CN104829540A - Bromo-chloro dimethyl hydantoin synthesis method - Google Patents

Abstract

The present invention relates to a kind of synthesis method of bromochlorodimethylhydantoin, especially sodium sulfamate, sodium glycine, urea or their mixture is added into the dimethylhydantoin solution as sodium hypochlorite stabilizer, and the stabilizer can be mixed with oxidant Hypochlorous acid forms oxidative ligands that serve as a medium for the oxidative halogenation of dimethylhydantoin for the halogenation of dimethylhydantoin. The stabilizer can not only prevent the decomposition of sodium hypochlorite, but also prevent its deep oxidation and decomposition of dimethylhydantoin, thereby improving the synthesis yield and reducing the production cost. The invention does not use volatile and highly corrosive chemical raw materials, the reaction process is easy to control, the production process is safe and environment-friendly, and can meet the requirements of industrial production.

Description

A kind of synthetic method of bromochlorodimethylhydantoin

technical field

The invention relates to a synthesis method of bromochlorodimethylhydantoin, in particular adding a sodium hypochlorite stabilizer to the dimethylhydantoin solution, the stabilizer can form an oxidizing ligand with the oxidant hypochlorous acid, as dimethylhydantoin Because the medium of oxidative halogenation improves the reaction conditions, it belongs to the field of fine chemical industry.

Background technique

Bromochlorodimethylhydantoin is a new type of sterilizing and disinfecting water treatment agent, widely used in industrial water treatment systems, indoor and outdoor swimming (bath) pools, sanitation systems and aquaculture water environment disinfection treatment, can kill a variety of bacteria and Viruses, prevention and treatment of aquaculture animal diseases caused by bacteria and viruses. Because of its high effective halogen content, good stability, low odor, slow release, and no irritation to skin and mucous membranes, it has a tendency to replace chlorine and chlorinated isocyanuric acid biocides. At present, the market demand is rapidly increasing to several The improvement of synthetic methods has also received extensive attention.

The preparation methods of bromochlorodimethylhydantoin include indirect halogenation of hypohalite, indirect halogenation of bromide and chlorine, and direct halogenation of halogen and alkali. The hypohalite indirect halogenation method uses hypohalite as the halogenating agent to indirectly halogenate 5,5-dimethylhydantoin. The production process and equipment of this method are relatively simple, and no dangerous chemical raw materials are used. The disadvantage is the oxidation ability of hypohalite Too strong and the raw materials are easy to decompose, which affects the reaction yield and raw material consumption, making it difficult for industrial application. The bromide and chlorine indirect halogenation method uses chlorine gas to oxidize the bromide ion in the bromide to bromine, brominates 5,5-dimethylhydantoin, and then chlorinates it. Although this method does not directly use volatile bromine raw material, but the consumption of chlorine gas is relatively large. In addition, the use, storage and transportation of raw material chlorine gas have high requirements, which is not suitable for small-scale intermittent production. The direct halogenation method of halogen and alkali is to add dimethyl hydantoin to the reaction mother liquor, first add bromine for bromination, and then introduce chlorine gas for chlorination, after the reaction is complete, separate bromohalogen hydantoin and precipitate, wash the precipitate, and dry to obtain the finished product. The mother liquor can be recycled. This method is the most commonly used production method for bromohalogenated hydantoin. The disadvantage is that bromine and chlorine gas are volatile and highly corrosive chemical products, which require high production equipment and process operations, and prominent safety and environmental protection issues.

Contents of the invention

The purpose of the present invention is to overcome the outstanding shortcomings of the existing bromochlorodimethylhydantoin synthesis method in terms of safety and environmental protection, and provide a safe and environmentally friendly synthesis method of bromochlorodimethylhydantoin with a simple production process and no use of dangerous chemical raw materials .

The principle and main process of the present invention is to add sodium hypochlorite stabilizer in the dimethylhydantoin solution, when adding oxidant sodium hypochlorite in the reaction process, the stabilizer can form oxidation ligand with hypochlorous acid, it acts as dimethylhydantoin Oxidative halogenation medium, oxidizing sodium bromide in the reaction solution to bromine in situ, and the bromine produced by the reaction is then reacted with dimethylhydantoin to generate monobromodimethylhydantoin, so that the bromine in the reaction solution The sodium is fully utilized, and the oxidation ligand further oxidizes the sodium chloride in the reaction solution to chlorine, and the chlorine produced by the reaction is chlorinated with bromodimethylhydantoin to generate bromochlorodimethylhydantoin. The oxidation ligand formed by the stabilizer and hypochlorous acid improves the stability of sodium hypochlorite and reduces its oxidation activity, which can prevent the decomposition of sodium hypochlorite and prevent its deep oxidation and decomposition of dimethylhydantoin raw materials.

