EP0586442B1 - Use of isomeric 1,1,1-trialkyl-2-phenylethane derivatives as odoriferous substances, and fragrances containing these substances - Google Patents

Abstract

The invention concerns the use, as odoriferous substances, of isomeric 1,1,1-trialkyl-2-phenylethane derivatives of general formula (I), in which R1 to R3, independently of each other, are alkyl groups with 1 to 3 C-atoms and R4 is hydrogen or an alkyl, acyl, alkoxycarbonyl or alkoxyalkyl group with a total of 2 to 5 C-atoms. These compounds, in particular the 2,2-dimethyl-1-phenylpropyl ester of acetic acid, have a complex rosy/woody character and high scent-emanation power, and can be mixed with each other or with other odoriferous substances in widely varying proportions, generally 1-70 % by wt. relative to the overall composition, to give new fragrances. These compositions can be used for perfuming cosmetic preparations and industrial products, as well as in alcohol fragances.

Description

The invention relates to the use of isomeric 1,1,1-trialkyl-2-phenyl-ethane derivatives as fragrances.

Many natural fragrances are available in completely inadequate amounts, measured by demand. For example, 5,000 kg of rose petals are required to obtain 1 kg of rose oil; the consequences are a very limited world annual production and a high price. It is therefore clear that the fragrance industry has a constant need for new fragrances with interesting fragrances to complement the range of naturally available fragrances and to make the necessary adjustments to changing fashionable tastes, as well as the ever-increasing need for odor improvers for everyday products such as To be able to cover cosmetics and cleaning agents.

Acetic acid (1-phenyl-2,2,2-trichloroethyl) ester is a well-known, commercially available fragrance which has a mild floral-rosy smell. However, halogenated compounds are increasingly viewed critically by the consumer, so that there is a need for suitable substitutes.

In addition, there is generally a constant need for synthetic fragrances which can be produced cheaply and with a constant quality and which have desired olfactory properties, ie pleasant, as close to natural and qualitatively novel odor profiles as possible possess sufficient intensity and are able to advantageously influence the fragrance of cosmetic and consumer goods. It was therefore looked for compounds that should have characteristic new odor profiles with high adhesive strength, odor intensity and radiance.

Erfindungsgegenstand ist daher die Verwendung isomerer 1,1,1-Trialkyl-2-phenyl-ethan-Derivate der allgemeinen Formel (I), worin

• die Reste R¹ bis R³ unabhängig voneinander Alkylgruppen mit 1 bis 3 C-Atomen
• der Rest R⁴ eine Alkyl- oder Acylgruppe mit 1 bis 5 C-Atomen oder eine Alkoxycarbonyl- oder eine Alkoxyalkylgruppe mit 2 bis 5 C-Atomen bedeuten, als Riechstoffe.

It has now been found that 1,1,1-trialkyl-2-phenylethane derivatives of the general formula (I) meet this requirement excellently in all respects and advantageously as fragrances with differently nuanced floral, woody, spicy scents good adhesive strength can be used.

The subject of the invention is therefore the use of isomeric 1,1,1-trialkyl-2-phenyl-ethane derivatives of the general formula (I), in which

• the radicals R¹ to R³ independently of one another alkyl groups with 1 to 3 carbon atoms
• the radical R⁴ is an alkyl or acyl group with 1 to 5 carbon atoms or an alkoxycarbonyl or an alkoxyalkyl group with 2 to 5 carbon atoms, as fragrances.

The C atom directly adjacent to the phenyl radical in the compounds of the general formula (I) represents a center of chirality, so that these compounds can exist in various spatial forms. In the context of conventional syntheses, the compounds according to the invention are obtained as mixtures of the corresponding isomers and as such are used as a fragrance used. If desired, however, the enantiomerically pure compounds can also be used alone as a fragrance.

Bevorzugt ist die Verwendung derjenigen Verbindungen der allgemeinen Formel (I) als Riechstoffe, bei denen die Reste R¹ bis R³ Methylgruppen bedeuten, insbesondere derjenigen, bei denen darüber hinaus der Rest R⁴ einen Acylrest mit 1 bis 3 C-Atomen bedeutet.The products to be used as fragrances according to the invention are produced by methods known per se in preparative organic chemistry. For example, pivalinaldehyde can be converted to 2,2-dimethyl-1-phenyl-propanol (II) by Grignard reaction with phenylmagnesium bromide, which can be converted, for example, by reaction with acetic anhydride in pyridine or dimethylaminopyridine to acetate (Ia), with dimethyl carbonate to carbonate ( Ib) or with ethyl vinyl ether in the presence of an acidic catalyst to form the acetal (Ic).

