Method for preparing 4-methyl-4-(2-furanmethylthio)-2-pentanone

A technology of furan methylthio and methyl groups is applied in the field of preparation of edible fragrance monomers, and can solve the problems of difficult industrialized continuous production, irritating odor of triethylamine, influence on product aroma quality, etc., so as to save the solvent recovery step, Sensory quality assurance, effect of simplified operation

Inactive Publication Date: 2009-12-23
TIANJIN CHEM REAGENT RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] 1. After the reaction is completed, the yield is about 60%, and the relatively low yield causes waste of raw materials and energy;
[0008] 2. The boiling point of the solvent ether is low, there is a risk of inflammability and explosion, and it is not easy for industrialized continuous production;
[0009] 3. The triethylamine used as a catalyst has an obvious pungent smell. If it is not handled properly, it will affect the aroma quality of the product

Method used

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  • Method for preparing 4-methyl-4-(2-furanmethylthio)-2-pentanone
  • Method for preparing 4-methyl-4-(2-furanmethylthio)-2-pentanone

Examples

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Embodiment 1

[0035] Add 9.6 grams of sodium hydroxide, 190 milliliters of water in the 500ml flask that is equipped with electric stirring, thermometer, reflux device and dropping funnel, start stirring and make sodium hydroxide dissolve, be configured into 5% sodium hydroxide aqueous solution (sodium hydroxide content is 1.2 times of theoretically calculated molar weight), then 22.8 grams of 2-furyl mercaptan (the molar ratio of 2-furyl mercaptan and mesityl oxide is 1: 1.1) was added dropwise at 10 ℃, and then at the same temperature Add 21.6 grams of mesityl oxide (1.1 times the theoretically calculated molar weight), react the feed solution at 50°C for 3.5 hours, cool the feedstock to 15°C, adjust the pH to 6 with 10% sulfuric acid, separate the organic phase, and wash twice , and the separated organic phase was dried again, and the fraction at 86°C / 40Pa was collected by distillation to obtain the product 4-methyl-4-(2-furylmethylthio)-2-pentanone with a yield of 81%.

Embodiment 2

[0037] Add 12.8 grams of sodium hydroxide, 115 milliliters of water in the 500ml flask that is equipped with electric stirring, thermometer, reflux device and dropping funnel, start stirring and make sodium hydroxide dissolve, be configured into 10% sodium hydroxide aqueous solution (sodium hydroxide The content is 1.6 times of the theoretically calculated molar weight), then 22.8 grams of 2-furyl mercaptan (the molar ratio of 2-furyl mercaptan and mesityl oxide is 1: 1.5) was added dropwise at 20 ° C, and then at the same temperature Add 29.4 grams of mesityl oxide (1.5 times the theoretically calculated molar weight), react the feed solution at 70°C for 1.5 hours, cool the feedstock to 10°C, adjust the pH to 6.5 with 5% sulfuric acid, separate the organic phase, and wash twice , and the separated organic phase was dried again, and the fraction at 86°C / 40Pa was collected by distillation to obtain the product 4-methyl-4-(2-furylmethylthio)-2-pentanone with a yield of 80.56%.

Embodiment 3

[0039] Add 15.7 grams of potassium hydroxide, 142 milliliters of water in the 500ml flask that is equipped with electric stirring, thermometer, reflux device and dropping funnel, start stirring and make potassium hydroxide dissolve, be configured into 10% potassium hydroxide aqueous solution (potassium hydroxide The content is 1.4 times of the theoretically calculated molar weight), then 22.8 grams of 2-furyl mercaptan (the molar ratio of 2-furyl mercaptan and mesityl oxide is 1: 1.3) was added dropwise at 15 ° C, and then at the same temperature Add 25.5 grams of mesityl oxide (1.3 times the theoretically calculated molar weight), react the feed solution at 60°C for 2 hours, cool the feedstock to 10°C, adjust the pH to 7 with 8% sulfuric acid, separate the organic phase, and wash twice , and the separated organic phase was dried again, and the fraction at 86° C. / 40 Pa was collected by distillation to obtain the product 4-methyl-4-(2-furylmethylthio)-2-pentanone with a yield of...

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Abstract

The invention relates to a method for preparing 4-methyl-4-(2-furanmethylthio)-2-pentanone, which comprises the steps of: (1) performing the reaction of alkaline aqueous solution and 2-furanmethanethiol at a temperature of between 10 and 20 DEG C, and then mixing the obtained product with mesityl oxide; (2) increasing the temperature of the mixture to be between 50 and 70 DEG C, and performing a reflux reaction for 1.5 to 3.5 hours; (3) cooling a reaction liquid to be between 5 and 15 DEG C after the reaction is finished, and using sulfuric acid to neutralize the reaction liquid until the pH value is between 6 and 7; and (4) separating to obtain an organic phase, and then obtaining the 4-methyl-4-(2-furanmethylthio)-2-pentanone through washing, separation, drying and distillation. The method adopts water as a reaction solvent, remarkably improves the safety of the operation of a reaction system, saves a solvent recovery step at the same time, and simplifies the operation; the yield of products is improved to 80 percent from 60 percent at the same time, which reduces the waste of raw materials; and at the same time, no other miscellaneous gas substances are introduced during the preparation, which has more reliable guarantee on the sensory quality of perfume compounds.

Description

technical field [0001] The invention relates to the preparation of a food flavor monomer, in particular to a preparation method of 4-methyl-4-(2-furylmethylthio)-2-pentanone. Background technique [0002] Furanyl aliphatic ketone sulfide fragrance compounds are important food flavor monomers, which are widely used in edible flavoring essences, and it provides the required flavor characteristics for various convenience foods. U.S. Patent No. 4,271,082 (1981) provides a preparation method for 4-methyl-4-(2-furylthio)-2-pentanone, one of the fragrance compounds, and its reaction formula is: [0003] [0004] Its preparation process is: [0005] Dissolve 0.55 mol of mesityl oxide (4-methyl-3-penten-2-one) and 0.5 g of triethylamine in ether solvent, and add 0.5 mol of 2-furyl methylsulfur dropwise at 10°C while stirring Alcohol, then the material was heated to reflux for 1 hour, then cooled, washed twice with 5% sulfuric acid, and then washed to neutrality. After the ether ...

Claims

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Application Information

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IPC IPC(8): C07D307/38
Inventor 王淑萍
Owner TIANJIN CHEM REAGENT RES INST
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