JPS5833210B2 - Method for producing new aldehyde compounds - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing novel aldehyde compounds.

The novel aldehydes of the present invention have the following general formula (wherein R1
, R2 and R3 (representing a methyl group) each have a hydrogen atom**.

Among the aldehydes of the general formula I, a particularly preferred class are the aldehydes of the general formula, in which R1 and R2 have the meanings given above.

According to the method provided by the present invention, the aldehydes of the general formula I are prepared by the general formula
acetals of the general formula (in which R, R1 and R2 have the meanings given above) or enol ethers of the general formula (in which R, R1 and R2 have the meanings given above) It is produced by reacting an alkenol with an acidic catalyst.

C1 to C indicated by R in general formulas ■ and ■
The alkyl group in 5 is a straight or branched alkyl group such as methyl, ethyl, propyl, impropyl or hexyl group.

R preferably represents an ethyl group.

Particularly suitable aldehydes of formula Ia from the point of view of aroma are (a) alkenols of formula (3) in which Ra represents a hydrogen atom (for example, 2-methyl-3-buten-2-ol);
(b) react with an acetal of the formula (2) or an enol ether of the formula (2) in which R2 represents a hydrogen atom or a methyl group, or (b) an alkenol of the formula (2) in which R represents a methyl group (e.g. 3-methyl-1-pentene-3- ol) can be prepared by reacting with an acetal moiety of the formula (2) or an enol ether of the formula (2) in which R2 represents a hydrogen atom.

Acetal of formula ■ or enol ether of formula ■ and formula ■
The reaction of with alkenols can be carried out in a manner known per se (for example Swiss Patent Specification No. 416,596).

Thus, as acidic catalyst it is possible to use, for example, sulfuric acid or mineral acids such as, in particular, phosphoric acid.

However, strong organic acids such as oxalic acid, trichloroacetic acid, p-)luenesulfonic acid, acid salts such as potassium bisulfite, or Lewis acids such as boron trichloride, boron trifluoride or zinc chloride may also be used. Can be done.

According to a particularly preferred embodiment, pyridine hydrohalides, in particular pyridine hydrochloride, are used as acidic catalysts, since the aldehydes of formula (1) are obtained in particularly good yields.

The catalyst concentration in the reaction mixture is conveniently about 2-5% by weight;
In particular, it amounts to about 3-4% by weight, which corresponds to about 1 catalytic amount relative to the amount of acetal or enol ether starting material used.
/10 molar equivalent.

Reactions using this catalyst are preferably carried out in the presence of a solvent.

Particularly suitable solvents are aromatic hydrocarbons, such as benzene, toluene or xylene.

However, it is also possible to use high-boiling petroleum ethers or chlorinated aliphatic hydrocarbons, such as, for example, methylene chloride, ethylene chloride or trichloroethylene.

A particularly preferred solvent is toluene.

In a preferred embodiment, this reaction is carried out under atmospheric pressure.

An acetal of formula ■ or an enol ether of formula ■ or a mixture of these acetals and enol ethers,
For example, the reaction mixture is heated to the reflux temperature in the presence of an alknol of formula (1) and a catalyst in one of the abovementioned solvents, and the alcohol ROH formed during the reaction is continuously distilled off from the reaction mixture (e.g. the solvent used as an azeotrope with).

Preferably, the total volume of the reaction mixture as well as the initial proportions of this reaction component are equal to the addition of solvent and/or alknol (alknol is the alkanol ROH formed during the reaction).
(a small amount is distilled off at the same time as the water is distilled off).

acetal of formula ■ or enol ether of formula ■,
The maximum molar ratio of formula ■ to alknol is approximately 1:1.5
reach.

The solvent should be used, for example, in an amount equivalent to about twice the amount of acetal (or enol ether) and alkenol by weight.

