A process for producing furanol using by-product as solvent

Abstract

The invention discloses a furanol production process using a byproduct as a solvent, firstly carrying out an etherification reaction, reacting with catechol, methallyl chloride, sodium carbonate and a solvent as raw materials, wherein the solvent is composed of ethylene glycol monomethyl ether and 2,5-dimethyl-2-hexanol, and the mass ratio of 2,5-dimethyl-2-hexanol is 0-80%; then carrying out a cyclization reaction, distilling off the etherification solvent, then adding xylene and a catalyst, and reacting to obtain furanol. The present invention separates the byproduct 2,5-dimethyl-2-hexanol from the etherification liquid after the etherification reaction, and circulates back to the etherification reaction to use as a solvent. This process is a comprehensive utilization of the byproduct 2,5-dimethyl-2-hexanol, which can replace all or part of the traditional ethylene glycol monomethyl ether solvent, saving production costs; and the byproduct 2,5-dimethyl-2-hexanol can also be used as an extraction solvent for phenol recovery, fully utilized, and environmentally friendly.

Description

Technical Field

[0001] The invention relates to a furanol production process using byproducts as solvents, in particular to comprehensive utilization of etherification byproduct 2,5-dimethyl-2-hexanol. Background Art

[0002] The chemical name of furanol is 2,3-dihydro-2,2-dimethyl-7-benzofuranol. It is mainly used as an important intermediate for the synthesis of pesticides such as carbofuran (furadan), carbofuran butysulfuron, carbofuran benfuracarb, oxadiazine, furoline, etc. It can also be widely used for pest control of crops such as cotton, rice, corn, soybeans, sugarcane, sorghum and fruit trees, and has the effect of shortening the crop production period and promoting crop growth and development, which can effectively increase the yield of crops; it can also be used as a pharmaceutical intermediate. The main method of industrial production at home and abroad is to prepare 2-(2-methylallyloxy)phenol through etherification reaction of catechol and methyl allyl chloride, and then generate furanol through transposition and cyclization under the condition of catalyst.

[0003] In the etherification reaction of catechol and methyl allyl chloride, ethylene glycol monomethyl ether is used as a solvent to improve the selectivity of 2-(2-methylallyloxy)phenol, which is relatively expensive. During the etherification reaction, methyl allyl chloride condenses under alkaline conditions to produce a by-product 2,5-dimethyl-2-hexanol. In the current production process, 2,5-dimethyl-2-hexanol is incinerated as a by-product of the etherification reaction, which not only wastes resources but also increases environmental pressure.

[0004] In addition, in the production process of phenol products, wastewater often contains a small amount of various phenols. The existing process generally uses N503 (N, N-bis (1-methylheptyl) acetamide) extraction agent or methyl isobutyl ketone extraction and recovery. If the etherification by-product 2,5-dimethyl-2-hexanol is used as the extraction agent, the utilization rate of 2,5-dimethyl-2-hexanol can be improved, turning waste into treasure and saving costs. Summary of the invention

[0005] The purpose of the present invention is to provide a method for comprehensively utilizing 2,5-dimethyl-2-hexanol, a byproduct of furanol etherification, including separation technology of 2,5-dimethyl-2-hexanol, using 2,5-dimethyl-2-hexanol as a solvent for etherification reaction to replace all or part of ethylene glycol monomethyl ether, and using 2,5-dimethyl-2-hexanol as an extractant to replace N503 or methyl isobutyl ketone. The method not only saves production costs, but also solves environmental protection problems and realizes the transformation of waste into treasure.

