Preparation method of methyl jasmonate and application thereof in fertilizer

Abstract

The present application relates to a kind of methyl jasmonate preparation method, with (E)-4-oxo decan-7-enal as raw material, in the presence of ionic liquid, by cyclization reaction, addition reaction, deacidification reaction, methyl jasmonate is prepared, reaction process does not need complex post-processing.The preparation method of the present application has simple process steps, ionic liquid can simultaneously catalyze the above-mentioned reaction, improve reaction yield and product purity, reduce the reaction time, and the reaction condition is mild, only room temperature can be reacted, more suitable for industrialization.In addition, the methyl jasmonate prepared by the method of the present application has high purity, can be directly used as fertilizer additive, without further purification treatment.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis, specifically to a method for preparing methyl jasmonate and its application in fertilizers. Background Technology

[0002] Methyl jasmonate (MeJA), as an important plant signaling molecule and biostimulant, possesses various potential applications and synergistic effects. Methyl jasmonate can enhance plant stress resistance; it can act as an "early warning" for plants, activating their defense systems (such as producing antioxidant enzymes, osmotic regulators, and secondary metabolites), enabling them to better survive and maintain growth when faced with abiotic and biotic stresses such as drought, salinity, high temperature, low temperature, heavy metal pollution, and pests and diseases. Furthermore, by improving plant survival rates and health under stress, methyl jasmonate can indirectly help plants utilize nutrients in the soil and fertilizers more effectively, thereby maintaining or even increasing yields under adverse conditions. Under normal conditions, moderate concentrations of MeJA can sometimes positively impact the growth of specific crops by regulating the expression of growth-related genes (but high concentrations may inhibit growth). Some studies have shown that MeJA treatment can affect root development (such as increasing lateral roots) or regulate the expression of nutrient transport proteins, thereby improving the plant's ability to absorb major nutrients such as nitrogen, phosphorus, and potassium. Therefore, methyl jasmonate can be added to fertilizer formulations designed for specific stresses (such as drought-resistant or salt-tolerant fertilizers) or to improve quality (such as fertilizers specifically for high-quality fruits). It can also be used in conjunction with conventional fertilizers (such as during foliar spraying or root irrigation) during anticipated stresses (such as drought forecasts) or critical periods of quality formation to enhance fertilizer effectiveness under adverse conditions or to specifically improve quality. Methyl jasmonate is commonly used as an additive for foliar spraying (most frequently), root irrigation (drip irrigation, root drenching), or seed treatment. It can also be combined with solid fertilizers as a slow-release formulation or coating component.

[0003] Therefore, integrating methyl jasmonate as a fertilizer synergist, stress-resistance additive, or quality improver into fertilizer products or using it in combination with other fertilizers is its most promising application direction in the fertilizer field. This will help achieve the modern agricultural goals of "reducing application while increasing efficiency," enhancing crop stress resistance, and improving the quality of agricultural products. Although large-scale commercial application is still under development, its potential in precision agriculture and green agriculture is enormous.

[0004] To date, the methods for synthesizing methyl jasmonate both domestically and internationally include the following: I. Synthetic route of adipic acid In 1987, Hideaki Kataoka et al. reported a synthetic route for preparing methyl jasmonate from adipate ester in a total yield of 60% through six steps.

[0005]

[0006] The key step in this synthetic route is the decarbonylation reaction to form a conjugated cyclopentenone under palladium acetate catalysis.

[0007] II. Cyclopentenol Route The route starts from cyclopentenol, passes through VB 12 Methyl jasmonic acid can be prepared by catalysis and four-step reaction with an overall yield of 20%.

[0008]

[0009] III. cis-4-heptenic acid route This route starts with 4-heptenic acid and proceeds through 7 steps to produce methyl jasmonic acid, with an overall yield of 23.8%.

[0010]

[0011]

[0012] Existing methods suffer from long reaction routes, low yields, and low product purity. Therefore, developing a method for preparing methyl jasmonate with mild reaction conditions, simple steps, high yield, and easy purification has significant economic and social value. Summary of the Invention

[0013] The purpose of this invention is to provide a method for preparing methyl jasmonate, so as to solve the technical problems existing in the prior art, such as long reaction time, low yield, low purity, and lack of environmental friendliness.

