CN102939968A - Quaternary ammonium salt germicidal algicide and synthetic method and application thereof - Google Patents

Abstract

式中X：—CH₂OCH₂CH₃，R选自C₃-C₁₆碳的烷基。本产品以邻苯二胺和乙酸为原料通过闭环、取代和季铵盐化而得到，其用途是在工业循环冷却水中作为杀菌灭藻剂的应用，本产品易于降解，对环境友好。A kind of quaternary ammonium salt bactericidal algicide is 1-methyl ethyl ether base-2-methyl-3-R base benzimidazole quaternary ammonium salt shown in the following chemical formula:

In the formula, X: —CH ₂ OCH ₂ CH ₃ , R is selected from C ₃ -C ₁₆ carbon alkyl groups. This product is obtained from o-phenylenediamine and acetic acid through ring closure, substitution and quaternization. It is used as a bactericide and algicide in industrial circulating cooling water. This product is easy to degrade and is environmentally friendly.

Description

A kind of quaternary ammonium salt bactericidal algicide and its synthesis method and application

1. Technical field

The invention relates to a water treatment agent and a preparation method thereof, in particular to an industrial circulating cooling water treatment agent and a preparation method thereof, specifically a quaternary ammonium salt bactericide and algaecide, a synthesis method and application thereof.

2. Background technology

In 1915, Jocobs synthesized quaternary ammonium salt surfactant for the first time, and pointed out that this compound had a certain bactericidal effect, but it did not attract attention. In 1935, Domagk further studied the relationship between its bactericidal effect and its chemical structure. After Wetzel conducted a clinical disinfection test, it gradually attracted attention. In 1964, my country studied the bactericidal effect of a quaternary ammonium compound - benzalkonium bromide (brogeramine), and it was recommended as a disinfectant after 1971.

Quaternary ammonium surfactants all contain an ionized nitrogen atom as an important symbol, and can be divided into hydrophilic cations and hydrophobic long chains from the structure. The bactericidal mechanism of quaternary ammonium salt type surfactants is mainly accomplished by the adsorption of positive ion head groups on the surface of negatively charged bacteria and changing the permeability of bacterial cell walls. The base and the hydrophilic group penetrate deeply into the lipid layer and protein layer of the bacterial cells respectively, leading to the loss of enzyme activity and protein denaturation, which makes the metabolism of microorganisms abnormal, and can also cause cell autolysis and death. Due to the combined effect of the above two effects, the quaternary ammonium salt type surfactant has a strong bactericidal ability. Quaternary ammonium fungicides are not affected by water hardness, have low toxicity and no cumulative toxicity, are particularly effective against bacteria and algae under alkaline conditions, and have strong slime stripping and dispersing effects.

There are many classification methods of quaternary ammonium salt biocides. According to the number of long chains in the molecule, there are two types: single-chain quaternary ammonium salt and double-chain quaternary ammonium salt; according to the number of nitrogen cations, it can be divided into single-chain quaternary ammonium salt, Diquaternary ammonium salts and triple quaternary ammonium salts, etc.; classified according to their molecular structure, those whose hydrophobic groups are completely alkyl are called fatty quaternary ammonium salts; those containing alcoholic hydroxyl groups are called alcohol ether quaternary ammonium salts, and those containing imidazoline structures are called It is imidazoline quaternary ammonium salt, and other quaternary ammonium salts are classified into other categories.

In recent years, the synthesis of benzimidazole compounds has become a hot topic. How to quickly and easily synthesize benzimidazole and its salts is the key. There are several methods:

① Synthesis using o-phenylenediamine and carboxylic acid (and its derivatives) as raw materials;

②Synthesis of o-phenylenediamine and aldehyde as raw materials;

③The synthesis of o-phenylenediamine and thiocyanic acid as raw materials;

④ Synthesis of o-halogenated nitrobenzene and aldehyde as raw materials;

⑤ Synthesis of o-nitroaniline as raw material;

⑥Synthesis of amines and acyl compounds as raw materials.

