RU2795926C2 - Compound of a carboxic acid ether, method for its production and flavoring composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a carboxylate compound of formula (1) wherein R is an alkyl group having 2 to 6 carbon atoms, which can be used as a raw material for flavoring compositions and which has a fruity flavor, to a flavoring composition containing it, and to a method of receiving it. The method for preparing the compound of formula 1 consists in reaction of the compound represented by formula (2) with carbon monoxide in the presence of hydrogen fluoride, followed by reaction with an alcohol having 2 to 6 carbon atoms.

EFFECT: obtaining a compound of a carboxic acid ether.

4 cl, 1 tbl, 4 ex

Description

The field of technology to which the invention belongs

[0001]

The present invention relates to a novel carboxylate compound, a process for producing the same, and a fragrance composition containing the carboxylate compound, and in particular, the present invention relates to a carboxylate compound that can be used as a raw material for fragrance compositions, a process for producing the same, and a fragrance composition. containing a carboxylate compound.

State of the art

[0002]

It is known that some esters are compounds that can be used as flavorings. For example, rose-scented geranyl acetate, methyl jasmonate, which has a sweet jasmine-type aroma, Fruitate (ethyl tricyclo[5.2.1.0 ^2,6 ]decane-2-carboxylate), which has a fruity aroma, and methyl benzoate, which has an intense dried fruit aroma, can be used as flavoring ingredients. compositions. Furthermore, Patent Document 1 describes that a camphene-derived carboxylate compound has a refreshing pine aroma.

Link List

Patent Documents

[0003]

Patent Document 1: WO 2012/063433

The essence of the invention

Technical task

[0004]

The object of the present invention is to provide a novel carboxylate compound having a fruity aroma, a method for producing the same, and a flavoring composition containing the carboxylate compound.

The solution of the problem

[0005]

The inventors of the present invention synthesized various compounds and investigated their aromas, and found that some carboxylate compounds have a fruity aroma, which led to the implementation of the present invention.

[0006]

The present invention provides the following aspects <1> to <4>.

<1> The carboxylate compound represented by the formula (1).

[0007]

where R is an alkyl group having 2 to 6 carbon atoms.

[0008]

<2> The carboxylate compound according to <1>, where R is an ethyl group, an n-propyl group, or an isopropyl group.

<3> A flavoring composition containing a carboxylate compound represented by the formula (1).

[0009]

where R is an alkyl group having 2 to 6 carbon atoms.

[0010]

<4> A method for producing a carboxylate compound represented by formula (1) by reacting a compound represented by formula (2) with carbon monoxide in the presence of hydrogen fluoride, and then reacting with an alcohol having 2 to 6 carbon atoms.

[0011]

where R is an alkyl group having 2 to 6 carbon atoms.

[0012]

Useful effects of the invention

[0013]

The carboxylate compound of the present invention has a fruity aroma and can be used as a fragrance ingredient in a wide range of products such as toiletries, soaps and clothes detergents. In addition, according to the method for producing a carboxylate compound of the present invention, a carboxylate compound can be produced in an industrially cost-effective manner.

Description of Embodiments

[0014]

The present invention will be described below using embodiments. It should be noted that in the following description, the words "from A to B" indicating a numerical range mean "greater than or equal to A and less than or equal to B" (when A<B) or "less than or equal to A and greater than or equal to B" (when A>B). In other words, the phrases "from A to B" indicate numerical ranges that include the endpoints of A and B.

In addition, the terms "parts by weight" and "% by weight" are synonymous with the terms "parts by weight" and "% by weight", respectively.

[0015]

[Carboxylate Compound]

The carboxylate compound of the present invention is represented by formula (1) below.

[0016]

where R is an alkyl group having 2 to 6 carbon atoms.

[0017]

In the formula (1), R represents an alkyl group having 2 to 6 carbon atoms. An alkyl group having 2 to 6 carbon atoms is preferably a straight or branched alkyl group, and examples thereof include an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a pentyl group, and hexyl group. Among the above, from the point of view of flavoring properties, ethyl group, n-propyl group and isopropyl group are preferable, and ethyl group is more preferable.

[0018]

The carboxylate compound represented by the formula (1) has a stereoisomer, and may be an exoisomer or an endoisomer, or a mixture of exo and endoisomers in any ratio, and is not particularly limited.

