GB2233645A - 2-Acyl-indanes and perfume compositions containing them - Google Patents

Abstract

The invention relates to 2-acyl-indanes of formula I below, to the use of these compounds for the improvement of the fragrance of perfume compositions and to perfume compositions containing one or more of these compounds as perfume components. <IMAGE> in which R1, R3 and R4 each represent C1-4 alkyl; R2 and R5 each represent H, CH3 or C2H5; R6, R7, R8, R9 each represent H or CH3; and the total number of carbon atoms in the above compound is at most 21.

Description

ALKYL-SUBSTITUTED 2-ACYL-INDANES, THE USE OF THESE COMPOUNDS FOR THE IMPROVEMENT OF THE FRAGRANCE OF PERFUME COMPOSITIONS, AS WELL AS PERFUME COMPOSITIONS CONTAINING THESE COMPOUNDS AS PERFUME COMPONENTS The invention relates to alkyl-substituted 2-acylindanes, to the use of these compounds for the improvement of the fragrance of perfume compositions, as well as to perfume compositions containing one or more of these compounds as perfume components.

There is a constant need for new synthetic odoriferous substances which are capable of imparting new fragrance notes to perfume compositions or to improve or intensify existing fragrance notes.

It has now been found that alkyl-substituted 2-acylindanes according to formula I of the reaction scheme, in which R1, R3 and R4 each represent an alkyl group having 1-4 carbon atoms, R2 and R5 each represent hydrogen, a methyl group or an ethyl group, R6, R7, R8 and Rg each represent hydrogen or a methyl group and the total number of carbon atoms in the formula is at most 21, are valuable perfume components and have a very positive influence on the quality of perfumes in which they are used. The compounds have pleasant and long-lasting fragrances with woody, floral, musk-, amber- and ionone-like aspects. They are all new.

Preferred are those acyl-indanes in which R1 represents an alkyl group having 1-3 carbon atoms, R3 and R4 each represent a methyl or ethyl group, R2 and R5 each represent hydrogen or a methyl or ethyl group and at most two of R6-R9 represent methyl and the others represent hydrogen, as well as the use of these compounds in perfume compositions, and also perfume compositions which contain these compounds. More particularly, a preference is expressed for the compounds in which R2 represents hydrogen and R5 a methyl or ethyl group, one of R7 and Rg represents a methyl group and the other, as also R6 and R8, hydrogen, as well as the use of these compounds in perfume compositions, and also perfume compositions which contain these compounds.

A few simple 2-acyl-indanes are known, see for example Chem. Abstr. 80, 145131e; 78, 973283; 83, 96989s; 71, 83348j; 105, 115070b; 75, 129251k; 79, 115338q and 107, 58617a. See also R. Verh et al., Tetrahedron 38 (1982), p.p. 3649-60 and G.L.B. Carlson et al., J. Am. Chem.

Soc. 97 (1975), p.p. 347-54. These compounds appear to be mainly of scientific importance; a possible use in perfumery is not mentioned.

In EP-B-024 306 and US-A-4,481,133 the use is described of various alkyl-substituted tetralins and indanes as fragrance and flavouring material, which, however, differ greatly from the compounds according to the present invention, since the acyl group therein is situated in the l-position. In the cited application it is indicated on page 2 that the tetralins are preferred.

Among the particularly interesting compounds only one indane-carboxylic acid ester is mentioned, but otherwise in this application attention is paid almost exclusively to the tetralins.

The compounds according to the invention can be prepared according to methods known for similar compounds, e.g.