Among them, o-phenylenediamine and carboxylic acid (and its derivatives) are the most commonly used raw materials, and o-phenylenediamine and aldehydes are the most commonly used raw materials. The synthesis conditions usually include heating and catalysts, and some special methods have appeared in recent years, such as new experimental methods such as photocatalysis and microwave catalysis.

Circulating cooling water treatment technology is one of the main methods of industrial water saving. Since industrial cooling water accounts for 70-80% of industrial water consumption, realizing water recycling and increasing the concentration ratio is the key to industrial water conservation. If the recirculating cooling system draws make-up water from the city water supply or from a well, the amount of microorganisms in the make-up water is usually very low. However, the open circulating cooling water system constantly has dust entering and microbes are sent in with the wind. When there is a certain amount of nutrients, the microbes will multiply rapidly.

The use of biocides to control the microorganisms in the cooling water system is a commonly used and effective method at present, that is, to control the reproduction of microorganisms by adding biocides with different functions to the cooling water.

Oxidizing biocides are cheap and efficient, and this high performance/price ratio makes them still dominate the control of microorganisms in cooling water systems. For large-scale cooling water systems, the applicant has not seen so far that no oxidizing biocide is used, but only non-oxidizing biocide is used. Non-oxidizing biocides are another large category of biocides in cooling water treatment. They are basically organic compounds. In some respects, they are more convenient and effective than oxidizing biocides.

Among the currently used non-oxidizing biocides, quaternary ammonium biocides have broad-spectrum biocidal properties and are effective against bacteria, algae, and fungi. Unlike oxidizing biocides, they are less affected by pH and have low toxicity to the environment. It is environmentally friendly, has good performance/price ratio, and is easy to use, store and transport. It is the most widely used and is one of the main hotspots in the field of biocidal research and application.

3. Contents of the invention

Aiming at the existing water quality and the shortcomings of traditional non-oxidizing biocides, the present invention aims to provide a new type of non-oxidizing bactericide and algicide with novel structure and good performance for the circulating cooling water system. The problem to be solved is to design a new type of biocide The structure of ammonium salt fungicides and algicides is designed and synthesized, and the new synthetic fungicides and algicides are characterized, and their bactericidal and algicidal activities are confirmed.

The bactericidal and algaecide claimed in the present invention belongs to quaternary ammonium salts, chemical name: 1-methyl ethyl ether base-2-methyl-3-R base benzimidazole quaternary ammonium salt, has following chemical formula:

X-methyl ether group (—CH ₂ OCH ₂ CH ₃ ), R-alkyl group (C ₃ -C ₁₆ ); R is preferably an alkyl group with C ₈ -C ₁₆ carbons.

The preparation method of this compound uses o-phenylenediamine as a starting material, including the preparation of intermediates, the synthesis of target products, and the separation, washing and purification of each unit process. The preparation of the intermediates is the preparation of o-phenylenediamine and acetic acid The mass percent concentration of 80-90% phosphoric acid and 80-90% polyphosphoric acid solvent was stirred and reacted at 110-130°C for 8-12 hours, and then the intermediate (I) 2-methylbenzimidazole, phosphoric acid and polyphosphoric acid was isolated and obtained. The volume ratio of phosphoric acid is 2:1-1:2, and the reaction formula is as follows:

Intermediate (I) and chloromethyl ethyl ether use 35-45% sodium hydroxide solution as a solvent in the mass percent concentration, and react with stirring at 80-100°C for 8-12 hours in the presence of a phase transfer catalyst tetrabutylammonium bromide After separation, the intermediate (II) 1-methylethyl ether base-2-methylbenzimidazole is obtained, and the addition amount of tetrabutylammonium bromide is 1-2% of the quality of the intermediate (I). The reaction formula is as follows:

Finally, the synthesis of the target product, intermediate (II) and bromoalkane (RBr, R is an alkyl group with 3-16 carbons) in acetonitrile solvent at 75-85 ° C stirred for 8-12 hours and then separated to obtain the target product 1- Methyl ether -2-methyl-3-R base benzimidazole quaternary ammonium salt (hereinafter referred to as benzimidazole quaternary ammonium salt), the reaction formula is as follows:

In the formula: R: an alkyl group with 3-16 carbons, X: —CH ₂ OC ₂ H ₅ .

