A process for the preparation of benzofuranones

Abstract

The application belongs to the technical field of chemical process, and discloses a preparation method of benzofuranone, which comprises the following steps: S1, putting o-chlorobenzoic acid, lye and quinoline copper complex into a pressurized kettle and reacting for 8-10 hours; S2, cooling the reaction liquid in the step S1 to below 25 DEG C, slowly adding concentrated hydrochloric acid into the reaction kettle under stirring, and adjusting the pH to 3-4; S3, transferring the reaction liquid in the step S2 into a dehydration kettle, putting toluene into the dehydration kettle, heating to 90-110 DEG C, and co-boiling and dehydrating, and then transferring to a cyclization kettle; S4, putting an acid catalyst into the cyclization kettle, stirring the dehydration material, and performing a cyclization reaction to generate benzofuranone. The application has the beneficial effects that the quinoline copper complex is used as a catalyst, the yield is increased by 11% compared with copper chloride, the yield of the improved method can reach 96%, the reaction temperature and the reaction pressure are reduced, the reaction conditions are improved, and the energy consumption and the safety coefficient are reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chemical processes, and particularly relates to a preparation method of benzofuranone. BACKGROUND

[0002] 3-benzofuranone is a very important fine chemical product and organic synthesis intermediate, and is widely applied in the fields of medicines, antioxidants and the like. Traditional synthesis of 3-benzofuranone mainly uses phenol and chloroacetyl chloride as raw materials, and is synthesized through acylation, rearrangement and cyclization steps, which is complicated, has low yield and needs a large amount of catalyst, thereby causing environmental pollution.

[0003] A synthesis method of methoxybenzofuranone is disclosed in Chinese patent application No. 201910069832.1, in which o-chlorophenylacetic acid, liquid alkali and a catalyst are reacted, and then concentrated hydrochloric acid is used for acidification, distillation and dehydration. After dehydration, cyclization is performed, and then alkali washing, water washing and concentration are performed. Trimethyl orthoformate, acetic anhydride and synthesized benzofuranone are reacted, and then deacidification, dissolution, water washing and desolubilization are performed to obtain methoxybenzofuranone. In the existing synthesis method using o-chlorophenylacetic acid as a raw material, the catalyst is usually copper chloride, but copper chloride corrodes equipment and has a high requirement on the equipment. In the cyclization process, concentrated sulfuric acid is used as a catalyst, and the concentrated sulfuric acid cannot be collected and recycled after the reaction is completed. A large amount of alkali liquor needs to be used for neutralization, the amount of reagent is large, and the operation process is complicated. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of benzofuranone, which has the effects of high yield, mild reaction and no corrosion to equipment.

[0005] The above technical purpose of the present application is achieved by the following technical scheme: a preparation method of benzofuranone, comprising the following steps:

[0006] S1, o-chlorophenylacetic acid, alkali liquor and quinoline copper complex are put into a pressurized kettle, and reacted for 8-10 hours;

[0007] S2, the reaction liquid in step S1 is cooled to below 25 DEG C, and concentrated hydrochloric acid is slowly added into the reaction kettle under stirring to adjust the pH to 3-4;

[0008] S3, the reaction liquid in step S2 is transferred into a dehydration kettle, toluene is put into the dehydration kettle, and the temperature is raised to 90-110 DEG C for azeotropic distillation and dehydration. After dehydration, the reaction liquid is transferred into a cyclization kettle;

[0009] S4, an acid catalyst is put into the cyclization kettle, and the dehydration material is stirred to perform cyclization reaction to generate benzofuranone.

[0010] The application further provides that the method further comprises the following steps: after the cyclization is completed, centrifugation is performed to separate the solid acid catalyst from the material, the centrifuged material is placed in an alkali washing kettle, an alkali reagent is added, and after stirring and mixing, the mixture is left to separate into layers, after the alkali washing is completed, the organic matter is subjected to water washing and distillation at 80 DEG C to remove toluene, and when the toluene distillate obtained from the distillation kettle is not collected, the system is switched to a benzofuranone product tank, and the benzofuranone product can be obtained.

[0011] The application further provides that the mass ratio of the o-chlorophenylacetic acid to the quinoline copper complex is 50:1.

[0012] The application further provides that the reaction temperature of the pressurized kettle is 150 DEG C, and the reaction pressure is 0.4 Mpa.

[0013] The application further provides that the catalyst is a sulfonated activated carbon solid acid catalyst.