Among these, the exoisomer is preferred in terms of ease of production and flavoring properties.

[0019]

[Method for producing a carboxylate compound]

The carboxylate compound of the present invention (the carboxylate compound represented by formula (1)) can be advantageously produced commercially by a method in which the compound represented by formula (2) is reacted with carbon monoxide in the presence of hydrogen fluoride (hereinafter also referred to as "HF"), followed by the reaction with an alcohol having 2 to 6 carbon atoms.

Specifically, the compound represented by formula (2) is subjected to carbonylation by reaction with carbon monoxide in the presence of hydrogen fluoride (HF), whereby the acid fluoride represented by formula (3) is obtained. Then, the acid fluoride represented by the formula (3) is esterified by reacting it with an alcohol having 2 to 6 carbon atoms in the presence of hydrogen fluoride.

[0020]

where R is an alkyl group having 2 to 6 carbon atoms.

[0021]

(Compound represented by formula (2))

The compound represented by formula (2) is 2-ethylidene-norbornene and can be obtained by hydrogenation of 5-ethylidene-2-norbornene (ENB). It should be noted that ENB is known as a raw material for ethylene propylene diene (EPDM) rubber.

[0022]

(Carbon monoxide)

The carbon monoxide used in the present invention may contain an inert gas such as nitrogen or methane. The partial pressure of carbon monoxide during the reaction is in the range of preferably 0.5 to 5 MPa(g), and more preferably 1 to 3 MPa(g). If the partial pressure of carbon monoxide is higher than 0.5 MPa(g), then the carbonylation reaction proceeds quite quickly, and heterogeneity and side reactions such as polymerization do not occur at the same time, and an alicyclic carbonyl compound, which is the target product, can be obtained with high output. In addition, from the point of view of the load on the equipment, it is preferable that the partial pressure of carbon monoxide does not exceed 5 MPa(g).

[0023]

(hydrogen fluoride)

The HF used in the present invention is a reaction solvent as well as a catalyst and a starting material, and therefore it is preferable to use substantially anhydrous HF. The amount of HF used in terms of molar ratio relative to the starting compound represented by formula (2) is preferably 4 to 25 times more, and more preferably 6 to 15 times more. If the molar ratio of HF is 4 times or more, the carbonylation reaction proceeds efficiently, heterogeneity and side reactions such as polymerization can be suppressed, and a carbonyl compound which is an intended product can be obtained in high yield. In addition, from the viewpoint of raw material cost and productivity, it is preferable to use HF at 25 times or less molar ratio.

[0024]

(reactive solvent)

The carbonylation reaction can use a solvent that completely dissolves the starting materials and is inert to HF. For example, saturated hydrocarbon compounds such as hexane, heptane and decane can be used. The presence or absence and the amount of solvent used are not particularly limited and may be appropriately selected. However, from the viewpoint of suppressing the polymerization reaction and increasing the yield, the mass ratio of solvent to the starting compound of formula (2) is preferably 0.2 to 2.0 times, and from the viewpoint of productivity and energy efficiency, the mass ratio of solvent is preferably 0.5 to 1 ,2-fold.

[0025]

(Reaction conditions of carbonylation)

The carbonylation reaction can be carried out in any manner, such as batch, semi-batch or continuous, which is not particularly limited.

The carbonylation reaction temperature is preferably -50°C to 30°C, and more preferably -30°C to 20°C. From the point of view of the reaction rate, the reaction is preferably carried out at a temperature of -50°C or higher. In addition, from the viewpoint of reducing the number of generated isomers, the reaction is preferably carried out at a temperature of 30°C or lower.

The carbonylation reaction time is preferably at least 1 hour from the point of view of ensuring the completeness of the reaction, and preferably not more than 5 hours from the point of view of the reaction efficiency. The end point of the reaction is not particularly limited, and, for example, the reaction can be stopped when the uptake of carbon monoxide stops.

[0026]

In the carbonylation reaction, an acid fluoride (formula (3)) is formed with the help of HF and carbon monoxide. The resulting acid fluoride reaction solution (carbonylation reaction solution) can be purified by a conventional method such as distillation after distilling off excess HF, and then the purified acid fluoride solution can be used as a raw material in a subsequent esterification step. However, a method for producing a carboxylate compound by reacting, as it is, a carbonylation reaction solution containing an HF catalyst with an alcohol is generally used.