[0006] The technical scheme of the present invention is as follows: A process for producing furanol using a by-product as a solvent, (1) an etherification reaction, wherein the materials are fed in a molar ratio of catechol: methyl allyl chloride: sodium carbonate: solvent = 1:1.0-1.5:0.5-0.75:3-8, the reaction temperature is 95-110°C, and the reaction time is 1-10 hours at normal pressure, wherein the solvent is composed of ethylene glycol monomethyl ether and 2,5-dimethyl-2-hexanol, and the mass ratio of 2,5-dimethyl-2-hexanol is 0-80%;

[0007] (2) removing the solvent, filtering the etherified liquid after the above etherification reaction to remove the generated sodium chloride, removing the by-product 2,5-dimethyl-2-hexanol and the solvent under reduced pressure, and subjecting the intermediate product to the next step of reaction;

[0008] (3) cyclization reaction, adding xylene and a catalyst aluminum isopropoxide to the intermediate product obtained in step (2), wherein the mass of xylene added is 60-75% of the total mass of the cyclization reaction raw materials, the reaction temperature is 165-185° C., the reaction pressure is 0.05-0.25 MPa, and the reaction time is 2-10 h to obtain furanol.

[0009] Preferably, the mass ratio of 2,5-dimethyl-2-hexanol in the solvent during the etherification reaction is preferably 40-80%.

[0010] The process of purifying 2,5-dimethyl-2-hexanol is as follows: after the etherification reaction is completed, it is firstly distilled under reduced pressure at a vacuum degree of 5 Kpa and a temperature of 95°C to distill out water, ethylene glycol monomethyl ether and 2,5-dimethyl-2-hexanol under reduced pressure, and then the distillate is distilled at 30 Kpa and a temperature of 70°C to distill out water and 2,5-dimethyl-2-hexanol through azeotropic distillation, and then 2,5-dimethyl-2-hexanol is obtained by layering and recycled for the etherification reaction.

[0011] Preferably, when recovering phenols, 2,5-dimethyl-2-hexanol is used as an extractant instead of N503 extractant or methyl isobutyl ketone.

[0012] Beneficial effects: The present invention separates the byproduct 2,5-dimethyl-2-hexanol from the etherification liquid after the etherification reaction, and recycles it back to the etherification reaction for use as a solvent, which can replace all or part of the ethylene glycol monomethyl ether solvent; in the current production process, 2,5-dimethyl-2-hexanol is used as an etherification reaction byproduct for incineration, which not only wastes resources but also increases environmental pressure. In addition, 2,5-dimethyl-2-hexanol can also be used as an extractant for phenol recovery, thereby improving the utilization rate of 2,5-dimethyl-2-hexanol, turning waste into treasure, and saving production costs. Implementation

[0013] The present invention is further illustrated by the following specific examples. Example

[0014] The etherification reaction liquid was distilled under reduced pressure at a vacuum degree of 5 Kpa and a temperature of 95°C to evaporate all the water, ethylene glycol monomethyl ether and 2,5-dimethyl-2-hexanol, and then the distillate was distilled at 30 Kpa and a temperature of 70°C. The distillate was separated into layers, and gas chromatography analysis of the oil layer showed that the content of 2,5-dimethyl-2-hexanol was 99.5%, the content of ethylene glycol monomethyl ether was 0.1%, and the content of water was 0.4%. Example

[0015] (1) The etherification reaction was carried out at a molar ratio of catechol: methallyl chloride: sodium carbonate: solvent = 1:1.2:0.6:8, at a reaction temperature of 105°C and at normal pressure for 5 hours. The mass percentage of ethylene glycol monomethyl ether in the solvent was 60%, the mass percentage of 2,5-dimethyl-2-hexanol was 40%, the conversion rate of o-benzene was 98.3%, and the selectivity of 2-(2-methylallyloxy)phenol was 88.5%.

[0016] (2) According to the method of Example 1, the etherified liquid was filtered to remove the generated sodium chloride, and all the solvents and the by-product 2,5-dimethyl-2-hexanol were removed by reduced pressure distillation, and the remainder was the intermediate product.

[0017] (3) Cyclization reaction: xylene and catalyst aluminum isopropoxide were added to the intermediate product obtained in step (2), the mass percentage of xylene added was 60% of the total mass of the cyclization reaction raw materials, the reaction temperature was raised to 165° C., the reaction pressure was 0.05 MPa for 10 h, and the furanol yield was 62.5%. Example

[0018] (1) The etherification reaction was carried out in a molar ratio of catechol: methallyl chloride: sodium carbonate: solvent = 1:1.2:0.6:8, the reaction temperature was 105°C, the reaction time was 5 h at normal pressure, wherein the mass percentage of ethylene glycol monomethyl ether in the solvent was 20%, the mass percentage of 2,5-dimethyl-2-hexanol was 80%, the conversion rate of o-benzene was 98.8%, and the selectivity of 2-(2-methylallyloxy)phenol was 88.4%.

[0019] (2) According to the method of Example 1, the etherified liquid was filtered to remove the generated sodium chloride, and all the solvents and the by-product 2,5-dimethyl-2-hexanol were removed by reduced pressure distillation, and the remainder was the intermediate product.

[0020] (3) Cyclization reaction: xylene and aluminum isopropoxide catalyst were added to the intermediate product obtained in step (2), the mass percentage of xylene added was 75% of the total mass of the cyclization reaction raw materials, the reaction temperature was raised to 165° C. for 10 h, the pressure was 0.1 MPa, and the furanol yield was 62.1%. Example

[0021] (1) The etherification reaction was carried out in a molar ratio of catechol: methallyl chloride: sodium carbonate: solvent = 1:1.2:0.6:8, the reaction temperature was 105°C, the reaction time was 5 hours at normal pressure, and the solvent was ethylene glycol monomethyl ether. The conversion rate of o-benzene was 98.1%, and the selectivity of 2-(2-methylallyloxy)phenol was 87.6%;

[0022] (2) The etherified liquid was filtered to remove the generated sodium chloride and ethylene glycol monomethyl ether was distilled under reduced pressure according to the method of Example 1, and the remainder was the intermediate product.

[0023] (3) Cyclization reaction: xylene and catalyst aluminum isopropoxide were added to the intermediate product obtained in step (2), the mass percentage of xylene added was 60% of the total mass of the cyclization reaction raw materials, the reaction temperature was raised to 165° C. for 10 h, the pressure was 0.05 MPa, and the furanol yield was 61.5%. Example

[0024] (1) The etherification reaction was carried out in a molar ratio of catechol: methallyl chloride: sodium carbonate: solvent = 1:1:0.5:3, the reaction temperature was 95°C, and the reaction was carried out at normal pressure for 10 hours. The mass percentage of ethylene glycol monomethyl ether in the solvent was 20%, the mass percentage of 2,5-dimethyl-2-hexanol was 80%, the conversion rate of o-benzene was 98.4%, and the selectivity of 2-(2-methylallyloxy)phenol was 88.2%.

[0025] (2) According to the method of Example 1, the etherified liquid was filtered to remove the generated sodium chloride, and all the solvents and the by-product 2,5-dimethyl-2-hexanol were removed by reduced pressure distillation, and the remainder was the intermediate product.

[0026] (3) Cyclization reaction: xylene and catalyst aluminum isopropoxide were added to the intermediate product obtained in step (2), the mass percentage of xylene added was 70% of the total mass of the cyclization reaction raw materials, the reaction temperature was raised to 185° C., the reaction pressure was 0.05 MPa for 2 h, and the furanol yield was 61.8%. Example

[0027] (1) The etherification reaction was carried out in a molar ratio of catechol: methallyl chloride: sodium carbonate: solvent = 1:1.5:0.75:6, the reaction temperature was 110°C, and the reaction was carried out at normal pressure for 1 hour. The mass percentage of ethylene glycol monomethyl ether in the solvent was 60%, the mass percentage of 2,5-dimethyl-2-hexanol was 40%, the conversion rate of o-benzene was 98.1%, and the selectivity of 2-(2-methylallyloxy)phenol was 88.1%.

[0028] (2) According to the method of Example 1, the etherified liquid was filtered to remove the generated sodium chloride, and all the solvents and the by-product 2,5-dimethyl-2-hexanol were removed by reduced pressure distillation, and the remainder was the intermediate product.

