Synthesis of watermelon ketone

A synthesis method and watermelon ketone technology are applied in the synthesis field of fragrance compounds, can solve the problems of harsh reaction conditions, low reaction yield, lack of general application prospects, etc., and achieve the effects of convenient operation, mild reaction conditions and high product yield.

Inactive Publication Date: 2009-05-13
HUAIAN WAN BANG SPICE IND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The disadvantage of this synthetic route is that the Dickmann condensation requires the use of a strong base NaH as a reagent, the reaction conditions are harsh, the reaction yield is low, and it is difficult to industrialize production, so this synth

Method used

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Add 2000ml methanol to a 5000ml four-necked round bottom flask equipped with a thermometer, a reflux condenser and a stirrer, protect it under nitrogen, add 400g triethylamine, 40g potassium iodide, 300g4-methylcatechol, 10gPEG-400 in turn, and heat To 65°C, slowly add a mixed solution of 300g of 3-dichloroacetone and 350ml of methanol dropwise, and continue to insulate and reflux for 5 hours after the drop; during the reaction process, take samples for GC analysis, cool, and filter with suction to obtain the crude product, and the filtrate removes methanol at 80°C Add 600ml of ethyl acetate to the crude product, wash with saturated brine until neutral, and recover ethyl acetate; Distill under reduced pressure, collect 270 grams of watermelon ketone fraction, and use 500 grams of 1:2 methanol and n-hexane mixed solvent for secondary crystallization of the fraction , to obtain 195 grams of white crystalline watermelon ketone, with a content of 98.9%, and a yield of 45.3%....

Embodiment 2

[0020] Add 2200ml of methanol into a 5000ml four-necked round bottom flask equipped with a thermometer, reflux condenser, and stirrer, protect it with nitrogen, add 500g of pyridine, 50g of potassium iodide, 350g of 4-methylcatechol, and 17.5g of PEG-400 in sequence, and heat to 68°C, slowly add dropwise a mixed solution of 350g of 3-dichloroacetone and 450ml of methanol, and continue to insulate and reflux for 5.5 hours after the drop; during the reaction process, take samples for GC analysis, cool, and suction filter to obtain the crude product, and the filtrate is removed below 80°C Remove methanol; add 500ml ethyl acetate to the crude product, wash with saturated brine until neutral, and recover ethyl acetate; distill under reduced pressure, collect 290 grams of watermelon ketone fraction, and use 650 grams of 1:2 methanol:n-hexane mixed solvent for the fraction Secondary crystallization gave 216 grams of white crystalline watermelon ketone product with a content of 98.9% a...

Embodiment 3

[0022] Add 2000ml methanol to a 5000ml four-necked round-bottomed flask equipped with a thermometer, a reflux condenser, and an agitator. Under nitrogen protection, add 425g triethylamine, 45g potassium iodide, 300g4-methylcatechol, and 12.5gPEG-400 in sequence. Heat to 70°C, slowly add a mixed solution of 300g of 3-dichloroacetone and 350ml of methanol dropwise, and continue to insulate and reflux for 6 hours after the drop; during the reaction, take samples for GC analysis, cool, and filter with suction to obtain the crude product, and the filtrate is removed at 80°C Methanol; add 600ml of ethyl acetate to the crude product, wash with saturated saline until neutral, and recover ethyl acetate; distill under reduced pressure, collect 270 grams of watermelon ketone fraction, and use 500 grams of 1:2 methanol and n-hexane mixed solvent for the second fraction Crystallized to obtain 208 grams of white crystalline watermelon ketone, with a content of 99.1%, and a yield of 46.2%.

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Abstract

The invention discloses a method for synthesizing watermelon ketone. Under the protection of nitrogen, inorganic or organic base, PEG-400, potassium iodide, methanol, and 4-methyl pyrocatechol are added into a reactor and are heated to be between 65 and 70 DEG C, then 1,3-dichloroacetone is dripped into the mixture, and the mixture is subjected to reflux reaction under thermal insulation for 5 to 6 hours after the dripping is finished; a crude product is obtained through cooling and suction filtration, and the methanol is recovered; ethyl acetate is added into the crude product, a saturated saline solution is used to scrub to be neutral, and the ethyl acetate is recovered; and the reduced pressure distillation is performed, and a distillate is recrystallized by a mixed solvent of the methanol and n-hexane to obtain a white crystalline solid, namely the watermelon ketone, wherein the mass ratio of the 4-methyl pyrocatechol to the 1,3-dichloroacetone is 1 to 1, the mass ratio of the inorganic or organic base to the 4-methyl pyrocatechol is between 1 to 0.7 and 0.75, the mass ratio of the potassium iodide to the 4-methyl pyrocatechol is between 1 to 7.0 and 7.5, the mass ratio of the PEG-400 to the 4-methyl pyrocatechol is between 1 to 20 and 30, and the mass ratio of the methanol to the n-hexane in the mixed solvent is 1 to 2. The method adopts a one-pot method to synthesize a target product, and has the advantages of mild reaction conditions, convenient operation, and high product yield.

Description

technical field [0001] The present invention relates to a kind of synthesis method of fragrance compound, specifically a kind of synthesis method of watermelon ketone. Background technique [0002] Watermelon ketone, foreign trade name is Calone / Watermelon ketone, chemical name is 7-methyl-3,4-dihydro(2H)-1,5-benzodioxepen-3-one. [0003] In recent years, watermelon ketone has been widely used in the daily chemical products and cosmetics market. Because watermelon ketone itself has a fresh, fruit-like, soft and sweet smell, it also contains marine and algae, which gives people a dreamlike feeling. It can bring a new concept to the formulation of perfume, so it has become the first choice of many perfume experts at home and abroad. At present, there are only a few companies in the world producing watermelon ketone. my country’s demand for watermelon ketone mainly depends on imports. There are few reports on the synthesis method of watermelon ketone. In US Patent US3517031, 4...

Claims

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Application Information

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IPC IPC(8): C07D321/10
Inventor 林祥陈兆刚陈文昌许竹青
Owner HUAIAN WAN BANG SPICE IND CO LTD
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