[0014] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing methyl jasmonate, characterized in that the reaction formula of the preparation method is: ; The reaction steps include the following: 1) In the presence of an ionic liquid, (E)-4-oxodec-7-enal shown in Formula 1 undergoes a cyclization reaction to prepare intermediate 2; 2) Intermediate 2 is subjected to an addition reaction with dimethyl malonate, followed by a decarboxylation reaction to obtain methyl jasmonic acid; The ionic liquid is selected from .

[0015] Furthermore, the reaction temperature in step 1) is 110℃~130℃, and the reaction time is 0.5~2 hours.

[0016] Further, in step 1), the mass-to-volume ratio of (E)-4-oxodec-7-enal to the ionic liquid is 1:3~20, in g / mL, more preferably 1:5~10.

[0017] Further, in step 2), the molar ratio of dimethyl malonate to (E)-4-oxodec-7-enal in step 1) is 1.0~2.0:1, preferably 1.0~1.5:1, and most preferably 1.2:1.

[0018] Furthermore, in step 2), the addition reaction is carried out at a temperature of -5℃ to 5℃ for a reaction time of 5 to 7 hours.

[0019] Furthermore, adipic acid was added to the decarboxylation reaction in step 2).

[0020] Furthermore, the decarboxylation reaction temperature in step 2) is 180~210℃.

[0021] Furthermore, the decarboxylation reaction time in step 2) is 5 to 7 hours.

[0022] Furthermore, the preparation method of the present invention includes the following steps: 1) Add (E)-4-oxodec-7-enal and ionic liquid as shown in Formula 1 to the reactor. Heat to 110℃~130℃ and react for 0.5~2 hours. After the reaction is complete, cool the reaction solution to room temperature. It can be used directly for the next reaction without post-treatment. 2) Add 31.7g of methyl malonate to the reaction solution in step 1), stir at -5~5℃ for 5~7, then add water, heat to 50~60℃ and react for 1~3 hours, then adjust the pH to 2~4, extract three times with chloroform, combine the chloroform layers, dry with anhydrous magnesium sulfate, remove chloroform, remove excess dimethyl malonate by vacuum distillation, and proceed directly to the next reaction step with the product; Add adipic acid to the above product, heat to 180-210℃, react for 5-7 hours, cool to room temperature, add chloroform, wash with saturated sodium bicarbonate solution and saturated sodium chloride solution, dry with anhydrous magnesium sulfate, remove solvent, and then purify by column chromatography to obtain the product methyl jasmonate.

[0023] Furthermore, the present invention also provides the use of methyl jasmonate as a fertilizer additive.

[0024] Furthermore, the methyl jasmonate obtained by the method of the present invention has high purity and can be directly used as a fertilizer additive without further purification.

[0025] In recent years, the unique solvent properties of ionic liquids have led to their widespread application in synthesis and catalysis. Building upon this foundation, the inventors have conducted extensive research and discovered that, in the presence of the functionalized ionic liquid of this invention, reactions in steps 1) and 2) can be achieved under relatively mild conditions, with both high product yield and purity. The ionic liquid of this invention acts as both a solvent and a catalyst, ensuring smooth reaction progress while reducing reaction byproducts and improving product purity. Furthermore, the absence of additional solvents during the reaction process saves costs and reduces wastewater generation during post-treatment, meeting green environmental protection requirements.

[0026] The beneficial effects of this invention are as follows: 1) This invention provides a method for preparing methyl jasmonate, using (E)-4-oxodec-7-enal as raw material, and in the presence of ionic liquid, methyl jasmonate is obtained through cyclization reaction, addition reaction and deacidification reaction. The reaction process does not require complicated post-processing, which can save operating costs and labor costs, and is more suitable for industrialization.

[0027] 2) The preparation method of the present invention has simple process steps. The ionic liquid can simultaneously catalyze the above reaction, improve the reaction yield and product purity, reduce the reaction time, and the reaction conditions are mild, requiring only room temperature.