as indicated in the reaction scheme, in which R1 to Rg have the meanings given above. In this scheme the step II- > III is a generally known Grignard reaction between an aldehyde or ketone and a phenyl magnesium halogenide which can be carried out as usual. In step III- > IV, the alcohol thus obtained is subsequently converted with aqueous HC1 or HBr into the corresponding halogenide. In step IV- > V this halogenide is reacted with the sodium or potassium salt of a ss-diketone, preferably the potassium salt. These salts can be prepared as described in Organic Synthesis, Coll. Vol. IV, p. 869.The new p- diketone V thus obtained is reacted in step V- > VI with 2 equivalents of the desired alkyl magnesium halogenide, immediately followed by a reaction with a so-called hard electrophile such as acetyl chloride, acetic acid anhydride or the corresponding trichloro or trifluoro compounds. In this manner the a,p-unsaturated ketone VI is obtained directly, which in the last step, VI-I, ring-closure is effected with a strong proton acid such as polyphosphoric acid or, preferably, a very strong proton acid, e.g. as described in Science 206, p.p. 1319 and in Fieser & Fieser, Reagents for Organic Synthesis, Vol. 2, p.p. 397 and 402.

Generally, in this manner a mixture of different stereoisomers of the desired compound is obtained, which can be separated by usual methods, particularly column, gas and high pressure liquid chromatographic methods.

However, for the use as raw material for perfumes, such a separation of isomers is not necessary.

As already mentioned, the 2-acyl-indanes according to the invention are valuable raw materials for perfumes, preference being given to the compounds having 16-21 carbon atoms and in particular to the compounds having 17-20 carbon atoms. Although the compounds according to the invention themselves have no particularly powerful fragrance, when added to other odoriferous materials or perfume compositions they have an extra harmonizing and rounding-off effect, often described by perfumers as "radiation". This effect is already achieved for some of these compounds at concentrations from 0.1 part per million (ppm) w/w in a perfume composition.The amounts in which the compounds according to the invention can be used in perfume compositions or in products to be perfumed can, however, vary within broad limits and depend inter alia on the nature of the product in which the compound is used, on the nature and the amount of the other components in the perfume composition and on the fragrance effect aimed at. Therefore it is only possible to give very wide limits, which, however, provide the expert with sufficient information to be able on his own to use the compounds according to the invention. In many cases an amount of only 1 ppm in a perfume composition is already sufficient to obtain a clearly perceptible fragrance effect. In order to obtain special fragrance effects, it is also possible, however, to use amounts up to 1% and sometimes even up to 5% in a composition.In many cases it is preferable to use no more than 0.1% in a perfume composition. In perfumed products these concentrations are proportionally lower, depending on the amount of composition used in the product.

By the expression "perfume composition" is meant here a mixture of perfume components and possible adjuvants, dissolved in a suitable solvent or mixed with a powdered substrate if so desired, that is used to impart a desired fragrance to the skin and/or all kinds of products. Examples of such products are: soaps, detergents, air fresheners, pomanders, candles, cosmetics, such as creams, ointments, lotions, toilet waters, pre- and after-shave lotions, talcum powders, hair care agents, body deodorants and anti-perspirants.

Perfume components and mixtures thereof which, in combination with the compounds according to the invention, can be used for the preparation of perfume compositions are for example: natural products such as essential oils, absolutes, resinoids, resins, concretes, etc., and synthetic fragrance materials such as hydrocarbons, alcohols, aldehydes, ketones, ethers, acids, esters, acetals, ketals, nitriles, etc., including saturated and unsaturated compounds, aliphatic, carbocyclic and heterocyclic compounds.

