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Preparation method of 7-hydroxy-4-methylcoumarin

A technology of methyl coumarin and hydroxyl group is applied in the field of preparation of intermediates, can solve the problems of serious pollution, cannot be reused, and difficult to recover, and achieves the effects of high product yield, easy recovery and simple process

Inactive Publication Date: 2010-06-09
周成云
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] In the traditional process, concentrated sulfuric acid is used as a catalyst, although it is cheap, but it has disadvantages such as poor selectivity, prone to side reactions such as oxidation and sulfonation, low yield, serious pollution, and cannot be reused.
In response to these shortcomings, in recent years, ZrO 2 / H 2 SO 4 Solid superacid, tin tetrachloride, p-toluenesulfonic acid, and polyethylene-loaded acid are catalysts to catalyze the synthesis of hymecoumarin. Although certain effects have been achieved, tin tetrachloride and p-toluenesulfonic acid cannot be recycled and reused. Pollution is large and ZrO 2 / H 2 SO 4 Small particles, difficult recycling, high cost, cumbersome and complicated preparation process of catalyst polyethylene-loaded acid, etc., hinder product quality, and it is difficult to achieve mass production in industry

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The preparation method of 7-hydroxyl-4-methylcoumarin comprises the following steps:

[0018] a. Diatomaceous earth supported catalyst:

[0019] Take 20g of sulfuric acid and 20g of p-toluenesulfonic acid, add water to prepare a 5% solution, weigh 20g of diatomite and soak in the acid solution for 12 hours, filter with suction and dry the diatomite in an oven at 100°C, then Roasting at 550° C. for 4 hours in a muffle furnace to obtain a diatomite-supported catalyst;

[0020] b, the preparation of 7-hydroxyl-4-methylcoumarin:

[0021] Add 100 g of resorcinol, 100 g of ethyl acetoacetate, and 10 g of catalyst into the flask, and stop heating after reacting for 3 hours at 90°C, remove the catalyst by filtration, distill off the ethyl acetoacetate under reduced pressure to obtain a crude product. The crude product was put into ice water to precipitate a precipitate, which was filtered and collected to form a white solid, which was recrystallized with 95% ethanol to obtain...

Embodiment 2

[0023] The preparation method of 7-hydroxyl-4-methylcoumarin comprises the following steps:

[0024] a. Diatomaceous earth supported catalyst:

[0025] Take 20g of sulfuric acid and 15g of p-toluenesulfonic acid, add water to prepare an 8% solution, weigh 15g of diatomite and soak in the acid solution for 8 hours, filter with suction and dry the diatomite in an oven at 90°C, then Calcined at 600° C. for 2 hours in a muffle furnace to obtain a diatomite-supported catalyst.

[0026] b, the preparation of 7-hydroxyl-4-methylcoumarin:

[0027] Add 100 g of resorcinol, 120 g of ethyl acetoacetate, and 15 g of catalyst into the flask, and stop heating after reacting for 2 hours at 120° C., remove the catalyst by filtration, evaporate ethyl acetoacetate under reduced pressure to obtain a crude product. The crude product was put into ice water, and a precipitate was precipitated. The precipitate was filtered and collected, and a white solid was precipitated. It was recrystallized wi...

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PUM

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Abstract

The invention discloses a preparation method of 7-hydroxy-4-methylcoumarin, comprising the following steps of: adding a certain amount of resorcinol, ethyl acetoacetate and catalyst in a flask, heat in the stirring state, filtering and removing the catalyst after the reaction is finished to obtain filtrate, evaporating and removing solvent and the excessive ethyl acetoacetate from the filtrate by using a rotary evaporator, dissolving crystals out to obtain a crude product, and recrystallizing the crude product by using 95 percent of ethanol to obtain white crystals. The process has the advantages of simple process and high efficiency and is suitable for actual production.

Description

technical field [0001] The invention relates to a preparation method of an intermediate, in particular to a preparation method of 7-hydroxy-4-methylcoumarin. Background technique [0002] 7-Hydroxy-4-methylcoumarin (also known as hydroxymethylcoumarin), is a white crystal, an important intermediate for the synthesis of spices, medicines, pesticides, dyes, and can also be used as choleretic, analgesic, The traditional synthesis method is the Pechmann method, which uses concentrated sulfuric acid to catalyze the reaction of ethyl acetoacetate and resorcinol, and domestic production is also based on this process. [0003] In the traditional process, concentrated sulfuric acid is used as a catalyst, although it is cheap, but it has disadvantages such as poor selectivity, prone to side reactions such as oxidation and sulfonation, low yield, serious pollution, and cannot be reused. In response to these shortcomings, in recent years, ZrO 2 / H 2 SO 4 Solid superacid, tin tetrach...

Claims

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Application Information

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IPC IPC(8): C07D311/16
Inventor 周成云
Owner 周成云
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