[0014] The application further provides that the solid acid catalyst is prepared according to the following steps:

[0015] S1, the activated carbon is mixed with 50% oleum, heated for 5-8 hours to obtain a sulfonated activated carbon product;

[0016] S2, after the sulfonated activated carbon product is cooled, the filtrate is washed with deionized water until neutral, and the sulfonated activated carbon solid acid catalyst is obtained after drying.

[0017] The application further provides that the activated carbon is pretreated with potassium permanganate, and the pretreatment steps are as follows: a 5%-10% potassium permanganate solution is prepared, the activated carbon is mixed with the potassium permanganate solution, stirred for 1-2 hours, then the potassium permanganate in the activated carbon is washed clean with deionized water, and the pretreated activated carbon is obtained after drying.

[0018] The application has the following beneficial effects:

[0019] 1. The quinoline copper complex is used as the catalyst, and the yield is increased by 11% compared with the yield of copper chloride, the improved yield can reach 96%, the reaction temperature and the reaction pressure are reduced, the reaction conditions are improved, the energy consumption and the safety factor are reduced, the copper chloride corrodes the equipment, and the improved process can be completed by using ordinary equipment.

[0020] 2. The solid acid catalyst is used, the catalyst can be recovered after the cyclization reaction is completed, and the catalyst can be reused, the acid content in the material after the cyclization is completed is small, the alkali washing can be performed by using a small amount of alkali liquor, the waste water generated is small, and the reaction time is shortened.

[0021] 3. The activated carbon is non-polar, the water absorption capacity is general, and the activated carbon absorbs water mainly by using micropores to adsorb water molecules, and the water molecules are still free water inside the activated carbon; the activated carbon is pretreated by potassium permanganate, the aromatic carbon atoms on the surface of the activated carbon are oxidized into hydroxyl groups, the introduction of the hydroxyl groups on the activated carbon can improve the adsorption effect of the activated carbon on water molecules, the water molecules generated by the ring closing reaction are combined with the hydroxyl groups through hydrogen bonds to form combined water, the activity is low, and the ring closing reaction can be promoted, the yield of benzofuranone is improved, and the hydrolysis of water molecules on the sulfonic acid groups on the solid acid catalyst can be reduced. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0023] Embodiment 1

[0024] A preparation method of benzofuranone, characterized in that the method comprises the following steps:

[0025] S1, 500 kg of o-chlorobenzoic acid is put into 1500 kg of 30% sodium hydroxide aqueous solution, mixed with 10 kg of copper chloride, and then put into a pressure kettle, and the reaction is carried out for 8-10 h, the reaction temperature of the pressure kettle is 180 DEG C, and the reaction pressure is 0.6 Mpa;

[0026] S2, the reaction liquid in step S1 is cooled to below 25 DEG C, and under the stirring state, concentrated hydrochloric acid is slowly added into the reaction kettle, and the pH is adjusted to 3-4;

[0027] S3, the reaction liquid in step S2 is transferred into a dehydration kettle, toluene is put into the dehydration kettle, the temperature is raised to 90-110 DEG C, and the dehydration is carried out by azeotropic distillation, and after the dehydration is completed, it is transferred into a cyclization kettle;

[0028] S4, concentrated sulfuric acid is put into the cyclization kettle, and the dehydration material is stirred to carry out the cyclization reaction, and benzofuranone is generated;

[0029] S5, after the cyclization is completed, an alkali reagent is added, and after stirring and mixing, it is left to separate into layers, after the alkali washing is completed, the organic matter is washed with water, and toluene is distilled at 80 DEG C, when the toluene distillate obtained from the distillation kettle is not obtained, the benzofuranone product tank is switched, and the benzofuranone product can be obtained.

[0030] The yield of benzofuranone obtained is 86%.

[0031] Embodiment 2

[0032] A method for preparing a benzofuranone, characterized in that it comprises the following steps:

[0033] S1, 500 kg of o-chlorobenzoic acid is put into 1500 kg of 30% sodium hydroxide aqueous solution, mixed with 10 kg of quinoline copper complex, and then put into a pressure kettle, and reacted for 8-10 h, the reaction temperature of the pressure kettle is 150 DEG C, and the reaction pressure is 0.4 Mpa;

[0034] S2, the reaction liquid in step S1 is cooled to below 25 DEG C, and under stirring, concentrated hydrochloric acid is slowly added into the reaction kettle to adjust the pH to 3-4;

