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Method for preparing dihydro safrole

A technology of dihydrosafrole and dihydroxybenzene, applied in the direction of organic chemistry, can solve the problems of low rearrangement yield, many reaction steps, high industrialization cost, etc.

Active Publication Date: 2006-10-25
中山凯中有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Wherein method (1) has the disadvantages of low single-pass reaction conversion rate and high industrialization cost, while method (2) has many reaction steps, low rearrangement yield, and is not easy for large-scale industrialization

Method used

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  • Method for preparing dihydro safrole
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  • Method for preparing dihydro safrole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] (1) In the reactor with condensing reflux, stirring and dropping and heating device, add 111.3g catechol, 500ml dichloroethane, 166g ZnCl 2 , stir, cool down to 0-5°C, slowly add 140g of propionyl chloride dropwise, drop it in about 2 hours, then raise the temperature to 20°C, continue to react for 15 hours, after the reaction is completed, add water to dilute, separate the organic phase, and carry out Pickling and washing with water, drying over sodium sulfate, precipitation, and recrystallization of the residue with ethanol to obtain 144 g of solid 3,4-dihydroxypropiophenone, melting point: 145-146°C, content: 98%, yield: 85%.

[0027] (2) 85g of solid 3,4-dihydroxypropiophenone obtained in the last step is dissolved in 300ml ethanol, and the Pd / C catalyst of 2g5% is added, then the mixture is placed in an autoclave, and under a pressure of 10atm Hydrogenation at 40-45°C, after hydrogenation for about 6 hours, the reaction is over, the mixture is filtered, the filtrat...

Embodiment 2

[0030] (1) In the reactor with condensing reflux, stirring and dropping and heating device, add 111.3g catechol, 240ml dichloroethane, 2ml70% perchloric acid, stir, cool to 10~15°C, Slowly add 144g of propionic anhydride dropwise, drop it in about 2 hours, then raise the temperature to 20°C, and continue the reaction for 15 hours. dissolved, and the residue was recrystallized from ethanol to obtain 136.5 g of solid 3,4-dihydroxypropiophenone, melting point: 145-146° C., content: 98.1%, and yield: 80.5%.

[0031] (2) 85g of solid 3,4-dihydroxypropiophenone obtained in the last step is dissolved in 900ml ethanol, and the Pd / C catalyst of 5g5% is added, then the mixture is placed in an autoclave, and under a pressure of 10atm Hydrogenation at 20-25°C, after hydrogenation for about 7 hours, the reaction is over, the mixture is filtered, the filtrate is desolvated under reduced pressure, and the residue is recrystallized with ethanol to obtain 69g of solid 4-propylcatechol, melting...

Embodiment 3

[0034] (1) In the reactor with condensing reflux, stirring and dropping and heating device, add 111.3g catechol, 240ml dichloroethane, 170g AlCl3 , stirred, cooled to 0-5°C, slowly added dropwise 280g of propionyl chloride, dripped in about 2 hours, then raised to 70°C, continued to react for 15 hours, after the reaction was completed, the post-treatment was the same as in Example 1 step (1) to obtain a solid 104g of 3,4-dihydroxypropiophenone, the content is 97%, and the yield is 61%.

[0035] (2) 85g of solid 3,4-dihydroxypropiophenone obtained in the last step is dissolved in 600ml ethanol, and the Pd / C catalyst of 2g5% is added, then the mixture is placed in an autoclave, and under a pressure of 60atm Hydrogenation at 40-45° C. After hydrogenation for about 6 hours, the reaction was completed, and the aftertreatment was the same as step (2) of Example 1 to obtain 70 g of solid 4-propylcatechol with a content of 98% and a yield of 91%.

[0036] (3) Dissolve 31 g of solid 4-...

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Abstract

This invention relates to dihydro safrole preparation method. Catechol is used as material, goal product if got through propionyltion, reducing and methylenation three steps reaction. The technique condition is mild, generating cost is low, product whole yield is high, purity is high, so it is good preparation method that has wide industrial prospect.

Description

technical field [0001] The invention relates to a preparation method of dihydrosafrole. Background technique [0002] Dihydrosafrole is an important chemical intermediate, which is widely used in the synthesis of medicines, pesticides and spices, especially as an important raw material for the preparation of high-efficiency pesticide synergist piperonyl butoxide. Its structural formula is as follows: [0003] [0004] For a long time, dihydrosafrole is mainly prepared by catalytic hydrogenation of safrole extracted from natural sassafras oil. But in recent years, along with the rising of safrole consumption, in addition the requirements of various countries' governments to environmental protection regulations are more and more strict, this kind of sassafras oil that is produced as raw material with sassafras tree root is facing global resource depletion, causes two on the world market The price of hydrosafrole rises sharply, which seriously restricts the production of a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D317/50
Inventor 林彬
Owner 中山凯中有限公司
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