To obtain the highest yields, the progress of the reaction is conveniently followed by taking a reaction sample and analyzing it, for example, by gas chromatography, and heating is discontinued as soon as about 95% of the acetal or enol ether reaction components have reacted: In this case, the yield of aldehyde of formula (1) reaches 70% or more.

Generally, the reaction time required for this is approximately 20 hours.

The resulting aldehyde of formula (1) can be isolated from the reaction product mixture by methods known per se, expediently by fractional distillation.

Advantageously, the catalyst used is neutralized before the distillation by addition of an inorganic or organic base such as sodium acetate, caustic soda, sodium carbonate, ammonia, a tertiary amine such as triethylamine or pyridine, etc., and then optionally Remove from reaction mixture.

The unknown acetals of formula (1) and enol ethers of formula (2) can be prepared essentially according to known methods (for example according to Belgian Patent Specification No. 650,657).

The aldehydes of the formula (1) according to the invention, especially the aldehydes of the formula Ia, have interesting odor-emitting properties.

As is clear from the description below, its properties can generally be described as hesveridin-like and fresh.

This totally surprising fresh property is also important.

This aroma characteristic is unique to aldehydes of formula (1), and in particular to aldehydes of formula Ia, as shown by the tests below with lower and higher congeners of formula Ia.

2,5-dimethyl-2-(3'-methyl-2'-phthene)yl-4-hexenal: Hesveridin-like (lemon), bluish, tangy, fruity and floral.

This aldehyde is suitable as a troughsort regulator for floral and/or green compositions.

For example, increasing the diffusibility of woody and chypre compositions.

5-Methyl-2-(3'-methyl-2'-butenecoyl-4-hexenal: hespridin-like, very fresh,
Natural blue, floral (rose-like), anise and lavender notes.

This aldehyde is particularly suitable for floral compositions such as musier, lilac, gardenia, giving them "lightness" and pronounced diffusibility.

However, the properties of fusier and animal compositions are also improved by this aldehyde.

5-methyl-2-(3'-methyl-7-butenephyll-
4-Hebutinal: Similar to the aldehydes above, but with stronger fruit-like and green-like properties.

2,5-dimethyl-2-(3'-methyl-2'-phthene)yl-4-heptenal: Similar to hesveridin; greenish, somewhat woody.

Owing to the interesting odor properties of the aldehydes according to the invention, which make them stand out from all structurally related aldehydes, the aldehydes of formula (1) are therefore used as fragrance agents.

Used as a fragrance in the production of fragrance compositions, e.g. perfumes, or in the fragrance of all kinds of products, e.g. cosmetics such as soaps, detergents, bleaching detergents, aerosols or ointments, face powder, make-up, bath salts, etc. be done.

The concentration of aldehyde used in formula (■) is, for example, approximately 0.1 depending on the application.
It can vary over a wide range from about 20% by weight.

For use in fragrance compositions, preferred concentrations range from about 1 to about 5% by weight.

Accordingly, the present invention covers within its scope (a) a fragrance composition comprising an aldehyde of formula (I) as an odor-imparting ingredient, and (b) an odor-imparting amount of an aldehyde of formula (I) or a fragrance composition as defined above. It will be appreciated that the term also includes methods of imparting fragrance to a substance by applying or encapsulating it to the substance.

The following examples illustrate the process provided by the present invention: Example 1 320 g of 2-methyl-3-buten-2-ol, crystalline phosphoric acid 2? and 2,5-dimethyl-4-hexenal diethylacetal 5001 are charged in this order into a suitable reaction vessel with stirring.

The mixture is then heated under reflux for 5 hours while passing nitrogen through it.

In this way, the temperature drops from 107°C to 102°C.

The reflux condenser is then replaced by a column with a distillation bridge, and the ethanol produced is gradually distilled off over a period of 6 to 8 hours.

In this way, the temperature rises continuously to 140°C.

At this temperature, with the same rate of heating, the distillation begins to proceed more rapidly and the temperature at the top decreases (formation of isoprene from methylbutynol).