[0027]

(Alcohol)

The alcohol used in the present invention is an alcohol containing 2 to 6 carbon atoms.

The alcohol containing 2 to 6 carbon atoms is not particularly limited, and may be appropriately selected according to the purpose, and examples include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, pentanol, and hexanol . Among these, ethanol, n-propanol, isopropanol, n-butanol and isobutanol are preferred; ethanol, n-propanol and isopropanol are more preferred, and ethanol is even more preferred.

The use amount of the alcohol containing 2 to 6 carbon atoms is not particularly limited, and can be suitably selected according to the purpose, and with respect to the starting compound of formula (2), the molar ratio of its use amount is preferably 0.5 to 2, 0, more preferably 0.8 to 1.7, and even more preferably 1.0 to 1.7.

[0028]

(Esterification reaction conditions)

From the viewpoint of increasing the yield, the esterification reaction temperature is preferably not lower than -20°C, and from the viewpoint of suppressing side reactions such as ester decomposition and dehydration of the added alcohol, the reaction temperature is preferably not more than 20°C.

The esterification reaction time is preferably at least 0.5 hours from the point of view of completion of the reaction, and preferably at most 3 hours from the point of view of reaction efficiency. The end point of the reaction is not particularly limited, and for example, the reaction can be stopped when no increase in the heat of reaction is observed.

[0029]

The esterified product thus obtained is a solution of the carboxylate/HF complex. When the carboxylate/HF complex solution is heated, the bonds between the carboxylate and HF are broken, and the HF can be vaporised, recovered, and reused. The decomposition operation of this complex should be carried out as quickly as possible in order to avoid deterioration of the product by heating, isomerization and the like. To accelerate the thermal decomposition of the complex, it is preferable, for example, to decompose the complex by refluxing a solvent inert to HF (eg, a saturated aliphatic hydrocarbon such as heptane or an aromatic hydrocarbon such as toluene). In addition, when the reaction solution is extracted into ice water, preferably, for example, the reaction solution is extracted into ice water from the bottom of the autoclave and separated into an oil phase and an aqueous phase, after which the oil phase is washed twice with 2 wt. aqueous sodium hydroxide solution and twice with distilled water, and then dehydrated with anhydrous sodium sulfate. The solution thus obtained is further passed through an evaporator to remove low-boiling compounds and the like, and then subjected to rectification with a rectifier having a theoretical plate number of about 20, whereby a purified carboxylate compound can be obtained.

[0030]

It should be noted that the carboxylate compound of the present invention may be produced in a manner other than that described above. For example, as shown in the following schemes, an aldehyde compound (formula (4)) obtained by the Diels-Alder reaction between cyclopentadiene and 2-ethylacrolein can be oxidized to give a carboxylic acid compound (formula (5)), then a carboxylic acid compound is reacted with an alcohol having 2 to 6 carbon atoms to obtain an ester compound (formula (6)), and the ester compound can then be hydrogenated to obtain a carboxylate compound of the present invention (carboxylate compound represented by formula (1)). In addition, the carboxylic acid compound represented by the formula (5) can be obtained by the Diels-Alder reaction between cyclopentadiene and 2-ethylacrylic acid (2-methylenebutyric acid).

[0031]

where R is an alkyl group having 2 to 6 carbon atoms.

[0032]

The carboxylate compound of the present invention has a fruity aroma and can therefore be used alone or in combination with other ingredients as a fragrance ingredient in products such as soaps, shampoos, rinses, detergents, cosmetics, sprays, fragrances, perfumes, and bath salts. . Use as a synthetic intermediate for foodstuffs, pharmaceuticals, agrochemicals, liquid crystals, and the like can also be contemplated.

[0033]

[Fragrance Composition]

The flavoring composition of the present invention contains a carboxylate compound represented by formula (1).

The flavoring composition of the present invention can be obtained by mixing and combining one or more types of carboxylate compounds represented by formula (1) with another commonly used flavoring component or a desired flavoring composition. The mixing amount of the carboxylate compound represented by the formula (1) differs depending on the type of flavoring composition, type of target flavor, flavor intensity, and the like, however, adding 0.01 to 90 wt. to the flavoring composition is preferred, and the addition of 0.1-50% of the mass. is more preferred.

