A kind of synthetic method of ethyl salicylate

A technology of ethyl salicylate and a synthesis method, which is applied in the chemical industry, can solve the problems of failing to meet the needs of industrial reactions, easily introducing other impurities, and low yields, achieving short synthesis and product purification steps, and overcoming product yields Not high, the effect of high reaction product yield

Active Publication Date: 2020-05-19
GUANGZHOU XINGQUN PHARMA
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

A solid superacid is an acid stronger than 100% sulfuric acid, such as using The solid superacid catalyst catalyzes the reaction of salicylic acid and ethanol, and the yield can reach 89% (referring to "Fine Petrochemical Industry", 1997 (7): 3); The solid superacid catalyst catalyzes the reaction of salicylic acid and ethanol, and the yield of ethyl salicylate can reach 84.6% (referring to "Inner Mongolia Petrochemical Industry", 2001, 27:37), but after utilizing this type of solid superacid to catalyze the reaction The processing is more complicated, and other impurities are easily introduced. The obtained ethyl salicylate has unknown risks when it is used for clinical use, and the preparation of solid superacid is time-consuming, usually one week, and the reusability of the solid superacid has yet to be determined. Further exploration, it is difficult to be used in industrial production
[0004] P-toluenesulfonic acid can also achieve better results as an acid-catalyzed reaction between salicylic acid and ethanol. For example, patent application 201410632341 discloses a method for the synthesis of ethyl salicylate catalyzed by p-toluenesulfonic acid. First, the raw materials and catalyst are heated and stirred After a period of time, reflux in a microwave reaction device for a period of time, and finally transfer to a distillation device for reaction, the yield of ester can reach 89%, but there are many devices required when using this method for preparation, and the post-treatment process is complicated. Toluene Sulfonic acid is difficult to remove, and the obtained ethyl salicylate has potential risks for medicinal use
[0005] Sodium bisulfate catalyst has stable performance during catalysis, is insoluble in organic matter, easily soluble in water, has good catalytic activity, and the yield can reach 70-80% (see "Industrial Catalysis", 2006, 14 (5), 42-44), but Its yield is not high even under pressurized conditions, which cannot meet the needs of industrial reactions
[0006] Sulfuric acid catalyzed synthesis of ethyl salicylate is a common method. Under sulfuric acid catalyzed conditions, salicylic acid and ethanol undergo esterification reaction through heating to generate ethyl salicylate, which is obtained during the synthesis of ethyl salicylate by this conventional method. Low product yield, easy to cause waste of raw materials

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A kind of synthetic method of ethyl salicylate
  • A kind of synthetic method of ethyl salicylate
  • A kind of synthetic method of ethyl salicylate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] Synthesis: Put 15.0kg of 95% ethanol, 1.0kg of sulfuric acid and 50.0kg of salicylic acid into a glass-lined reaction tank in sequence, heat and reflux until about 50% or more (approximate range is enough), stop the reflux when the salicylic acid dissolves, and start distillation and collection ethanol in water. When the temperature of the reaction system rose to 110°C, add 95% ethanol to the reaction system at a rate of 2.9L / h (every 1kg of salicylic acid added ethanol 0.058L), and the temperature control of the reaction system was about 110°C. ℃, and the ethanol recovery ratio is 60%. Judge the remaining amount of salicylic acid in the reaction system, stop adding ethanol if the requirement is met, and continue to collect ethanol distilled between 100-120°C. The volume of the glass-lined reaction tank is 50L.

[0049] The method for judging the residual amount of salicylic acid in the reaction system is: during the esterification reaction, detect the concentration o...

Embodiment 2

[0053] Synthesis: Put 5.0kg of 95% ethanol, 1.0kg of sulfuric acid and 30.0kg of salicylic acid into a glass-lined reaction tank in turn, heat and reflux until about 50% of the salicylic acid dissolves, stop the reflux, and start distillation to collect the ethanol aqueous solution. When the temperature of the reaction system rose to 105° C., add 95% ethanol to the reaction system at a rate of 5.1 L / h (every 1 kg of salicylic acid added ethanol 0.17 L), and the temperature control of the reaction system was about 100 ℃, and the ethanol recovery ratio was 56%. Judge the remaining amount of salicylic acid in the reaction system, stop adding ethanol if the requirement is met, and continue to collect ethanol distilled between 100-120°C.

[0054] The method for judging the residual amount of salicylic acid in the reaction system is: detect the concentration of the low-concentration ethanol recovered during the esterification reaction, and when the ethanol concentration is greater t...

Embodiment 3

[0058] Synthesis: Put 40.0kg of 90% ethanol, 5.0kg of sulfuric acid and 50.0kg of salicylic acid into a glass-lined reaction tank in sequence, heat and reflux until about 50% or more of the salicylic acid dissolves, stop the reflux, and start distillation to collect the aqueous ethanol solution. When the temperature of the reaction system rises to 110°C, add 90% ethanol to the reaction system at a rate of 9.75L / h ((per hour, every 1kg of salicylic acid adds ethanol 0.195L)), and the temperature of the reaction system is controlled by about It was 118° C., and the ethanol recovery ratio was 63%. Judge the remaining amount of salicylic acid in the reaction system, stop adding ethanol if the requirement is met, and continue to collect ethanol distilled between 100-120°C.

[0059] The method for judging the residual amount of salicylic acid in the reaction system is: detect the concentration of the low-concentration ethanol recovered during the esterification reaction, and when th...

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

The invention belongs to the field of chemical engineering, and particularly discloses a synthetic method of ethyl salicylate with high purity and conforming to drug use. The method comprises the steps of using sulfuric acid for catalytic synthesis of the ethyl salicylate, washing a product and purifying the product; a mixture of ethanol and water is collected while ethanol with high concentration is added to a reaction system in the synthesis process, forward esterification reaction can be effectively promoted, and the improvement of the reaction yield is facilitated; the obtained ethyl salicylate product is high in purity, no unknown impurities are introduced, the requirements of the drug use are met, the quality is guaranteed from raw materials, and the unknown risk of the product during clinical use is reduced.

Description

technical field [0001] The invention belongs to the field of chemical industry, in particular to a method for synthesizing ethyl salicylate with high purity and suitable for medicinal use. Background technique [0002] Ethyl salicylate is a colorless liquid with a special aroma similar to holly, and it gradually turns yellow-brown when exposed to light or left for a long time. It can be used medicinally as a fixative for daily flavors or food flavors; it can be used as an intermediate, such as for salicylamide, ethyl acetylsalicylate, ethyl nitrosalicylate; it can also be used Used as a solvent, such as a solvent for nitrocellulose, etc., is an important class of ester compounds. [0003] The catalysts that can catalyze the reaction of salicylic acid and ethanol to generate ethyl salicylate mainly include solid superacid catalysts, p-toluenesulfonic acid catalysts, sodium bisulfate catalysts and concentrated sulfuric acid catalysts. A solid superacid is an acid stronger th...

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): C07C67/08C07C67/54C07C69/84
CPCC07C67/08C07C67/54C07C69/84
Inventor 刘艳平万安凤郑春香朱炳坤孙维广高建胜张伟王彬彬谢洁娜黄嘉鸿陈永波李王波
Owner GUANGZHOU XINGQUN PHARMA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap