A dicarboxylic acid diDDMP ester compound, preparation method and application thereof

Abstract

The invention discloses a dicarboxylic acid diDDMP ester compound, a preparation method and an application thereof. In the present application, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) and diisopropyl dicarboxylate are used as raw materials to prepare four dicarboxylic acid diDDMP esters. The structural formula of the dicarboxylic acid diDDMP ester compound is as follows: The compound has good storage stability and flavoring stability. When added to cigarettes, it can not only increase the sweetness in the mouth, but also neutralize the alkaline substances in the smoke, soften the smoke, and improve the smoke permeability and fineness, and has potential application value.

Description

Technical Field

[0001] The invention relates to the technical field of tobacco flavor synthesis, and in particular to a dicarboxylic acid diDDMP ester compound, a preparation method and application thereof. Background Art

[0002] Ester compounds are common flavor substances in tobacco, with a sweet or fruity aroma, which can be coordinated with the aroma of tobacco, enrich the aroma of tobacco, enhance the aroma quality, and improve the aftertaste of cigarettes. Ester compounds are also an excellent latent aroma substance. They undergo thermal cracking reactions at high temperatures to release carboxylic acid, alcohol or phenolic aroma substances, adjust the pH of smoke, make the smoke taste mellow, and increase the smoke concentration and aroma volume to improve the quality of cigarettes. 2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) has a prominent sweet taste in taste, which can significantly improve the sweetness of cigarette smoke and highlight the "sweet" and "smooth" taste characteristics of cigarettes. Non-volatile acids can also adjust the pH of tobacco, improve the quality of smoking, make the taste mellow, increase the smoke concentration, improve the mellowness of smoke, and play an acid-base balance role in the smoke. Therefore, chemical synthesis methods can be used to design and synthesize ester compounds that have both advantages and add them to cigarettes as tobacco flavors.

[0003] The traditional method for synthesizing dicarboxylic acid esters mainly uses strong acids such as concentrated sulfuric acid as catalysts. This method has disadvantages such as long reaction time, many by-products, and serious environmental pollution. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a dicarboxylic acid diDDMP ester compound, a preparation method and an application thereof, which activates a hydroxyl functional group substrate through a synergistic catalytic strategy of ruthenium metal and a boron compound, thereby improving the chemical conversion rate and having the advantages of high reaction yield and easy operation.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] A dicarboxylic acid diDDMP ester compound, the structural formula of the dicarboxylic acid diDDMP ester compound is as follows:

[0007]

[0008] Preferably, the structural formula of the dicarboxylic acid diDDMP ester compound is as follows:

[0009]

[0010] A method for preparing a dicarboxylic acid diDDMP ester compound comprises the following steps:

[0011] (1) In a reaction flask, add the raw material 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP), isopropyl dicarboxylate, a catalyst and a solvent in sequence, and heat to 80-120° C. to react for 24-48 hours;

[0012] (2) After the reaction is completed, the reaction solution is washed with a saturated sodium carbonate solution, the organic phase is separated and dried over anhydrous sodium sulfate, the organic solvent is evaporated under reduced pressure, and the crude product is separated by silica gel column chromatography to obtain dicarboxylic acid diDDMP ester;

[0013] The reaction formula is as follows:

[0014]

[0015] Preferably, in step (1), the molar ratio of DDMP to isopropyl dicarboxylate is (2-4):1.

[0016] Preferably, in step (1), the catalyst is a mixture of ruthenium trichloride and boron tribromide, wherein the molar ratio of ruthenium trichloride to boron tribromide is 1:(1-3), and the molar ratio of the catalyst to the raw material DDMP is (0.01-0.20):1.

[0017] Preferably, in step (1), the solvent is a mixture of hexafluorobenzene, trifluorotoluene or 1,3,5-tris(trifluoromethyl)benzene or more.

[0018] The invention discloses an application of a dicarboxylic acid diDDMP ester compound in cigarettes.

[0019] Preferably, the total amount of the dicarboxylic acid diDDMP ester compound added to the cigarette is 10 to 100 ppm based on the weight of the tobacco.