A total of 425 r/l of distillate is recovered.

After the reaction is complete, the reaction product is cooled, diethyl ether is added, and the ethereal solution is washed with sodium bicarbonate solution and water and then dried.

After distilling off the solvent, the crude product is fractionally distilled in vacuo.

Boiling point 115-117℃/20mmHg, n¥3=1.4
688 2,5-dimethyl-2-(3'-methyl-2'
-Butenephyll-4-hexenal 240g (49%/
lh) is obtained.

Example 2 2-Methyl-3-buten-2-ol 8.6P.

0.11 g of 85% phosphoric acid and 30.8 g of 1-ethoxy-2,5-dimethyl-1,4-hexadiene are mixed in a suitable autoclave.

After pressurizing with nitrogen (5 kg/cA), the autoclave was placed in an oil bath (preheated to 165°C) and the internal temperature was 165°C.
Heat to ±5°C for 1.5 hours.

In this way, the internal pressure can reach a maximum of 10.4 kg/crt.
Reach i.

After cooling the autoclave, the excess pressure is vented and the reaction mixture is treated with approximately ITLl of triethylamine and fractionally distilled in vacuo.

Boiling point 112-113℃/13 mmHg 1n'7
= 1.4680 2,5-dimethyl-2-(3'-methyl-2'-butenecoyl-4-hexenal 10.6?
(54%/lh) is obtained.

Purity by gas chromatography is approximately 85%.

Example 3 2,5-dimethyl-4-hexenal diethylacetal 400f, 2-methyl-3-buten 2-ol 258
100 (l) of toluene and 24 g of pyridine hydrochloride with a thermometer, dripping Pt and 40 CI'I with a distillation bridge.
Place in a reaction vessel equipped with an L Vigreux column.

The mixture is heated to boiling point and the toluene/ethanol azeotrope containing a small amount of 2-methyl-3-buten-2-ol is slowly distilled off through a Vigreux column.

At the same rate as this solvent distillation, fresh toluene (total amount 3 k
Pour g) from the dripping funnel.

After 7 hours, an additional 43 g of 2-methyl-3-buten-2-ol is added and distillation is continued for a total run of 20 hours.

After this time approximately 90% of the starting material had reacted.

Stop the addition of fresh toluene and distill off as much of the solvent remaining in the reaction flask as possible.

This reaction mixture was mixed with 16% sodium acetate. and vacuum fractional distillation.

2,5-dimethyl-2-[ with a boiling point of 112°C/12°Hg
3'-Methyl-21-butenecoyl-4-hexenal 29Of! (74%/lh) is obtained.

Example 4 By a method similar to that described in Example 1, 2-methyl-3
-buten-2-ol 1712, crystalline phosphoric acid 2g and 5
-Methyl-4-hexenal diethylacetal 398
f? The mixture is heated under reflux for 5 hours while stirring and passing nitrogen gas.

After pouring the generated ethanol, the internal temperature of the flask was 133-1.
Distill slowly through the column until 35°C is reached.

This temperature is achieved after about 6 hours and 285 g of distillate are distilled out.

Post-processing is performed in a manner similar to that described in Example 1.

Boiling point 102-114'c/10mmHg, n2f
3 = 1.4661 of 5-methyl-2-(3'-methyl-2'-butenephyl-4-hexenal (28%/1
h) 105P is obtained.

Example 5 In a manner analogous to that described in Example 3, 5-methyl-4-
Hexenal diethylacetal 4002.2-methyl-3-buten-2-ol 275g, toluene 1ooo
y and pyridine hydrochloride 25'? React for 7 hours.

Further 50 g of 2-methyl-3-buten-2-ol are added and the reaction is stopped after 20 hours (total reaction time).

Post-treatment was performed by adding 20% sodium acetate to the crude product before vacuum distillation.
After addition of , the method described in Example 3 is followed.