Preference is given to using those compounds of the general formula (I) as odoriferous substances in which the radicals R¹ to R³ are methyl groups, in particular those in which the radical R⁴ is also an acyl radical having 1 to 3 carbon atoms.

The use of acetic acid (2,2-dimethyl-1-phenyl-propyl) ester (Ia) as a fragrance is particularly preferred.

Hingegen ist bekannt, daß 4-tert.-Butylcyclohexylacetat, das als Strukturmerkmale ebenfalls einen tert.-Butyl- sowie einen Acetylrest enthält über Geruchseigenschaften verfügt, die als holzig, blumig beschrieben werden (K. Bauer et.al. "Common Fragrance and Flavor Materials", VCH-Verlagsgesellschaft, Weinheim 1990, S. 69).The preparation of acetic acid (2,2-dimethyl-1-phenyl-propyl) ester (Ia) has already been described in the literature, see (a) DJCollins, HA Jacobs, Aust. J. Chem 1986 (39) 2095; (b) H. Sternerup, Acta Chem. Scand., Ser. B, 1974 (28) 969. However, in no case is there any information about any olfactory properties of the compound (Ia).

On the other hand, it is known that 4-tert-butylcyclohexyl acetate, which also contains a tert-butyl and an acetyl radical as structural features, has odor properties that are described as woody, flowery (K. Bauer et al. "Common Fragrance and Flavor Materials ", VCH publishing company, Weinheim 1990, p. 69).

Compound (Ia) in particular has remarkable odor properties that are very much in demand in perfumery, namely rosy-woody with complex shades and great charisma. This particular olfactory characteristic of the rose type. is original and new and deviates significantly from the olfactory characteristics of the acetic acid (1-phenyl-2,2,2-trichloroethyl) ester known as a fragrance, which is particularly surprising. In perfume compositions, the compound (Ia) enhances the harmony and charisma as well as the adhesion, whereby the dosage can be adjusted to the desired fragrance note, taking into account the other components of the composition.

These olfactory properties were not predictable and it was not to be expected that the compound (Ia) would be advantageous in a range which is not covered by known fragrances such as acetic acid (1-phenyl-2,2,2-trichloroethyl) ester can be used as a fragrance or as a component of fragrance compositions. This also confirms the general experience that the olfactory properties of known odoriferous substances do not allow any conclusive conclusions to be drawn about the properties of structurally related compounds, because neither the mechanism of the Fragrance perception, the influence of the chemical structure on the fragrance perception are sufficiently researched, so it cannot normally be predicted whether a change in the structure of known fragrances will change the olfactory properties and whether these changes will be assessed positively or negatively.

Because of their odor profile, the compounds of the formula (I) are particularly suitable for modifying and enhancing known compositions. In particular, their extraordinary olfactory strength should be emphasized, which generally contributes to the refinement of the composition.

• (a) Naturprodukte wie Baummoos-Absolue, Basilikumöl, Agrumenöle wie Bergamotteöl, Mandarinenöl, usw., Mastix-Absolue, Myrtenöl, Palmarosaöl, Patchouliöl, Petitgrainöl, Paraguay, Wermutöl,
• (b) Alkohole wie Farnesol, Geraniol, Linalool, Nerol, Phenylethylalkohol, Rhodinol, Zimtalkohol, Sandalore [3-Methyl-5-(2.2.3-trimethylcyclopent-3-en-1-yl)pentan-2-ol], Sandela [3-Isocamphyl-(5)-cyclohexanol],
• (c) Aldehyde wie Citral, Helional^R, α-Hexylzimtaldehyd, Hydroxycitronellal, Lilial^R [p-tert.-Butyl-α-methyldihydrozimtaldehyd], Methylnonylacetaldehyd,
• (d) Ketone wie Allyljonon, α-Jonon, β-Jonon, Methyljonone.
• (e) Ester wie Allylphenoxyacetat, Benzylsalicylat, Cinnamylpropionat, Citronellylacetat, Citronellylethoxylat, Decylacetat, Dimethylbenzylcarbinylacetat, Etyhlacetoacetat, Hexenylisobutyrat, Linalylacetat, Hethyldihydrojasmonat, Vetiverylacetat,
• (f) Lactone wie γ-Undecalacton, 1-Oxaspiro[4.4]nonan-2-on

