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Synthesis method of watermelon ketone

A synthetic method, the technology of watermelon ketone, applied in the field of synthesis of spice compounds, can solve the problems of no actual industrialization reports, many reagents and solvents, increased production costs, etc., and achieve the effect of easy separation and purification, less impurities, and improved quality

Active Publication Date: 2021-11-16
江西开源香料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The third method: it was proposed by a Canadian chemist, using chloroacetonitrile as a starting material, using a synthetic route similar to the etherification method to synthesize watermelon ketone, the yield is general, and sodium hydride is used as a strong base reagent in the synthesis process, and No actual industrialization report
But also there is following shortcoming: 1) reaction step is too long, and four-step reaction just can obtain target product; 2) used reagent and solvent are too many, as vanadium pentoxide, pyran, hydrogen peroxide, potassium permanganate, hydrochloric acid , ether, dimethylformamide, etc.; 3) although the yield of each step is all more than 80%, the sum of the four steps is only about 52%; 4) the production cost is high, because there are many operating steps and many reagents are used, so Production costs also increase

Method used

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  • Synthesis method of watermelon ketone
  • Synthesis method of watermelon ketone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Embodiment 1: synthetic watermelon ketone precursor alcohol

[0032] The reaction vessel is a 2000mL four-necked flask with a thermometer, a mechanical stirrer, a reflux condenser and a constant pressure dropping funnel.

[0033]Under the protection of nitrogen, 500mL of dimethyl sulfoxide is added in the reaction flask, stirred, and 124.13g (1.0mol) 4-methylcatechol and 212g sodium carbonate (2.0mol) are added in the reaction flask, and the addition speed is controlled so that The reaction solution does not form a viscous solid. After the addition, raise the temperature to make the temperature of the reaction solution reach 100°C, and then dissolve 154.77g (1.2mol) of 1,3-dichloropropanol in 200mL of dimethyl sulfoxide from constant pressure Add the dropping funnel dropwise into the reaction bottle, after 6h the addition of 1,3-dichloropropanol is completed dropwise, continue to stir and react at this temperature for 4h, after the reaction is completed, cool the reacti...

Embodiment 2

[0034] Embodiment 2: take Dess-Martin reagent as oxidant synthesis watermelon ketone

[0035] The reaction vessel is a 500mL four-necked flask with a thermometer, a magnetic stirrer, a reflux condenser and a constant pressure dropping funnel.

[0036] The watermelon ketone precursor alcohol (2.376g, 13.2mmol) prepared in Example 1 was dissolved in 40mL of dry dichloromethane, and this solution was added dropwise to 80mL of dichloromethane (dissolved with 8.08g , 19.7mmol, 1.5eqv of Dess-Martin reagent), after stirring for 3.5h, 120mL of ether was added to the reaction mixture to obtain a white suspension, which was then treated with 100mL of 1N sodium hydroxide, and two phases were obtained after 15min. The organic layer was washed with 1N sodium hydroxide, brine, and pure water respectively, dried with magnesium sulfate, and diethyl ether was evaporated to obtain 2.35 g of watermelon ketone crude product with a yield close to 100%. After recrystallization, 2.14 g of watermelo...

Embodiment 3

[0038] Embodiment 3: investigate the watermelon ketone yield in different solvents with Dess-Martin reagent oxidant

[0039] The ratio of the reaction substrate to the oxidant, the reaction temperature and the post-treatment method of the reaction solution are the same as in Example 2, and the results are shown in Table 1.

[0040] Table 1 uses Dess-Martin reagent oxidizing agent again in the watermelon ketone yield in different solvents

[0041] Test No. test solvent Crystallized watermelon ketone (g) Watermelon ketone yield (purity) 1 tert-butanol 1.91g 81％(99.0％) 2 butanone 1.88g 80％(99.1％) 3 ethyl acetate 2.02g 86％(99.1％) 4 Dimethyl sulfoxide 2.12g 90％(99.1％)

[0042] As can be seen from the results in Table 1, the above-mentioned several solvent yields have reached more than 80%, and the highest yield of dimethyl sulfoxide has reached 90%. Therefore, when using the Dess-Martin reagent oxidant to synthesize watermelon In ...

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Abstract

The invention belongs to the technical field of synthesis of perfume compounds, and particularly relates to a synthesis method of watermelon ketone. The specific synthesis method comprises the following steps: at room temperature, firstly adding a solvent and periodic acid into a reaction container, uniformly stirring, then dropwise adding watermelon ketone precursor alcohol (I) dissolved by the solvent into the reaction container, stirring to react for 3-7 hours, filtering, carrying out rotary evaporation on filtrate to obtain a watermelon ketone crude product, and recrystallizing to obtain a watermelon ketone finished product (II). According to the present invention, the reaction product 3, 4-dihydro-7-methyl-2H-1, 5-benzoxazole-3-alcohol (I) of 4-methylcatechol and 1, 3-dichloropropanol is adopted as the starting material, the high-iodine reagent oxidation reaction is performed to obtain the high yield and high purity watermelon ketone (II), and the method has advantages of simple process, high product yield, high product purity, low cost and suitableness for industrial production.

Description

technical field [0001] The invention belongs to the technical field of synthesis of spice compounds, and in particular relates to a synthesis method of watermelon ketone. Background technique [0002] Watermelon ketone (chemical name: 3,4-dihydro-7-methyl-2H-1,5-benzoxazol-3-one) is a precious spice in flavors and fragrances, a substance with unique marine odor characteristics Sex, synthesized for the first time by Beereboom, Cameron and Stephens (Pfizer). In the past ten years, watermelon ketone has been widely used in daily chemicals and cosmetics. Although most foreign perfumes have gradually applied watermelon ketone, it has not been widely used in the domestic flavor and fragrance market because of its relatively expensive price. Watermelon ketone not only has a fresh, fruity, soft and sweet smell, but also has a marine, algae, and dreamy feeling. It has been favored by the majority of consumers. Provides a broad space for development. [0003] At present, there are...

Claims

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Application Information

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IPC IPC(8): C07D321/10
CPCC07D321/10
Inventor 阎圣刚廖鸿儒廖国荣曾德振
Owner 江西开源香料有限公司