[0028] 3) The ionic liquid of the present invention is easy to separate and can be reused after simple activation. At the same time, no additional solvent needs to be added during the reaction process, which saves production costs, meets the requirements of green environmental protection, and is conducive to industrial production.

[0029] 4) The methyl jasmonate obtained by the method of the present invention has high purity and can be directly used as a fertilizer additive without further purification. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The present invention will be further explained below with reference to specific embodiments.

[0032] Example 1: Preparation of Ionic Liquids The ionic liquid was prepared according to the method described in the literature (Study on the performance of choline-based basic ionic liquid in the synthesis of sec-butanol, Chen Jie et al., Journal of Chemical Industry and Engineering, 2023, 74(9): 3716-3730). The specific steps are as follows: .

[0033] Choline chloride (1 mol, 139 g) was dissolved in methanol (500 ml), and sodium methoxide (1 mol, 54 g) was added and dissolved under vigorous stirring. The mixture was heated to 60 °C and reacted for 24 h. After cooling to room temperature, the precipitate was removed by filtration, and the filtrate was rotary evaporated to remove the solvent, finally obtaining the alkaline ionic liquid catalyst. .

[0034] Example 2

[0035] 1) Add 33.6 g (0.2 mol) of (E)-4-oxodec-7-enal (as shown in Formula 1) and 200 mL of ionic liquid to a reaction vessel equipped with a thermometer, magnetic stirrer, and condenser. After stirring thoroughly, the temperature was raised to 120°C and the reaction was allowed to proceed for 1 hour. The reaction progress was monitored by GC. Once complete, the reaction solution was cooled to room temperature. No further processing was required; it could be used directly for the next reaction.

[0036] 2) Add 31.7 g (0.24 mol) of methyl malonate to the reaction solution from step 1), stir for 6 hours in an ice bath (0-5℃), then add 50 ml of water, heat to 50℃ and react for 2 hours. Adjust the pH to approximately 3 with 10% dilute hydrochloric acid, extract three times with chloroform, combine the chloroform layers, and dry with anhydrous magnesium sulfate. After removing chloroform, remove excess dimethyl malonate by vacuum distillation, and proceed directly to the next reaction step.

[0037] Add 25 g of adipic acid to the above product, heat to 190 °C, react for 6 hours, cool to room temperature, add 250 mL of chloroform, wash three times with saturated sodium bicarbonate solution, wash three times with saturated sodium chloride solution, and dry with anhydrous magnesium sulfate. Remove the solvent, and then purify by column chromatography to obtain 39.5 g of methyl jasmonate, with a yield of 88.2% and a purity of 99.5%.

[0038] Example 3 1) Add 33.6 g (0.2 mol) of (E)-4-oxodec-7-enal (as shown in Formula 1) and 200 mL of ionic liquid to a reaction vessel equipped with a thermometer, magnetic stirrer, and condenser. After stirring thoroughly, the temperature was raised to 110°C and the reaction was allowed to proceed for 2 hours. The reaction progress was monitored by GC. Once the reaction was complete, the reaction solution was cooled to room temperature. No further processing was required; it could be used directly for the next reaction.

[0039] 2) Add 40.0 g (0.30 mol) of methyl malonate to the reaction solution from step 1), stir for 6 hours in an ice bath (0~5℃), then add 50 ml of water, heat to 50℃ and react for 2 hours. Then add 10% dilute hydrochloric acid to adjust the pH to about 3, extract three times with chloroform, combine the chloroform layers, and dry with anhydrous magnesium sulfate. After removing chloroform, remove excess dimethyl malonate by vacuum distillation, and proceed directly to the next reaction step.

[0040] Add 20 g of adipic acid to the above product, heat to 200 °C, react for 5 hours, cool to room temperature, add 250 mL of chloroform, wash three times with saturated sodium bicarbonate solution, wash three times with saturated sodium chloride solution, and dry with anhydrous magnesium sulfate. Remove the solvent, and then purify by column chromatography to obtain 38.4 g of methyl jasmonate, with a yield of 85.7% and a purity of 99.6%.

