EP0833883A1

EP0833883A1 - Cyclohexyl-substituted alkanols

Info

Publication number: EP0833883A1
Application number: EP96918659A
Authority: EP
Inventors: Thomas Markert
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1995-06-12
Filing date: 1996-06-03
Publication date: 1998-04-08
Also published as: WO1996041853A1; JPH11507681A; DE19521364A1

Abstract

Cyclohexyl-substituted alkanols have the general formula (I), in which the residues R<1> to R<3> independently represent hydrogen or an alkyl group with 1 to 4 C atoms; the residue R<4> stands for hydrogen or an alkyl group with 1 to 4 C atoms; and Cy stands for a cyclohexyl group. Theses compounds are characterised by interesting and very penetrating scents and are useful as odoriferous materials, for example in cosmetic preparations or technical products or in alcohol-based perfumes.

Description

"Cyclohexyl Substituted Alkanols"

Field of the Invention

The invention relates to the use of cyclohexyl-substituted alkanols of the structure given below as fragrances.

State of the art

In the Journal of Chemical Society 1940. Pages 1266-1268, M.F. Carroll's manufacture of phenylhexenones. Cinnamon alcohol was reacted with acetoacetic ester in the presence of sodium acetate. Carroll isolated 4-phenyl-hex-5- en-2-one (synonym: 3-phenyl-l-hexen-5-one) in this reaction in addition to cinnamon alcohol and citric acetate. After fractional distillation, however, the latter compound was only isolated in a purity of 60%. A further increase in the purity of the ketone to 96% was achieved only by hydrolysis and permanganate oxidation of the by-products. The article by M.F. Carroll made no statements.

An alternative possibility for producing the phenylhexenone described by Carroll is described by IV Machinskaya, VA Barkhash, AT Prudchenko; Zhur. Obshchei Khim. 1960. (30), 2357-2362. Here, the ketone is produced by Grignard reaction of l-bromo-3-acetoxy-l-phenyl-l-butene with vinyl magnesium bromide. In this publication, too, no information is given about the olfactory properties of the ketone. 4-Phenyl-5-hexen-2-one was also detected in the product mixture in the pyrolysis of 2,3-dihydrofuran (A. Accary, Y. Infarnet, J. Huet; CR Acad. Sei, Ser. C 275 , 1972 (1), pages 53-56). In this publication, too, there is no information about the olfactory characteristics of the ketone.

Many natural fragrances are available in completely inadequate amounts, measured according to need. 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 fragrance notes in order to supplement the range of naturally available fragrances and to make the necessary adaptations to changing fashionable tastes, as well as the constantly increasing need for odor improvers for everyday products To cover needs such as cosmetics and cleaning agents.

It is therefore clear that the fragrance industry has a constant need for new fragrances with interesting fragrance notes, in order to supplement the range of naturally available fragrances and to make the necessary adaptations to changing fashionable tastes, as well as the constantly increasing need for odor improvers for everyday products ¬ Chen needs such as cosmetics and cleaning agents.

In addition, there is generally a constant need for synthetic odoriferous substances which can be produced cheaply and with constant quality and which have desired olfactory properties, ie which have pleasant odor profiles which are as close to nature as possible and of high quality and are of sufficient intensity and capable of To influence the scent of cosmetic and consumer goods advantageously. In other words, there is a constant need for connections which have characteristic new odor profiles with high adhesive strength, odor intensity and radiance. Description of the invention

It has now been found that the compounds of the general formula (I) meet the above requirements excellently in all respects and can advantageously be used as fragrances with differently nuanced odor notes with good adhesive strength. In particular, it has been found that the compounds of the formula (I) have an improved odor intensity over compounds of the prior art which are structurally close to them, i.e. develop their effect at lower concentrations.