[0034]

Another flavor component that can be used in combination with the carboxylate compound of the present invention is not particularly limited and can be appropriately selected according to the purpose. Examples include:

hydrocarbons such as limonene, α-pinene, β-pinene, terpinene, cedren, longifolene and valencene;

[0035]

alcohols such as linalool, citronellol, geraniol, nerol, terpineol, dihydromyrcenol, ethyllinalool, farnesol, nerolidol, cis-3-hexenol, cedrol, menthol, borneol, β-phenylethyl alcohol, benzyl alcohol, phenylhexanol, 2,2,6- trimethylcyclohexyl-3-hexanol, 1-(2-tert-butylcyclohexyloxy)-2-butanol, 4-isopropylcyclohexanemethanol, 4-methyl-2-(2-methylpropyl)tetrahydro-2H-pyran-4-ol, 2-methyl-4 -(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-ol, isocamphylcyclohexanol and 3,7-dimethyl-7-methoxyoctan-2-ol;

phenols such as eugenol, thymol and vanillin;

[0036]

esters such as linalyl formate, citronellyl formate, geranyl formate, n-hexyl acetate, cis-3-hexenyl acetate, linalyl acetate, citronellyl acetate, geranyl acetate, nelyl acetate, terpinyl acetate, nopylacetate, bornyl acetate, isobornyl acetate, o-tert-butylcyclohexyl acetate, p-tert-butylcyclohexyl acetate, tricyclodecene ylacetate , benzyl acetate, styralyl acetate, cinnamyl acetate, dimethylbenzylcarbinyl acetate, 3-pentyltetrahydropyran-4-ylacetate, citronellyl propionate, tricyclodecenyl propionate, allylcyclohexyl propionate, ethyl 2-cyclohexyl propionate, benzyl propionate, citronellyl butyrate, dimethylbenzylcarbinyl n-butyrate, tricyclo decenyl isobutyrate, methyl 2-nonenoate, methyl benzoate, benzyl benzoate , methyl cinnamate, methyl salicylate, n-hexyl salicylate, cis-3-hexenyl salicylate, geranyl tiglat, cis-3-hexenyl tiglat, methyl jasmonate, methyl dihydro jasmonate, methyl 2,4-dihydroxy-3,6-dimethyl benzoate, ethyl methyl phenyl glycidate, methyl anthranilate, and fruitate;

[0037]

aldehydes such as n-octanal, n-decanal, n-dodecanal, 2-methylundecanal, 10-undecenal, citronellal, citral, hydroxycitronellal, dimethyltetrahydrobenzaldehyde, 4(3)-(4-hydroxy-4-methylpentyl)-3-cyclohexene -1-carbaldehyde, 2-cyclohexylpropanal, p-tert-butyl-α-methylhydrocinnamic aldehyde, p-isopropyl-α-methylhydrocinnamic aldehyde, p-ethyl-α,α-dimethylhydrocinnamic aldehyde, α-amylcinnamic aldehyde, α-hexylcinnamic aldehyde, piperonal and α-methyl-3,4-methylenedioxyhydrocinnamic aldehyde;

[0038]

ketones such as methylheptenone, 4-methylene-3,5,6,6-tetramethyl-2-heptanone, amylcyclopentanone, 3-methyl-2-(cis-2-penten-1-yl)-2-cyclopenten-1- he, methylcyclopentenolone, pink ketone, γ-methylionone, α-ionone, carbon, menthone, camphor, nutkatone, benzylacetone, anisylacetone, methyl-β-naphthylketone, 2,5-dimethyl-4-hydroxy-3(2H)-furanone, maltol, 7-acetyl-1,2,3,4,5,6,7,8-octahydro-1,1,6,7-tetramethylnaphthalene, muscone, civeton, cyclopentadecanone and cyclohexedecenone;

[0039]

acetals and ketals such as acetoaldehyde ethylphenylpropyl acetal, citraldiethyl acetal, phenylacetoaldehyde glycerol acetal, and ethyl acetoacetate ethylene glycol ketal;

ethers such as anethole, β-naphthyl methyl ether, β-naphthyl ethyl ether, limonene oxide, rosen oxide, 1,8-cineole, racemic or photoactive dodecahydro-3a,6,6,9a-tetramethylnaphtho[2,1-b]furan;

nitriles such as citronellyl nitrile;

