EP1069176A1 - Aliphatic esters and their use as perfume ingredients - Google Patents

Abstract

Esters of formula <IMAGE> in which the wavy line indicates that the asymmetric carbon located in position 2, can adopt an R or S type configuration, R1 represents a methyl or ethyl radical and R2 represents an ethyl, linear or branched propyl radical , or isobutyl, in the form of an optically active isomer or in the form of a mixture of isomers, are useful as a perfuming ingredient for the preparation of perfuming compositions or perfumed articles, to which they impart odorous notes of fruity type, very natural.

Description

dans laquelle la ligne ondulée indique que le carbone asymétrique situé en position 2, peut adopter une configuration de type R ou S, R₁ représente un radical méthyle ou éthyle et R₂ représente un radical éthyle, propyle linéaire ou ramifié, ou isobutyle, sous forme d'un isomère optiquement actif ou sous forme d'un mélange d'isomères.The present invention relates to the field of perfumery. It relates more particularly to a compound of formula

in which the wavy line indicates that the asymmetric carbon located in position 2, can adopt an R or S type configuration, R ₁ represents a methyl or ethyl radical and R ₂ represents an ethyl radical, linear or branched propyl, or isobutyl, under as an optically active isomer or as a mixture of isomers.

The esters of formula (I) have very useful odorous qualities and appreciated. They can therefore be used to prepare perfumes, perfume compositions and scented items. They are used to impart fragrant notes with character very natural fruity.

The compound of formula (I) in which R ₁ represents a methyl radical and R ₂ represents an ethyl radical, namely (S) -2-ethyl tert-butoxypropanoate, is known. This compound is in fact described as a synthesis intermediary by G. Cainelli, M. Panunzio, E. Bandini, G. Martelli and G. Spunta in Tetrahedron; IN ; 52; 5; 1996; 1685-1698. However, there is no description in the prior art of the odor of this compound or of any utility in perfumery.

The other compounds represented by formula (I) are new.

Many esters with a structure similar to the compounds (I) are known. We can quote for example Rev. Agroquim. Tecnol. Food. (1986), 26 (4), 597-601 which describes the use of ethyl 2-ethoxypropanoate as a racemic mixture for flavoring cheese, especially parmesan. Many others compounds having a structure close to that of the compounds which are the subject of the present invention have been described in the field of organic synthesis, but to our knowledge, in the prior art there is no reference or even suggestion of the possible usefulness of these esters as perfuming ingredients.

Now, we have now unexpectedly discovered that the esters of formula (I) have completely surprising olfactory properties in view of the art that make their use in perfumery very interesting.

The compounds of formula (I) are characterized by an odor whose note of fruity type head, very natural, makes them particularly appreciated by perfumers. The intensity of this note varies from one compound to another. In addition, the subnotes which which accompany it and which also vary from one compound to another, allow outsourcing to basic compositions a whole range of olfactory nuances and thus make each compound capable of contributing to the variety of the perfumer's palette.

Thus, we find for example in the fragrant notes of several esters according to the invention, a connotation of the chamomile type. This is particularly distinct in the odor of ethyl (R) -2- (1,1-dimethylpropoxy) propanoate whose note fruity is also very sustained. Ethyl (S) -2- (1,1-dimethylpropoxy) propanoate has a more spicy odor but which also includes a fragrant sub-note of chamomile type, this time accompanied by notes recalling 2-acetyl-4-methyl-4-pentanoate ethyl (EP B1 0178532; origin: Firmenich SA, Geneva, Switzerland), lees de wine, linalool or coriander. The chamomile note of (S) -2-tert-butoxypropanoate propyl is accompanied by a licorice type sub-note with a very nice peach-apricot connotation.

Isobutyl (S) -2-tert-butoxypropanoate and (S) -2- (1,1-dimethylpropoxy) isopropyl propanoate, the smell of which also has a connotation reminding the chamomile, are less powerful in intensity than the last mentioned compounds.

Ethyl (S) -2-tert-butoxypropanoate has an odor which the fruity character is also velvety, ethereal, sweet, but it also has notes reminiscent of mint. Its fresh smell keeps the natural side common to all compounds of the invention.

