Synthetic method of halogenated polystyrene hydantoin

Abstract

The invention discloses a synthetic method of halogenated polystyrene hydantoin. The synthetic method is a one-step synthetic method. The preparation method comprises the following steps: firstly, preparing a raw material for synthesizing halogenated polystyrene hydantoin, and synthesizing 1-halogen-5, 5-dimethyl hydantoin from 5, 5-dimethyl hydantoin and halogen under an alkaline condition; halogenated polystyrene hydantoin, namely 1-halogen-3-(4-polystyrene-benzyl)-5, 5-dimethyl hydantoin, is synthesized from chloromethyl polystyrene and monohalogenated dimethyl hydantoin in one step, so that the synthesis efficiency is high, the cost is low, and large-scale production is facilitated. Meanwhile, halogenated polystyrene hydantoin is synthesized in the solvent, so that swelling of polystyrene is facilitated, the yield is increased, the reaction time is short, the synthesis efficiency is high, and the cost is greatly reduced. The mother liquor is recycled, and the mother liquor contains a large amount of materials during preparation, so that waste liquid discharge is avoided, and the wastewater treatment cost is reduced; and waste is turned into wealth, so that the cost is reduced, the waste can be recycled for multiple times, the wastewater output is reduced, and the wastewater treatment cost and the production cost are further reduced.

Description

Technical Field

[0001] This invention relates to the field of thiophene and its derivatives preparation technology, and more particularly to a method for synthesizing halogenated polystyrene-hydantoin. Background Technology

[0002] Currently, there are two main structural formulas for halogenated polystyrene hydantoin. One is the structural formula disclosed in the invention patent "Highly Cross-linked Microbial Polystyrene Hydantoin Particles" applied for by Auburn University, as shown below.

[0003] Another example is the structural formula disclosed in the invention patent "Polystyrene-supported halogenated hydantoin and its synthesis method and application" applied for by East China Normal University, as shown below.

[0004] The two structural formulas above belong to two types of halogenated polystyrene hydantoins, both of which are immobilized halogenated hydantoins and have disinfection, sterilization, and algae-killing functions. After completing the disinfection, sterilization, and algae-killing tasks, they are converted into polystyrene immobilized hydantoins, which are insoluble in water and have no impact on water quality. In addition, halogenated polystyrene hydantoins also have the characteristics of very slow halogen release and a long applicable period, namely "slow-release and long-lasting". Therefore, they have a good application prospect in the field of high-end disinfection and sterilization.

[0005] These two types of halogenated polystyrene-hydantoin synthesis methods share a common characteristic: both are two-step processes. The first step synthesizes polystyrene-hydantoin, and the second step involves halogenation to synthesize the halogenated polystyrene-hydantoin. The second step is conducted in an aqueous phase, which is a solid-liquid two-phase reaction. This results in low halogenation efficiency, requiring both halogen and alkali to be in excess by 50% to 150%. The halogenation process is lengthy, leading to high post-processing costs and consequently, a high price for halogenated polystyrene-hydantoin, hindering large-scale production.

[0006] Therefore, the development of a new synthesis method is urgently needed. Summary of the Invention

[0007] To address the problems of solid-liquid two-phase reaction, low halogenation efficiency, long halogenation time, high post-processing costs, and high price of halogenated polystyrene-hydantoin in existing synthesis methods, this application proposes a synthesis method for halogenated polystyrene-hydantoin.

[0008] To achieve the objectives of this invention, the following technical solution is provided: A method for synthesizing halogenated polystyrene-hydantoin, the specific steps of which are as follows: Step S1: Synthesis of 1-halo-5,5-dimethylhydantoin The 1-halo-5,5-dimethylhydantoin includes 1-chloro-5,5-dimethylhydantoin and 1-bromo-5,5-dimethylhydantoin; The preparation of 1-chloro-5,5-dimethylhydantoin 5,5-Dimethylhydantoin is first dissolved in an alkaline solution, stirred, and chlorine gas is slowly passed through until the pH reaches 8. After stopping the chlorine gas flow, the reaction continues for 1-2 hours. The product is filtered to obtain a wet product, which is then washed twice to remove adhering impurities. The wet product is then dried to obtain the finished product 1-chloro-5,5-dimethylhydantoin.

