.79 (c 0.25, EtOH).

Absolute stereochemistry confirmation of (-)-nefopam:

As (-)-nefopam HCI salt absolute stereochemistry was reported (Acta Chem. Scand. B 38 (1984) No. 4, 327-329), the above obtained (-)-nefopam free base was converted into HCI salt.

A mixture of (-)-Nefopam (50 mg, 0.19 mmol) in isopropyl alcohol (0.3 mL) under nitrogen atmosphere was heated to 50 °C and stirred for 30 min. To this mixture was added concentrated HCI (0.03 mL) under the same temperature and the mixture was stirred for 10 min. The mixture was cooled to 0 °C. The precipitate obtained was filtered, washed with cold isopropyl alcohol (2 x 0.5 mL) and dried under vacuum to afford (-)-nefopam.HCI salt (25 mg, 43%) as an off-white solid.

¹ H NMR (400 MHz, D ₂ 0): 7.54 - 7.41 (m, 6H), 7.38 - 7.34 (m, 2H), 7.29 (br d, J = 7.4 Hz, 1 H), 6.06 (s, 1 H), 5.63 (br s, 1 H), 4.56-4.33 (m, 2H), 4.21 (dt, J = 14.2, 3.5 Hz, 1 H), 3.50- 3.39 (m, 1 H), 3.23 (dt, J = 14.6, 3.5 Hz, 1 H), 3.05 (br s, 3H);

LC-MS: 99.88%; m/z 254.2 [M + H] ⁺ ; (column; Ascentis Express C18, (50 x 3.0 mm, 2.7 pm); RT 1.76 min. 0.025% Aq. TFA + 5% ACN: ACN + 5% 0.025% Aq. TFA, 1.2 mL/min).

HPLC (purity): 98.89%; (column: X SELECT CSH C18 (150 x 4.6 mm, 3.5 pm); RT 5.55 min; 0.05% TFA + 5% ACN: ACN + 5% 0.05% TFA; 1.0 mL/min, Diluent: ACN: H20). Chiral HPLC: Rt = 14.90 min (100.00%); (Chiralcel-OJ-H, 250 x 4.6 mm, 5.0 pm); mobile phase (A) 0.1 % DEA in n-Hexane (B) EtOH: MeOH (50: 50) (A: B :: 95 : 05); flow Rate: 1.0 mL/min);

Observed SOR for (-)-Nefopam HCI salt: [a]20D -134.04 (c 0.1 , DMSO); [a]20D -108.29 (c 0.7, MeOH).

Reported SOR for (-)-Nefopam HCI salt: (Acta Chem. Scand. B 38 (1984) No. 4, 327-329) [a]22D -1 19 (c 1 , DMSO); [a]20D -100.4 (c 0.7, MeOH).

From this it was confirmed that (-)-nefopam is an (R)-3,4,5,6-tetrahydro-5-methyl-1 -phenyl-1 H- 2,5-benzoxazocine hydrochloride.

Example 3: Reduction of earthy olfactory note by a composition comprising racemic nefopam A sensory test was used to demonstrate the effect of a racemic solution of nefopam (in its free base form) on the perception of the earthy olfactory note of different compounds. The composition comprising nefopam was prepared by diluting racemic nefopam in its free base form in ethanol at a concentration of 107 mg/ml

The test comprised in a first step, microinjecting the earthy compound, nefopam or earthy compound + nefopam in 20 L TedlarTM bags specially conceived for gas sampling, previously loaded with a known volume of pure air (from oil free compressor with additional charcoal filters). The earthy compounds were solubilized in ethanol at a suitable concentration (see table 2) and injected in the 20 L TeldarTM bag. The final concentration in the bag varied between 7 mg/m ^3, to 383 mg/m ³ , (table 2), depending on the odor strength of the compound while the concentration of nefopam in the bags was fixed at 54 mg/m ³ .

Table 2

The odor presentation device comprised a cylinder filled with clean air. The bag was inserted in the cylinder and connected to a sampling installation in the cylinder by means of a valve. By controlled injection of clean air into the cylinder, the interior pressure was raised and the sampling air was pressed in a controlled manner out of the sample container through the opened valve. This sampling air was transferred to the nose of the corresponding sensory odor panel member by means of a funnel. By this means, each sensory odor panel member received an identical sample with a standardized volume flow and a constant provision time. The outlet flow rate was between 10-20 L/min (in order to avoid any mixing with ambient air before reaching the nose).

The expert panel of five assessors entered the room 15 minutes before starting the test. The basic standard test was a rating in intensity and the use of the closest chemical descriptors according to the following order of presentation:

1. earthy compound

2. Mix : earthy compound (at same concentrations as for 1 ) + Nefopam.

Each assessor could smell for few seconds. A pause of minimum 1 minute was considered between presentations.

The individual rating was done with a resolution of 0.5 on a scale ranging from 0 (no odor) to 5 (saturating odor).

The following results (Table 3) show that the typical earthy olfactory note associated with the tested compounds was strongly reduced when it was smelled in the presence of racemic nefopam. In contrast, the intensity of the other olfactory notes associated to the different compounds was not significantly decreased. This indicated that the odorless racemic solution of nefopam produced a strong attenuation/inhibition of the perception of the earthy note shared by different odorant molecules.

Table 3

Example 4: Effect associated to the enantiomers of nefopam.

Both enantiomers of nefopam, (+)-nefopam and (-)-nefopam in their free base from obtained as described in examples 1 and 2, respectively, were assessed separately as blockers of the perception of the earthy note of geosmin, using the same procedure as described in example 3. The results are shown in Table 4.

Table 4

(-)-Nefopam induced a strong reduction of the perception of the earthy note of geosmin for all the panelists.