Among the compounds of the invention, (S) -2- (1,1-dimethylpropoxy) propanoate propyl is a fragrance ingredient of choice. It has an odor whose top note fruity is accompanied by smoky and refreshing notes. The smell keeps its side natural. In the background, it recalls that of 8-p-menthen-2-ol acetate, with also a floral connotation, linalool, citrata mint. This floral, fruity note with sage connotation clary, citrata mint, has a fresh, very natural side, which is why it is particularly appreciated by perfumers. In addition, (S) -2- (1,1-dimethylpropoxy) propyl propanoate has been compared to dihydromyrcenol (origin: International Flavors & Fragrances), known to bring fragrant notes giving a freshness effect floral and aromatic in fragrance compositions. However, we discovered, at term of this comparison, which the compound of the invention presents in a completely advantageous a smell whose freshness is more of aromatic, sage and bergamot type, while dihydromyrcenol has a more aromatic, lavender odor. The current invention therefore makes a new and unexpected contribution to the permanent problem of the search for new fragrance ingredients, capable of industrial synthesis and of a diverse and at least as advantageous use as that of the known compounds and available on the market.

The compounds of the invention are equally suitable for use in fine perfumery, in perfumes, eau de toilette or aftershave lotions, than others common jobs in perfumery such as perfuming soaps, shower gels or bath, hygiene products, or hair treatment products like shampoos or after shampoos or other hair care products, as well as body deodorants and ambient deodorants, or cosmetic preparations.

Esters (I) can also be used in applications such as as liquid or solid detergents intended for the treatment of textiles, fabric softeners or in detergent compositions or cleaning products intended for cleaning of dishes or various surfaces, for domestic or industrial use.

In these applications, the compounds of the invention can be used alone or in mixture with other perfuming ingredients, solvents or adjuvants of use current in perfumery. The nature and variety of these co-ingredients does not call for a more detailed description here, which should not be exhaustive, the skilled person being able to choose them by its general knowledge and according to the nature of the product to be perfumed and of the desired olfactory effect.

These fragrance ingredients belong to chemical classes too as varied as alcohols, aldehydes, ketones, esters, ethers, acetates, nitriles, hydrocarbons terpenic, heterocyclic nitrogen or sulfur compounds, as well as essential oils of natural or synthetic origin. Many of these ingredients are also listed in reference texts such as the book by S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, New Jersey, USA, or more recent versions, or in other works of a similar nature.

The proportions in which the compounds according to the invention can be incorporated in the aforementioned miscellaneous products vary in a range of values extent. These values depend on the nature of the article or product you want to scent and the desired olfactory effect, as well as the nature of the co-ingredients in a composition given when the compounds of the invention are used in mixture with perfume co-ingredients, solvents or adjuvants commonly used in the art.

By way of example, we can cite typical concentrations of the order of 5 to 30% or even more, by weight of the compound relative to the weight of the perfume composition in which it is incorporated. Concentrations much lower than these can be used when this compound is directly applied in the fragrance of various consumption mentioned above.

a)

, Amberlyst ®

b) R₂OH , tétraisopropylorthotitanate

dans lequel les symboles ont le même sens que dans la formule (I). La fonction hydroxyle du lactate d'éthyle est alkylée dans la première étape ; puis, si nécessaire, une transestérification du produit intermédiaire conduit à l'ester désiré. Ces deux étapes sont des réactions standards, bien connues de l'homme du métier.The compounds of formula (I) are synthesized in one or two stages from ethyl lactate in optically active form or in the form of a mixture of isomers, according to the following general scheme:

at)

, Amberlyst ®

b) R ₂ OH, tetraisopropylorthotitanate

in which the symbols have the same meaning as in formula (I). The hydroxyl function of ethyl lactate is alkylated in the first step; then, if necessary, transesterification of the intermediate product leads to the desired ester. These two steps are standard reactions, well known to those skilled in the art.

The invention will now be described in more detail using the following examples in which the temperatures are given in degrees Celsius and the abbreviations have the usual meaning in art.

