WO1993010068A1

WO1993010068A1 - Butenol derivatives, their preparation and their use

Info

Publication number: WO1993010068A1
Application number: PCT/EP1992/002611
Authority: WO
Inventors: Thomas Markert; Volker Porrmann
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1991-11-22
Filing date: 1992-11-13
Publication date: 1993-05-27
Also published as: DE4203790A1

Abstract

The invention concerns butenol derivatives of general formula (I), in which R1 is hydrogen or an alkyl group with 1 to 4 C-atoms and R2 is an alkyl group with 1 to 4 C-atoms, with the provision that R2 is not a methyl group if R1 is a methyl group. These compounds are odiforous substances with interesting fragrances and considerable diffusion power.

Description

"Butenol derivatives, their production and use"

Field of the Invention

The invention relates to new butenol derivatives, a process for their preparation and their use as fragrances.

State of the art

Many natural fragrances are available in completely inadequate amounts, measured according to need. From a perfume point of view, sandalwood oil is particularly valued and valuable. It is obtained from the heartwood of sandalwood, a tropical semi-parasite found in India and Malaysia, by steam distillation. Heartwood appears after about ten years and only begins to develop more quickly in twenty-year-old trees. Fully grown trees are cleared at the age of 30 to 60 years because the roots are particularly rich in fragrant heartwood [cf. E. T. Morris, Dragoco Report 1983 (30), 40]. It is therefore understandable that fragrance research is constantly striving to develop suitable substitutes for natural sandalwood oil.

RENaipawer outlined the focal points in the development of suitable substitutes for natural sandalwood oil in a review [in: BMLawrence, BDMookherjee, BJWillis (ed.): "Flavors and Fragrances: A World Perspective"; Elsevier Publishers, Amsterdam 1988]. Alcohols with a 2,2,3-trimethyl-3-cyclopentenyl group are known from European patent EP 155 591 B1. However, this group contains a side chain which is either saturated or has a double bond in position. The US patent US 4,052,341 relates to 3-methyl-5- (2,2 _r 3-trimethyl-3-cyclopenten-l-yl) pentan-2-ol. This alcohol is compared in Table I (columns 3 and 4 of the US patent) with certain analogs, isomers and homologues; of these compounds, seven have a saturated side chain and one compound, 3-methyl--5- (2,2,3-trimethyl-3-cyclopenten-l-yl) -3-penten-2-ol, has an unsaturated side chain. In the description, the superior effect of 3-methyl-5- (2,2,3-trimethyl-3-cyclopenten-l-yl) pentan-2-ol in terms of odor intensity is then compared to the other compounds in Table I issued here (column 4).

It is therefore clear from the context described 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 and the constantly increasing demand of odor improvers for everyday products such as cosmetics and cleaning agents.

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, i.e. have pleasant, near-natural and qualitatively novel odor profiles of sufficient intensity and are able to advantageously influence the fragrance of cosmetic and consumer goods. It was therefore sought to find compounds which should 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. The present invention therefore relates to butenol derivatives of the general formula (I)

wherein the radical Rl is hydrogen or an alkyl group having 1 to 4 carbon atoms and the radical R ^{2 is} an alkyl group having 1 to 4 carbon atoms, with the meaning of a methyl group being excluded for R ² if Rl is a methyl group.

Those compounds of the general formula (I) according to the invention are particularly preferred in which the radical R ^{1 is} hydrogen, methyl or ethyl and the radical R ^{2 is} methyl, ethyl, propyl or isopropyl. 4-Methyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) 4-hexen-3-ol, 4-ethyl-6- (2,2,3-trimethyl) are very particularly preferred -3-cyclopenten-l-yl) -4-hexen-3-o and 2,4-dimethyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) 4-hexen-3-ol .

Another object of the invention is a process for the preparation of butenol derivatives of the general formula (I), in which R ¹ and R ^{2 have} the meaning given above, by condensation of α-campholenaldehyde with the corresponding aldehydes or ketones to give the corresponding unsaturated compounds Carbonyl compounds and subsequent reduction of the carbonyl function of these compounds z. B. with complex hydrides for OH function.

The new compounds (I) are prepared by known synthetic organic chemical processes. The starting material is α campholenaldehyde, which can be reacted in the presence of conventional catalysts with corresponding short-chain aldehydes and ketones, for example 2-butano or 3-pentanone, in a mixed aldol condensation, with the corresponding α, ß-unsaturated compounds being eliminated directly via intermediate aldol condensation products Aldol condensation products are obtained. The reaction is expediently carried out with an excess de more reactive and volatile components. Examples of suitable catalysts are sodium hydroxide, sodium ethanolate, sodium id, potassium tert-butoxide or heterogeneous catalysts such as potassium fluoride on aluminum oxide. The carbonyl function of the aldol condensation products can be reduced to the OH group in a further reaction, for example by means of complex hydrides such as lithium aluminum hydride or lithium or sodium borohydride. In this way, the butenol derivatives of the general formula (I) are obtained. The compounds (I) can then be purified by customary methods, for example by distillation.