[0009] The present invention is further configured such that, in step S1, the 5,5-dimethylhydantoin is in excess by 3-10%.

[0010] Because the stability at position 1 of 5,5-dimethylhydantoin is greater than that at position 3, and because the final pH is high, 5,5-dimethylhydantoin is in excess, and the reaction is extended by 1-2 hours, the final product is 1-chloro-5,5-dimethylhydantoin.

[0011] The preparation of 1-bromo-5,5-dimethylhydantoin 5,5-Dimethylhydantoin was first dissolved in an alkaline solution, and the mixture was stirred. Bromine, in an amount equal to 0.48 moles of 5,5-dimethylhydantoin, was added to the reactor. Chlorine gas was then slowly introduced until the pH reached 8. After stopping the chlorine gas introduction, the reaction continued for 1-2 hours. The wet product was obtained by filtration. The wet product was washed twice to remove adhering impurities. The wet product was then dried to obtain the finished product 1-bromo-5,5-dimethylhydantoin, with a bromine yield of over 95%.

[0012] The present invention is further configured such that, in step S1, the 5,5-dimethylhydantoin is in excess by 6-10%.

[0013] The present invention is further configured such that, in step S1, the molar ratio of 5,5-dimethylhydantoin to bromine is 1:0.3-0.6; The present invention is further configured such that, in step S1, the molar ratio of 5,5-dimethylhydantoin to bromine is 1:0.48; The present invention is further configured such that the mother liquor contains excess 5,5-dimethylhydantoin and sodium bromide, which can be used interchangeably, and the yield can be further improved after the interchangeability.

[0014] Because the stability of 5,5-dimethylhydantoin at position 1 is greater than that at position 3, and because the final pH is higher, 5,5-dimethylhydantoin is in excess, and bromine is slightly less than 5,5-dimethylhydantoin, the reaction is extended for another 1-2 hours, and finally 1-bromo-5,5-dimethylhydantoin is obtained.

[0015] Step S2, Synthesis of 1-Halo-3-(4-polystyrene-benzyl)-5,5-dimethylhydantoin Step S201: At room temperature, first add 200 ml of tetrahydrofuran or DMF to the reactor, then add 20 g of chloromethyl polystyrene, and allow the chloromethyl polystyrene to swell in tetrahydrofuran or DMF for 2 hours.

[0016] Step S202: Start stirring, grind 4-7g of sodium hydroxide or potassium hydroxide into powder, add it to the reaction vessel, wait for the alkali to completely dissolve, raise the temperature to 55-75℃, and form a premixed solution for later use. Step S203: Add 15-22g of 1-halo-5,5-dimethylhydantoin to the premixed solution described in step S202, and react at 55-75℃ for 4-6h.

[0017] Step S204: Stop the reaction, cool down to below 30°C and start filtration. The mother liquor from the first filtration is kept separately. The filter cake is washed once with dilute hydrochloric acid and then washed 2-3 times with pure water until there are no chloride ions, thus obtaining the wet product.

[0018] Step S205: Dry the wet product under reduced pressure at 60℃ for 5-8 hours to obtain 22-25g of halogenated polystyrene hydantoin.

[0019] The present invention is further configured such that in step S203, 1-halo-5,5-dimethylhydantoin is added in 2-3 separate additions.

[0020] The present invention is further configured such that the mother liquor filtered in step S204 contains excess alkali and 1-halo-5,5-dimethylhydantoin, which can be recycled, thus avoiding waste liquid discharge and turning waste into treasure, thereby reducing costs.

[0021] The present invention is further configured such that the chloromethyl polystyrene has a spherical structure.

[0022] Compared with the prior art, the technical solution of this application has the following beneficial effects: 1. This application employs a one-step synthesis method; by first preparing the raw materials for synthesizing halogenated polystyrene-hydantoin, 1-halo-5,5-dimethylhydantoin is synthesized by reacting 5,5-dimethylhydantoin with a halogen under alkaline conditions. The one-step synthesis of halogenated polystyrene-hydantoin, namely 1-halo-3-(4-polystyrene-benzyl)-5,5-dimethylhydantoin, using chloromethyl polystyrene and monohalodimethylhydantoin, is highly efficient, low-cost, and suitable for large-scale production.

