Preparation method of 5-chloro-8-hydroxyquinoline and purification method thereof

Abstract

The invention discloses a preparation method of 5-chloro-8-hydroxyquinoline and a purification method thereof, which aims at solving the problem when 4-chloro-2-aminophenol, 4-chloro-2-nitrophenol andglycerol ring are used to obtain 5-chloro-8-hydroxyquinoline, the reaction process is difficult to control, so that a large amount of tar can be generated, the reaction yield is low, the reaction operation is difficult, and a large amount of waste acid is generated after the post treatment. Boric acid and insoluble organic solvents being added into the reaction solution is the innovation of the preparation method, by the method, the acuteness of direct production of acrolein from sulphuric acid and glycerol is mitigated by boric acid, the speed of the acrolein polymerization to generate the tar is reduced, the yield and the safety are effectively improved, and a small amount of an water-insoluble organic solvents can effectively prevent 4-chloro-2-nitrophenol from coagulating on the reactor wall, the problem that it is difficult to control in the process of production operation is solved, which shortens the reaction cycle and improves production efficiency. The preparation method of 5-chloro-8-hydroxyquinoline and purification method thereof has the advantages of less tar, high yield and safe reaction, and can effectively reduce waste acid production and is easy to industrialize.

Description

technical field

[0001] The invention relates to the field of organic synthesis, in particular to a preparation method of 5-chloro-8-hydroxyquinoline and a purification method thereof. Background technique

[0002] As a very useful fine chemical intermediate, 5-chloro-8-hydroxyquinoline is widely used in the production of agrochemicals, animal feed, disinfectants and preservatives, etc. At present, 5-chloro-8-hydroxyquinoline is mainly synthesized in the following two ways: 1) 5-chloro-8-hydroxyquinoline is obtained by chlorination of 8-hydroxyquinoline; 2) through 4-chloro-2- Aminophenol, 4-chloro-2-nitrophenol, and glycerol are ring-closed to obtain 5-chloro-8-hydroxyquinoline. Among them, the latter method has readily available raw materials and industrialization, and has been widely used. For example, patent CN102267943 (name: a method for preparing 5-chloro-8-hydroxyquinoline, publication date: 2011.12.07) has disclosed related synthesis process.

[0003] However, the...

Examples

Embodiment 1

[0042] In a 1000-liter reactor, add 173 kilograms of glycerin, 44 kilograms of water, 6.2 kilograms of boric acid, 87 kilograms of 4-chloro-2-nitrophenol, 143 kilograms of 4-chloro-2-aminophenol, and 10 kilograms of ethyl cyclohexane. 1 kg, warming up to 120 degrees Celsius, 288 kg of 98wt% sulfuric acid was added dropwise in 2 hours; After 150 degrees centigrade, keep warm until the end of the reaction, add 10wt% sodium hydroxide dropwise to pH = 7, and centrifuge to obtain a filter cake.

[0043] The filter cake obtained by centrifugation is dissolved with 728 kilograms of 7.5wt% hydrochloric acid aqueous solution, and is filtered after adding 10 kilograms of gacs for decolorization, and 268 kilograms of sodium chloride are added to the filtrate, and 5-chloro-8-hydroxyquinoline hydrochloride is filtered out; After part of the water is discharged, 200 kg of sodium chloride is recovered. Its 5-chloro-8-hydroxyquinoline hydrochloride was neutralized with 10wt% sodium hydroxide...

Embodiment 2

[0045]In a 1000-liter reactor, add 173 kg of glycerin, 44 kg of water, 12.4 kg of boric acid, 87 kg of 4-chloro-2-nitrophenol, 143 kg of 4-chloro-2-aminophenol, and 10 kg of ethylcyclohexane , the reactant in the reactor was warmed up to 120 degrees centigrade, and 288 kilograms of 98wt% sulfuric acid was added dropwise in 2 hours; kg, until the internal temperature of the reactor reaches 150 degrees Celsius, after the insulation reaction is completed, 10wt% sodium hydroxide is added dropwise to pH=7, and centrifuged to obtain a filter cake.

[0046] The filter cake obtained by centrifugation is dissolved with 728 kilograms of 7.5wt% hydrochloric acid aqueous solution, and is filtered after adding 10 kilograms of gacs for decolorization, and 268 kilograms of sodium chloride are added to the filtrate, and 5-chloro-8-hydroxyquinoline hydrochloride is filtered out; After part of the water is discharged, 200 kg of sodium chloride is recovered. Its 5-chloro-8-hydroxyquinoline hydr...

Embodiment 3

[0048] In a 1000-liter reactor, add 173 kilograms of glycerin, 44 kilograms of water, 18.6 kilograms of boric acid, 87 kilograms of 4-chloro-2-nitrophenol, 143 kilograms of 4-chloro-2-aminophenol, and 10 kilograms of ethyl cyclohexane. 1 kg, warming up to 120 degrees Celsius, 288 kg of 98wt% sulfuric acid was added dropwise in 2 hours; After 150 degrees centigrade, keep warm until the end of the reaction, add 10wt% sodium hydroxide dropwise to pH = 7, and centrifuge to obtain a filter cake.