The compounds (I) according to the invention have remarkable odor properties. Another object of the invention is therefore the use of the compounds of general formula (I) as fragrances.

The compounds (I) and in particular 4-methyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-ol are distinguished by their sandal scent with very complex shades and large Charisma.

The odor profile of the compounds (I) is original and novel compared to the prior art mentioned. In addition, the odor intensity of the compounds (I) is higher than that of the closest prior art; For the detection of the improved odor intensity, reference is made to the determination of the odor threshold values in the example section.

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 butenol derivatives (I) had sandal notes was not predictable and is therefore a further confirmation of the general experience that the olfactory properties of known fragrances do not allow any conclusions to be drawn about the properties of structurally related compounds, because neither Mechanism of fragrance perception the influence of the chemical structure on the fragrance perception are sufficiently researched, so it cannot normally be predicted whether a a change in the structure of known odoriferous substances leads to a change in the olfactory properties and whether these changes are 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 used with numerous known fragrance ingredients, e.g. combine 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, pal arosa oil, patchouli oil, petitgrain oil, Wer utöl, myrrh oil, olibanum oil

(b) alcohols such as farnesol, geraniol, linalool, nerol, phenylethyl alcohol, rhodinol, cinnamon alcohol, Sandalore [3-methyl-5- (2.2.3-trimethylcyclopent-3-en-l-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, ionone, β-ionone, isoraldein, methyl ionone,

(e) esters such as allylphenoxyacetate, benzyl salicylate, cinnamyl propionate, citronellyl acetate, citronellyl ethoxylate, decyl acetate, dimethylbenzylcarbyl acetate, ethyl acetoacetate, hexenyl isobutyrate, linalyl acetate, methyl dihydrojasyl acetate, cyclohexyl acetate, vetyl hexyl acetate

(f) Lactones such as gamma-undecalactone, l-0xaspiro [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, ambroxan .

It is also remarkable how the compounds of structure (I) smell the notes of a wide range of known grain Round off and harmonize positions without dominating in an unpleasant way. 4-Methyl-6- (2,2,3-trimethyl-3-cylopentenl-yl) -4-hexen-3-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 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 both for perfuming cosmetic preparations such as lotions, creams, sha poos, soaps, ointments, powders, aerosols, toothpastes, mouthwashes, deodorants and in alcoholic perfumery (eg Eaux de Cologne, Eaux de Toilette, extras) 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 the precursors for the connections according to the invention

Example 1 ; 4-methyl-6- (2, 2, 3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-one

In a 2 1 three-necked flask, 243 g (1.6 mol) of α-campholenaldehyde were mixed with 688 g (8 mol) of diethyl ketone under a nitrogen atmosphere. With cooling with an ice bath and stirring, 64 g of sodium methylate solution (30% in methanol) were metered in continuously at an internal temperature of 30 ° C. within 45 minutes. After the addition, the reaction mixture was stirred for a further 5 hours at room temperature and left to stand overnight. For working up, the excess diethyl ketone was distilled off, the residue was taken up in 200 ml of ether and carefully neutralized with 10% hydrochloric acid. The organic phase was separated and washed three times with saturated sodium chloride solution. After drying over sodium sulfate, the mixture was filtered and concentrated on a rotary evaporator. The residue of 435 g of reaction mixture was purified by distillation over a 12 cm Vigreux column. The main fraction passed at 90-93 ° C / 0.03 mbar. A purity of 95% (GC) was achieved. The IR spectrum (film on NaCl) showed characteristic absorption bands at 2954, 1670 (uns. Ketone), 1381 and 1360 (according to methyl groups) and at 798 cm " ^1. Odor: slightly floral, rose, spicy, woody.