[0023] 2. This application synthesizes halogenated polystyrene hydantoin in a solvent, which is beneficial for the swelling of polystyrene, improves the yield, shortens the reaction time, increases the synthesis efficiency, significantly reduces costs, and facilitates the market promotion of the finished product.

[0024] 3. This application avoids waste liquid discharge and reduces wastewater treatment costs by recycling the mother liquor during the preparation of 1-bromo-5,5-dimethylhydantoin, and by using an excess of 5,5-dimethylhydantoin and sodium bromide in the mother liquor. Furthermore, it turns waste into treasure, and can be recycled several times to reduce the amount of wastewater generated, thereby further reducing wastewater treatment costs and production costs.

[0025] 4. This application avoids waste liquid discharge and reduces wastewater treatment costs by recycling the filtered mother liquor, which contains excess alkali and 1-halo-5,5-dimethylhydantoin during the preparation of halogenated polystyrene hydantoin. Furthermore, it turns waste into treasure, and can be recycled several times to reduce the amount of wastewater generated, thereby further reducing wastewater treatment costs and production costs. Detailed Implementation

[0026] Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available conventional products.

[0027] In the following embodiments: Example 1

[0028] A method for synthesizing halogenated polystyrene-hydantoin, wherein the halogenated polystyrene-hydantoin is chlorinated polystyrene-hydantoin, the specific steps of which are as follows: Step S1: Synthesis of 1-chloro-5,5-dimethylhydantoin 5,5-Dimethylhydantoin is first dissolved in an alkaline solution, stirred, and chlorine gas is slowly passed through until the pH reaches 8. After stopping the chlorine gas flow, the reaction continues for 1-2 hours. The product is filtered to obtain a wet product, which is then washed twice to remove adhering impurities. The wet product is then dried to obtain the finished product 1-chloro-5,5-dimethylhydantoin.

[0029] The present invention is further configured such that, in step S1, the 5,5-dimethylhydantoin is in excess by 3-10%.

[0030] Because the stability at position 1 of 5,5-dimethylhydantoin is greater than that at position 3, and because the final pH is high, 5,5-dimethylhydantoin is in excess, and the reaction is extended by 1-2 hours, the final product is 1-chloro-5,5-dimethylhydantoin.

[0031] Step S2, Synthesis of 1-chloro-3-(4-polystyrene-benzyl)-5,5-dimethylhydantoin Step S201: First, add 200 ml of tetrahydrofuran or DMF to the reaction vessel, then add 20 g of chloromethyl polystyrene, and let the chloromethyl polystyrene swell in tetrahydrofuran or DMF for 2 hours.

[0032] Step S202: Start stirring, grind 4-7g of sodium hydroxide or potassium hydroxide into powder, add it to the reaction vessel, wait for the alkali to completely dissolve, and raise the temperature to 55-75℃.

[0033] Step S203: Add 15-22g of 1-chloro-5,5-dimethylhydantoin in 2-3 portions and react at 55-75℃ for 4-6 hours.

[0034] Step S204: Stop the reaction, cool down to below 30°C and start filtration. The mother liquor from the first filtration is kept separately. The filter cake is washed once with dilute hydrochloric acid and then washed 2-3 times with pure water until there are no chloride ions, thus obtaining the wet product.

[0035] Step S205: Dry the wet product under reduced pressure at 60℃ for 5-8 hours to obtain 22-25g of chlorinated polystyrene hydantoin.

[0036] The present invention is further configured such that: chloromethyl polystyrene accounts for more than 20% of the total weight and participates in the reaction, and is white or pale yellow in color, while chloropolystyrene is white. Example 2

[0037] Yield = Amount of 1-bromo-5,5-dimethylhydantoin / Amount of bromine * 100%.

