CN108003096B

CN108003096B - Method for preparing ethoxyquinoline through WO3/AC/SO3H concerted catalysis

Info

Publication number: CN108003096B
Application number: CN201711336619.XA
Authority: CN
Inventors: 韦长梅; 支三军; 蒋正静; 朱安峰; 夏敏
Original assignee: Huaiyin Normal University
Current assignee: Huai'an Runlong Technology Co ltd
Priority date: 2017-12-14
Filing date: 2017-12-14
Publication date: 2021-07-20
Anticipated expiration: 2037-12-14
Also published as: CN108003096A

Abstract

The invention discloses a WO₃/AC/SO₃A method for preparing ethoxyquinoline by H concerted catalysis comprises adding phenetidine, toluene and WO into a reactor equipped with a stirrer, a thermometer and a condenser₃/AC/SO₃A H catalyst; when the temperature of the reaction solution reaches, dropwise adding acetone into the reactor; after the acetone is dropwise added, carrying out reflux reaction, and detecting the reaction end point by TLC; neutralizing with sodium bicarbonate water solution, standing for layering, extracting water phase with toluene, and mixing organic phases; drying with anhydrous sodium sulfate, filtering, evaporating the solvent under normal pressure, and distilling under reduced pressure to obtain brown viscous oily liquid ethoxyquinoline. The invention uses a solid catalyst WO with two functions of super acid and sulfonic acid₃/AC/SO₃The H is used for preparing the ethoxyquinoline by the condensation of the p-phenetidine and the acetone under the concerted catalysis, so that the reaction time can be obviously shortened, the byproducts are reduced, the operation is simple and convenient, and the method has an industrial application prospect.

Description

Method for preparing ethoxyquinoline through WO3/AC/SO3H concerted catalysis

Technical Field

The invention relates to a preparation method of ethoxyquinoline, in particular to WO₃/AC/SO₃H is a method for preparing ethoxyquinoline by concerted catalysis.

Background

The ethoxyquin is a common antioxidant in feed and food industries, prevents the deterioration of vitamins A, D, E and the like and fatty oxygen in the ethoxyquin, prevents the oxidation discoloration of natural pigments, has certain mildew-proof and fresh-keeping effects, and has good oxidation resistance and odor resistance and low price. Ethoxyquin may also be used to protect rubber against aging, with very good weatherability and flex-crack resistance. The ethoxyquin is mainly prepared by taking phenetidine and acetone as raw materials and performing dehydration condensation in the presence of catalysts and solvents such as iodine, p-toluenesulfonic acid, solid superacid, inorganic acid and the like. Wuchunking et al have made a good review on the catalyst studies for synthesizing ethoxyquinoline. The commercial application of ethoxyquinoline has been for many years, but the ethoxyquinoline synthesis process still has the defects of long reaction time, low product yield, high process cost, high impurity content and the like. CN92100074.X reports that p-phenetidine and acetone are used as raw materials, and the condensation reaction is completed through a pseudo-pressure reaction, and then the ethoxyquinoline crude oil is obtained through cooling, neutralization, water washing separation, distillation and vacuum rectification. The key point of the technology is that the 'pseudo-pressure reaction' is adopted, and the reaction which can be finished only by heating and pressurizing is finished under the condition of heating and normal pressure; in addition, benzene, toluene or xylene which generates azeotropy with water is added as a solvent in the reaction. However, the method has the disadvantages of complicated operation, large solvent consumption, long production period and environmental pollution. The iodine catalyst is used, so that the dosage is large, the price is high, the side reaction is more, and the product yield is low.

Disclosure of Invention

The invention aims to: there is provided a WO₃/AC/SO₃The method for preparing ethoxyquinoline by H concerted catalysis has the advantages of simple operation, small solvent consumption, short production period, environmental pollution avoidance and high product yield.

The technical solution of the invention is as follows: adding phenetidine, toluene and WO into a reactor equipped with a stirrer, a thermometer and a condenser₃/AC/SO₃A H catalyst; when the temperature of the reaction solution reaches, dropwise adding acetone into the reactor; after the acetone is dropwise added, carrying out reflux reaction, and detecting the reaction end point by TLC; neutralizing with sodium bicarbonate water solution, standing for layering, extracting water phase with toluene, and mixing organic phases; drying with anhydrous sodium sulfate, filtering, evaporating the solvent under normal pressure, and distilling under reduced pressure to obtain brown viscous oily liquid ethoxyquinoline.

