Synthesis process of cyclooctane spice

Abstract

The invention relates to a synthesis process of cyclooctene, which comprises the following steps: by taking cyclooctadiene and alkyl aldehyde as raw materials, carrying out addition reaction under the action of a catalyst and an organic amine additive to synthesize a series of perfume molecules with a cyclooctene skeleton. The perfume has native fragrance, natural fragrance, flower fragrance, green fragrance and costustoot, and can be applied to the field of high-end perfume and fragrance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of organic synthesis, and in particular to a synthesis process of cyclooctane flavor. BACKGROUND

[0002] Cyclooctadiene is currently mainly used for synthesizing noble metal ligands or as an additive for olefin polymerization, but the overall market usage is small, therefore, developing a more promising application direction can better consume the production capacity of cyclooctadiene. In the field of essence and fragrance, cyclooctadiene has the advantages of high added value and wide application field, therefore, developing a series of cyclooctane flavor molecules with high added value from cyclooctadiene has strong commercial value.

[0003] Cyclooctene and its derivatives as new flavor raw materials have potential in the flavor industry due to their unique chemical properties such as high volatility, stability and compatibility with biomolecules. The aroma characteristics of such compounds include: a combination of woody, green and slightly fruity notes, which can be compounded with other flavors (such as rose ether, citronellal) to enhance the stereoscopic effect of aroma, and can be used in the fields of perfume, cosmetics, food essence, air freshener, etc., to provide unique aromatic characteristics. Such compounds also have good chemical stability, which can ensure the stability of aroma. In recent years, with the growing demand for personalized fragrance from consumers, developing new, stable and unique aroma flavor molecules has become a hot topic in the industry.

[0004] The currently reported patents mainly use cyclooctene as a raw material to synthesize cyclooctane flavor through acylation reaction. Such methods need to partially hydrogenate cyclooctadiene first, which has long steps, and produces equivalent amounts of organic acid or hydrogen halide, which has strong corrosiveness, high equipment requirements, and the disadvantages of poor yield and selectivity. Therefore, it is urgent to develop a new synthesis process of cyclooctane flavor. SUMMARY

[0005] The purpose of the present application is to overcome the deficiencies in the prior art and provide a process for synthesizing cyclooctane flavor with high selectivity.

[0006] To achieve the above-mentioned purpose of the application, the present application provides the following technical solutions:

[0007] A synthesis process of cyclooctane flavor, comprising the following steps: using cyclooctadiene (Formula I) and alkyl aldehyde (Formula II) as raw materials, under the action of a catalyst and an organic amine additive, an addition reaction is carried out to synthesize cyclooctane flavor (Formula III).

[0008] The reaction route is as follows:

[0009]

[0010] R is an alkyl group, preferably an alkyl group having a carbon number of 1-5, such as methyl, ethyl, propyl, isopropyl, and the like.

[0011] In the present application, the catalyst comprises a metal Ni monomer and a double nitrogen ligand. The metal Ni monomer comprises one or more of nickel chloride, nickel bromide, nickel acetate, bis(1,5-cyclooctadiene)nickel, and nickel methyl chloride dimer, and the amount of the metal Ni monomer is 0.01-0.5 mol% of cyclooctadiene, preferably 0.03-0.1 mol%.

[0012] The double nitrogen ligand comprises one or more of the following substances shown in the structural formulae L1-L5, and the amount of the double nitrogen ligand is 0.8-1.5 eq. of the molar amount of the metal Ni monomer, preferably 1.0-1.1 eq.

[0013]

[0014] In the formulae L1-L5, Me is a methyl group, t Bu is a tert-butyl group.

[0015] In the present application, the organic amine additive is one or more of methylamine, ethylamine, isopropylamine, diisopropylamine, triethylamine, aniline, cyclohexylamine, DBU, and ethylenediamine, and the amount of the organic amine additive is 0.01-0.5 wt.% of the amount of cyclooctadiene, preferably 0.05-0.35 wt.%.

[0016] In the present application, the temperature of the addition reaction is 60-150°C, preferably 80-120°C, and the pressure is normal pressure.

[0017] In the present application, the solvent used in the addition reaction is one or more of hexane, pentane, heptane, octane, cyclohexane, toluene, xylene, trichloromethane (chloroform), 1,2-dichloroethane, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, ethylene glycol, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, diethyl ether, and tetrahydrofuran, and the amount of the solvent is 0.2-4.0 times, preferably 0.3-1 times, the mass of cyclooctadiene.