[0029] (3) Cyclization reaction: xylene and aluminum isopropoxide catalyst were added to the intermediate product obtained in step (2), the mass percentage of xylene added was 60% of the total mass of the cyclization reaction raw materials, the reaction temperature was raised to 165° C., the reaction pressure was 0.25 MPa for 5 hours, and the furanol yield was 62.4%. Example

[0030] (1) The etherification reaction was carried out at a molar ratio of catechol: methallyl chloride: sodium carbonate: solvent = 1:1.2:0.6:8, at a reaction temperature of 110°C and at normal pressure for 5 hours. The mass percentage of ethylene glycol monomethyl ether in the solvent was 40%, the mass percentage of 2,5-dimethyl-2-hexanol was 60%, the conversion rate of o-benzene was 98.5%, and the selectivity of 2-(2-methylallyloxy)phenol was 88.4%.

[0031] (2) According to the method of Example 1, the etherified liquid was filtered to remove the generated sodium chloride, and all the solvents and the by-product 2,5-dimethyl-2-hexanol were removed by reduced pressure distillation, and the remainder was the intermediate product.

[0032] (3) Cyclization reaction: xylene and catalyst aluminum isopropoxide were added to the intermediate product obtained in step (2), the mass percentage of xylene added was 70% of the total mass of the cyclization reaction raw materials, the reaction temperature was raised to 165° C., the reaction pressure was 0.25 MPa for 2 h, and the furanol yield was 62.3%. Example

[0033] A 10% phenol aqueous solution was prepared and extracted with N503 and 2,5-dimethyl-2-hexanol at 30°C. The results showed that the distribution coefficient when N503 was used as the extractant was 30.5, and the distribution coefficient when 2,5-dimethyl-2-hexanol was used as the extractant was 30.2. Example

[0034] A 5% aqueous solution of catechol was prepared and extracted with methyl isobutyl ketone and 2,5-dimethyl-2-hexanol at 30°C. The results showed that the distribution coefficient was 8.0 when methyl isobutyl ketone was used as the extractant, and the distribution coefficient was 8.2 when 2,5-dimethyl-2-hexanol was used as the extractant.

Claims

1. A process for producing furanol using a by-product as a solvent, characterized in that: (1) Etherification reaction, wherein the materials are added in a molar ratio of catechol: methallyl chloride: sodium carbonate: solvent = 1:1.0-1.5:0.5-0.75:3-8, the reaction temperature is 95-110°C, and the reaction time is 1-10 hours under normal pressure, wherein the solvent is composed of ethylene glycol monomethyl ether and 2,5-dimethyl-2-hexanol, and the mass ratio of 2,5-dimethyl-2-hexanol is 0-80%; (2) removing the solvent, filtering the etherified liquid after the above etherification reaction to remove the generated sodium chloride, removing the by-product 2,5-dimethyl-2-hexanol and the solvent under reduced pressure, and subjecting the intermediate product to the next step of reaction; The process of purifying 2,5-dimethyl-2-hexanol is as follows: after the etherification reaction is completed, the vacuum degree is 5Kpa and the temperature is 95°C, and the water, ethylene glycol monomethyl ether and 2,5-dimethyl-2-hexanol are distilled out under the vacuum degree, and the distillate is then distilled at 30Kpa and the temperature is 70°C, and the water and 2,5-dimethyl-2-hexanol are distilled out by azeotropic distillation, and then the 2,5-dimethyl-2-hexanol is obtained by layering; the 2,5-dimethyl-2-hexanol obtained by the above purification is recycled for the etherification reaction; (3) cyclization reaction, adding xylene and a catalyst aluminum isopropoxide to the intermediate product obtained in step (2), wherein the mass of xylene added is 60-75% of the total mass of the cyclization reaction raw materials, the reaction temperature is 165-185° C., the reaction pressure is 0.05-0.25 MPa, and the reaction time is 2-10 h to obtain furanol.

2. The process for producing furanol using a by-product as a solvent according to claim 1, characterized in that: The mass ratio of 2,5-dimethyl-2-hexanol in the solvent during the etherification reaction is 40-80%.

3. The process for producing furanol using a by-product as a solvent according to claim 1, characterized in that: 2,5-Dimethyl-2-hexanol was used as the extractant for phenol recovery.