Wherein, phenetidine, toluene and WO₃/AC/SO₃The mass ratio of the H catalyst is 1: 0.955: 0.179-0.193; the molar ratio of phenetidine to acetone is 1: 2.5; the reaction temperature is 110-130 ℃, and the reaction time is 2-4 h.

Wherein, the mass concentration of the sodium bicarbonate water solution is 8-10%.

Among them, WO₃/AC/SO₃The preparation method of the H catalyst comprises the following steps: soaking activated carbon in nitric acid solution at room temperature, filtering, washing with methanol to neutrality, and drying; WO₃Mixing with treated active carbon, and calcining and activating in a muffle furnace; cooling, taking out, soaking in concentrated sulfuric acid, and soaking in anhydrous ethanolRefluxing, filtering, washing with absolute ethyl alcohol to neutrality, drying to obtain the catalyst WO₃/AC/SO₃H。

Wherein, the mass concentration of the nitric acid is 25-30%, the dipping time of the activated carbon in the nitric acid solution is 20-24h, and the drying temperature of the activated carbon is 120-140 ℃; activated carbon and WO₃The mass ratio of (A) to (B) is 2: 1; calcining and activating for 8-10h at 450-500 ℃ in a muffle furnace; WO₃The mass ratio of/AC to concentrated sulfuric acid is 1: 2.12-2.21, WO₃The immersion time of the/AC in the concentrated sulfuric acid is 20-24 h; WO₃/AC/SO₃The drying temperature of the H catalyst is 80-100 ℃.

The invention has the advantages that: use of solid catalyst WO having both super acid and sulfonic acid functions₃/AC/SO₃The H is used for preparing the ethoxyquin oline by the condensation of the phenetidine and the acetone under the synergistic catalysis, so that the reaction time is obviously shortened, the byproducts are reduced, the product yield is high, the operation is simple and convenient, the method is a new technology for preparing the ethoxyquin oline, and the industrial application prospect is realized.

Detailed Description

The technical solution of the invention is further illustrated below with reference to specific examples, which are not to be construed as limiting the technical solution.

Example 1: dipping 200g of activated carbon in 2L of nitric acid solution with the mass concentration of 25% for 24h at room temperature, filtering, washing with methanol until the pH is =7, and drying at 120 ℃; mixing 100g of WO3 with the treated activated carbon, and calcining and activating for 10 hours at 450 ℃ in a muffle furnace; after cooling, the catalyst was taken out and immersed in 552g of concentrated sulfuric acid for 20h, refluxed in absolute ethyl alcohol for 2h, filtered, washed to neutrality with absolute ethyl alcohol, and dried at 80 ℃ to obtain the catalyst WO3/AC/SO 3H.

Example 2: dipping 200g of activated carbon in 2L of nitric acid solution with mass concentration of 28% for 22h at room temperature, filtering, washing with methanol until pH =7, and drying at 130 ℃; mixing 100g of WO3 with the treated activated carbon, and calcining and activating for 9 hours in a muffle furnace at 480 ℃; after cooling, the catalyst was taken out and immersed in 552g of concentrated sulfuric acid for 22h, refluxed in absolute ethyl alcohol for 2h, filtered, washed to neutrality with absolute ethyl alcohol, and dried at 90 ℃ to obtain the catalyst WO3/AC/SO 3H.

Example 3: dipping 200g of activated carbon in 2L of 30% nitric acid solution by mass concentration for 20h at room temperature, filtering, washing with methanol until the pH is =7, and drying at 140 ℃; 100g of WO3 is mixed with treated activated carbon and calcined and activated for 8 hours in a muffle furnace at 500 ℃; after cooling, the catalyst was taken out and immersed in 552g of concentrated sulfuric acid for 24 hours, refluxed in absolute ethyl alcohol for 2 hours, filtered, washed to neutrality with absolute ethyl alcohol, and dried at 100 ℃ to obtain the catalyst WO3/AC/SO 3H.