[0038] A method for synthesizing halogenated polystyrene-hydantoin, wherein the halogenated polystyrene-hydantoin is brominated polystyrene-hydantoin, differing from Example 1 in that the steps are as follows: The preparation of 1-bromo-5,5-dimethylhydantoin 5,5-Dimethylhydantoin was first dissolved in an alkaline solution, and the mixture was stirred. Bromine, in an amount equal to 0.48 moles of 5,5-dimethylhydantoin, was added to the reactor. Chlorine gas was then slowly introduced until the pH reached 8. After stopping the chlorine gas introduction, the reaction continued for 1-2 hours. The wet product was obtained by filtration. The wet product was washed twice to remove adhering impurities. The wet product was then dried to obtain the finished product 1-bromo-5,5-dimethylhydantoin, with a bromine yield of over 95%.

[0039] The present invention is further configured such that, in step S1, the 5,5-dimethylhydantoin is in excess by 6-10%.

[0040] The present invention is further configured such that, in step S1, the molar ratio of 5,5-dimethylhydantoin to bromine is 1:0.3-0.6; The present invention is further configured such that, in step S1, the molar ratio of 5,5-dimethylhydantoin to bromine is 1:0.48; The present invention is further configured such that the mother liquor contains excess 5,5-dimethylhydantoin and sodium bromide, which can be used interchangeably, and the yield can be further improved after the interchangeability.

[0041] Because the stability of 5,5-dimethylhydantoin at position 1 is greater than that at position 3, and because the final pH is higher, 5,5-dimethylhydantoin is in excess, and bromine is slightly less than 5,5-dimethylhydantoin, the reaction is extended for another 1-2 hours, and finally 1-bromo-5,5-dimethylhydantoin is obtained.

[0042] Step S2, Synthesis of 1-bromo-3-(4-polystyrene-benzyl)-5,5-dimethylhydantoin Step S201: First, add 200 ml of tetrahydrofuran or DMF to the reaction vessel, then add 20 g of chloromethyl polystyrene, and let the chloromethyl polystyrene swell in tetrahydrofuran or DMF for 2 hours.

[0043] Step S202: Start stirring, grind 4-7g of sodium hydroxide or potassium hydroxide into powder, add it to the reaction vessel, wait for the alkali to completely dissolve, and raise the temperature to 55-75℃.

[0044] Step S203: Add 15-22g of 1-bromo-5,5-dimethylhydantoin in 2-3 portions and react at 55-75℃ for 4-6 hours.

[0045] Step S204: Stop the reaction, cool down to below 30°C and start filtration. The mother liquor from the first filtration is kept separately. The filter cake is washed once with dilute hydrochloric acid and then washed 2-3 times with pure water until there are no chloride ions, thus obtaining the wet product.

[0046] Step S205: Dry the wet product under reduced pressure at 60℃ for 5-8 hours to obtain 22-25g of brominated polystyrene hydantoin.

[0047] The present invention is further configured such that: chloromethyl polystyrene accounts for more than 20% of the total weight and participates in the reaction, and is white or pale yellow in color; and brominated polystyrene is pale yellow.

[0048] The above description is merely a preferred embodiment of the present invention and does not limit the present invention. Those skilled in the art should understand that various modifications and changes can be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined by the claims.

Claims

1. A method for the synthesis of halogenated polystyrene hydantoin, characterized by, The halogenated polystyrene hydantin is chlorinated polystyrene hydantin, and specifically comprises the following steps: Step S1, synthesis of 1-chloro-5, 5-dimethylhydantin First, dissolve 5, 5-dimethylhydantin in lye, start stirring, slowly pass chlorine gas until PH = 8, stop passing chlorine gas and continue to react for 1-2 h, filter to obtain a wet product, wash the wet product twice to remove the adhering impurities, and dry the wet product to obtain the finished product 1-chloro-5, 5-dimethylhydantin; Step S2, synthesis of 1-chloro-3- (4-polystyrene-benzyl) -5, 5-dimethylhydantin Step S201, first add tetrahydrofuran or DMF 200 ml and then chloromethyl polystyrene 20 g to a reaction kettle at room temperature, so that the chloromethyl polystyrene is swelled in tetrahydrofuran or DMF for 2 h; Step S202, start stirring, grind sodium hydroxide or potassium hydroxide 4-7 g into powder, add to the reaction kettle, wait for the base to be completely dissolved, increase the temperature to 55-75 ℃, and form a premixed solution for standby; Step S203, add 1-halo-5, 5-dimethylhydantin 15-22 g to the premixed solution in step S202, and react at 55-75 ℃ for 4-6 h; Step S204, stop the reaction, cool to below 30 ℃, and then start filtering, the first filtrate is reserved separately, the filter cake is first washed with dilute hydrochloric acid once, and then washed with pure water 2-3 times until there is no chlorine ion, to obtain a wet product; Step S205, dry the wet product at 60 ℃ under reduced pressure for 5-8 h to obtain chlorinated polystyrene hydantin 22-25 g.