The present invention relates to the use of aromatic carbonyl compounds of the general formula (I)

R ¹ -CH-CHR2-CH-CHR3-CH R ⁴ (I)

I I

OH Cy

wherein

the radicals R 1 to R 3 independently of one another are hydrogen or an alkyl group having 1 to 4 carbon atoms,

the radical R ^{4 is} hydrogen or an alkyl group having 1 to 4 carbon atoms and

Cy is a cyclohexyl group

mean as fragrances.

In a preferred embodiment of the invention, the radical * is methyl. In a further preferred embodiment, the radicals R2 and R3 are hydrogen. Again, those compounds are preferred in which R ^{4 is} hydrogen, methyl or ethyl. Of these latter compounds (I), 4-cyclohexyl-hexan-2-ol is very particularly preferred. It is characterized by an olfactory characteristic, in which rose, damascone and woody notes dominate and excellent stability in formulations of cosmetics and perfumery.

The compounds (I) are prepared by known synthetic organic chemical methods. The compounds (I) are preferably produced in a 2-stage process. In a first step, an aromatic and unsaturated carbonyl compound is produced from the corresponding allyl alcohols (eg cinnamon alcohol) using the so-called Carroll reaction, the carbonyl group, C = C double bond and phenyl group of which are then completely hy in the usual way ¬ is third.

Carroll reaction in the context of the present invention means the conversion of allyl alcohols into gam a-delta-unsaturated ketones. In a first variant of the reaction, the allyl alcohol is converted into the corresponding allyl acetoacetate by reaction with acetoacetic ester, from which the alpha-allylacetoacetic acid is formed by [3,3] sigmatropic rearrangement (Claisen rearrangement) thermal decarboxylation gives the desired gamma-delta unsaturated ketone (I). The allyl acetoacetate can be used in bulk or formed in situ.

In a second variant of the Carroll reaction, which is exemplified in a review article by G.B. Bennett is addressed (see: Synthesis 1977, pages 589-606), the allyl alcohol is reacted with a vinyl ether or an alkoxyalkene. When using vinyl ethers, aldehydes (I) are formed, when using alkoxyalkenes, aldehydes (I) or ketones (I), depending on the nature of the alkoxyalkene used. For example, the reaction of cinnamon alcohol with 1-methoxypropene gives an aldehyde, the reaction of cinnamon alcohol with 2-methoxypropene gives a ketone. Acetals or allyl vinyl ethers can be assumed as intermediate compounds in these reactions.

In a preferred embodiment of the invention, allyl alcohols are reacted with 2-alkoxyalkenes, in particular 2-methoxypropene, in the Carroll reaction. The intermediate allyl vinyl ether can be isolated or subjected directly to the subsequent [3,3] sigmatropic rearrangement to the corresponding ketone (I) in situ.

In Scheme 1 below, the course of the Carroll reaction is sketched as an example for the reaction of cinnamon alcohol with 2-methoxypropene (for the experimental implementation of the reaction, reference is made to Example 1 below).

The invention therefore furthermore relates to a process for the preparation of the cyclohexyl-substituted alkanols (I) by a Carroll reaction from the corresponding allyl alcohols, together with complete hydrogenation of the carbonyl group, the C =C double bond and the phenyl group of the in the Carroll reaction obtained primary product. Here is the variant in which, in the course of the Carroll reaction, the [3,3] -sigmatropic rearrangement via the Allyl vinyl ether takes place and in which the allyl alcohol used at the beginning of the synthesis is reacted with a 2-alkoxyalkene, preferred since this type of production ensures a particularly high product purity and thus the desired high olfactory quality of the compounds (I) is ensured.

The compounds (I) in which R ¹ denotes a methyl group are distinguished by a floral, fruity odor which gains intensity from fresh wood notes.

In perfume compositions, the compounds (I) enhance the harmony and charisma as well as the adhesion, the dosage being matched to the desired fragrance note taking into account the other constituents of the composition.

The fact that the compounds (I) have floral-fruity and woody notes was not predictable and is therefore a further confirmation for the general experience that the olfactory properties of known fragrances do not allow any conclusive conclusions to be drawn about the properties of structurally related compounds, because neither the mechanism of the fragrance perception and the influence of the chemical structure on the fragrance perception have been 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. Particularly to be emphasized is their extraordinary olfactory strength, which generally contributes to the refinement of the composition.