Example 1 Preparation of the compounds of formula (I) a) (S) -2- (1,1-dimethylpropoxy) ethyl propanoate

A mixture of 3534 g (50.5 mole) of isoamylene, 600 g (5.08 mole, [α] ^D ₂₀ = -12.4 °) of (S) was kept stirring at 10 ° for 66 h ) -ethyl lactate and 20 g of Amberlyst® 15. The reaction mixture was then filtered and washed 3 times using 1 l of Na ₂ CO ₃ in 10% solution. After distillation (pressure = 20 × 10 ² Pa, bath at 110 °), 692.2 g of ethyl (S) -2- (1,1-dimethylpropxy) propanoate were obtained with a purity of 95% and a yield of 69 %.

Analytical data:

Pe (20 x 10 ² Pa) = 80 °

[α] ^D ₂₀ = -42.21 ° (CHCl ₃ )

NMR ^(1H) (360 MHz; CDCl _3): 0.89 (t, J = 7.2Hz, 3H); 1.13 (s, 3H); 1.14 (s, 3H); 1.27 (t, J = 7.2 Hz, 3H); 1.33 (d, J = 7.2 Hz, 3H); 4.1 (q, J = 7.2 Hz, 1H); 4.18 (split q, J = 7.2Hz, 2H).

MS: 188 (M ⁺ , 0), 173 (3), 159 (18), 115 (19), 101 (21), 71 (100), 43 (65).

b) (S) -2- (1,1-dimethylpropoxy) propylate propanoate

Was heated to reflux, with stirring, a mixture of 535 g (2.8 mole) of (S) -2- (1,1-dimethylpropxy) propanoate obtained under a) , 430 g (7.1 mole ) of propanol and 8 g (28 mmol) of tetraisopropylorthotitanate (origin: Fluka ), and the ethanol produced was separated on a Vigreux column with a distillation head (max. head temperature: 95 °). After having cooled the mixture, it was washed successively with a 10% ice / HCl mixture, water, NaHCO ₃ in solution and finally brine. 539 g of propyl (S) -2- (1,1-dimethylpropxy) propanoate were thus obtained with a purity of 97.2% and a yield of 94%.

Analytical data:

Pe (20 x 10 ² Pa) = 83 °

[α] ^D ₂₀ = -49 ° (CHCl ₃ )

NMR ^(1H) (360 MHz; CDCl _3): 0.89 (t, J = 7.2Hz, 3H); 0.96 (t, J = 7.2 Hz, 3H); 1.13 (s, 3H); 1.14 (s, 3H); 1.35 (d, J = 7.2 Hz, 3H); 4.08 (t, J = 7.2 Hz, 2H); 4.11 (q, J = 7.2Hz, 1H).

NMR ( ¹³ C) (90.5 MHz; CDCl ₃ ): 8.5 (q); 10.4 (q); 20.5 (q); 22.0 (t); 25.1 (q); 33.5 (t); 66.2 (t); 67.3 (d); 175.2 (s).

MS: 202 (M ⁺ , 0), 187 (1), 173 (11), 131 (9), 115 (27), 71 (100), 43 (52).

c, d) (S) -2- (1,1-dimethylpropoxy) isobutyl propanoate and (S) -2- (1,1-dimethylpropoxy) isopropyl propanoate

These two compounds were synthesized in two stages. The first step is that described under a) . The second was carried out according to an operating protocol similar to that described under b), by choosing the alcohol used as reagent according to the desired final product (see diagram 1).

Analytical data: • (S) -2- (1,1-dimethylpropoxy) isobutyl propanoate

[α] ^D ₂₀ = -46.1 ° (CHCl ₃ )

NMR ^(1H) (360 MHz; CDCl _3): 0.89 (t, J = 7Hz, 3H); 0.95 (t, J = 7Hz, 6H); 1.30 and 1.35 (2s, 6H); 1.36 (d, J = 7Hz, 3H); 3.9 (d, J = 7Hz, 2H); 4.12 (q, J = 7Hz, 1H).

NMR ( ¹³ C) (90.5 MHz; CDCl ₃ ): 8.5 (q); 19.1 (q); 20.6 (q); 25.0 (q); 27.8 (d); 33.5 (t); 67.2 (d); 70.7 (t); 77.1 (s); 175.2 (s).

MS: 216 (M ⁺ , 0), 187 (4), 145 (3), 131 (20), 115 (25), 71 (100), 43 (40).

