Unlock instant, AI-driven research and patent intelligence for your innovation.

Technique for preparing 3,4,5-trihydroxybenzoic acid methyl ester

A technology of methyl trihydroxybenzoate and preparation process, applied in 3 fields, can solve problems such as increasing production cost, increasing difficulty of adsorbent, etc., and achieves the effects of reducing emissions, high industrial application value, and simple process

Inactive Publication Date: 2006-07-26
湖南先伟阳光生物科技有限公司
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Methyl gallate does not have the report of preparation method, because methyl alcohol boiling point is low, can not adopt azeotropic water-carrying agent to carry out dehydration, but can adopt water-absorbing agent, as water-absorbing agents such as anhydrous calcium chloride, calcium sulfate or molecular sieve, in dehydration At the same time, the water-absorbing agent will also absorb a large amount of methanol, which increases the production cost; and methanol is a toxic chemical product, and the emission and leakage must be minimized during production, thus increasing the difficulty of adsorbent disposal

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] The liquid raw material in the raw material tank is input into the high-level metering tank through the delivery pump, and then enters the reaction kettle, while the solid raw material is directly added from the feeding port on the reaction kettle. In the present embodiment, 100 grams of gallic acid, 200 milliliters of methanol, and 15 grams of the mixed catalyst are prepared from p-toluenesulfonic acid, phosphoric acid and activated carbon, and the weight ratio between the three is 15:1:1 . After the material is put into the reaction kettle, the temperature is raised to esterify, and the esterification temperature is kept at 68°C. The steam including water and methanol components evaporated from the esterification reaction kettle is separated in the rectification tower, and the reflux ratio R= 1-4. Keep the temperature at the top of the tower at 64.5°C. The steam at the top of the tower is condensed by the condenser and then passes through the reflux distributor. Part ...

Embodiment 2-9

[0024] implement

Embodiment 10-13

[0026] Reality

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A process for preparing 3,4,5-methyl trihydroxybenzoate includes adding gallic acid, methanol and catalyst to reactor, heating while esterifying to generate the mixture of water and methanol vapour, separating water from methanol in rectifying tower, returning the methanol back to reactor for continuous reaction until the esterifying reaction takes place for 8-14 hrs, filtering the resultant, cooling to obtain coarse crystals, water washing and recrystallizing. Its advantages are less pollution and high output rate.

Description

technical field [0001] The invention relates to a preparation process of methyl 3,4,5-trihydroxybenzoate. Background technique [0002] 3, 4, 5 methyl trihydroxybenzoate, also known as methyl gallate, is an important raw material in the pharmaceutical industry, and also a good antioxidant, widely used in chemical industry, light industry, and food industry As the synthesis of lower alcohol esters of gallic acid, the more classic method is to use sulfuric acid or p-toluenesulfonic acid as a catalyst to make gallic acid and corresponding lower alcohols undergo esterification reaction. Agent or azeotropic water agent is excluded. Methyl gallate does not have the report of preparation method, because methyl alcohol boiling point is low, can not adopt azeotropic water-carrying agent to carry out dehydration, but can adopt water-absorbing agent, as water-absorbing agents such as anhydrous calcium chloride, calcium sulfate or molecular sieve, in dehydration At the same time, the ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07C69/78C07C67/08
Inventor 陈兴达罗伟
Owner 湖南先伟阳光生物科技有限公司