[0041] Example 4 1) Add 33.6 g (0.2 mol) of (E)-4-oxodec-7-enal (as shown in Formula 1) and 250 mL of ionic liquid to a reaction vessel equipped with a thermometer, magnetic stirrer, and condenser. After stirring thoroughly, the temperature was raised to 130°C and the reaction was allowed to proceed for 1 hour. The reaction progress was monitored by GC. Once complete, the reaction solution was cooled to room temperature. No further processing was required; it could be used directly for the next reaction.

[0042] 2) Add 31.7 g (0.24 mol) of methyl malonate to the reaction solution from step 1), stir for 6 hours in an ice bath (0-5℃), then add 50 ml of water, heat to 50℃ and react for 2 hours. Adjust the pH to approximately 3 with 10% dilute hydrochloric acid, extract three times with chloroform, combine the chloroform layers, and dry with anhydrous magnesium sulfate. After removing chloroform, remove excess dimethyl malonate by vacuum distillation, and proceed directly to the next reaction step.

[0043] Add 30 g of adipic acid to the above product, heat to 200 °C, react for 5 hours, cool to room temperature, add 250 mL of chloroform, wash three times with saturated sodium bicarbonate solution, wash three times with saturated sodium chloride solution, and dry with anhydrous magnesium sulfate. Remove the solvent, and then purify by column chromatography to obtain 37.7 g of methyl jasmonate, with a yield of 84.2% and a purity of 99.5%.

[0044] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing methyl jasmonate, characterized in that, The reaction formula for the preparation method is: ； The reaction steps include the following: 1) In the presence of an ionic liquid, (E)-4-oxodec-7-enal shown in Formula 1 undergoes a cyclization reaction to prepare intermediate 2; 2) Intermediate 2 is subjected to an addition reaction with dimethyl malonate, followed by a decarboxylation reaction to obtain methyl jasmonic acid; The ionic liquid is selected from .

2. The method for preparing methyl jasmonate according to claim 1, characterized in that: the reaction temperature in step 1) is 110℃~130℃, and the reaction time is 0.5~2 hours.

3. The method for preparing methyl jasmonate according to claim 1, characterized in that: in step 1), the mass-to-volume ratio of (E)-4-oxodec-7-enal and the ionic liquid is 1:3~20, in g / mL.

4. The method for preparing methyl jasmonate according to claim 1, characterized in that: the molar ratio of dimethyl malonate to (E)-4-oxodec-7-enal in step 2) is 1.0~2.0:

1.

5. The method for preparing methyl jasmonate according to claim 1, characterized in that: the addition reaction in step 2) is carried out at a temperature of -5℃ to 5℃, and the reaction time is 5 to 7 hours.

6. The method for preparing methyl jasmonate according to claim 1, characterized in that: Adipic acid was also added during the decarboxylation reaction in step 2).

7. The method for preparing methyl jasmonate according to claim 1, characterized in that: the decarboxylation reaction temperature in step 2) is 180~210℃, and the decarboxylation reaction time is 5~7 hours.

8. The method for preparing methyl jasmonate according to claim 1, characterized in that it comprises the following steps: 1) Add (E)-4-oxodec-7-enal and ionic liquid as shown in Formula 1 to the reactor. Heat to 110℃~130℃ and react for 0.5~2 hours. After the reaction is complete, cool the reaction solution to room temperature. It can be used directly for the next reaction without post-treatment. 2) Add 31.7g of methyl malonate to the reaction solution in step 1), stir at -5~5℃ for 5~7, then add water, heat to 50~60℃ and react for 1~3 hours, then adjust the pH to 2~4, extract three times with chloroform, combine the chloroform layers, dry with anhydrous magnesium sulfate, remove chloroform, remove excess dimethyl malonate by vacuum distillation, and proceed directly to the next reaction step with the product; Add adipic acid to the above product, heat to 180-210℃, react for 5-7 hours, cool to room temperature, add chloroform, wash with saturated sodium bicarbonate solution and saturated sodium chloride solution, dry with anhydrous magnesium sulfate, remove solvent, and then purify by column chromatography to obtain the product methyl jasmonate.

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