5-Methyl-2-(3'-methyl-2-butenefil-
180 g (40%/lh) of 4-hexenal are obtained.

Example 6 In a similar manner to that described in Example 3, 2.5 dimethyl-
300 P of 4-hexenal diethylacetal is reacted with 225 g of 3-methyl-1-penten-3-ol in the presence of 17.4 S' of pyridine hydrochloride and 1000 rrLl of toluene.

After 12 hours, an additional 75 g of 3-methyl-1-penten-3-ol is added.

The reaction is completed after 30 hours (the entire process).

After adding 13 grams of sodium acetate to the crude mixture, the reaction product is fractionally distilled in vacuo.

2,5-dimethyl-2-(3'-methyl-2'-7"Tenfil-4- with boiling point 157~bn\3=1.4690
160 g of hebutinal is obtained.

Example 7 In a similar manner to that described in Example 3, 5-methyl-4-
150 g of hexenal diethyl acetal was mixed with 13 (l) of 3-methyl-1-penten-3-ol in the presence of 10.5 P of pyridine hydrochloride and 450 I of toluene.
React for 0 hours and add a further 25 g of 3-methyl-1-penten-3-ol after the first 15 hours.

After treatment according to Example 3, boiling point 125-126
75.79 % of 5-methyl-2-[3'-methyl-/-butenecoyl-4-hebutynal of °C/15 mmHg, n"f)=x, 46r5 are obtained.

The following example illustrates a typical fragrance composition containing the aldehyde of the present invention.

Example A Hyacinth type composition: Parts by weight 5-Methyl-2-(3'-methyl-/-butene]yl-4-hexenalphenylacetaldehyde (50%) 5 Indole (10%) 5 Skatole (1%) 5 Galbanum essense 10 Hydroatrobaraldehyde Dimethyla 10 Cetal eugenol 20 Ethyl phenyl cinnamate 30 Ethyl phenyl formate 30 Phenylpropyl alcohol 30 Benzyl acetate
30 citronellol
30 Ethyl phenyl salicylate
50 ethyl phenylbutyrate
50 Cinnamon Alcohol (Synthetic) 50 Hydroxy Citroneller fiv70 Phenylethyl Alcohol 18025 5-Methyl-2-(3'-methyl-2'-butenephyl-4-hexenal gives the composition excellent elegance and natural freshness.

Example B Composition of the chypre mold: Parts by weight 2,5-dimethyl-2-(3'-methyl 60-2
'-Butenephyl-4-hexenal frankincense (resin-like) 10 Daylily oil (10%) *10 Part by weight Methyl nonylacetaldehyde (1%) * 0 2,6,10-trimethyl-9-undecen-1-al (10%) ) 0 Undecylenaldehyde (10%) * γ-Undecalactone (1%) * Vetiver oil (Bourbon) Sandalwood oil (East India) Indian oil 1, 1, 4, 4-tetramethyl-6 Ethyl 7 - Acetyl root 2, 3, 4-tetrahydronaphthalene 0 0 0 0 0 0 Pure decolorized oak walnut aloe oil 0 0 Bergamot oil Hydroxycitronellal α-ionone citronellol (levorotatory) Phenylethyl alcohol Jasmine (absolute, synthetic) Part by weight 0 40 00 0 00 50 000 * Phthalic acid diethyl ester solution This 2,5-dimethyl-2-[3'-methyl-2'-butencoyl-4-hexenal imparts freshness and fruit-like properties to the chypre composition, and at the same time Increases diffusivity.

Claims (1)

[Scope of Claims] In producing a new aldehyde having the general formula (in the formula, R1, R2 and R3 each represent a hydrogen atom or a methyl group), the general formula (in the formula, R
o and R2 and R have the above meanings).
The above-mentioned process is characterized in that it is reacted with an acetal having an alkyl group containing 5 carbon atoms or an alkenol having the general formula, in which R3 has the meaning given above, in the presence of an acidic catalyst.