Examples of perfume components which can be used in combination with the compounds according to the invention are: geraniol, geranyl acetate, linalool, linalyl acetate, tetrahydrolinalool, citronellol, citronellyl acetate, dihydromyrcenol, dihydromyrcenyl acetate, tetrahydromyrcenol, terpineol, terpinyl acetate, nopol, nopyl acetate, 2-phenyl-ethanol, 2phenylethyl acetate, benzyl alcohol, benzyl acetate, benzyl salicylate, benzyl benzoate, styrallyl acetate, amyl salicylate, dimethylbenzyl carbinol, trichloromethylphenycarbinyl acetate, p-tert . butyl- cyclohexyl acetate, isononyl acetate, vetiveryl acetate, vetiverol, a-n-amyl-cinammic aldehyde, a-hexyl-cinammic aldehyde, 2-methyl-3- (p-tert.butylphenyl) -propanol, 2 methyl-3- (p-isopropylphenyl) -propanal, 3-(ptert.butylphenyl)-propanal, tricyclodecenyl acetate, tricyclodecenyl propionate, 4-(4-hydroxy-4 methylpentyl) -3-cyclohexene carbaldehyde, 4-(4-methyl-3pentenyl)-3-cyclohexene carbaldehyde, 4-acetoxy-3pentyl-tetrahydropyran, 3-carboxymethyl-2-pentylcyclopentane, 2-n-heptyl- cyclopentanon, 3-methyl-2pentyl-2-cyclopentanon, n-decanal, n-dodecanal, 9 decenol-1, phenoxyethyl isobutyrate, phenylacetaldehyde-dimethyl acetal, phenyl-acetaldehydediethyl acetal, geranyl nitrile, citronellyl nitrile, cedryl acetate, 3-isocamphyl- cyclohexanol, cedrylmethyl ether, isolongifolanon, aubepine nitrile, aubepine, heliotropine, coumarin, eugenol, vanillin, diphenyloxide, hydroxycitronellal, ionones, methyl ionones, isomethyl ionones, irones, cis-3-hexenol and esters thereof, indane musk fragrances, tetralin musk fragrances, isochromane musk fragrances, macrocyclic ketones, macrolactone musk fragrances, ethylene brassylate, aromatic nitro-musk fragrances.

Adjuvants and solvents containing compounds according to the invention which can be used are for example: ethanol, isopropanol, diethylene glycol monoethyl ether, dipropylene glycol, diethyl phthalate, triethyl citrate, etc.

The following examples serve solely to illustrate the preparation and use of the compounds according to the invention. The invention is, however, not limited thereto.

Example I Preparation of 2-acetyl-1-ethyl-3-isopropYl-1 6- dimethyl-indane A. For the preparation of l-para-tolyl-2methylpropanol-1, first of all para-tolyl magnesium bromide was prepared in a known manner from 38.4 g magnesium turnings and 300 g para-bromotoluene in 600 ml dry ether. Into the Grignard solution thus obtained, a solution of 110 g isobutyraldehyde in 200 ml dry ether was trickled in one hour under a nitrogen atmosphere, the temperature being kept below 150C by cooling. The reaction mixture was stirred for one hour more and subsequently poured into a mixture of 1000 g ice and 350 g concentrated hydrochloric acid. The layers were separated and the aqueous layer extracted three times with ether.The collected ether layers were washed neutral with saturated NaHC03 solution and subsequently dried on MgSO4. The solvent was evaporated and the residue distilled under reduced pressure, whereby 223 g of the desired alcohol was obtained; b.p.: 83-84eC/ 0.13kPa.

B. 1-Bromo-l-para-tolyl-2-methylpropane was prepared by stirring the alcohol obtained under A for 45 minutes at 45'C with 280 g of a 47 percent aqueous solution of HBr, separating the layers and treating the organic layer once more in the same manner with 280 g HBr solution. The collected acidic aqueous layers were extracted twice with 150 ml petroleum ether. The collected organic layers were washed twice with 150 ml ice water and once with saturated NaCl solution and dried on NgSO4. After evaporation of the solvent, 312 g of the desired bromide was obtained.

C. 3- -para-tolyl-2'-methylpropyl)-2,4-pentanedione was prepared by trickling 280 g (1.24 mol) of the bromide obtained under B into a suspension of 170 g (1.22 mol) potassium acetyl acetonate in 700 ml dimethyl sulphoxide at 20"C in about 5 hours. The reaction mixture was stirred a further 10 hours and subsequently poured into 1200 g ice/water mixture. The mixture was extracted three times with 250 ml pentane and the collected extracts were washed twice with 200 ml water.

The pentane solution was dried on MgS04 and subsequently concentrated by evaporation. The evaporation residue was fractionated under reduced pressure, whereby 76 g of the desired diketone was obtained; b.p.: 97"C/4Pa, m.p.: 86-92 C.