Example 2: 2-ethyl-4- (2,2,3-trimethyl-3-cyclopenten-l-yl) -2-buten-l-al

In a 1 1 three-necked flask equipped with a KPG stirrer, internal thermometer and reflux condenser, 152 g (1 mol) of α-campholenaldehyde were mixed at room temperature with 216 g of n-butyraldehyde under a nitrogen atmosphere and with stirring. The reaction vessel was cooled in an ice water bath and then 54 g (0.3 mol) of sodium methoxide solution (30% in methanol) were metered in continuously over one hour with vigorous stirring; the temperature of the reaction mixture rose to 75 ° C. at the beginning of the addition of sodium methoxide as a result of the exothermic reaction. The reaction mixture was then stirred for a further 5 hours at 50 ° C. and then left to stand overnight. Working up was careful with Neutralized acetic acid and washed 3 times with 200 ml of water. The organic phase was diluted with ether, dried over sodium sulfate, filtered and freed from ether and excess butyraldehyde on a rotary evaporator. The residue obtained (490 g) was distilled through a 12 cm Vigreux column in a high vacuum (0.15 mbar), giving 215 g of the main fraction (boiling point 100 ° C; purity 78% according to GC), which were further fractionated on a rotating band column was cleaned (GC purity: 97.4%). The IR spectrum (film on NaCL) showed characteristic absorption bands at 2956, 2708, 1690, 1641, 1361, 1329 and 799 cm ^-1 . Smell: fresh woody, fruity, Jonon note.

2. Preparation of the compounds according to the invention

Example 3: 4-methyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-ol

In a 250 ml three-necked flask, 1 g of sodium boranate was suspended in 50 ml of ethanol and 22.0 g of 4-methyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3- on (Example 1) continuously added dropwise at room temperature. After the weakly exothermic reaction had subsided, the mixture was stirred for an hour, the mixture was poured onto ammonium chloride / ice and extracted with ether. The organic phases were dried over sodium sulfate, filtered and concentrated. Distillation through a short Vigreux column and then through a rotary still gave 15 g of the main run with a boiling point of 108-110 ° C / 0.1 mbar with a GC purity of 98.4%. The IR spectrum (film on NaCl) showed bands at 3358 (-0H), 2955, 1381 and 1359 (according to dimethyl) and 1011 (C-0) cm " ^1. Odor: strong sandal and musk notes, fruity , green

Example 4: 3-ethyl-5- (2,2,3-trimethyl-3-cyclopenten-l-yl) -3-penten-2-o1

64.8 g (0.46 mol) of methyl odide were added dropwise to a stirred slurry of 11.2 g (0.46 mol) of magnesium shavings in 100 ml of anhydrous ether, with exclusion of moisture. 72 g (0.35 mol) of 2-ethyl-4- (2,2,3-trimethyl-3-cyclopenten-l-yl) -2-butenal were added to the solution of methyl magnesium iodide prepared in this way with the exclusion of moisture and a nitrogen atmosphere (Example 2) in 70 ml of absolute ether in 45 minutes so that the reaction mixture was kept under gentle reflux. The mixture was then left to react for 4 hours. After standing overnight, the mixture was poured into 1 liter of a saturated aqueous ammonium chloride solution. The organic phase was separated and the aqueous phase extracted with ether. The combined organic phases were dried over potassium carbonate and the residue obtained after the concentration (70 g) was distilled over a little sodium carbonate on a 12 cm rotating column column in a high vacuum. The main run was 52 g at 95 to 97 ° C and 0.03 mba; the GC purity was determined to be 93%. The IR spectrum (film on NaCl) showed bands at 3351 (-0H), 2957, 1374 and 1360 (according to diethyl as well as at 1114, 1090, 1072, 1056 and 1012 (C-0) CΠT *. Odor: intense creamy, fruity, woody, strong sandal note, milk note.

Example 5: 4-ethyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-ol In a dry 1 1 three-necked flask, 11.2 g (0.1 4 mol) of magnesium shavings are covered with 100 ml of anhydrous ether and 49.7 g (0.46 mol) of ethyl bromide are slowly metered in with stirring over the course of 40 minutes. 72 g of 2-ethyl-4- (2,2,3-trimethyl-3-cyclopenten-l-yl) -2-buten-l-al (Example 2) were subsequently added to the resulting solution of the Grignard reagent within 90 Dripped minutes. After all of the aldehyde had been added, the mixture was stirred at the reflux temperature for a further 5 hours. The reaction mixture was then stirred into 1 l of a saturated aqueous ammonium chloride solution and the organic phase was separated off. The water phase was extracted with ether and the combined organic phase was dried over potassium carbonate. After the solvent had been stripped off, a residue of 65 g remained which was distilled through a 12 cm Vigreux column. Yield: 37 g; Purity: 88% (according to GC). Further fractionation on a spinning band column gave 20.3 g of product with a boiling point of 100 to 102 ° C. at 0.1 mbar and a purity of 94% determined by gas chromatography. The IR spectrum (film on NaCl) showed the following bands: 3361 (-0H), 2957, 1379 and 1359 (according to dimethyl) and 1011 (C-0) and 799 (isol. C = C) cm ^-1 . Smell: strong sandal scent, fruit note. Example 6: 2,4-Dimethyl-6- (2,2, 3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-ol