sowie verschiedene weitere in der Parfümerie oft benutzte Komponenten wie Ketonmoschus, Indol, p-Menthan-8-thiol-3-on, Methyleugenol.The compounds of formula (I) can be combined with numerous known fragrance ingredients, for example other fragrances of natural, synthetic or partially synthetic origin, essential oils and plant extracts. The range of natural fragrances can include both volatile, medium and low volatile components and that of synthetic fragrances includes representatives from practically all classes of substances. Examples are:

• (a) Natural products such as tree moss absolute, basil oil, agricultural oils such as bergamot oil, mandarin oil, etc., mastic absolute, myrtle oil, palmarosa oil, patchouli oil, petitgrain oil, Paraguay, wormwood oil,
• (b) Alcohols such as farnesol, geraniol, linalool, nerol, phenylethyl alcohol, rhodinol, cinnamon alcohol, Sandalore [3-methyl-5- (2.2.3-trimethylcyclopent-3-en-1-yl) pentan-2-ol], Sandela [3-isocamphyl- (5) -cyclohexanol],
• (c) aldehydes such as citral, helional ^R , α-hexylcinnamaldehyde, hydroxycitronellal, lilial ^R [p-tert-butyl-α-methyldihydrocinnamaldehyde], methylnonylacetaldehyde,
• (d) Ketones such as allyl ionone, α-ionone, β-ionone, methyl ionone.
• (e) esters such as allylphenoxyacetate, benzyl salicylate, cinnamyl propionate, citronellyl acetate, citronellylethoxylate, decyl acetate, dimethylbenzylcarbinylacetate, ethylacetoacetate, hexenylisobutyrate, linalyl acetate, ethyldihydrojasmonate, vetiverylacetate
• (f) lactones, such as γ-undecalactone, 1-oxaspiro [4.4] nonan-2-one

as well as various other components often used in perfumery such as ketone musk, indole, p-menthan-8-thiol-3-one, methyleugenol.

Also noteworthy is the way in which the compounds of structure (I), in particular (Ia), round off and harmonize the olfactory notes of a wide range of known compositions, but without dominating in an unpleasant way.

The usable proportions of the compounds according to the invention or their mixtures in fragrance compositions range from 1 to 70 percent by weight, based on the mixture as a whole. Mixtures of the compounds (I) according to the invention and compositions of this type can be used for perfuming cosmetic preparations such as lotions, creams, shampoos, soaps, ointments, powders, aerosols, toothpastes, mouthwashes, deodorants as well as in alcoholic perfumery (e.g. Eau de Cologne, Eau de toilet, extraits) can be used. There is also an application for perfuming technical products such as detergents and cleaning agents, fabric softeners and textile treatment agents or tobacco. To perfume these various products, the compositions are added to them in an olfactory effective amount, in particular in a concentration of 0.05 to 2 percent by weight, based on the entire product. However, these values are not intended to represent any limit values, since the experienced perfumer can achieve effects with even lower concentrations or build new types of complexes with even higher doses.

The following examples are intended to explain the subject matter of the invention and are not to be interpreted as restrictive.

Examples 1. Preparation of precursor II

The compounds of the general formula I were prepared starting from 2,2-dimethyl-1-phenyl-propanol II, which was obtained as follows:
235.5 g (1.5 mol) of bromobenzene were added dropwise to 36.5 g (1.5 mol) of magnesium shavings in 300 ml of ether, the reaction mixture was diluted with a further 400 ml of ether and stirred under reflux for 30 minutes. After a solution of 103.3 g (1.2 mol) of pivalaldehyde in 130 ml of ether was added dropwise, the mixture was stirred under reflux for a further 2 hours and hydrolyzed with ice / ammonium chloride solution.
For working up, the organic phase was washed with NaHSO₄ and NaHCO₃ solution and finally with water, dried over sodium sulfate and the solvent removed in vacuo. This resulted in 196.5 g of crude product (99.7% of theory), which could be used without further purification.