[0018] Preferably, the catalyst is a complex of a metal Ni monomer and a double nitrogen ligand, and specifically, in the synthesis process of cyclooctane spices, the metal Ni monomer and the double nitrogen ligand are first subjected to a one-step complexation reaction, and then cyclooctadiene and an alkyl aldehyde, an organic amine additive are added to perform an addition reaction to obtain cyclooctane spices.

[0019] Specifically, the complexation reaction is carried out at room temperature, and the complexation reaction process is preferably accompanied by stirring, and the reaction duration is 5-50 min, preferably 10-30 min, and then the raw materials for preparing cyclooctane spices are added.

[0020] The cyclooctane spice obtained by the synthetic process has local fragrance, natural fragrance, floral fragrance, green fragrance and woody fragrance, and can be applied to high-end perfume and fragrance fields.

[0021] Compared with the prior art, the application has the beneficial effects that the use of bromide or alkali metal Mg is avoided, the corrosion is greatly reduced, the equipment requirement is reduced, the selectivity (>80%) and the yield are greatly improved compared with the 30% yield in the prior art, and the safety and economy of the process are obviously improved. DETAILED DESCRIPTION

[0022] In order to further illustrate the application, several specific implementation examples are given below, but the application is not limited to these examples.

[0023] Detection method and instrument:

[0024] (1) GC detection: Agilent 8890, chromatographic column: HP-INNOWAX (stationary phase polyethylene glycol, specification 30 m x 0.25 mm x 0.25 μm);

[0025] Temperature program: initial temperature 50℃, temperature rise to 80℃ at 5℃ / min, hold for 2min, then temperature rise to 240℃ at 15℃ / min, hold for 15min; injection port temperature: 230℃; FID detector temperature: 250℃; split injection, split ratio 30:1; injection volume: 1.0 μL; carrier gas flow rate (nitrogen): 1 mL / min; hydrogen flow rate: 30 mL / min; air flow rate: 400 mL / min; tail gas flow rate: 25 mL / min.

[0026] (2) Nuclear magnetic resonance analysis: Bruker 400MHz liquid nuclear magnetic resonance instrument, test temperature is 25℃.

[0027] Example 1

[0028] In a glove box, nickel chloride (0.06g) and ligand L1 (0.12g), toluene (34g) were added to a 1L reaction kettle, and the complex was stirred at room temperature (25℃) for 15min, then 1,5-cyclooctadiene (108.20g), acetaldehyde (48.43g), triethylamine (0.32g) were added to the reaction kettle, and the stirring was started, and the temperature was raised to 80℃, and the stirring was continued for about 3h. The reaction liquid was analyzed by GC detection through the sampling of the bottom tube inserted into the reaction kettle, and the raw material cyclooctadiene was completely converted, and the reaction was stopped, and then the solvent was removed to obtain acetylcyclooctene, and the selectivity of the reaction was 85.0%. The pure acetylcyclooctene 135.46g was obtained by column chromatography separation, and the mobile phase was petroleum ether / ethyl acetate (volume ratio 30:1), and the purity was 95.0%.

[0029] The structure of acetylcyclooctene (III-1) is as follows:

[0030]

[0031] NMR data of acetylcyclooctene (III-1):

[0032] 1 HNMR (400 MHz, CDC13): δ 5.65 (dt, J = 6.5, 10.8 Hz, 1H), 5.48 (dt, J = 6.5, 10.8 Hz, 1H), 2.45-2.52 (m, 1H), 2.35-2.43 (m, 2H), 2.16-2.30 (m, 2H), 2.12 (s, 3H), 2.05-2.16 (m, 1H), 1.40-1.85 (m, 6H). 13 CNMR (100 MHz, CDC13): δ 212.2, 130.5, 129.7, 51.6, 30.5, 28.2, 28.0, 27.9, 25.8, 24.2.