In a dry 1 1 three-necked flask, 11.2 g (0.46 mol) of magnesium shavings were covered with 100 ml of absolute ether, and 56.6 g (0.46 mol) of isopropyl bromide were added dropwise with stirring in the course of 30 minutes so that the reaction mixture was kept under gentle reflux. 67.2 g (0.35 mol) of 2-methyl-4- (2,2,3-trimethyl-3-cyclopenten-l-yl) -2-butene were added to the Grignard reagent prepared in this way. l-al, prepared according to Example IV, 1 of US Pat. No. 4,052,341, was metered in over the course of 45 minutes with stirring. After the aldehyde had been added, the mixture was stirred at the reflux temperature for a further 5 hours and left to stand at room temperature overnight. The reaction mixture was then poured into 500 ml of a saturated aqueous ammonium chloride solution and extracted 3 times with 100 ml of ether each time. The organic phases were washed with water and dried over potassium carbonate. After filtering and concentrating, 48.3 g of residue remained, which were distilled on a 12 cm Vigreux column under high vacuum. The main run of 36 g went from 113 to 118 ° C and 0.09 mbar and was not further purified. The IR spectrum (film on NaCl) showed bands at 3397 (-0H), 2953, 1382 and 1359 (according to dimethyl) as well as at 1012 (C-0) and 798 (isol. C = C) CΠT *. Smell: woody, fresh, sandal note, balsamic.

3- Preparation of the comparative example

Comparative Example 1: 3-methyl-5- (2,2,3-trimethyl-3-cyclopenten-l-yl) pentan-2-ol

3-Methyl-5- (2,2,3-trimethyl-3-cyclopenten-l-yl) pentan-2-ol was prepared according to the information in US Pat. No. 4,052,341. 4. Determination of the odor threshold values

The odor intensity of the compounds according to the invention was determined in comparison with 3-methyl-5- (2,2,3-trimethyl-3-cyclopenten-l-yl) pentan-2-ol. For this purpose, solutions of the odoriferous substances to be investigated were prepared in dipropylene glycol and diluted in each case until an odor could just be perceived; the minimum concentration determined in this way by a panel of 16 test persons for the perception of the smell of the respective fragrance is referred to as the odor threshold. For reasons of better comparability, the concentration for the odor threshold value determined for Comparative Example 1 was designated as 1.0 and the values of Examples 3 to 6 according to the invention based on this.

It was found that the compounds of Examples 3 to 6 had significantly lower odor threshold values than the comparative example, see Table 1. For example, a value of 0.05 for Examples 3 and 4 means that the typical sandal smell is already present 20 times higher dilution could be perceived than that of the comparative example.

Table 1: Relative odor threshold values

5. Composition example

u i e fantasy composition

The addition of 35 parts of 4-methyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-ol, prepared according to Example 3, to the mixture gave the composition a natural appearance Wood note with balsamic and animal Accents that perfectly rounded off the overall composition and enhanced the flowery character. A similar effect could not be achieved by adding 35 parts of commercially available sandal bodies or 35 parts of East Indian sandwood oil.

Claims

Patent claim Q che

1. β-utenol derivatives of the general formula (I)

wherein the radical * is hydrogen or an alkyl group having 1 to 4 carbon atoms and the radical R ^{2 is} an alkyl group having 1 to 4 carbon atoms, with the meaning of a methyl group being excluded for R ² if R 1 is a methyl group.

2. butenol derivatives according to claim 1, wherein the radical R * is hydrogen, methyl or ethyl and the radical R ^{2 is} methyl or ethyl.

3. 4-methyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-ol.

4. 4-ethyl-6- (2,2,3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-ol.

5. 2,4-dimethyl-6- (2,2 _r 3-trimethyl-3-cyclopenten-l-yl) -4-hexen-3-ol.

6. Process for the preparation of butenol derivatives of the general formula (I)

wherein the radical R ^{1 is} hydrogen or an alkyl group having 1 to 4 carbon atoms and the radical R ^{2 is} an alkyl group having 1 to 4 carbon atoms, with the meaning of a methyl group being excluded for R ² if Rl is a methyl group, by condensation of α-campholenaldehyde with the corresponding aldehydes or ketones to the corresponding unsaturated carbonyl compounds and subsequent reduction of the carbonyl function of these compounds z. B. with complex hydrides for OH function.

7. Use of the butenol derivatives according to one of claims 1 to 5 as fragrances.

8. Fragrance compositions containing one or more butenol derivatives of the formula (I) according to Claims 1 to 5 in an amount of 1-70% by weight, based on the overall composition.

9. Use of one or more butenol derivatives of the formula (I) according to claim 1 to 5 as fragrances in cosmetic preparations, technical products or alcoholic perfumery.