[0035] S3, the reaction liquid in step S2 is transferred into a dehydration kettle, toluene is put into the dehydration kettle, heated to 90-110 DEG C, and co-boiling distillation dehydration is carried out, and after dehydration is completed, it is transferred into a cyclization kettle;

[0036] S4, concentrated sulfuric acid is put into the cyclization kettle, and the dehydration material is stirred to carry out cyclization reaction to generate benzofuranone;

[0037] S5, after the cyclization is completed, an alkali reagent is added, and after stirring and mixing, it is left to separate into layers, after alkali washing is completed, the organic matter is washed with water, and toluene is distilled at 80 DEG C, when the toluene distillate obtained from the distillation kettle is not taken out, it is switched to a benzofuranone product tank, and the benzofuranone product can be obtained.

[0038] The yield of benzofuranone is 93%, which shows that by using quinoline copper complex as a catalyst, the reaction temperature and reaction pressure are reduced, the reaction conditions are improved, and the energy consumption and safety factor are reduced.

[0039] Example 3

[0040] A method for preparing a benzofuranone, characterized in that it comprises the following steps:

[0041] S1, 500 kg of o-chlorobenzoic acid is put into 1500 kg of 30% sodium hydroxide aqueous solution, mixed with 10 kg of quinoline copper complex, and then put into a pressure kettle, and reacted for 8-10 h, the reaction temperature of the pressure kettle is 150 DEG C, and the reaction pressure is 0.4 Mpa;

[0042] S2, the reaction liquid in step S1 is cooled to below 25 DEG C, and under stirring, concentrated hydrochloric acid is slowly added into the reaction kettle to adjust the pH to 3-4;

[0043] S3, the reaction liquid in step S2 is transferred into a dehydration kettle, toluene is put into the dehydration kettle, heated to 90-110 DEG C, and co-boiling distillation dehydration is carried out, and after dehydration is completed, it is transferred into a cyclization kettle;

[0044] S4, concentrated sulfuric acid is put into the cyclization kettle, and the dehydration material is stirred to carry out cyclization reaction to generate benzofuranone;

[0045] S5, after the cyclization is completed, centrifugal separation is performed to separate the solid acid catalyst from the material, the centrifuged material is placed in an alkali washing kettle, an alkali reagent is added, and after stirring and mixing, the mixture is allowed to stand and separate into layers, after the alkali washing is completed, the organic matter is washed with water and distilled at 80°C to remove toluene, when the toluene distillate obtained from the distillation kettle is not collected, the system is switched to a benzofuranone product tank, and the benzofuranone product can be obtained.

[0046] The acid catalyst is a sulfonated activated carbon solid acid catalyst, which is prepared by the following steps:

[0047] S1, the activated carbon is pretreated with potassium permanganate, the pretreatment steps are as follows: a 5% to 10% potassium permanganate solution is prepared, the activated carbon is mixed with the potassium permanganate solution, stirred for 1 to 2 hours, then the potassium permanganate in the activated carbon is washed clean with deionized water, and the pretreated activated carbon is obtained after drying.

[0048] S2, the activated carbon is mixed with 50% oleum, heated for 5 to 8 hours, and the sulfonated activated carbon product is obtained;

[0049] S3, after the sulfonated activated carbon product is cooled, the filtrate is washed with deionized water until it is neutral, and the sulfonated activated carbon solid acid catalyst is obtained after drying.

[0050] The yield of benzofuranone is 98%, the sulfonated activated carbon solid acid catalyst can be recycled for 4 times, and the solid acid catalyst is convenient for catalyst recovery and reuse after the completion of the cyclization reaction.

[0051] Example 4

[0052] A method for preparing benzofuranone, characterized in that it comprises the following steps:

[0053] S1, 500 kg of o-chlorobenzoic acid is placed in 1500 kg of 30% sodium hydroxide aqueous solution, mixed with 10 kg of quinoline copper complex, and then put into a pressure kettle, the reaction is carried out for 8 to 10 hours, the reaction temperature of the pressure kettle is 150°C, and the reaction pressure is 0.4 Mpa;

[0054] S2, the reaction liquid in step S1 is cooled to below 25°C, and under stirring, concentrated hydrochloric acid is slowly added into the reaction kettle to adjust the pH to 3 to 4;

[0055] S3, the reaction liquid in step S2 is transferred into a dehydration kettle, toluene is put into the dehydration kettle, and the temperature is raised to 90 to 110°C for azeotropic distillation dehydration, and after the dehydration is completed, it is transferred into a cyclization kettle;