[0040]

lactones such as γ-nonalactone, γ-undecalactone, σ-decalactone, γ-jasmolactone, coumarin, cyclopentadecanolide, cyclohexadecanolide, ambrettolide, ethylene brassylate and 11-oxahexadecanolide; And

natural essential oils and natural extracts of orange, lemon, bergamot, mandarin, peppermint, spearmint, lavender, chamomile, rosemary, eucalyptus, sage, basil, rose, geranium, jasmine, ylang ylang, anise, clove, ginger, nutmeg , cardamom, cedar, Japanese cypress, vetiver, patchouli and labdanum. In addition, these and other flavor components may be blended singly or in combinations of two or more.

[0041]

The carboxylate compound represented by the formula (1) imparts an excellent fruity aroma, and therefore, the fragrance composition containing the carboxylate compound represented by the formula (1) can be used as a fragrance component for various products such as perfumes and cosmetics, health and hygiene materials, various products, food, parapharmaceutical products and pharmaceuticals, to improve the flavor of the prepared product.

[0042]

The fragrance composition containing the carboxylate compound represented by formula (1) can be used as a fragrance component for various products, including, for example, perfume products such as perfumes and colognes; hair cosmetics such as shampoos, rinses, hair tonics, hair creams, mousses, gels, pomades, sprays; skin cosmetics such as facial lotions, serums, creams, emulsions, face masks, cream bases, face powders, lipsticks and various types of make-up; various health and sanitation detergents such as dishwashing detergents, laundry detergents, softeners, disinfectant detergents, deodorizers, room fragrances, furniture care products, glass cleaners, furniture cleaners, floor cleaners, disinfectants, insecticides and bleaches; parapharmaceuticals such as toothpaste, mouthwash, bath salts, antiperspirants, and permanent waving solutions; other products such as toilet paper and tissue paper; pharmaceuticals and food products.

[0043]

In addition, the amount of the flavoring composition of the present invention that is mixed with the product is not particularly limited and can be properly selected according to the purpose, however, the amount of the carboxylate compound represented by the formula (1) that is mixed with the product is preferably 0.001-50 % wt. and more preferably 0.01-20% of the mass.

Examples

[0044]

The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to these examples.

[0045]

<Conditions for Gas Chromatography Analysis>

Gas chromatography was carried out using a gas chromatograph ("GC-2010 Plus", available from Shimadzu Corporation) and a capillary column ("HR-1" (0.32 mm ∅ × 25 m, available from Shinwa Chemical Industries Ltd). As a condition temperature increase, the temperature was raised from 100° C. to 310° C. at a rate of 5° C./min.

[0046]

<GC-MS>

A JMS-T100GCV GC/MS spectrometer available from JEOL Ltd. was used.

[0047]

< ¹ H-NMR and ¹³ C-NMR spectroscopy>

The measurements were carried out under the following conditions.

Device: JNM-ECA500 NMR spectrometer available from JEOL Ltd.

Internal standard substance: tetramethylsilane (TMS)

[0048]

<Yield of carboxylate compound, isomer ratio>

- Yield of carboxylate compound (mole%) = (number of moles of carboxylate compound)/(number of moles of 2-ethylidenenorbornane) × 100

- Isomer ratio (%) = (number of moles of 2-ethylnorbornane-exo-2-carboxylate)/(total moles of carboxylate compound) × 100

[0049]

Synthesis Example 1

(Preparation of 2-ethylidene-norbornene by hydrogenation of 5-ethylidene-2-norbornene (ENB))