2. Preparation of the compounds I according to the invention Example 1 : Acetic acid (2,2-dimethyl-1-phenyl-propyl) ester (Ia)

Ausbeute:

121,9g (93,4 % d. Theorie)

Siedepunkt (0,1 mbar):

53 - 58 °C

Geruch:

rosig, holzig

IR (Film):

1742 cm⁻¹ (V_C=O Acetat)
740, 705 cm⁻¹ (δ_C-H monosubstituierter Aromat)

¹H-NMR (CDCl₃):

0,92 ppm (S,9H,(CH₃)₃-C)
2,06 ppm (S,3H,CH₃-CO)
5,46 ppm (S,1H,CH-O-COCH₃)
7,23 ppm (M,5H,aromat. Protonen)

MG (GC/MS):

C₁₃H₁₈O₂ ber.: 206,29 gef.:206 (Isomere)

0.6 g (4.9 mmol) of dimethylaminopyridine were added to 103.9 g (0.63 mol) of alcohol II in 90 g (0.88 mol) of acetic anhydride, the mixture was stirred at room temperature for 30 minutes and then at 100 ° C. for 2 hours.
For working up, it was diluted with 200 ml of ether and washed with 2N-HCl, 1N-NaHCO₃ solution and water. After drying over sodium sulfate and distilling off the ether and excess acetic anhydride in vacuo, the residue was distilled at 0.1 mbar.

Yield :

121.9g (93.4% of theory)

Boiling point (0.1 mbar) :

53-58 ° C

Smell :

rosy, woody

IR (film) :

1742 cm⁻¹ (V _{C = O} acetate)
740, 705 cm⁻¹ (δ _CH monosubstituted aromatic)

1 H-NMR (CDCl₃) :

0.92 ppm (S, 9H, (CH₃) ₃-C)
2.06 ppm (S, 3H, CH₃-CO)
5.46 ppm (S, 1H, CH -O-COCH₃)
7.23 ppm (M, 5H, aromatic protons)

MG (GC / MS) :

C₁₃H₁₈O₂ calc .: 206.29 found: 206 (isomers)

Example 2 : Carbonic acid (2,2-dimethyl-1-phenyl-propyl) methyl ester (Ib)

Ausbeute:

63,6 g (87 % d. Theorie)

Siedepunkt (0,1 mbar):

48,5 - 49,5 °C

Geruch:

würzig-blumig, typische Carbonat-Note

IR (Film):

1750 cm⁻¹ (V_C=O Acetat)
748, 705 cm⁻¹ (δ_C-H monosubstituierter Aromat)

¹H-NMR (CDCl₃):

0,95 ppm (S,9H,(CH₃)₃-C)
3,71 ppm (S,3H,CH₃-O-CO)
5,30 ppm (S,1H,CH-O-CO)
7,28 ppm (M,5H,aromat. Protonen)

MG (GC/MS):

C₁₃H₁₈O₂ ber.: 222,28 gef.:222 (Isomere)

11.0 g (0.36 mol) of sodium hydride (80% in paraffin were suspended in 150 ml of dimethyl carbonate (DMC), over 0.5 hours with 55.0 g (0.33 mol) of 2,2-dimethyl-1 phenyl propanol II in 150 ml of DMC and stirred and refluxed for a further 2 hours For working up, the mixture was poured onto 500 g of ice, the aqueous phase was extracted with about 300 ml of ether, the combined organic phases were washed with water, dried over sodium sulfate and the solvents were removed in vacuo After distillation at 0.1 mbar, 63.6 g remained as a colorless crystalline mass.