[0020] The above technical solution of the present invention has the following beneficial effects:

[0021] The present application uses 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) and diisopropyl dicarboxylate as raw materials to prepare four dicarboxylic acid diDDMP esters. This type of compound has good storage stability and flavoring stability. When added to cigarettes, it can not only increase the sweetness in the mouth, but also neutralize the alkaline substances in the smoke, soften the smoke, and improve the smoke permeability and fineness, and has potential application value. DETAILED DESCRIPTION

[0022] Various exemplary embodiments of the present invention will now be described in detail. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0023] Example 1

[0024] A method for preparing a dicarboxylic acid diDDMP ester compound comprises the following steps:

[0025] (1) In a reaction flask, add the raw materials 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (2.88 g, 20 mmol), diisopropyl succinate (1.01 g, 5 mmol), ruthenium trichloride (0.10 g, 0.5 mmol), boron tribromide (0.25 g, 1 mmol) and hexafluorobenzene (25 mL) in sequence, and heat to 80°C for 36 h;

[0026] (2) After the reaction was completed, the reaction solution was washed with a saturated sodium carbonate solution, the organic phase was separated and dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the crude product was separated by silica gel column chromatography to obtain 1.24 g of di-DDMP succinate with a yield of 67.0%.

[0027] Example 2

[0028] A method for preparing a dicarboxylic acid diDDMP ester compound comprises the following steps:

[0029] (1) In a reaction flask, add the raw materials 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (2.88 g, 20 mmol), diisopropyl glutarate (1.73 g, 8 mmol), ruthenium trichloride (0.20 g, 1 mmol), boron tribromide (0.25 g, 1 mmol) and trifluorotoluene (25 mL) in sequence, and heat to 100°C for 48 h;

[0030] (2) After the reaction was completed, the reaction solution was washed with a saturated sodium carbonate solution, the organic phase was separated and dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the crude product was separated by silica gel column chromatography to obtain 1.94 g of diDDMP glutarate with a yield of 63.2%.

[0031] Example 3

[0032] A method for preparing a dicarboxylic acid diDDMP ester compound comprises the following steps:

[0033] (1) In a reaction flask, add the raw materials 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (2.88 g, 20 mmol), diisopropyl adipate (1.84 g, 8 mmol), ruthenium trichloride (0.20 g, 1 mmol), boron tribromide (0.25 g, 1 mmol) and hexafluorobenzene (25 mL) in sequence, and heat to 90°C for 48 h;

[0034] (2) After the reaction was completed, the reaction solution was washed with a saturated sodium carbonate solution, the organic phase was separated and dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the crude product was separated by silica gel column chromatography to obtain 2.07 g of diDDMP adipate with a yield of 65.0%.

[0035] Example 4

[0036] A method for preparing a dicarboxylic acid diDDMP ester compound comprises the following steps:

[0037] (1) In a reaction flask, add the raw materials 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (2.88 g, 20 mmol), diisopropyl heptane (1.88 g, 10 mmol), ruthenium trichloride (0.20 g, 1 mmol), boron tribromide (0.25 g, 1 mmol) and 1,3,5-tris(trifluoromethyl)benzene (25 mL) in sequence, and heat to 120°C for 24 h.

[0038] (2) After the reaction was completed, the reaction solution was washed with a saturated sodium carbonate solution, the organic phase was separated and dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the crude product was separated by silica gel column chromatography to obtain 2.55 g of di-DDMP pimelate with a yield of 62.0%.

[0039] Compound structure characterization:

[0040] (1) Di-DDMP succinate: 1 H NMR (600MHz, CDCl3) δ4.52 (dd, J = 10.5, 6.0 Hz, 2H), 4.43 (dd, J = 12.1, 6.0 Hz, 2H), 4.05 (dd, J = 12.1, 10.5 Hz, 2H), 2.60 (t, J = 7.1 Hz, 4H), 2.16 (s, 6H). 13 C NMR (150MHz, CDCl3) δ190.2,171.5,162.1,111.6,83.4,67.2,29.4,15.5.