2. The method of claim 1, wherein the halogenated polystyrene hydantoin is characterized by, In step S1, the 5, 5-dimethylhydantin is 3-10% in excess.

3. The method of claim 1, wherein the 2-thiopheneethanol is synthesized by the reaction of 2-thiopheneboronic acid with 2-bromoethanol in the presence of a catalyst. In step S203, the 1-halo-5, 5-dimethylhydantin is added in 2-3 portions.

4. The method of claim 1, wherein the 2-thiopheneethanol is synthesized by the reaction of 2-thiopheneboronic acid with 2-bromoethanol in the presence of a catalyst. The filtrate in step S204 contains excess base and 1-halo-5, 5-dimethylhydantin, which is recycled.

5. A method for the synthesis of halogenated polystyrene hydantoin, characterized by, The halogenated polystyrene hydantin is brominated polystyrene hydantin, and specifically comprises the following steps: Step S1, synthesis of 1-bromo-5, 5-dimethylhydantin First, dissolve 5, 5-dimethylhydantin in lye, start stirring, add bromine 0.48 times the molar amount of 5, 5-dimethylhydantin to the reaction kettle, then slowly pass chlorine gas until PH = 8, stop passing chlorine gas and continue to react for 1-2 h, filter to obtain a wet product, wash the wet product twice to remove the adhering impurities, and dry the wet product to obtain the finished product 1-bromo-5, 5-dimethylhydantin; Step S2, synthesis of 1-bromo-3- (4-polystyrene-benzyl) -5, 5-dimethylhydantin Step S201, first add tetrahydrofuran or DMF 200 ml and then chloromethyl polystyrene 20 g to a reaction kettle at room temperature, so that the chloromethyl polystyrene is swelled in tetrahydrofuran or DMF for 2 h; Step S202, start stirring, grind sodium hydroxide or potassium hydroxide 4-7 g into powder, add to the reaction kettle, wait for the base to be completely dissolved, increase the temperature to 55-75 ℃, and form a premixed solution for standby; Step S203, add 1-halo-5, 5-dimethylhydantin 15-22 g to the premixed solution in step S202, and react at 55-75 ℃ for 4-6 h; Step S204, stop the reaction, and cool down to below 30℃ to start the filtration. The mother liquor filtered out in the first time is kept separately. The filter cake is washed with dilute hydrochloric acid first, and then with pure water for 2-3 times until there is no chloride ion. The wet product is obtained. Step S205, the wet product is dried at 60℃ under reduced pressure for 5-8h to obtain chlorinated polystyrene hydantin 22-25g.

6. The method of claim 5, wherein the halogenated polystyrene hydantoin is synthesized by the reaction of a halogenated polystyrene and hydantoin in the presence of a base. In the step S1, the 5,5-dimethylhydantin is in excess of 6-10%.

7. The method of claim 5, wherein the 2-thiopheneethanol is synthesized by the reaction of 2-thiopheneboronic acid with 2-bromoethanol in the presence of a catalyst. The molar ratio of the 5,5-dimethylhydantin to bromine is 1:0.3-0.

6.

8. The method of claim 5, wherein the 2-thiopheneethanol is synthesized by the process of: ###0002### 2-thiopheneethanol In the step S203, the 1-halo-5,5-dimethylhydantin is added in 2-3 times.

9. The method of claim 5, wherein the 2-thiopheneethanol is synthesized by the process of: ###0002### 2-thiopheneethanol The mother liquor filtered out in the step S204 contains excess alkali and 1-halo-5,5-dimethylhydantin, which is recycled.

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