D. 4-Methyl-3- (1 '-para-tolyl-2 '-methylpropyl) -3- hexen-2-one was prepared as follows: A solution of 0.75 mol ethyl-magnesium bromide in 600 ml ether was brought under a nitrogen atmosphere, whereafter, while being continuously stirred, at 204C in 1.5 hours a solution of 61.5 g (0.25 mol) of the diketone obtained under C in 250 ml ether was trickled.

During the reaction ethane escaped. The reaction mixture was stirred a further 12 hours at room temperature and under nitrogen. Subsequently, with stirring, a solution of 160 g (2.0 mol) acetyl chloride in 400 ml ether was trickled, the temperature being kept below 5ec by cooling. The mixture was stirred a further 3 hours at about 10"C, whereafter it was poured into an ice-cold solution of 200 g sodium acetate in 1000 litres water.

The mixture was stirred and subsequently the layers were separated. The aqueous layer was extracted twice with ether. The collected ether layers were washed with saturated NaHCO3 solution and dried on MgSO4. The ether was evaporated and the residue purified by flashchromatography over a column with 1000 g silica gel 230400 mesh with ether/pentane 0-10%/100-90% as eluent. A yield of 15 g of the desired ketone was obtained.

E. 15 g of the ketone obtained under D was dissolved in 200 g polyphosphoric acid and heated for 8 hours at 80 e C The reaction mixture was thereafter poured into 1000 litres ice water and subsequently this mixture was extracted three times with toluene. The toluene extract was washed neutral with NaHCO3 solution, dried on MgSO4 and subsequently concentrated by evaporation. The residue was purified by flash-chromatography over 200 g silicagel 230-400 mesh with ether/pentane 0-10%/100-90% as eluent. The fractions were concentrated and, by distillation under reduced pressure, traces of solvent were removed. Yield: 3 g of the desired compound as a 5:1 mixture of the (lRS,2SR,3SR) isomer and the (1SR,2SR,3SR) isomer.

NMR (100 MHz, 6 in ppm relative to TMS, solution in CC14): 0.76 (3H,d,J=7Hz); 0.85 (3H,t,J=7Hz); 0.87 (3H,d,J=7Hz); 0.93 (3H,s); 1.9 (2H,m); 2.0-2.6 (lH,m); 2.15 (3H,s); 2.30 (3H,s); 3.18 (lH,d,J=9Hz); 3.74 (lH,dd,J=9Hz,J=4Hz); 6.68 (lH,broad s); 6.8-7.1 (2H).

IR (v in cam~1, solution in CC14): 3110, 3079, 3043, 3004, 1712, 1612, 1584, 1497, 1387, 1381, 1377, 1367, 1362, 1351, 1272, 1231, 1159, 879. (pure): 827, 799.

Example II Preparation of 2-acetvl-1-ethvl-3-isoronv1-1 .4- dimethyl-indane This compound was prepared in accordance with the manner described in Example I starting from ortho-bromotoluene. The yield in the last step, the ring-closure, could be improved by a higher reaction temperature, e.g.

about 1200 C, and/or by using a stronger acid, e.g. HBF4 etherate. The final product was again fractionated by flash-chromatography over a silica gel column with pentane/ether as eluent. The fractions were concentrated by evaporation and traces of solvent removed by distillation under reduced pressure. The (1RS,2SR,3SR) isomer (a) and the (1SR,2SR,3SR) isomer (b) of the desired compound were obtained in a ratio of 5:2.

a NMR (100 MHz, 6 in ppm relative to TMS, solution in CC14): 0.57 (3H,d,J=7Hz); 0.82 (3H,d,J=7Hz); 0.87 (3H,s); 0.92 (3H,t,J=7Hz); 1.90 (2H,m); 2.15 (3H,s); 2.29 (3H,s); 2.60 (lH,m); 3.17 (lH,d,J=8Hz); 3.90 (lH,dd,J=8Hz,J=5Hz); 6.6-7.1 (3H).