[0041] (2) DiDDMP glutarate: 1 H NMR (600MHz, CDCl3) δ4.50(dd,J=10.4,6.0Hz,2H),4.44(dd,J=12.1,6.0Hz,2H),4.04(dd,J=12.1,10.4Hz,2H),2.60(m,4H),2.18(s,6H),2.02(m,2H). 13C NMR (150MHz, CDCl3) δ190.2,171.4,162.1,111.5,83.4,67.2,33.4,20.4,15.4.

[0042] (3) DiDDMP adipate: 1 H NMR (600MHz, CDCl3) δ4.50(dd,J=10.5,6.0Hz,2H),4.43(dd,J=12.1,6.0Hz,2H),4.05(dd,J=12.1,10.5Hz,2H),2.30(m,4H),2.18(s,6H),1.59(m,4H). 13 C NMR (150MHz, CDCl3) δ190.1,171.5,162.1,111.6,83.4,67.2,26.4,24.3,15.5.

[0043] (4) Di-DDMP Pimelate: 1 H NMR (600MHz, CDCl3) δ4.52 (dd, J=10.5, 6.0Hz, 2H), 4.43 (dd, J=12.1, 6.0Hz, 2H), 4 .05(dd,J=12.1,10.5Hz,2H),2.35(m,4H),2.16(s,6H),1.55(m,4H),1.30(m,2H). 13 C NMR (150MHz, CDCl3) δ190.1,171.5,162.1,111.6,83.4,67.2,28.4,26.7,24.7,15.5.

[0044] Application Example 1

[0045] A certain amount of DDMP diesters I to IV prepared in the above Examples 1 to 4 were weighed respectively, and diluted with ethanol to form a 5% solution for later use.

[0046] Weigh 100 g of blank cigarette tobacco without flavoring or adding materials, spread it evenly on a clean tray, spray compounds I to IV evenly on the tobacco, respectively, to prepare cigarettes with a ratio of compounds I to IV to tobacco of 10 ppm, 50 ppm and 100 ppm, respectively, seal and place for 4 h, dry in a 50°C oven, humidify with distilled water to the standard moisture content (12%), roll into standard cigarettes, balance the moisture content (humidity 60% ± 2%, temperature 22 ± 1°C) for 48 h, and then evaluate the smoking.

[0047] The control sample is a blank cigarette, and the control sample is balanced under the same temperature and humidity conditions for 48 hours.

[0048] The sensory evaluation results of the spices are shown in Table 1.

[0049] Table 1: Smoking results of compounds I to IV with fragrance

[0050]

[0051]

[0052] It can be seen from Table 1 that compounds I to IV all have the effects of significantly enhancing the "sweet aftertaste" of cigarette smoke, improving and modifying the aroma of cigarettes, reducing irritation, improving the taste of smoking, and making the aftertaste clean and comfortable.

[0053] Although the present invention has been disclosed as above by the embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various choices and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is limited by the claims and their equivalents.

Claims

1. A method for preparing a dicarboxylic acid diDDMP ester compound, characterized in that: The following steps are involved: (1) In a reaction flask, raw materials 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP), isopropyl dicarboxylate, a catalyst and a solvent are added in sequence, and the temperature is raised to 80-120° C. for reaction for 24-48 hours; the catalyst is a mixture of ruthenium trichloride and boron tribromide, wherein the molar ratio of ruthenium trichloride to boron tribromide is 1:(1-3); the solvent is a mixture of hexafluorobenzene, trifluorotoluene or 1,3,5-tris(trifluoromethyl)benzene; (2) After the reaction is completed, the reaction solution is washed with a saturated sodium carbonate solution, the organic phase is separated and dried over anhydrous sodium sulfate, the organic solvent is evaporated under reduced pressure, and the crude product is separated by silica gel column chromatography to obtain dicarboxylic acid diDDMP ester; The reaction formula is as follows:

2. The method for preparing dicarboxylic acid diDDMP ester compounds according to claim 1, characterized in that: In step (1), the molar ratio of DDMP to isopropyl dicarboxylate is (2-4):

1.

3. The method for preparing dicarboxylic acid diDDMP ester compounds according to claim 1, characterized in that: In step (1), the molar ratio of the catalyst to the raw material DDMP is (0.01-0.20):1.

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