A stainless steel autoclave having an internal volume of 200 ml, equipped with a magnetic stirrer, three inlets at the top and one outlet at the bottom, and capable of controlling the internal temperature with a jacket, was charged with 2.0 g of Cu-Cr catalyst (" N-203S" available from JGC Catalysts and Chemicals Ltd.) and 30 g of heptane (guaranteed purity, available from Wako Pure Chemical Corporation) and activated for 1 hour at 170° C. under 1 MPa(g) hydrogen pressure. After cooling, 100 g of 5-ethylidene-2-norbornene (available from Tokyo Chemical Industry Co., Ltd.) was further added, and the mixture was stirred and subjected to a hydrogenation reaction for 2 hours at 90°C and a hydrogen pressure of 2 MPa(g) . The reaction solution was filtered to remove the catalyst, and heptane, which is a solvent, was distilled off, and 89 g of a liquid reaction product (hereinafter, may also be referred to as "reaction solution") containing 2-ethylidenenorbornane at a concentration of 95 mass% was obtained. and 2-ethylnorbornane at a concentration of 5% wt. (yield: 88 mole % (yield calculated from total moles of 2-ethylidene-norbornane and 2-ethylnorbornane relative to moles of starting material 5-ethylidene-2-norbornene). Yield of 2-ethylidene-norbornane was 84 mole % (calculated from moles of 2-ethylidenenorbornane relative to the number of moles of 5-ethylidene-2-norbornene).

The reaction equation is shown below.

[0050]

[0051]

Example 1

(Preparation of ethyl 2-ethylnorbornane-2-carboxylate by carbonylation and esterification of 2-ethylidenenorbornane)

The experiment was carried out using a stainless steel autoclave capable of controlling the internal temperature with a jacket. The autoclave had an internal volume of 500 ml and was equipped with a magnetic stirrer, three inlets at the top and one outlet at the bottom.

First, the interior of the autoclave was purged with carbon monoxide, after which 158 g (7.9 mol) of hydrogen fluoride was introduced and the temperature of the liquid was adjusted to 0° C., and then the pressure was raised to 2 MPa (g) with carbon monoxide.

While the reaction temperature and reaction pressure were maintained at 0° C. and 2 MPa(g), respectively, a mixed solution of 82 g of the reaction solution prepared in Synthesis Example 1 (2-ethylidenenorbornane concentration: 95 mass%, concentration 2 -ethylnorbornane: 5 wt %), and 82 g of heptane (purity assured, available from Wako Pure Chemical Corporation) were fed from the top of the autoclave over 60 minutes, and a carbonylation reaction was carried out. After the feed was stopped, stirring was continued for about 20 minutes until carbon monoxide uptake was no longer observed.

[0052]

Then, while the reaction temperature was maintained at 0° C., 46 g of ethanol (1.0 mol, 1.6 times the molar ratio of the starting material 2-ethylidenenorbornane) was supplied from the top of the autoclave for 15 minutes, and the esterification was carried out for 1 h with stirring. The reaction solution was extracted from the bottom of the autoclave into ice water, and the oil phase and the aqueous phase were separated, after which the oil phase was washed twice with 100 ml of 2 wt%. aqueous sodium hydroxide solution and twice with 100 ml of distilled water, and then dehydrated with 10 g of anhydrous sodium sulfate.

[0053]

Low-boiling compounds were removed from the obtained liquid using an evaporator, after which the liquid was subjected to distillation (distillation temperature: 150°C, vacuum degree: 60 Torr (8.0 kPa)) using a rectifier having a number of theoretical plates of 20, and then analyzed using gas chromatography using an internal standard. As a result, the yield of the carboxylate compound (a mixture of exo- and endoisomers) was 94.1 mol.% (standard 2-ethylidenenorbornane). The yield of the main product ethyl 2-ethylnorbornane-2-exocarboxylate was 84.9 mol.% (standard 2-ethylidenenorbornane, isomer ratio 90.3%).

The main product was analyzed by GC-MS (CI ⁺ ), and the results showed a molecular weight of 197.15 ([M+H] ⁺ ) relative to the molecular weight of 196.29 of the target product. In addition, ¹ H-NMR chemical shift value and ¹³ C-NMR chemical shift value (δ ppm, TMS standard) in deuterated chloroform solvent were obtained further, and from these results, the main product was identified as ethyl- 2-ethylnorbornane-2-carboxylate. It should be noted that when identified by NMR, [2] means a carbon atom or a hydrogen atom bonded to the indicated carbon atom, denoted by the reference position 2 in the following chemical formula. The same applies below.