• (S) -2- (1,1-dimethylpropoxy) isopropyl propanoate

[α] ^D ₂₀ = -49.2 ° (CHCl ₃ )

NMR ^(1H) (360 MHz; CDCl _3): 0.89 (t, J = 7Hz, 3H); 1.30 and 1.35 (2s, 6H); 1.50 and 1.52 (2d, J = 7Hz, 6H); 1.32 (d, J = 7Hz, 3H); 4.06 (q, J = 7Hz, 1H); 5.04 (hept., J = 7Hz, 1H).

NMR ( ¹³ C) (90.5 MHz; CDCl ₃ ): 8.5 (q); 20.4 (q); 21.7 (2q); 25 (q); 25.1 (q); 33.5 (t); 67.4 (d); 67.8 (d); 174.7 (s).

MS: 202 (M ⁺ , 0), 173 (6), 145 (5), 131 (19), 115 (20), 71 (100), 59 (20), 43 (47).

e) (S) -2-ethyl tert-butoxypropanoate

The compound was prepared in one step according to a procedure similar to that described under a) by choosing the suitable reagent as described in scheme 1 (step a).

Analytical data:

[α] ^D ₂₀ = -41 ° (CHCl ₃ )

NMR ^(1H) (360MHz, CDCl _3): 1.20 (s, 9H); 1.28 (t, J = 8Hz, 3H); 1.35 (d, J = 8Hz, 3H); 4.11 (q, J = 7Hz, 1H); 4.19 (dq, J = 1.7Hz, 2H).

NMR ( ¹³ C) (90.5 MHz, CDCl ₃ ): 14.2 (q); 20.5 (q); 27.8 (q); 60.6 (t); 67.6 (d); 74.8 (s); 175.1 (s).

SM: 174 (M ⁺ , 1), 159 (4), 101 (40), 73 (12), 57 (100), 45 (10), 41 (21), 39 (6), 29 (19), 27 (8).

f, g) (S) -2-tert-butoxypropanoate, propyl and (S) -2-tert-butoxypropanoate, isobutyl

These two compounds were synthesized in two stages. The first step is that described under e) . The second was carried out according to an operating protocol similar to that described under b), by choosing the alcohol used as reagent according to the desired final product (see diagram 1).

Analytical data: • (S) -2-propyl tert-butoxypropanoate

[α] ^D ₂₀ = -50 ° (CHCl ₃ )

NMR ^(1H) (360MHz, CDCl _3): 0.96 (t, J = 7Hz, 3H); 1.20 (s, 9H); 1.34 (d, J = 7Hz, 3H); 1.68 (m, 2H); 4.09 (m, 2H); 4.12 (q, J = 7Hz, 1H).

NMR ( ¹³ C) (90.5 MHz, CDCl ₃ ): 10.4 (q); 20.6 (q); 22.0 (t); 27.8 (q); 66.3 (t); 67.6 (d); 74.8 (s); 175.2 (s).

MS: 188 (M ⁺ , <0.5), 173 (3), 101 (60), 57 (100).

• (S) -2-isobutyl tert-butoxypropanoate

[α] ^D ₂₀ = -49.2 ° (CHCl ₃ )

NMR ( ¹ H) (360MHz, CDCl ₃ ): 0.94 (2d, J = 7Hz, 6H); 1.20 (s, 9H); 1.35 (d, J = 7Hz, 3H); 3.90 (d, J = 7Hz, 2H); 4.13 (q, J = 7Hz, 1H).

NMR ( ¹³ C) (90.5 MHz, CDCl ₃ ): 19.1 (2q); 20.6 (q); 27.8 (d); 27.8 (q); 67.5 (d); 70.8 (t); 74.8 (s); 175.1 (s).

MS: 202 (M ⁺ , <0.5), 131 (5), 101 (30), 57 (100).

h) (R) -2- (1,1-dimethylpropoxy) ethyl propanoate

This compound was synthesized in one step according to a protocol identical to that described under a) , using (R) -lactate of ethyl ([α] ^D ₂₀ = + 11 °) as starting material.

Analytical data:

[α] ^D ₂₀ = + 48.8 ° (CHCl ₃ )

NMR ^(1H) (360MHz, CDCl _3): 0.89 (t, J = 7Hz, 3H); 1.30 and 1.35 (2s, 6H); 1.28 (t, J = 7Hz, 3H); 1.34 (d, J = 7Hz, 3H); 4.1 (q, J = 7Hz, 1H); 4.19 (split q, J = 7Hz, 2H).

