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A kind of preparation method of 2-hydroxy-4-carboxyquinoline

A technology of carboxyquinoline and hydroxyl, which is applied in the field of production and preparation of diobucaine hydrochloride intermediate 2-hydroxy-4-carboxyquinoline, can solve the problems of high safety hazards, simplify operations, reduce production costs, and avoid a large amount of waste water Effect

Active Publication Date: 2021-04-30
山东诚汇双达药业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, there are high potential safety hazards in production

Method used

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  • A kind of preparation method of 2-hydroxy-4-carboxyquinoline

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] Put 400kg of glacial acetic acid into a 1000L reactor, and add 100kg of isatin, 160kg of malonic acid, and 15kg of sodium acetate under stirring. Heated to reflux and reacted at reflux for 6 hours. Cool down to room temperature after the reaction, carry out decompression evaporation to remove glacial acetic acid, add 300kg deionized water to stir and crystallize, after filtration, the solid is first rinsed with cold 40kg glacial acetic acid, and then rinsed with cold 40kg methanol to obtain 2-hydroxy- The wet product of 4-carboxyquinoline was dried at 45-70°C for 24 hours after rejection filtration to obtain 124.7kg of 2-hydroxy-4-carboxyquinoline with a yield of 97% and a liquid phase purity of 99.6%.

Embodiment 2

[0042] Put 400kg of recovered glacial acetic acid into a 1000L reactor, and add 100kg of isatin, 160kg of malonic acid, and 15kg of sodium acetate under stirring. Heated to reflux and reacted at reflux for 6 hours. Cool down to room temperature after the reaction, decompress to remove glacial acetic acid, add 300kg deionized water to stir and crystallize, after filtration, the solid is rinsed with cold 30kg glacial acetic acid, and then rinsed with cold 30kg methanol to obtain 2-hydroxy- The wet product of 4-carboxyquinoline was dried at 45-70°C for 24 hours after rejection filtration to obtain 125 kg of 2-hydroxy-4-carboxyquinoline with a yield of 97.3% and a liquid phase purity of 99.6%.

Embodiment 3

[0044] Put 300kg of glacial acetic acid into a 1000L reactor, and add 50kg of isatin, 100kg of malonic acid, and 15kg of sodium carbonate under stirring. Heated to reflux and reacted at reflux for 4 hours. Cool down to room temperature after the reaction, carry out vacuum distillation to remove glacial acetic acid, add 300kg deionized water to stir and crystallize, after filtration, the solid is first rinsed with cold 20kg glacial acetic acid, and then rinsed with cold 10kg methanol to obtain 2-hydroxy- The wet product of 4-carboxyquinoline was dried at 45-70°C for 24 hours after rejection filtration to obtain 61.7kg of 2-hydroxy-4-carboxyquinoline with a yield of 96% and a liquid phase purity of 99.5%.

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Abstract

The invention belongs to the technical field of chemical synthesis, and in particular relates to a production and preparation method of a dibucaine hydrochloride intermediate 2-hydroxy-4-carboxyquinoline. The method comprises the following steps: (1) placing glacial acetic acid in a reaction kettle, adding isatin, malonic acid and sodium acetate under stirring; (2) heating the solution in step (1) to reflux, and then cooling down after refluxing to room temperature; (3) in step (2), the material is evaporated under reduced pressure to remove glacial acetic acid (recovery is applied mechanically); (4) in step (3), deionized water is added to the material after the glacial acetic acid is evaporated to stir and crystallize, and After the crystallization is completed, it is filtered, rinsed with glacial acetic acid first, and then rinsed with methanol, and the wet product is dried to obtain 2-hydroxy-4-carboxyquinoline. The synthesis method adopts the process of "one spoon of stew" to obtain the target product, which simplifies the operation, shortens the production cycle, and reduces the production cost; the obtained product has high purity and high yield, and is suitable for large-scale production.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a production and preparation method of diobucaine hydrochloride intermediate 2-hydroxyl-4-carboxyquinoline. Background technique [0002] 2-Hydroxy-4-carboxyquinoline is an important intermediate of Dibucaine Hydrochloride, and has broad application prospects in the fields of catalysis, molecular conductors, luminescent materials, molecular magnets, and nonlinear optics. [0003] The current synthetic process route is mainly to obtain acetyl isatin by reflux reaction of isatin and acetic anhydride, and then hydrolyze and rearrange N-acetyl isatin in aqueous sodium hydroxide solution to obtain the product. To obtain a product with high liquid phase purity, it needs to be refined. During the preparation of N-acetyl isatin, the throwing process has a very strong odor, which is not suitable for the current situation of safety and environmental protection. And ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D215/50
CPCC07D215/50
Inventor 赵忠贵王永广薛其蒙刘学文许林杰
Owner 山东诚汇双达药业有限公司