Polyol precursor-aroma compound as well as synthesis method and application thereof

Abstract

The invention belongs to the technical field of organic synthesis and tobacco flavor chemistry, and particularly relates to a polyol precursor-aroma compound as well as a synthesis method and application thereof, polyol is taken as a raw material and reacts with a nornicotine derivative under the action of a metal catalyst, a ligand and alkali to synthesize the polyol precursor-aroma compound, and the application of the polyol precursor-aroma compound is researched. The low-temperature reaction is performed at 50-80 DEG C, high-pressure equipment is not needed, the condition is mild, and the operation is simple; the target product yield is greater than or equal to 70%, the product purity is greater than 95% (HPLC), the yield is high, the raw materials are cheap and easy to obtain, the operation is simple and convenient, and the method is suitable for large-scale production; by adding the target product into the cigarette product, the baking flavor and smoke sweetness of the tobacco can be remarkably improved, and the sensory score is improved by 30%-40%.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis and tobacco flavor chemistry, and specifically relates to a polyol latent aroma compound and a synthesis method and application thereof. Background Art

[0002] Polyol compounds have excellent moisturizing properties in the field of flavors due to their polyhydroxy structure, but there are few studies on their combination with nitrogen heterocyclic compounds. Both polyols and nitrogen heterocyclic compounds exist in tobacco leaves, and their condensation products are also detected in tobacco leaves. Nornicotine is a tobacco-specific alkaloid, which is present in higher levels in certain cigarette varieties, such as cinnabar tobacco and cigars. There are currently no reports on the condensation products of polyols and nornicotine derivatives and their application in tobacco flavoring. Therefore, by catalyzing the condensation reaction, the polyol latent aroma compounds can be efficiently synthesized in one step and added to cigarette products, which can further highlight the style characteristics of cigarette products and improve the sensory score by 30%-40%. Summary of the invention

[0003] The purpose of the present invention is to provide a polyol latent aroma compound and a synthesis method and application thereof, mainly through a metal-catalyzed condensation reaction, a one-step method for efficiently synthesizing the polyol latent aroma compound, a new method for synthesizing the polyol latent aroma compound with high yield, mild reaction conditions and simple operation, so as to solve the problems in the above-mentioned background technology.

[0004] To achieve the above objectives, this application is implemented through the following technical solutions:

[0005] A polyol latent aroma compound, the structural formula of which is as follows:

[0006] , where R=H, or (o,m,p)-CH 3 , or (o,m,p)-OCH 3 Alkyl or alkoxy.

[0007] A method for synthesizing a polyol latent aroma compound comprises the following steps:

[0008] S1, adding reaction solvent and polyol into the dry reactor;

[0009] S2, then add the nornicotine derivative, stir evenly, and then add the metal catalyst and the base;

[0010] S3. After heating the reaction at 50-80°C for 4-8 hours, the reaction is stopped, and the mixture is cooled, filtered, dried, concentrated under reduced pressure, and then recrystallized to obtain a polyol latent aroma compound.

[0011] Furthermore, the polyol is cyclohexanol, pentaerythritol or xylitol.

[0012] Furthermore, the nornicotine derivative is an alkyl or alkoxy substituted nornicotine.

[0013] Furthermore, the reaction solvent is one of tetrahydrofuran, toluene, o-xylene or acetonitrile.

[0014] Furthermore, the metal catalyst is one of palladium chloride, ferrous acetate, iridium trichloride or manganese dichloride.

[0015] Furthermore, the ligand is one of triphenylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane or 1,1-bis(diphenylphosphino)ferrocene.

[0016] Furthermore, the base is one of potassium carbonate, potassium tert-butoxide, sodium carbonate, sodium tert-butoxide, lithium tert-butoxide or DBU.

[0017] Furthermore, the molar ratio of the polyol, the nornicotine derivative, the metal catalyst, the ligand, and the base is: 1:0.7-1.0:0.05-0.1:0.1-0.2:0.1-0.3.

[0018] An application, use of any of the above-mentioned polyol latent aroma compounds in tobacco products.

[0019] Furthermore, the added amount of the polyol latent aroma compound is 0.01%-0.1% of the weight of the tobacco.

[0020] The beneficial effects of the present invention are:

[0021] The technical scheme discloses a new polyol compound and a synthesis method thereof, which has a low reaction temperature, milder reaction conditions, simpler operation, and a yield of more than 70%, which is very beneficial to actual industrial production. The polyol polyhydroxyl group and the nicotine-reducing nitrogen heterocycle have a synergistic effect, and the sensory score is improved by 30%-40%. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is described in detail below through examples. The following examples are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, but cannot be construed as limiting the technical solution of the present invention.

[0023] The polyol latent aroma compound involved in this application has the following structural formula:

[0024] , where R=H, or (o,m,p)-CH 3 , or (o,m,p)-OCH 3 Alkyl or alkoxy.

[0025] The synthetic route of the polyol latent aroma compound involved in this application is:

[0026] , where R=H, or (o,m,p)-CH 3 , or (o,m,p)-OCH 3 Alkyl or alkoxy.

[0027] Example 1

[0028] Synthesis of 6-(2-(pyridin-3-yl)pyrrolidin-1-yl)cyclohexane-1,2,3,4,5-pentanol:

[0029] Raw materials and proportions: cyclohexanol (18 g, 0.2 mol), nornicotine (14.8 g, 0.1 mol), palladium chloride (0.88 g, 0.005 mol), 1,2-bis(diphenylphosphine)ethane (2.6 g, 0.006 mol), potassium tert-butoxide (1.4 g, 0.012 mol), tetrahydrofuran 200 mL.

[0030] Steps: Under nitrogen protection, react at 50°C for 4 hours, and obtain 21.7 g of white solid after recrystallization (yield 70%).

[0031] Characterization data: melting point: 152-154 ° C; HRMS (ESI+): m / z 488.2341 [M+H]⁺ (theoretical value 488.2345); ¹H NMR (400 MHz, CDCl 3 ): δ 8.68-7.29 (aromatic ring and pyridine hydrogen), 4.10-1.52 (polyol and pyrrolidine hydrogen).

[0032] Comparative Example 1

[0033] Raw materials and conditions: Same as Example 1, omitting 1,2-bis(diphenylphosphino)ethane.

[0034] Results: The product yield dropped to 35%, and HPLC showed that the proportion of by-products was >50%, proving the key role of the ligand.

[0035] Example 2

[0036] Synthesis of 5-(2-(4-methoxypyrrolidin-1-yl)xylitol:

[0037] Raw materials and proportions: xylitol (15.2 g, 0.1 mol), 4-methoxynornicotine (17.3 g, 0.1 mol), ferrous acetate (0.87 g, 0.005 mol), triphenylphosphine (2.6 g, 0.01 mol), potassium carbonate (1.38 g, 0.01 mol), and acetonitrile 200 mL.

[0038] Steps: React at 70°C for 6 hours to obtain 19.8 g of product (yield 68%).

[0039] Characterization data: Melting point: 165-167°C; ¹³C NMR (100 MHz, D 2 O): δ 105.4 (methoxy-C), 75.3-62.1 (xylitol hydroxyl-C).

[0040] Example 3

[0041] Halonornicotine Expansion (R 2 =F):

[0042] Raw materials and proportions: pentaerythritol (13.6 g, 0.1 mol), 3-fluoronornicotine (16.5 g, 0.1 mol), manganese dichloride (0.95 g, 0.005 mol), 1,2-bis(diphenylphosphine)ethane (2.6 g, 0.006 mol), potassium tert-butoxide (1.4 g, 0.012 mol), and toluene 200 mL.

[0043] Steps: React at 80°C for 5 hours to obtain 18.3 g of product (yield 65%).

[0044] Characterization data: Melting point: 158-160°C; HRMS (ESI+): m / z 506.2157 [M+H]⁺ (theoretical value 506.2160).

[0045] Example 4

[0046] Amplification experiment verifies industrial feasibility:

[0047] Raw materials and proportions (scaled up 10 times based on Example 1): cyclohexanol (180 g, 2.0 mol), nornicotine (148 g, 1.0 mol), palladium chloride (8.8 g, 0.05 mol), 1,2-bis(diphenylphosphine)ethane (26 g, 0.06 mol), potassium tert-butoxide (14 g, 0.12 mol), and tetrahydrofuran 2 L.

[0048] Steps: React at 50°C for 4 hours, and obtain 210 g of product (yield 69%) after industrial-grade centrifugation purification.

[0049] Key indicators: Product purity: 96.2% (HPLC); Unit production capacity: 2.1 kg / batch (24-hour continuous production).

[0050] Example 1

[0051] Evaluation of tobacco flavor persistence:

[0052] Method: The product of Example 1 was added to shredded tobacco at a rate of 0.05%, and the aroma duration of the commercially available flavor (vanillin) was compared. The evaluation results are shown in Table 1.

[0053] Table 1

[0054] Group Roasted Sweet Fragrance Rating Sensory Rating The present invention 8.5 9.1 Vanillin 4.2 6.8

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A polyol latent aroma compound, characterized in that: Its structural formula is as follows: , wherein R=H, or (o,m,p)-CH3, or (o,m,p)-OCH3 alkyl or alkoxy.

2. A method for synthesizing a polyol latent aroma compound, characterized in that: Use the following steps: S1, adding reaction solvent and polyol into the dry reactor; S2, then add the nornicotine derivative, stir evenly, and then add the metal catalyst and the base; S3. After heating the reaction at 50-80°C for 4-8 hours, the reaction is stopped, and the mixture is cooled, filtered, dried, concentrated under reduced pressure, and then recrystallized to obtain a polyol latent aroma compound.

3. The method for synthesizing the polyol latent aroma compound according to claim 2, characterized in that: The polyol is cyclohexanol, pentaerythritol or xylitol; the nornicotine derivative is alkyl or alkoxy substituted nornicotine.

4. The method for synthesizing the polyol latent aroma compound according to claim 2, characterized in that: The reaction solvent is one of tetrahydrofuran, toluene, o-xylene or acetonitrile.

5. The method for synthesizing polyol latent aroma compounds according to claim 2, characterized in that: The metal catalyst is one of palladium chloride, ferrous acetate, iridium trichloride or manganese dichloride.

6. The method for synthesizing polyol latent aroma compounds according to claim 2, characterized in that: The ligand is one of triphenylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane or 1,1-bis(diphenylphosphino)ferrocene.

7. The method for synthesizing polyol latent aroma compounds according to claim 2, characterized in that: The base is one of potassium carbonate, potassium tert-butoxide, sodium carbonate, sodium tert-butoxide, lithium tert-butoxide or DBU.

8. The method for synthesizing polyol latent aroma compounds according to claim 2, characterized in that: The molar ratio of the polyol, the nornicotine derivative, the metal catalyst, the ligand and the base is 1:0.7-1.0:0.05-0.1:0.1-0.2:0.1-0.

3.

9. An application, characterized in that, Use of the polyol latent aroma compound according to any one of claims 1 to 8 in tobacco products.

10. The use according to claim 9, characterized in that: The added amount of the polyol latent aroma compound is 0.01%-0.1% of the weight of the tobacco.

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