Yield :

63.6 g (87% of theory)

Boiling point (0.1 mbar) :

48.5 - 49.5 ° C

Smell :

spicy-floral, typical carbonate note

IR (film) :

1750 cm⁻¹ (V _{C = O} acetate)
748, 705 cm⁻¹ (δ _CH monosubstituted aromatic)

1 H-NMR (CDCl₃) :

0.95 ppm (S, 9H, (CH₃) ₃-C)
3.71 ppm (S, 3H, CH₃-O-CO)
5.30 ppm (S, 1H, CH-O-CO)
7.28 ppm (M, 5H, aromatic protons)

MG (GC / MS) :

C₁₃H₁₈O₂ calc .: 222.28 found: 222 (isomers)

Example 3 : 2,2-Dimethyl-1-phenyl-propyl-1- (1-ethoxy-ethyl) ether (Ic)

Ausbeute:

53,2 g (90 % d. Theorie)

Siedepunkt (0,1 mbar):

54 °C

Geruch:

schwach holzig

IR (Film):

740, 705 cm⁻¹ (δ_C-H monosubstituierter Aromat)

¹H-NMR (CDCl₃):

Diastereomerengemisch
0,92 ppm (S,9H,C(CH₃)₃)
1,15 und 0,85 ppm (T,3H,O-CH₂-CH₃)
1,21 und 1,27 ppm (D,3H,O-CH-CH₃)
3,21 und 3,54 ppm (M,1H,O-CH₂-CH₃)
4,29 und 4,00 ppm (S,1H,C₆H₅-CH-O)
4,44 und 4,56 ppm (Q,1H,O-CH-O)
7,17 - 7,27 ppm (M,5H,aromat. Protonen)

MG (GC/MS):

C₁₃H₁₈O₂ ber.: 236,36 gef.:236 (Isomere)

41.0 g (0.25 mol) of 2,2-dimethyl-1-phenyl-propanol II and 250 mg of p-toluenesulfonic acid in 100 ml of ether were stirred with 18.7 for 1 hour g (0.26 mol) of ethyl vinyl ether were added. After stirring for a further 2.5 hours at room temperature, the mixture was washed with 5% NaHCO 3 solution and water, dried over sodium sulfate and the ether was removed in vacuo. Distillation of the residue at 0.15 mbar gave 53.2 g of a colorless liquid.

Yield :

53.2 g (90% of theory)

Boiling point (0.1 mbar) :

54 ° C

Smell :

weakly woody

IR (film) :

740, 705 cm⁻¹ (δ _CH monosubstituted aromatic)

1 H-NMR (CDCl₃) :

Mixture of diastereomers
0.92 ppm (S, 9H, C (CH₃) ₃)
1.15 and 0.85 ppm (T, 3H, O-CH₂- CH ₃)
1.21 and 1.27 ppm (D, 3H, O-CH- CH ₃)
3.21 and 3.54 ppm (M, 1H, O- CH ₂-CH₃)
4.29 and 4.00 ppm (S, 1H, C₆H₅- CH -O)
4.44 and 4.56 ppm (Q, 1H, O-CH-O)
7.17 - 7.27 ppm (M, 5H, aromatic protons)

MG (GC / MS) :

C₁₃H₁₈O₂ calc .: 236.36 found: 236 (isomers)

Claims (6)

1. The use of isomeric 1,1,1-trialkyl-2-phenylethane derivatives corresponding to general formula (I)

   

   in which

   - R¹ to R³ independently of one another are C₁₋₃ alkyl groups and

   - R⁴ is a C₁₋₅ alkyl or acyl group or an alkoxycarbonyl group or a C₂₋₅ alkoxyalkyl group,

   as fragrances.
2. The use of isomeric 1,1,1-trialkyl-2-phenylethane derivatives as claimed in claim 1, in which R¹ to R³ are methyl groups, as fragrances.
3. The use of isomeric 1,1,1-trialkyl-2-phenylethane derivatives as claimed in claim 2, in which R⁴ is a C₁₋₃ acyl radical, as fragrances.
4. The use of isomeric 1,1,1-trialkyl-2-phenylethane derivatives as claimed in claim 3, in which R⁴ is an acetyl group, as fragrances.
5. Fragrance compositions, characterized by a content of a 2,2-dialkyl-1-phenylpropane derivative (I) according to claims 1 to 4 in a quantity of 1 to 70% by weight, based on the composition as a whole.
6. The use of mixtures of 1,1,1-trialkyl-2-phenylethane derivatives (I) according to claims 1 to 4 together with known natural and synthetic fragrance components as fragrances in cosmetic preparations, in commercial products or in alcohol-based perfumery.