A method for preparing resorcinol

Abstract

The present invention discloses a method for preparing resorcinol. Diisopropylbenzene dihydroperoxide is reacted under the conditions of a catalyst and an auxiliary agent to prepare resorcinol. In the present invention, an ionic liquid is used as a cracking catalyst, and an organotin compound is used as a reaction auxiliary agent. By using this method, after reacting for 5 - 10 minutes, the cracking conversion rate of diisopropylbenzene dihydroperoxide can reach over 99%, and the selectivity of resorcinol can reach over 99.5%. At the same time, the process flow can be greatly simplified, and the generation amount of three wastes can be reduced.

Description

Technical Field

[0001] The present invention belongs to the field of organic synthesis and relates to a method for preparing resorcinol by cracking dihydroperoxide - 1,3 - diisopropylbenzene. Background Art

[0002] Resorcinol is mainly used as a pharmaceutical intermediate and special material. Currently, manufacturers of resorcinol globally are mainly distributed in Japan and China. Among them, Sumitomo Corporation of Japan and Zhejiang Longsheng Company are the two major producers and also representatives of two production processes (oxidation process and nitration process), and they have respectively built plants with a production capacity of >2 wt / a. In China, Sichuan Yibin North Special Chemical Industry and Wuhai Shilian Environmental Protection Technology Co., Ltd. have respectively built plants with a production capacity of thousands of tons.

[0003] Sumitomo Corporation of Japan uses m - diisopropylbenzene to prepare dihydroperoxide - 1,3 - diisopropylbenzene through two - step oxidation with air and hydrogen peroxide, and then uses sulfuric acid as a catalyst to crack dihydroperoxide - 1,3 - diisopropylbenzene to prepare resorcinol, which involves steps such as neutralization quenching, water washing, coalescence separation, extraction, stripping, and rectification. The operation is complex, and sodium sulfate wastewater is generated, resulting in high three - waste treatment costs.

[0004] Patent US4339615A reports the use of sulfuric acid, phosphoric acid, perchloric acid, and quenching with alkali after the cracking reaction, which has the problems of a long process flow and difficult treatment of high - salt wastewater; Patent US6350921B1 reports the use of sulfuric acid, SO3, phosphoric acid, hydrochloric acid, boron trifluoride, and p - toluenesulfonic acid as catalysts, all of which require neutralization treatment, resulting in a long process and high wastewater treatment costs; Patent US4283570 reports that solid acids such as cation exchange resin, silica - alumina, and silica - titania can be used as cracking catalysts, but peroxides can cause the resin catalyst to powder, resulting in a short service life of the catalyst, and the acidity of silica - alumina and silica - titania is weak, resulting in low reaction efficiency; Patent US4849549 reports the use of boron trifluoride - ether complex, ferric chloride, and stannic chloride as cracking catalysts, with weak acidity of the catalysts and low reaction efficiency; Patent US4424382 reports the use of superacids such as C1 - 18 perfluoroalkylated superacids and polymeric perfluorosulfonic acid resin (Nafion - H) as catalysts, with high catalyst costs and high costs for treating fluorine - containing solid waste. Summary of the Invention

[0005] To solve the above problems, the present invention provides a method for preparing resorcinol by cracking dihydroperoxide - 1,3 - diisopropylbenzene, which can greatly simplify the process flow, reduce the generation amount of three wastes, and reduce the three - waste treatment cost. By using the method of the present invention, the cracking conversion rate of dihydroperoxide - 1,3 - diisopropylbenzene can reach more than 99% and the selectivity of resorcinol can reach more than 99.5% after reacting for 5 - 10 minutes.

[0006] To achieve the above technical effects, the present invention adopts the following technical solutions:

[0007] A method for preparing resorcinol, wherein dihydroperoxide - 1,3 - diisopropylbenzene is reacted under the conditions of a catalyst and an auxiliary agent to prepare resorcinol. Preferably, the method comprises the following steps:

[0008] 1) Dissolve dihydroperoxide - 1,3 - diisopropylbenzene in a solvent, heat up to the reaction temperature, and establish reflux.

[0009] 2) Add the catalyst and the auxiliary agent to the above reaction solution, start the reaction, and prepare resorcinol.

[0010] In the present invention, after the reaction is completed, the resorcinol product is obtained by rectification separation, and the catalyst and the auxiliary agent are taken out from the bottom of the rectification column and recycled to the reaction system.

[0011] In the present invention, the catalyst is an ionic liquid, and the ionic liquid includes metal - based ionic liquids and non - metal - based ionic liquids. Preferably, it is a non - metal - based ionic liquid, including but not limited to quaternary ammonium salt - based non - metal ionic liquids, quaternary phosphonium salt - based non - metal ionic liquids, alkylpyridine - based non - metal ionic liquids, and alkylimidazole - based non - metal ionic liquids. Preferably, it is an alkylimidazole - based non - metal ionic liquid, and further preferably 1 - ethyl - 3 - methylimidazolium dicyanamide, 1 - butyl - 3 - methylimidazolium chloride, 1 - butyl - 3 - methylimidazolium trifluoroacetate, 1 - butyl - 3 - methylimidazolium p - toluenesulfonate, 1 - hexyl - 3 - methylimidazolium chloride, 1 - pentyl - 3 - methylimidazolium bromide, 1,2 - dimethyl - 3 - hydroxyethylimidazolium hexafluorophosphate, 1,2 - dimethyl - 3 - hydroxyethylimidazolium bis(trifluoromethanesulfonyl)imide, 1,2 - dimethyl - 3 - hydroxyethylimidazolium tetrafluoroborate, 1,2 - dimethyl - 3 - hydroxyethylimidazolium p - toluenesulfonate, 1 - butyl - 2,3 - dimethylimidazolium bis(trifluoromethanesulfonyl)imide, 1 - butyl - 2,3 - dimethylimidazolium tetrafluoroborate. Preferably, they are 1 - butyl - 3 - methylimidazolium p - toluenesulfonate and 1 - butyl - 2,3 - dimethylimidazolium tetrafluoroborate.

[0012] In the present invention, the dosage of the ionic liquid is 0.01 - 0.5% of the mass of dihydroperoxide - 1,3 - diisopropylbenzene, and further preferably 0.1 - 0.3%.

[0013] In the present invention, the auxiliary agent is an organotin compound, including but not limited to methyltriethyltin, butyltriethyltin, octyltriethyltin, phenyltriethyltin, dimethyldiethyltin, dipropyldiethyltin, dibutyldiethyltin, dioctyldiethyltin, diphenyldiethyltin, trimethylethyltin, tripropyethyltin, tributylethyltin, trioctylethyltin, tricyclohexylethyltin, triphenylethyltin, tetraethyltin, tetrabutyltin, tetraphenyltin, heptyltriethyltin, stannous octoate, dibutyltin dilaurate, monobutyltin triisooctoate, preferably dibutyltin dilaurate and monobutyltin triisooctoate; the dosage of the organotin compound is 0.01-0.1% of the mass of dihydroperoxide-1,3-diisopropylbenzene, preferably 0.02-0.05%.

[0014] In the present invention, the preparation method of dihydroperoxide-1,3-diisopropylbenzene is as follows: mix dihydroxy-1,3-diisopropylbenzene and toluene, heat up to 40-50 °C, add sulfuric acid and hydrogen peroxide, react for 2-3 h, and obtain a toluene solution of dihydroperoxide-1,3-diisopropylbenzene through oil-water phase separation; cool the toluene solution of dihydroperoxide-1,3-diisopropylbenzene to -10 °C, crystallize and filter to obtain solid dihydroperoxide-1,3-diisopropylbenzene.

[0015] In the present invention, the solvent is a mixed solvent of toluene and acetone. Among them, the dosage of toluene is 5-30 times the mass of dihydroperoxide-1,3-diisopropylbenzene, preferably 8-10 times; the dosage of acetone is 10-50 times the mass of dihydroperoxide-1,3-diisopropylbenzene, preferably 20-30 times.

[0016] In the present invention, the reaction temperature can be selected from 30-90 °C, preferably 50-70 °C, and the reaction pressure is 38 KPa(A)-286 KPa(A).

[0017] In the present invention, acetone and toluene are recovered by rectification. The rectification pressure is atmospheric pressure, the number of trays is 10-15, and the reflux ratio is 0.5-1; the operating pressure of the resorcinol separation column is 1-5 KPa(A), the number of trays is 40-50, and the reflux ratio is 2-3. The catalyst and the auxiliary agent are returned to the cracking reaction system through bottom draw.

[0018] In the present invention, an ionic liquid is used as a cracking catalyst, and an organotin compound is used as a reaction auxiliary agent. The ionic liquid and the organotin compound can be recycled by rectification, without involving steps such as neutralization quenching, water washing, coalescence separation, extraction, and stripping, which can greatly simplify the process flow, reduce the generation amount of three wastes, and reduce production costs. Using this method, the cracking conversion rate of dihydroperoxide-1,3-diisopropylbenzene can reach more than 99% after reacting for 5-10 min, and the selectivity of resorcinol can reach more than 99.5%.

[0019] The catalytic mechanism of the ionic liquid is speculated as follows: In the present invention, an ionic liquid is used as the catalyst. Compared with concentrated sulfuric acid, the ionic liquid has weak acidity, which can reduce the occurrence of side reactions such as dehydration, demethanolization, and deoxidation, and improve the reaction selectivity. To enhance the catalytic performance of the catalyst, an organotin compound is used as a reaction assistant in the present invention. The tin atom has a lone pair of electrons and has a stabilizing effect on the intermediate containing a positive ion, which can further improve the reaction selectivity.

[0020] The above reaction mechanism route is as follows:

[0021] Specific embodiments

[0022] The present invention will be further described below in conjunction with the embodiments. It should be noted that the embodiments do not constitute a limitation on the scope of protection required by the present invention.

[0023] The detection methods used in the embodiments will be introduced below:

[0024] (1) HPLC method

[0025] In the present invention, high performance liquid chromatography is used to analyze the reaction conversion rate and selectivity. The chromatographic analysis conditions are as follows:

[0026] Instrument model: LC-6A high performance liquid chromatograph (Shimadzu)

[0027] Analysis column: CLC-SIL 150*6.0mm (Shimadzu)

[0028] Preparation column: Zorbax SIL 250*9.4mm (Column Bond)

[0029] Mobile phase: diethyl ether: ethanol: isopropanol: ethylcyclohexane = 13:4:4:65 (v / v)

[0030] Flow rate: 0.8 ml / min

[0031] Column temperature: room temperature

[0032] Wavelength of ultraviolet detector (Shimadzu SPD-6AV ultraviolet-visible spectrophotometric detector): 235 nm

[0033] Source of raw materials:

[0034] Dihydrogen peroxide-1,3-diisopropylbenzene Wuhan Lanaibai Pharmaceutical Chemical Co., Ltd.

[0035] 1-Butyl-3-methylimidazolium p-toluenesulfonate Wuhan Pulov Bio-Tech Co., Ltd.

[0036] 1-Butyl-2,3-dimethylimidazolium tetrafluoroborate Kangdis Chemical Co., Ltd.

[0037] 1,2-Dimethyl-3-hydroxyethylimidazolium hexafluorophosphate, Beijing Huawei Ruike Chemical Co., Ltd.

[0038] Dibutyltin dilaurate, Shandong Huian Chemical Co., Ltd.

[0039] Monobutyltin triisooctanoate, Jiangsu Pulesi Biotechnology Co., Ltd.

[0040] Tetraphenyltin, TCI Reagent Co., Ltd.

[0041] Example 1

[0042] 10 g of dihydroperoxide-1,3-diisopropylbenzene, 50 g of toluene and 100 g of acetone were added to a 500 mL stainless steel reactor equipped with a reflux condenser. After the reactor was purged with nitrogen three times, the system pressure was controlled at 286 KPa(A) using a back pressure valve, and the temperature of the reactor was raised to 90 °C through a circulating oil bath.

[0043] Meanwhile, 0.001 g of 1-butyl-3-methylimidazolium p-toluenesulfonate and 0.001 g of dibutyltin dilaurate were added to the system. The reaction time was started, and the reaction was carried out for 10 min. Sampling and analysis were performed. By HPLC analysis, the conversion rate of dihydroperoxide-1,3-diisopropylbenzene was 99.53%, and the selectivity for resorcinol was 99.89%.

[0044] The reaction solution was recovered for acetone and toluene by distillation. The distillation pressure was atmospheric pressure, the number of trays was 15, and the reflux ratio was 0.5; the operating pressure of the resorcinol separation column was 1 KPa(A), the number of trays was 50, and the reflux ratio was 2. The catalyst and additives were withdrawn from the bottom of the column and returned to the cracking reaction system.

[0045] Example 2

[0046] 10 g of dihydroperoxide-1,3-diisopropylbenzene, 300 g of toluene and 500 g of acetone were added to a 1000 mL stainless steel reactor equipped with a reflux condenser. After the reactor was purged with nitrogen three times, the system pressure was controlled at 38 KPa(A) using a vacuum pump, and the temperature of the reactor was raised to 30 °C through a circulating oil bath.

[0047] Meanwhile, 0.05 g of 1-butyl-2,3-dimethylimidazolium tetrafluoroborate and 0.01 g of monobutyltin triisooctanoate were added to the system. The reaction time was started, and the reaction was carried out for 5 min. Sampling and analysis were performed. By HPLC analysis, the conversion rate of dihydroperoxide-1,3-diisopropylbenzene was 99.47%, and the selectivity for resorcinol was 99.86%.

[0048] The reaction solution recovers acetone and toluene through distillation. The distillation pressure is atmospheric pressure, the number of trays is 10, and the reflux ratio is 1; the operating pressure of the resorcinol separation column is 5 KPa(A), the number of trays is 40, and the reflux ratio is 3. The catalyst and additives are withdrawn from the bottom of the column and returned to the cracking reaction system.

[0049] Example 3

[0050] 10 g of dihydroperoxide-1,3-diisopropylbenzene, 200 g of toluene, and 300 g of acetone were added to a 1000 mL stainless steel reactor with reflux condensation. After purging the reactor with nitrogen three times, the system pressure was controlled at 82 KPa(A) using a vacuum pump, and the temperature of the reactor was raised to 50 °C through a circulating oil bath.

[0051] Meanwhile, 0.02 g of 1,2-dimethyl-3-hydroxyethylimidazolium hexafluorophosphate and 0.005 g of tetraphenyltin were added to the system, and the reaction time was started. After reacting for 7 min, a sample was taken for analysis. By HPLC analysis, the conversion rate of dihydroperoxide-1,3-diisopropylbenzene was 99.19%, and the selectivity for resorcinol was 99.54%.

[0052] The reaction solution recovers acetone and toluene through distillation. The distillation pressure is atmospheric pressure, the number of trays is 13, and the reflux ratio is 0.8; the operating pressure of the resorcinol separation column is 3 KPa(A), the number of trays is 45, and the reflux ratio is 2.5. The catalyst and additives are withdrawn from the bottom of the column and returned to the cracking reaction system.

[0053] Comparative Example 1

[0054] 10 g of dihydroperoxide-1,3-diisopropylbenzene, 200 g of toluene, and 300 g of acetone were added to a 1000 mL stainless steel reactor with reflux condensation. After purging the reactor with nitrogen three times, the system pressure was controlled at 82 KPa(A) using a vacuum pump, and the temperature of the reactor was raised to 50 °C through a circulating oil bath.

[0055] 0.02 g of 1,2-dimethyl-3-hydroxyethylimidazolium hexafluorophosphate was added to the system, and the reaction time was started. After reacting for 7 min, a sample was taken for analysis. By HPLC analysis, the conversion rate of dihydroperoxide-1,3-diisopropylbenzene was 98.03%, and the selectivity for resorcinol was 98.71%.

[0056] The reaction solution recovers acetone and toluene through distillation. The distillation pressure is atmospheric pressure, the number of trays is 13, and the reflux ratio is 0.8; the operating pressure of the resorcinol separation column is 3 KPa(A), the number of trays is 45, and the reflux ratio is 2.5. The catalyst is withdrawn from the bottom of the column and returned to the cracking reaction system.

[0057] Comparative Example 2

[0058] 10 g of 1,3-diisopropylbenzene dihydroperoxide, 200 g of toluene and 300 g of acetone were added to a 1000 mL stainless steel reactor equipped with a reflux condenser. After the reactor was purged with nitrogen three times, the system pressure was controlled at 82 KPa(A) using a vacuum pump. The reactor was heated by a circulating oil bath. After the temperature reached 50 °C, the reaction time was started. The reaction was carried out for 7 min, and then a sample was taken for analysis. By HPLC analysis, the conversion rate of 1,3-diisopropylbenzene dihydroperoxide was 6.44%, and the selectivity for resorcinol was 84.59%.

[0059] Comparative Example 3

[0060] 10 g of 1,3-diisopropylbenzene dihydroperoxide, 200 g of toluene and 300 g of acetone were added to a 1000 mL stainless steel reactor equipped with a reflux condenser. After the reactor was purged with nitrogen three times, the system pressure was controlled at 82 KPa(A) using a vacuum pump. The temperature of the reactor was raised to 50 °C by a circulating oil bath.

[0061] 0.02 g of 98% sulfuric acid was added to the system, and the reaction time was started. The reaction was carried out for 7 min, and then a sample was taken for analysis. By HPLC analysis, the conversion rate of 1,3-diisopropylbenzene dihydroperoxide was 97.31%, and the selectivity for resorcinol was 96.17%.

Claims

1. A method for preparing resorcinol, characterized in that, React dihydroperoxide-1,3-diisopropylbenzene under the conditions of a catalyst and an auxiliary agent to prepare resorcinol; The catalysts are 1-butyl-3-methylimidazolium p-toluenesulfonate, 1,2-dimethyl-3-hydroxyethylimidazolium hexafluorophosphate, 1,2-dimethyl-3-hydroxyethylimidazolium tetrafluoroborate, 1,2-dimethyl-3-hydroxyethylimidazolium p-toluenesulfonate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate; The auxiliary agents are selected from methyltriethyltin, butyltriethyltin, octyltriethyltin, phenyltriethyltin, dimethyldiethyltin, dipropyldiethyltin, dibutyldiethyltin, dioctyldiethyltin, diphenyldiethyltin, trimethylethyltin, tripropyethyltin, tributylethyltin, trioctylethyltin, tricyclohexylethyltin, triphenylethyltin, tetraethyltin, tetrabutyltin, tetraphenyltin, heptyltriethyltin, dibutyltin dilaurate, monobutyltin triisooctanoate.

2. The method according to claim 1, characterized in that, The catalyst is 1-butyl-3-methylimidazolium p-toluenesulfonate or 1-butyl-2,3-dimethylimidazolium tetrafluoroborate.

3. The method according to claim 1, wherein The dosage of the catalyst is 0.01-0.5% of the mass of dihydroperoxide-1,3-diisopropylbenzene.

4. The method according to claim 3, wherein The dosage of the catalyst is 0.1-0.3% of the mass of dihydroperoxide-1,3-diisopropylbenzene.

5. The method according to claim 1, wherein The auxiliary agents are selected from dibutyltin dilaurate and monobutyltin triisooctanoate.

6. The method according to claim 1, characterized in that, The dosage of the auxiliary agent is 0.01-0.1% of the mass of dihydroperoxide-1,3-diisopropylbenzene.

7. The method according to claim 6, wherein The dosage of the auxiliary agent is 0.02-0.05% of the mass of dihydroperoxide-1,3-diisopropylbenzene.

8. The method according to claim 1, wherein The method includes the following steps: 1) Dissolve dihydroperoxide-1,3-diisopropylbenzene in a solvent, heat up to the reaction temperature, and establish reflux; 2) Add the catalyst and the auxiliary agent to the above reaction solution, start the reaction, and prepare resorcinol.

9. The method according to claim 8, characterized in that, After the reaction is completed, the resorcinol product is obtained by rectification separation, and the catalyst and the auxiliary agent are taken out from the bottom of the rectification column and recycled to the reaction system.

10. The method according to claim 8, wherein The rectification pressure is atmospheric pressure, the number of trays is 10-15, and the reflux ratio is 0.5-1; the operating pressure of the resorcinol separation column is 1-5 KPa, the number of trays is 40-50, and the reflux ratio is 2-3.

11. The method according to claim 1, characterized in that, The preparation method of the dihydroperoxide-1,3-diisopropylbenzene is as follows: Mix dihydroxy-1,3-diisopropylbenzene and toluene, heat up to 40-50 °C, add sulfuric acid and hydrogen peroxide, react for 2-3 h, and obtain a toluene solution of dihydroperoxide-1,3-diisopropylbenzene through oil-water phase separation; Cool the toluene solution of dihydroperoxide-1,3-diisopropylbenzene to crystallize and filter to obtain solid dihydroperoxide-1,3-diisopropylbenzene.

12. The method according to claim 8, wherein The solvent is a mixed solvent of toluene and acetone. Among them, the dosage of toluene is 5-30 times the mass of dihydroperoxide-1,3-diisopropylbenzene; the dosage of acetone is 10-50 times the mass of dihydroperoxide-1,3-diisopropylbenzene.

13. The method according to claim 12, wherein The solvent is a mixed solvent of toluene and acetone. Among them, the dosage of toluene is 8-10 times the mass of dihydroperoxide-1,3-diisopropylbenzene; the dosage of acetone is 20-30 times the mass of dihydroperoxide-1,3-diisopropylbenzene.

14. The method according to claim 1, wherein The reaction temperature is 30 - 90 °C, and the reaction pressure is 38 KPa - 286 KPa.

15. The method according to claim 14, characterized in that, The reaction temperature is 50 - 70 °C.

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