The sodium hypochlorite stabilizer used in the present invention is sodium sulfamate, sodium glycine, urea or a mixture thereof, and its molar ratio of feeding is: sodium hypochlorite: stabilizer=1:0.1-0.2. Because the stabilizer is easily soluble in water, it is very easy to separate from the bromochlorodimethylhydantoin product, so it is easy to realize the repeated use of the stabilizer.

The technical scheme and synthetic steps that the inventive method takes are:

(1) Add dimethyl hydantoin, sodium bromide, sodium hypochlorite stabilizer and deionized water into the reactor, cool the reaction solution to 5-25°C with ice salt bath under stirring, slowly add sodium hypochlorite solution, when the reaction The bromination reaction is completed when the liquid turns from colorless to yellow and gradually turns white again;

(2) Further slowly add sodium hypochlorite solution to the bromination reaction solution, and at the same time add dilute hydrochloric acid to neutralize the alkali generated by the reaction, gradually a pale yellow precipitate of bromochlorodimethylhydantoin is formed, and the chlorination reaction temperature is controlled at 5-25°C. When the precipitation no longer increases and the gas is released, the chlorination reaction is completed, and the molar ratio of the feed is controlled as follows: dimethylhydantoin: sodium bromide: stabilizer: hydrochloric acid: sodium hypochlorite: deionized water=1:0.95-1.05:0.05- 0.5:2-2.5:2-2.5:10-50;

(3) Filter and separate the precipitate generated in the reaction solution, wash the precipitate with deionized water, and dry to obtain a high-purity bromochlorodimethylhydantoin product;

(4) Dimethylhydantoin and sodium bromide are added to the mother liquor after product separation, and the stabilizer in the mother liquor is recycled and entered into the next batch of synthesis.

The raw material dimethylhydantoin used in the technical solution of the present invention is an industrial product with a purity of 99.0%.

The raw material sodium hypochlorite solution adopted in the technical solution of the present invention is an industrial product of sodium hypochlorite with an available chlorine content of 5%-10%.

The sodium hypochlorite stabilizer adopted in the technical solution of the present invention is sodium sulfamate, sodium glycine and urea industrial products.

The raw material sodium bromide that adopts in the technical scheme of the present invention is solid industrial product, also can be the industrial by-product of recovery, for example, the sodium bromide solution by-product that industrial by-product hydrogen bromide absorbs with alkali obtains, adopts sodium bromide solution by-product to be able to Greatly reduce the cost of raw materials.

The present invention has the advantages of: (1) the sodium hypochlorite stabilizer is used to prevent the oxidative decomposition of dimethylhydantoin, the synthesis yield is improved, and the consumption of sodium hypochlorite is reduced simultaneously, thereby reducing the production cost; (2) the inventive method does not Using volatile and highly corrosive chemical raw materials, the reaction process is easy to control, the production process is safe and environmentally friendly, and can meet the requirements of industrial production.

Detailed ways

The object of the present invention is achieved in the following manner, which will be described in detail below in conjunction with the embodiments.

Example 1

Add 129.4g (1.0mol) of industrial dimethylhydantoin (99%), 103g (1.0mol) of sodium bromide, 11.9g (0.1mol) of sodium sulfamate, and 360g of deionized water into a 2000ml four-necked bottle. Cool down to 5°C with an ice-salt bath under stirring, start to drop 391g (1.1mol) of sodium hypochlorite solution with 10% available chlorine content, and finish adding in about 50 minutes, control the condensation reaction temperature at 5-10°C, when the reaction solution turns yellow When it gradually turns white again, the bromination reaction is complete. Further slowly add 355g (1.0mol) of sodium hypochlorite solution with an available chlorine content of 10%, and at the same time add about 487g (2.0mol) of hydrochloric acid with a concentration of 15% by weight to neutralize the alkali produced by the halogenation reaction, and gradually have bromochlorodimethyl Genhyne formed a pale yellow precipitate, controlled the chlorination reaction temperature at 5-25°C, and the chlorination reaction was completed when the precipitate no longer increased and gas was released. Vacuum filter the precipitate in the reaction solution, wash the precipitate twice with 200g of deionized water, and dry it in vacuum at 50-60°C to obtain 237.8g of bromochlorodimethylhydantoin product with a purity of 98.0% and a total yield of 96.5%.