[0054]

[0055]

¹ H NMR (500 MHz, CDCl ₃ ) δ (ppm): 0.76 (t, J=7.5 Hz, 3H, [9]), 0.90 (dd, J=12.5, 3.0 Hz, 1H, [5a <endo>]), 1.06-1.11 (m, 1H, [7a <endo>]), 1.19-1.21 (m, 1H, [3b] ), 1.23 (t, J=7.0 Hz, 3H, [13]), 1.28-1.32 (m, 1H, [3a]), 1.33-1.41 (m, 1H , [6a <endo>]), 1.45-1.50 (m, 1H, [7b <exo>]), 1.51-1.58 (m, 1H, [6b <exo>]), 1 .58-1.64 (m, 2H, [8]), 2.17-2.19 (m, 1H, [4]), 2.20-2.24 (m, 1H, [5b <exo> ]), 2.54 (br. d, J=4.0, 1H, [2]), 4.09-4.13 (m, 2H, [12])

[0056]

[0057]

¹³ C NMR (126 MHz, CDCl ₃ ) δ (ppm): 10.55 [9], 14.37 [13], 23.15 [6], 29.05 [7], 29.60 [ 8], 36.81 [4], 38.81 [3], 41.29 [5], 42.78 [2], 54.35 [1], 60.27 [12], 178.06 [10 ]

Ethyl 2-ethylnorbornane-2-carboxylate had a fruity-herbal-woody aroma.

[0058]

Example 2

(Preparation of n-propyl-2-ethylnorbornane-2-carboxylate by carbonylation and esterification of 2-ethylidenenorbornane)

Carbonylation, esterification, and workup of the reaction product were carried out in the same manner as in Example 1, except that the alcohol used in the esterification in Example 1 was replaced with n-propanol.

The resulting product was analyzed by gas chromatography, and the results showed that the yield of the carboxylate compound was 92.9 mol% (standard 2-ethylidenenorbornane), and the yield of the main product n-propyl-2-ethylnorbornane-exo-2-carboxylate was 83. 0 mol% (standard 2-ethylidenenorbornane, isomer ratio 89.4%).

The main product was analyzed by GC-MS (CI ⁺ ), and the results showed a molecular weight of 211.13 ([M+H] ⁺ ) relative to the molecular weight of 210.32 of the target product. In addition, ¹ H-NMR chemical shift value and ¹³ C-NMR chemical shift value (δ ppm, TMS standard) in deuterated chloroform solvent were obtained further, and from these results, the main product was identified as n- propyl 2-ethylnorbornane-2-carboxylate.

[0059]

[0060]

¹ H NMR (500 MHz, CDCl ₃ ) δ (ppm): 0.76 (t, J=7.5 Hz, 3H, [9]), 0.89-0.92 (m, 1H, [5b <endo>]), 0.93 (t, J=7.0 Hz, 3H, [14]), 1.05-1.11 (m, 1H, [7a <endo>]), 1, 18-1.22 (m, 1H, [3b]), 1.27-1.32 (m, 1H, [3a]), 1.33-1.40 (m, 1H, [6b <endo>] ), 1.45-1.51 (m, 1H, [7b <exo>]), 1.52-1.59 (m, 1H, [6a <exo>]), 1.60-1.67 ( m, 4H, [13], [8]), 2.17-2.19 (m, 1H, [4]), 2.20-2.24 (m, 1H, [5a<exo>]), 2.54 (broad d, J=3.5 Hz, 1H, [2]), 4.98-4.05 (m, 2H, [12])

[0061]

[0062]

¹³ C NMR (126 MHz, CDCl ₃ ) δ (ppm): 10.59 [9, 14], 22.16 [13], 23.16 [6], 29.06 [7], 29, 64 [8], 36.82 [4], 38.82 [3], 41.30 [5], 42.80 [2], 54.52 [1], 65.98 [12], 178.14 [10]

In addition, n-propyl-2-ethyl-norbornane-2-carboxylate had a fruity-herbal-woody aroma.

[0063]

Example 3

(Production of isopropyl 2-ethylnorbornane-2-carboxylate by carbonylation and esterification of 2-ethylidenenorbornane)

Carbonylation, esterification, and workup of the reaction product were carried out in the same manner as in Example 1, except that the alcohol used in the esterification in Example 1 was replaced with isopropanol.