[0049] The filter cake obtained by centrifugation is dissolved with 728 kilograms of 7.5wt% hydrochloric acid aqueous solution, and is filtered after adding 10 kilograms of gacs for decolorization, and 268 kilograms of sodium chloride are added to the filtrate, and 5-chloro-8-hydroxyquinoline hydrochloride is filtered out; After part of the water is discharged, 200 kg of sodium chloride is recovered. Its 5-chloro-8-hydroxyquinoline hydrochloride was neutralized with 10wt% sodium hydroxid...

technical field

[0001] The invention relates to the field of organic synthesis, in particular to a preparation method of 5-chloro-8-hydroxyquinoline and a purification method thereof. Background technique

[0002] As a very useful fine chemical intermediate, 5-chloro-8-hydroxyquinoline is widely used in the production of agrochemicals, animal feed, disinfectants and preservatives, etc. At present, 5-chloro-8-hydroxyquinoline is mainly synthesized in the following two ways: 1) 5-chloro-8-hydroxyquinoline is obtained by chlorination of 8-hydroxyquinoline; 2) through 4-chloro-2- Aminophenol, 4-chloro-2-nitrophenol, and glycerol are ring-closed to obtain 5-chloro-8-hydroxyquinoline. Among them, the latter method has readily available raw materials and industrialization, and has been widely used. For example, patent CN102267943 (name: a method for preparing 5-chloro-8-hydroxyquinoline, publication date: 2011.12.07) has disclosed related synthesis process.

[0003] However, the...

Examples

Embodiment 1

[0042] In a 1000-liter reactor, add 173 kilograms of glycerin, 44 kilograms of water, 6.2 kilograms of boric acid, 87 kilograms of 4-chloro-2-nitrophenol, 143 kilograms of 4-chloro-2-aminophenol, and 10 kilograms of ethyl cyclohexane. 1 kg, warming up to 120 degrees Celsius, 288 kg of 98wt% sulfuric acid was added dropwise in 2 hours; After 150 degrees centigrade, keep warm until the end of the reaction, add 10wt% sodium hydroxide dropwise to pH = 7, and centrifuge to obtain a filter cake.

[0043] The filter cake obtained by centrifugation is dissolved with 728 kilograms of 7.5wt% hydrochloric acid aqueous solution, and is filtered after adding 10 kilograms of gacs for decolorization, and 268 kilograms of sodium chloride are added to the filtrate, and 5-chloro-8-hydroxyquinoline hydrochloride is filtered out; After part of the water is discharged, 200 kg of sodium chloride is recovered. Its 5-chloro-8-hydroxyquinoline hydrochloride was neutralized with 10wt% sodium hydroxide...

Embodiment 2

[0045]In a 1000-liter reactor, add 173 kg of glycerin, 44 kg of water, 12.4 kg of boric acid, 87 kg of 4-chloro-2-nitrophenol, 143 kg of 4-chloro-2-aminophenol, and 10 kg of ethylcyclohexane , the reactant in the reactor was warmed up to 120 degrees centigrade, and 288 kilograms of 98wt% sulfuric acid was added dropwise in 2 hours; kg, until the internal temperature of the reactor reaches 150 degrees Celsius, after the insulation reaction is completed, 10wt% sodium hydroxide is added dropwise to pH=7, and centrifuged to obtain a filter cake.

[0046] The filter cake obtained by centrifugation is dissolved with 728 kilograms of 7.5wt% hydrochloric acid aqueous solution, and is filtered after adding 10 kilograms of gacs for decolorization, and 268 kilograms of sodium chloride are added to the filtrate, and 5-chloro-8-hydroxyquinoline hydrochloride is filtered out; After part of the water is discharged, 200 kg of sodium chloride is recovered. Its 5-chloro-8-hydroxyquinoline hydr...

Embodiment 3

[0048] In a 1000-liter reactor, add 173 kilograms of glycerin, 44 kilograms of water, 18.6 kilograms of boric acid, 87 kilograms of 4-chloro-2-nitrophenol, 143 kilograms of 4-chloro-2-aminophenol, and 10 kilograms of ethyl cyclohexane. 1 kg, warming up to 120 degrees Celsius, 288 kg of 98wt% sulfuric acid was added dropwise in 2 hours; After 150 degrees centigrade, keep warm until the end of the reaction, add 10wt% sodium hydroxide dropwise to pH = 7, and centrifuge to obtain a filter cake.

[0049] The filter cake obtained by centrifugation is dissolved with 728 kilograms of 7.5wt% hydrochloric acid aqueous solution, and is filtered after adding 10 kilograms of gacs for decolorization, and 268 kilograms of sodium chloride are added to the filtrate, and 5-chloro-8-hydroxyquinoline hydrochloride is filtered out; After part of the water is discharged, 200 kg of sodium chloride is recovered. Its 5-chloro-8-hydroxyquinoline hydrochloride was neutralized with 10wt% sodium hydroxid...