Example 4: a1000 mL four-necked flask was equipped with a stirrer, a thermometer and a condenser, and 139.8g (1 mol) of 98.6% p-phenetidine, 133.5g of 98.7% toluene and 26g of a catalyst were charged; when the temperature of the reaction solution reached 110 ℃, 133.2g (2.5 mol) of 99.0% acetone was added dropwise to the reactor; after the acetone is dropwise added, refluxing and reacting for 4 hours, and detecting the reaction end point by TLC; neutralizing with 10% sodium bicarbonate water solution, standing for layering, extracting water phase with toluene, and mixing organic phases; dried over anhydrous sodium sulfate, filtered, the solvent was distilled off at normal pressure, and then distilled under reduced pressure to obtain 210.1g of ethoxyquinoline as a brown viscous oily liquid, the yield was 96.8%, and the purity was 97.5%.

Example 5: a1000 mL four-necked flask was equipped with a stirrer, a thermometer and a condenser, and 139.8g (1 mol) of 98.6% p-phenetidine, 133.5g of 98.7% toluene and 25g of a catalyst were charged; when the temperature of the reaction solution reached 120 ℃, 133.2g (2.5 mol) of 99.0% acetone was added dropwise to the reactor; after the acetone is dropwise added, refluxing and reacting for 3 hours, and detecting the reaction end point by TLC; neutralizing with 9% sodium bicarbonate water solution, standing for layering, extracting water phase with toluene, and mixing organic phases; dried over anhydrous sodium sulfate, filtered, the solvent was distilled off at normal pressure, and then distilled under reduced pressure to obtain 207.7g of ethoxyquinoline as a brown viscous oily liquid in a yield of 95.7% and a purity of 96.3%.

Example 6: a1000 mL four-necked flask was equipped with a stirrer, a thermometer and a condenser, and 139.8g (1 mol) of 98.6% p-phenetidine, 133.5g of 98.7% toluene and 27g of a catalyst were charged; when the temperature of the reaction liquid is 130 ℃, adding 133.2g (2.5 mol) of 99.0% acetone dropwise into the reactor, and detecting the end point of the reaction by TLC; neutralizing with 8% sodium bicarbonate water solution, standing for layering, extracting water phase with toluene, and mixing organic phases; dried over anhydrous sodium sulfate, filtered, the solvent was evaporated under normal pressure, and then distilled under reduced pressure to obtain 206.4g of ethoxyquinoline as a brown viscous oily liquid in a yield of 95.1% and a purity of 95.6%.

Claims

1. A method for preparing ethoxyquinoline by catalyst concerted catalysis comprises the steps of adding phenetidine, toluene and a catalyst into a reactor provided with a stirrer, a thermometer and a condenser pipe; when the temperature of the reaction solution reaches, dropwise adding acetone into the reactor; after the acetone is dropwise added, carrying out reflux reaction, and detecting the reaction end point by TLC; neutralizing with sodium bicarbonate water solution, standing for layering, extracting water phase with toluene, and mixing organic phases; drying with anhydrous sodium sulfate, filtering, evaporating the solvent at normal pressure, and distilling under reduced pressure to obtain brown viscous oily liquid ethoxyquinoline; the method is characterized in that: the preparation method of the catalyst comprises the following steps: soaking activated carbon in nitric acid solution at room temperature, filtering, washing with methanol to neutrality, and drying; WO3 and the treated activated carbon are mixed and calcined and activated in a muffle furnace; after cooling, taking out WO3/AC, soaking in concentrated sulfuric acid, refluxing in absolute ethyl alcohol, filtering, washing with absolute ethyl alcohol to be neutral, and drying to obtain a catalyst; wherein the mass concentration of the nitric acid solution is 25-30%, the dipping time of the activated carbon in the nitric acid solution is 20-24h, and the drying temperature of the activated carbon is 120-140 ℃; the mass ratio of the activated carbon to WO3 was 2: 1; calcining and activating for 8-10h at 450-500 ℃ in a muffle furnace; the mass ratio of WO3/AC to concentrated sulfuric acid is 1: 2.12-2.21, the soaking time of WO3/AC in concentrated sulfuric acid is 20-24 h; the drying temperature of the catalyst is 80 ℃ to 100 ℃.

2. The method for preparing ethoxyquinoline by concerted catalysis of the catalyst according to claim 1, which is characterized in that: the mass ratio of the phenetidine, the toluene and the catalyst is 1: 0.955: 0.179-0.193; the molar ratio of phenetidine to acetone is 1: 2.5; the reaction temperature is 110-130 ℃, and the reaction time is 2-4 h.

3. The method for preparing ethoxyquinoline by concerted catalysis of the catalyst according to claim 1, which is characterized in that: the mass concentration of the sodium bicarbonate water solution is 8-10%.