The resulting product was analyzed by gas chromatography, and the results showed that the yield of the carboxylate compound was 92.4 mol% (standard 2-ethylidenenorbornane), and the yield of the main product isopropyl 2-ethylnorbornane-2-exocarboxylate was 81.2 mol% (standard 2-ethylidenenorbornane, isomer ratio 87.9%).

The main product was analyzed by GC-MS (CI ⁺ ), and the results showed a molecular weight of 211.12 ([M+H] ⁺ ) relative to the molecular weight of 210.32 of the target product. In addition, ¹ H-NMR chemical shift value and ¹³ C-NMR chemical shift value (δ ppm, TMS standard) in deuterated chloroform solvent were obtained further, and from these results, the main product was identified as isopropyl- 2-ethylnorbornane-2-carboxylate.

[0064]

[0065]

¹ H NMR (500 MHz, CDCl ₃ ) δ (ppm): 0.76 (t, J=7.0 Hz, 3H, [9]), 0.87-0.90 (m, 1H, [5b <endo>]), 1.05-1.11 (m, 1H, [7a <endo>]), 1.19-1.21 (m, 7H, [3b], [13], [15 ]), 1.29-1.30 (m, 1H, [3a]), 1.33-1.39 (m, 1H, [6b <endo>]), 1.45-1.51 (m, 1H, [7b <exo>]), 1.51-1.56 (m, 1H, [6a <exo>]), 1.56-1.64 (m, 2H, [8]), 2.16 -2.19 (m, 1H, [4]), 2.19-2.22 (m, 1H, [5a<exo>]), 2.54 (bd, J=4.0 Hz, 1H , [2]), 4.96-5.01 (m, 1H, [12])

[0066]

[0067]

¹³ C NMR (126 MHz, CDCl ₃ ) δ (ppm): 10.47 [9], 21.85-21.88 [13], [15], 23.16 [6], 29.08 [7], 29.53 [8], 36.80 [4], 38.74 [3], 41.25 [5], 42.79 [2], 54.25 [1], 67.22 [ 12], 177.49 [10]

In addition, isopropyl-2-ethyl-norbornane-2-carboxylate had a herbal-fruity-apple-woody aroma.

[0068]

Example 4

<Fragrance Composition>

According to the composition shown in Table 1 below, a flower-fruity flavor composition was prepared using the carboxylate compound obtained in Example 1.

[0069]

Table 1

Compound mass parts Benzaldehyde 3 Citronellol 70 CYCLACET (trade name)
(available from International Flavors & Fragrances, Inc.) 140 γ-undecalactone 10 Dimethylbenzylcarbinyl acetate 80 Ethylphenylacetate 6 GALAXOLIDE (trade name)
(available from International Flavors & Fragrances, Inc.)
50BB:50% in benzyl benzoate 180 Geraniol 85 Linalool 80 γ-Methylionone thirty Phenylethyl alcohol 155 Rosenoxide 6 TRIPLAL (trade name)
(available from International Flavors & Fragrances, Inc.) 5 VERTENEX (trade name)
(available from International Flavors & Fragrances, Inc.) 100 Compound Example 1 50 Total 1000

[0070]

The organoleptic evaluation was carried out by four experts with experience of five or more years, and the results showed that all the experts found that the flower-fruity flavor composition containing the compound of Example 1 had a strong fruity aroma, excellent palatability and excellent diffusion ability.

Industrial Applicability

[0071]

The new carboxylate compound of the present invention has a fruity aroma and its aroma is excellent, and thus the carboxylate compound of the present invention is effective as a fragrance component in a wide range of applications such as toiletries, soaps and clothes detergents. In addition, according to the method for producing a carboxylate compound of the present invention, a carboxylate compound can be produced in an industrially cost-effective manner.

Claims (11)

1. Carboxylate compound represented by formula (1)

, where R is an alkyl group having 2 to 6 carbon atoms. 2. The carboxylate compound according to claim 1, wherein R is an ethyl group, an n-propyl group, or an isopropyl group. 3. Flavoring composition containing a carboxylate compound represented by the formula (1)

, where R is an alkyl group having 2 to 6 carbon atoms. 4. A method for producing a carboxylate compound represented by formula (1) by reacting a compound represented by formula (2) with carbon monoxide in the presence of hydrogen fluoride, and then reacting with an alcohol having 2 to 6 carbon atoms

, where R is an alkyl group having 2 to 6 carbon atoms

.