IR (v in cam~1, solution in CC14): 3068, 3020, 1712, 1599, 1589, 1387, 1381, 1379, 1367, 1358, 1353(sh), 1284, 1160. (solvent CS2): 782, 772, 738.

b NMR: 0.46 (3H,t,J=7Hz); 0.50 (3H,d,J=7Hz); 0.77 (3H,d,J=7Hz); 1.28 (2H,m); 1.56 (3H,s), 2.24 (3H,s); 2.31 (3H,s); 2.60 (lH,m); 2.97 (lH,d,J=9Hz); 3.98 (lH,dd,J=9Hz,J=5Hz): 6.7-7.1 (3H).

IR (solution in CC14): 3068, 3043, 3018, 1712, 1599, 1590, 1387, 1381, 1377, 1367, 1360, 1350, 1164. (solvent CS2): 777, 739.

According to the method of Example II, the following compounds can also be prepared: 2-acetyl-3-isopropyl-1,1,6-trimethyl-indane 2-acetyl-3-isopropyl-1,1,4-trimethyl-indane 2-acetyl-1,3-diethyl-1,6-dimethyl-indane 2-acetyl-1,3-diethyl-1,4-dimethyl-indane 2-acetyl-1-ethyl-1, 6-dimethyl-3-propyl-indane 2-acetyl-l-ethyl-1, 4-dimethyl-3-propyl-indane Example III A perfume composition of the spicy type, for use in foam bath, was prepared according to the following recipe:: Darts bv weight Rosemary oil French 100 Isobornyl acetate 100 Linanyl acetate 100 a-n-amyl-cinnamic aldehyde 100 2-Butyl-4,4,6-trimethyl-1,3-dioxane 100 5-Acetyl-3-isopropyl-1,1,2,6-tetramethyl-indane 55 Linalool 50 Orange oil Florida 50 Coumarin 20 Methyl dihydrojasmonate 20 2-Methyl-3- (p-t. butylphenyl) -propanal 20 Decanal * 10 2-Methyl-undecanal * 10 Nonanal * 5 Labdanum absolute Spanish 5 2, 4-Dihydroxy-3, 6-dimethylbenzoic acid methyl 5 ester Total 750 * 10t solution in dipropylene glycol.

To the above perfume composition was added 0.015 parts by weight of 2-acetyl-l-ethyl-3-isopropyl-1, 6-dimethyl indan, obtained according to Example I, per 1000 parts by weight of the composition. The new composition thus obtained was judged, with respect to the original composition, to be fuller, warmer and radiant.

Example IV A perfume for an after-shave lotion was prepared according to the following recipe: parts bv weight Benzyl acetate 110 Amyl salicylate 110 Bergamot oil 90 Lemon oil 80 Geranium oil Bourbon 80 Citronellol 50 5-Acetyl-3-isopropyl-1,1,2,6-tetramethyl-indane 35 Heliotropine 35 Linalool 30 Mousse-de-chne absolute Yugoslavian 20 Lavender oil French 20 Petigrain oil 20 11-Oxahexadecanolide 10 Lime oil 10 2-Methyl-3-(p-tert.butylphenyl)-propanal 10 Coriander oil 10 3-Isocamphyl-cyclohexanol 10 2, 6-Dimethyl-heptanol-2 5 Pennyroyal oil 5 Eugenol 5 Ethyl vanillin * 5 Total 750 * 10% solution in dipropylene glycol.

To the above-mentioned perfume composition was added 0.025 parts by weight of 2-acetyl-1-ethyl-3-isopropyl1,4-dimethyl-indane, obtained according to Example II, per 1000 parts by weight of the composition. The new composition thus obtained was judged, with respect to the original composition, to be more rounded-off, fuller and radiant.

Example V An after-shave lotion, perfumed with the composition according to Example IV, was prepared according to the following recipe: A 0.3 parts by weight l-menthol 0.5 parts by weight Uvinol D 50 1) 30.2 parts by weight propylene glycol 535 parts by weight ethanol B 2.0 parts by weight aluminium-chlorohydrate allantoinate 2.0 parts by weight lactic acid 400 parts by weight distilled water C 20 parts by weight perfume (Example IV) 10 parts by weight Cremophor RH 40 2) 1) Trademark of BASF for 2,2',4,4' tetrahydroxybenzophenone 2) Trademark of BASF for a reaction product of hydrogenated castor oil and epoxyethane.