[0056] S4, the acid catalyst is put into the cyclization kettle, and the dehydration material is stirred to perform cyclization reaction to generate benzofuranone;

[0057] S5, after the ring closing, centrifugal separation is performed to separate the solid acid catalyst from the material, the centrifuged material is placed in an alkali washing kettle, an alkali reagent is added, and after stirring and mixing, the mixture is allowed to stand and separate into layers, after the alkali washing is completed, the organic matter is subjected to water washing and distillation at 80 DEG C to remove toluene, when the distillate toluene obtained from the distillation kettle is not collected, switching to a benzofuranone product tank is performed, and thus the benzofuranone product can be obtained.

[0058] The acid catalyst is a sulfonated activated carbon solid acid catalyst, which is prepared according to the following steps:

[0059] S1, the activated carbon is mixed with 50% oleum, heated for 5-8h, and a sulfonated activated carbon product is obtained;

[0060] S2, after the sulfonated activated carbon product is cooled, the filtrate is washed with deionized water until it becomes neutral, and then the sulfonated activated carbon solid acid catalyst is obtained after drying.

[0061] The yield of benzofuranone is 96%, and the sulfonated activated carbon solid acid catalyst can be recycled for 2 times, which indicates that the pretreatment of the activated carbon with potassium permanganate can oxidize the aromatic carbon atoms on the surface of the activated carbon into hydroxyl groups, introduce hydroxyl groups on the activated carbon, improve the adsorption effect of the activated carbon on water molecules, combine the water molecules produced in the ring closing reaction with the hydroxyl groups through hydrogen bonds to form combined water, and promote the ring closing reaction, thereby improving the yield of benzofuranone. At the same time, it can also reduce the hydrolysis of the sulfonic acid groups on the solid acid catalyst by water molecules, avoid the deactivation of the solid acid catalyst, and improve the number of times the solid acid catalyst can be used.

Claims

1. A process for the preparation of a benzofuranone, characterized in that: It comprises the following steps: S1, the o-chlorobenzoic acid, lye, quinoline copper complex into the autoclave, reaction 8~10h; S2, the reaction liquid in step S1 is cooled to below 25℃, and under stirring, concentrated hydrochloric acid is slowly added into the reaction kettle, and the pH is adjusted to 3~4; S3, the reaction liquid in step S2 is transferred into the dehydration kettle, toluene is put into the dehydration kettle, and the temperature is raised to 90~110℃, and the dehydration is carried out by co-boiling distillation, and after the dehydration is completed, it is transferred to the cyclization kettle; S4, the acid catalyst is put into the cyclization kettle, and the dehydration material is stirred to carry out cyclization reaction, and benzofuranone is generated; The acid catalyst is a sulfonated activated carbon solid acid catalyst; The sulfonated activated carbon solid acid catalyst is prepared by the following steps: S1, the activated carbon is mixed with 50% oleum, heated for 5~8h, and the sulfonated activated carbon product is obtained; S2, after the sulfonated activated carbon product is cooled, the filtrate is washed with deionized water until it is neutral, and the sulfonated activated carbon solid acid catalyst is obtained after drying; The activated carbon is pretreated with potassium permanganate, and the pretreatment steps are as follows: a 5%~10% potassium permanganate solution is prepared, the activated carbon is mixed with the potassium permanganate solution, stirred for 1~2h, then the potassium permanganate in the activated carbon is washed clean with deionized water, and the pretreated activated carbon is obtained after drying.

2. The method for preparing a benzofuranone according to claim 1, characterized in that: It also comprises the following steps: after the cyclization is completed, centrifugation is carried out, the sulfonated activated carbon solid acid catalyst is separated from the material, the centrifuged material is put into the alkali washing kettle, the alkali reagent is added, and after stirring and mixing, it is left to separate layers, after the alkali washing is completed, the organic matter is washed with water, distilled at 80℃ to remove toluene, and when the distillate toluene obtained from the distillation kettle is not collected, the benzofuranone product tank is switched, and the benzofuranone product can be obtained.

3. The method for preparing benzofuranone according to claim 1, characterized in that: The mass ratio of the o-chlorobenzoic acid to the quinoline copper complex is 50:

1.

4. The method for preparing a benzofuranone according to claim 1, characterized in that: The reaction temperature of the autoclave is 150℃, and the reaction pressure is 0.4Mpa.