MS: 188 (M ⁺ , 0), 173 (4), 159 (13), 115 (18), 101 (16), 71 (100), 55 (15), 43 (62).

i) (R) -2- (1,1-dimethylpropoxy) propyl propanoate

This compound was synthesized in two stages. The first step is that described under h) . The second step is carried out according to a protocol similar to that described under b) , using a suitable reagent as indicated in diagram 1.

Analytical data:

[α] ^D ₂₀ = + 51 ° (CHCl ₃ )

NMR ^(1H) (360MHz, CDCl _3): 0.89 (t, J = 7Hz, 3H); 0.96 (t, J = 7Hz, 3H); 1.30 and 1.35 (2s, 6H); 1.35 (d, J = 7Hz, 3H); 4.08 (t, J = 7Hz, 2H); 4.10 (q, J = 7Hz, 1H).

MS: 202 (M ⁺ , 0), 187 (3), 173 (13), 131 (10), 115 (36), 71 (100), 43 (36).

Example 2 Preparation of a perfuming composition for a eau de toilette for men

A basic composition for male eau de toilette was prepared from the following ingredients: Ingredients Parts by weight Benzyl acetate 40 Geranyl acetate 10 Linalyl acetate 100 Cedarleaf 20 Allyl amyl glycolate 10 Ambrox ® 20 Essence of Aspic 100 Bergamot essence 180 Citral 30 Coumarin 20 Tarragon essence 10 Essen Juniper synth 40 English clove essence 10 Lavender essence 120 Linalol 170 Lyral ® 60 Mandarin essence 30 Crystal foam 50 10% rose oxide 20 Siberian pine essence 20 Essence of patchouli 150 Polysantol ® 30 Amyl salicylate 20 Benzyl salicylate 440 Ylang extra 30 Zestover at 10% 70 Total 1800

The addition of 300 parts by weight of propyl (S) -2- (1,1-dimethylpropoxy) propanoate to this basic composition, made it possible to obtain a new composition whose smell has a clear herbaceous-fresh, slightly citrus connotation. The diffusion of the odor is markedly increased compared to that of the base composition. In addition, fragrant notes of this new composition make it more voluminous and also more sparkling.

Example 3 Preparation of a perfume composition for a body deodorant

A basic composition intended for a body deodorant was prepared from the following ingredients: Ingredients Parts by weight Allyl amyl glycolate 20 Ambrox ® at 10% 15 Bergamot synth. 180 Civet synth. at 1% 30 α-Damascone at 10% 50 Lorysia ® 10 Galaxolide ® 50 MIP 45 Galbex ® 30 Essence of Chinese Geranium 15 Hedione ® 60 Indolene 10% 10 Iso E super 10 Iralia ® 10 Gros Lavandin 50 Lyral ® 15 10% crystal foam 50 Tonalide ® 40 Vertofix heart 110 Total 750

Addition of 200 parts by weight of propyl (S) -2- (1,1-dimethylpropoxy) propanoate to this basic composition, the smell of which has a fresh, deodorant connotation, markedly increases the freshness of the top note as well as the impact of the fragrance and exalts the fragrant note conferred by the lavandin and adds a herbal connotation of type clary sage.

Claims (5)

Use of a compound of formula

in which the wavy line indicates that the asymmetric carbon located in position 2, can adopt an R or S type configuration, R ₁ represents a methyl or ethyl radical and R ₂ represents an ethyl radical, linear or branched propyl, or isobutyl, under as an optically active isomer or as a mixture of isomers, as a perfuming ingredient for the preparation of perfuming compositions or perfumed articles. Perfume composition or scent article containing as an ingredient active a compound of formula (I) as defined in claim 1. Perfumed article according to claim 2, in the form of a perfume or an eau de toilette, an aftershave lotion, a cosmetic preparation, a soap, shampoo or after shampoo or other hair care product, bath or shower gel, body deodorant or room deodorant, detergent or fabric softener or cleaning product. Compound of formula (I) as defined in claim 1, (S) -2-tert-butoxypropanoate ethyl being excluded. As compound according to claim 4, (S) -2- (1,1-dimethylpropoxy) propyl propanoate.