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 and moderately volatile components and that of synthetic fragrances include 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, wormwood oil, myrrh oil, olibanum oil,

(b) Alcohols like farnesol, geraniol, linalool, nero! , 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 ^, α-hexylcinnamaldehyde, hydroxycitronellal, lilial ^R [p-tert.-butyl-α-methyldihydrocinnamaldehyde], methylnonyl acetaldehyde,

(d) ketones such as allyl ionone, α-ionone, β-ionone, isoraldein, methyl ionone,

(e) esters such as allylphenoxyacetate, benzyl salicylate, cinna yl propionate, citronelly acetate, decyl acetate, dimethylbenzylcarbinylacetate, ethyl acetoacetate, hexenyl isobutyrate, linalyl acetate, methyl dihydrojasmonate, viethyl acetate, cyclohexyl acetate, cyclohexyl acetate, cyclohexyl acetate

(f) lactones such as gam a-undecalactone, l-0xaspiro [4.4] nonan-2-one,

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

Also noteworthy is the way in which the compounds of structure (I) round off and harmonize the olfactory notes of a wide range of known compositions, but without dominating in an unpleasant manner. 4-Cyclohexyl-hexan-2-ol is particularly noteworthy in this regard.

The compounds according to the invention contain centers of chirality, so that these compounds can exist in different spatial forms. In the context of conventional syntheses, the compounds according to the invention are obtained as mixtures of the corresponding isomers and are used as such as fragrances.

The usable proportions of the compounds according to the invention or their mixtures in fragrance compositions range from 1 to 70% by weight. percent, based on the total mixture. 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 (eg Eaux de Cologne , Eau de toilette, extras) can be used. There is also an application for perfuming technical products such as washing and cleaning agents, fabric softeners and textile treatment agents. 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 can build up novel 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.

B e i s p i e l e

I. Chemicals used

Cinnamon alcohol: 98% (Riedel de Haen) Isopropenyl methyl ether: 2-methoxypropene, 92% (Janssen) Cinnamaldehyde: 98% (Fluka)

II. Production of aromatic and unsaturated carbonyl compounds by Carroll reaction

Example 1; 4-phenyl-hex-5-en-2-one

67 g (0.5 mol) of cinnamon alcohol, 43.2 g (0.6 mol) of isopropenyl methyl ether, 3 g of propionic acid and 150 g of toluene were weighed out in succession in a 500 ml steel autoclave. The system was flushed once with nitrogen and then heated to 190 ° C. for 7 hours (until complete conversion), with an inherent pressure of 10 bar. The mixture was then freed from the solvent on a rotary evaporator in vacuo and distilled overhead. 85 g of crude product were obtained, which were fractionally distilled on a rotating column. At bottom temperatures between 155 and 165 ° C and head temperatures of 128-130 ° C / 15 mbar, 72.3 g of main run (this corresponds to 83% of theory) with a purity of 99.5% determined by gas chromatography were obtained. The IR spectrum (film on NaCl) shows 6 bands of medium strength in the range between 3060 and 2919 cm-1 and further bands at 1716, 1637, 1601, 1584, 1493, 1452, 1411, 1359, 1248, 1233, 1162, 1121 , 918, 753 and 702 cm ~ l.

III. Preparation of the compounds (I) by reduction of the primary Carroll products

Example 2: 4-Cyclohexyl-hexan-2-ol

40 g of 4-phenyl-hex-5-en-2-one (from Example 1) were dissolved in 100 ml of ethanol and 4 g of Ni55 / 5TS (nickel hardening catalyst from Ruhrchemie) were added, in one The mixture was 500 ml steel autoclave for 7 hours treated with vigorous stirring with 200 bar of hydrogen at 200 ° C internal temperature. At the start of the reaction, hydrogen had to be added several times. The mixture was then cooled and the catalyst was filtered off. After the ethanol had been distilled off, 39 g of residue remained, which were prepurified by short-path distillation and fractionated in a high-vacuum rotary column. 23.1 g of highly pure 4-cyclohexyl-hexan-2-ol (mixture of diastereomers) were obtained.