Example 2

129.4g (1.0mol) of dimethylhydantoin (1.0mol) and 103g (1.0mol) of sodium bromide were added to the mother liquor of Example 1, and 710g (2.0mol) of sodium hypochlorite solution with an available chlorine content of 10% was added slowly, and at the same time, 100% by weight The concentration of 15% hydrochloric acid is about 487g (2.0mol), and the reaction temperature is controlled at 5-25°C. When the precipitation no longer increases and gas is released, the chlorination reaction is completed. Vacuum filter the precipitate in the reaction solution, wash the precipitate twice with 200g of deionized water, and dry it in vacuum at 50-60°C to obtain 240.3g of bromochlorodimethylhydantoin product with a purity of 98.0% and a total yield of 97.5%.

Example 3

Add 129.4g (1.0mol) of industrial dimethylhydantoin (99%), 103g (1.0mol) of sodium bromide, 6.0g (0.1mol) of urea, and 360g of deionized water into a 2000ml four-necked bottle, and stir Cool down to 5°C with an ice-salt bath, start to add 391g (1.1mol) of sodium hypochlorite solution with 10% available chlorine dropwise, and finish adding in about 50 minutes. Control the condensation reaction temperature at 5-10°C. When it turns white, the bromination reaction is complete. Further slowly add 355 g (1.0 mol) of sodium hypochlorite solution with an available chlorine content of 10%, and add about 487 g (2.0 mol) of hydrochloric acid with a concentration of 15% by weight at the same time, gradually a pale yellow precipitate of bromochlorodimethylhydantoin is formed, controlling The chlorination reaction temperature is 5-25°C, and the chlorination reaction is completed when the precipitation no longer increases and gas is released. Vacuum filter the precipitate in the reaction solution, wash the precipitate twice with 200g of deionized water, and dry it in vacuum at 50-60°C to obtain 236.5g of bromochlorodimethylhydantoin product with a purity of 97.5% and a total yield of 95.5%.

Example 4

Add 129.4g (1.0mol) of dimethylhydantoin and 103g (1.0mol) of sodium bromide to the mother liquor of Example 3, further slowly add 710g (2.0mol) of sodium hypochlorite solution with an available chlorine content of 10%, and simultaneously add 100% by weight The concentration of 15% hydrochloric acid is about 487g (2.0mol), and the reaction temperature is controlled at 5-25°C. When the precipitation no longer increases and gas is released, the chlorination reaction is completed. Vacuum filter the precipitate in the completed reaction solution, wash the precipitate twice with 200 g of deionized water, and dry it in vacuum at 50-60° C. to obtain 237.8 g of bromochlorodimethylhydantoin product with a purity of 98.0% and a total yield of 96.5%.

Claims (2)

1. the synthetic method of a bromochlorodimethyl hydanton, it is characterized in that adding sodium hypochlorite stabilizer in dimethyl hydantion solution, when adding oxidizing agent sodium hypochlorite in reaction process, stablizer can be formed with hypochlorous acid and be oxidized ligand, as the medium of dimethyl hydantion oxidative halogenation, comprise following synthesis step:

(1) in reactor, dimethyl hydantion, Sodium Bromide, sodium hypochlorite stabilizer and deionized water is added, under agitation with cryosel bath, reaction solution is cooled to 5-25 DEG C, slowly add chlorine bleach liquor, when reaction solution is by colourless yellowing, when gradually becoming again white, bromination reaction completes;

(2) in bromination reaction liquid, slowly chlorine bleach liquor is added further, add the alkali that hydrochloric acid neutralization reaction produces simultaneously, bromochlorodimethyl hydanton pale yellow precipitate is had to be formed gradually, control chlorination reaction temperature 5-25 DEG C, when precipitation no longer increases and has gas to release, chlorination reaction completes, and controls molar ratio to be: dimethyl hydantion: Sodium Bromide: stablizer: hydrochloric acid: clorox: deionized water=1:0.95-1.05:0.05-0.5:2-2.5:2-2.5:10-50;

(3) sedimentation and filtration that generate in reaction solution is separated, by washed with de-ionized water precipitation, dry high purity bromochlorodimethyl hydanton product;

(4) supplement in the mother liquor after product separation and add dimethyl hydantion and Sodium Bromide, in mother liquor, stablizer recycles, and enters next batch synthesis.

2. the synthetic method of a kind of bromochlorodimethyl hydanton as claimed in claim 1, it is characterized in that adopted sodium hypochlorite stabilizer is thionamic acid sodium, Sodium Glycinate, urea or its mixture, its molar ratio is: clorox: stablizer=1:0.1-0.2.