The components mentioned under A, B and C were mixed separately to mixtures A, B and C. Mixture B was subsequently added to mixture A while being well stirred. Thereafter mixture C was added and the whole was homogenized by stirring. In this manner a somewhat astringent, pleasantly smelling after-shave lotion was obtained.

Claims (17)

1. Perfume compositions characterized by a content of one or more 2-acyl-indanes having the formula:

in which R1, R3 and R4 each represent an alkyl group having 1-4 carbon stoms, R2 and R5 each represent hydrogen, a methyl group or an ethyl group, R6, R7, R8 and Rg each represent hydrogen or a methyl group and the total number of carbon atoms is at most 21.

2. Perfume compositions according to claim 1, characterized by a content of one or more 2-acyl-indanes having the formula:

in which R1 represents an alkyl group having 1-3 carbon atoms, R3 and R4 each represent a methyl or ethyl group and at most two of R6-R9 represent methyl and the others hydrogen.

3. Perfume compositions according to claim 2, characterized by a content of one or more 2-acyl-indanes having the formula:

in which R2 represents hydrogen and R5 a methyl or ethyl group, one of R7 and Rg represents a methyl group and the other, as also R6 and R8, hydrogen.

4. Perfume compositions according to claim 3, characterized by a content of 2-acetyl-1-ethyl-3isopropyl-1,6-dimethyl-indane.

5. Perfume compositions according to claim 3, characterized by a content of 2-acetyl-l-ethylisopropyl-1,4-dimethyl-indane.

6. Perfume compositions according to claim 1, 2, 3, 4 or 5, in which the content of 2-acyl-indanes is at least 0.1 ppm.

7. Process for the preparation of perfume compositions, characterized in that to a mixture of usual perfume components one or more 2-acyl-indanes are added having the formula:

in which R1, R3 and R4 each represent an alkyl group having 1-4 carbon atoms, R2 and R5 each represent hydrogen, a methyl group or an ethyl group, R6, R7, R8 and Rg each represent hydrogen or a methyl group and the total number of carbon atoms is at most 21.

8. Process according to claim 7, characterized in that one or more 2-acyl-indanes are added having the formula:

in which R1 represents an alkyl group having 1-3 carbon atoms, R3 and R4 each represent a methyl or ethyl group and at most two of R6-R9 represent methyl and the others hydrogen.

9. Process according to claim 8, characterized in that one or more 2-acyl-indanes are added having the formula:

in which R2 represents hydrogen and R5 a methyl or ethyl group, one of R7 and Rg represents a methyl group and the others, as also R6 and R8, hydrogen.

10. Process according to claim 9, characterized in that 2-acetyl-l-ethyl-3-isopropyl-l, 6-dimethyl-indane is added.

11. Process according to claim 9, characterized in that 2-acetyl-1-ethyl-3-isopropyl-1,4-dimethyl-indane is added.

12. Process according to claim 7, 8, 9, 10 or 11, characterized in that at least 0.1 ppm of the 2-acylindane is added.

13. 2-Acyl-indanes having the formula:

in which R1, R3 and R4 each represent an alkyl group having 1-4 carbon atoms, R2 and R5 each represent hydrogen, a methyl group or an ethyl group, R6, R7, R8 and Rg each represent hydrogen or a methyl group and the total number of carbon atoms is at most 21.

14. 2-Acyl-indanes according to claim 13, in which R1 represents an alkyl group having 1-3 carbon atoms, R3 and R4 each represent a methyl or ethyl group and at most two of R6-R9 represent a methyl group and the others hydrogen.

15. 2-Acyl-indanes according to claim 14, in which R2 represents hydrogen and R5 a methyl or ethyl group, one of R7 and Rg represents a methyl group and the other, just as R6 and R8, hydrogen.

16. 2-Acetyl-1-ethyl-3-isopropyl-1, 6-dimethyl-indane.

17. 2-Acetyl-1-ethyl-3-isopropyl-1,4-dimethyl-indane.