[0033] Example 2

[0034] In a glove box, nickel chloride (0.10 g) and ligand L2 (0.2 g), tetrahydrofuran (40 g) were added into a 1 L reaction kettle, and the complex was stirred for 10 min at room temperature (25 °C), then 1,5-cyclooctadiene (108.20 g), acetaldehyde (49.20 g), isopropylamine (0.40 g) were added into the reaction kettle, and the reaction was stirred at 120 °C for about 2 h. The reaction solution was sampled through the bottom tube of the reaction kettle, and analyzed by GC. The raw material cyclooctadiene was completely converted, and the reaction was stopped. Then the solvent was removed to obtain acetylcyclooctene, and the selectivity of the reaction was 76.0%. The pure acetylcyclooctene was separated by column chromatography, and the mobile phase was petroleum ether / ethyl acetate (volume ratio 30:1) to obtain 121.65 g of pure acetylcyclooctene with a purity of 95.0%.

[0035] Example 3

[0036] In a glove box, nickel acetate (0.08 g) and ligand L4 (0.09 g), butyl acetate (100 g) were added into a 1 L reaction kettle, the complex was stirred at room temperature (25 °C) for 30 min, then 1,5-cyclooctadiene (108.20 g), acetaldehyde (47.63 g), ethylenediamine (0.20 g) were added into the reaction kettle, the stirring was started, the temperature was increased to 100 °C, the reaction was continued for about 3 h. The reaction was stopped by sampling through the bottom tube of the reaction kettle, the reaction liquid was analyzed by GC, the raw material cyclooctadiene was completely converted, then the solvent was removed to obtain acetylcyclooctene, the selectivity of the reaction was 84.0%. The pure product acetylcyclooctene 133.86 g was obtained by column chromatography separation, the mobile phase was petroleum ether / ethyl acetate (volume ratio 30:1), the purity was 95.0%.

Claims

1. A process for the synthesis of a cyclic octane fragrance, characterized in that: The synthesis process comprises the following steps: adding a catalyst and an organic amine additive into a reaction kettle, and then adding cyclooctadiene and an alkyl aldehyde into the reaction kettle to carry out an addition reaction.

2. The synthesis process of claim 1, wherein: The catalyst comprises a metal nickel monomer and a double nitrogen ligand; preferably, the metal nickel monomer comprises one or more of nickel chloride, nickel bromide, nickel acetate, bis(1,5-cyclooctadiene)nickel, and nickel methyl chloride dimer, and more preferably, the amount of the metal nickel monomer is 0.01-0.5 mol% of the molar amount of cyclooctene, and preferably 0.03-0.1 mol%.

3. The synthesis process of claim 2, wherein: The double nitrogen ligand comprises one or more of the substances shown in the structural formulae L1-L5, and preferably, the amount of the double nitrogen ligand is 0.8 eq.-1.5 eq. of the molar amount of the metal nickel monomer, and more preferably 1.0 eq.-1.1 eq.

4. The synthesis process of claim 1, wherein: The organic amine additive is one or more of methylamine, ethylamine, isopropylamine, diisopropylamine, triethylamine, aniline, cyclohexylamine, DBU, and ethylenediamine, and the amount of the organic amine additive is 0.01-0.5 wt% of the amount of cyclooctene, and preferably 0.05-0.35 wt%.

5. The synthesis process of claim 1, wherein: The alkyl aldehyde has the structure shown in formula II, wherein R is an alkyl group, preferably an alkyl group having a carbon number of 1-5, and more preferably one or more of methyl, ethyl, propyl, and isopropyl.

6. The synthesis process according to any one of claims 1 to 5, characterized in that: The metal nickel precursor and the double nitrogen ligand are first subjected to a complexation reaction, and then cyclooctadiene and the alkyl aldehyde and the organic amine additive are added to carry out an addition reaction to obtain the cyclooctane spice.

7. The synthesis process of claim 6, wherein: The temperature of the addition reaction is 60-150°C, and preferably 90-120°C.

8. The synthesis process of claim 6, wherein: The addition reaction is carried out in a solvent, and the solvent is one or more of hexane, pentane, heptane, octane, cyclohexane, toluene, xylene, chloroform, 1,2-dichloroethane, methanol, ethanol, isopropanol, n-butanol, ethylene glycol, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, diethyl ether, and tetrahydrofuran, and the amount of the solvent is 0.2-4.0 times the mass of cyclooctene, and preferably 0.3-1 times.

9. The cyclooctane spice synthesized by the synthesis process according to any one of claims 1-8 is applied in the field of high-end perfumes and fragrances.

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