Characterization:

GC: approx. 99.5% (mixture of diastereomers)

Sp: 80-82 ° / 0.15 mbar

Smell: Rose, Damascone note, fresh cedar wood

III. Composition example

Perfume concentrate for perfuming soap (floral-fresh fantasy composition):

Parts by weight

Phenylethanol 120

Cyclohexyl salicylate (from Henkel) 100

Lyral (IFF) 100

Neobergamate forte (Fa. Quest) 80

Isopropyl myristate 50

Benzyl acetate 50

Floramat (Henkel) 50

Arova N (Hüls AG) 50

Hydroxycitrone11a1 50

Ionon A 100 (Haarmann & Reimer) 40

4-phenylbutan-2-ol 40

Ylangδl 40

Brahmanol (Dragoco) 30

Lilial (Givaudan-Roure) 30

Linalool oxide 20

Hedione (Firmich) 20

Hydratropaaldehyde 20

Evernyl (Givaudan-Roure) 10

Floropal (Dragoco) 10

Isoeugenol 10

Vetiver oil 10

Geranyl acetate 10

Linalyl acetate 10

Aldehyde 13-13 (Henkel) 10

Rose oxide 6

Oxanone (from Stepan) 2 delta-decalactone 2

970 Replacing 20 parts of isopropyl myristate in the composition with 20 parts of 4-cyclohexyl-hexan-2-ol (according to Example 2) will result in the mixture shifting in place of the original floral, fruity character reminiscent of pear and apple aromas Aroma profile in the direction of a perfume formulation with a rose character. This gives the composition a perfume-like character that is lacking in the comparison, ie the 4-cyclohexyl-hexan-2-ol-free composition.

Claims

Patents test

1. Use of cyclohexyl-substituted alkanols of the general formula (I)

R ¹ -CH-CHR2-CH-CHR3-CH2R ⁴ (I)

I I

OH Cy

wherein

the radicals R ¹ to R independently of one another are hydrogen or an alkyl group having 1 to 4 carbon atoms,

the radical R ^{4 is} hydrogen or an alkyl group having 1 to 4 carbon atoms and

Cy is a cyclohexyl group

mean as fragrances.

2. Use according to claim 1, wherein the radical R * is methyl.

3. Use according to claim 1 or 2, wherein the radicals R2 and R are hydrogen.

4. Use according to any one of claims 1 to 3, wherein the radical R ⁴ denotes hydrogen, methyl or ethyl.

5. fragrance compositions containing one or more cyclohexyl-substituted alkanols (I) according to any one of claims 1 to 4 in an amount of 1 - 70 wt .-% (based on the total Kompositi¬ on).

6. Process for the preparation of cyclohexyl-substituted alkanols of the general formula (I) R1-CH-CHR2-CH-CHR3-CH ₂ R ⁴ (I)

I I

OH Cy

wherein

the radicals R ¹ to R3 independently of one another are hydrogen or an alkyl group having 1 to 4 carbon atoms,

the radical R ^{4 is} hydrogen or an alkyl group having 1 to 4 carbon atoms and

Cy is a cyclohexyl group

mean, by Carroll reaction from the corresponding allyl alcohols together with complete hydrogenation of the carbonyl group, the C = C double bond and the phenyl group of the primary product obtained in the Carroll reaction.

7. The method according to claim 6, wherein in the Carroll reaction the respective allyl alcohol is reacted with a 2-alkoxyalkene to give the corresponding allyl vinyl ether, which is then subjected to the [3,3] sigmatropic rearrangement.

8. The method according to claim 7, wherein one uses in the Carroll reaction as allyl alcohol, cinnamon alcohol and as 2-alkoxyalkene 2-methoxypropene.