The introduction of the aromatic ring and the N atom in the benzimidazole quaternary ammonium salt of the present invention can better improve the bactericidal activity of the compound, and the long carbon chain alkyl structure enables the bactericide to act on microorganisms better, and has an electron-withdrawing group The antibacterial activity is also greatly improved; in addition, the ether group contained in the structure makes it have good water solubility, and can have a better bactericidal and algae killing effect in water. This product is easy to degrade and is environmentally friendly.

The benzimidazole quaternary ammonium salt and the common fungicide 1227 (dodecyl dimethyl benzyl ammonium chloride) are compared for the bactericidal efficiency of heterotrophic bacteria, the minimum dosage is 50mg/L, the benzimidazole quaternary ammonium Salt has a certain bactericidal efficiency to heterotrophic bacteria, and its bactericidal efficiency has a certain relationship with the length of the carbon chain in the R group. When the carbon chain in the R group is less than 7, the bactericidal effect is lower than 1227, and the carbon chain length in the R group is 8-16, the bactericidal effect is significantly better than 1227, and the longer the carbon chain, the better the bactericidal effect, and the longer the action time, it still maintains 99% of the bactericidal efficiency after 48 hours.

The benzimidazole quaternary ammonium salt and the common fungicide 1227 are compared for the sterilization efficiency of sulfate reducing bacteria. When the carbon chain in the R group is less than 7, the bactericidal effect is lower than 1227, and the carbon chain length in the R group is 8-16. , the bactericidal effect is better than 1227, and the longer the carbon chain, the better the bactericidal effect.

The use of the benzimidazole quaternary ammonium salt is exactly the application as a bactericide and algicide in an industrial circulating cooling water system.

4. Specific implementation

1. Preparation of intermediate (I) 2-methylbenzimidazole

Add phosphoric acid with a solvent mass concentration of 85% and polyphosphoric acid with a mass concentration of 86% in a 250mL three-necked flask, the volume ratio of phosphoric acid and polyphosphoric acid is 1:1, heat with an electric heating mantle, turn on the stirrer, add o-phenylenediamine and acetic acid, Raise the temperature to 120-130°C and react for 10 hours. After the reaction is complete, cool the reaction solution, pour the reaction solution into a beaker, add dropwise 10% sodium hydroxide solution, adjust the pH to neutral, and a large amount of light yellow flocculent precipitates appear, continue to add dropwise until the pH reaches alkaline. After it was cooled to about 20-40°C, the crude product in the form of light yellow mud was obtained by suction filtration. Heat and melt the crude product, add activated carbon to decolorize after melting, cool down after decolorization, and recrystallize with ethanol-water solution to obtain intermediate (I).

The melting point of intermediate (I) 2-methylbenzimidazole was determined to be 175-176°C.

In the infrared analysis, the peak at 2920 is the peak of CH ₃ , the stretching vibration peak, 1470 is the absorption peak of NC, and 1540 is the absorption peak of the benzene ring.

In the ¹ H NMR spectrum of methylbenzimidazole, δ=7.2035～7.2465 corresponds to the H on the para position on the benzene ring, δ=7.5470～7.5773 corresponds to the H on the ortho position on the benzene ring, δ=2.6283～2.6944 corresponds to the 2 position on the imidazole ring The H on the methyl group, δ=10.6719 corresponds to the active H in NH.

2. Preparation of intermediate (II) 1-methylethyl ether-2-methylbenzimidazole

In a 100 mL three-necked flask, add sodium hydroxide with a mass concentration of 40%, 3 g of the intermediate (I) 2-methylbenzimidazole, and 0.05 g of a phase transfer catalyst tetrabutylammonium bromide. Heat the reaction solution to about 80-100°C, wait until 2-methylbenzimidazole is completely dissolved, add chloromethyl ether, and react for 10 hours. The reaction solution was cooled, the oil layer was separated, and the water layer was extracted several times with toluene. The separated oil layer was dried with anhydrous calcium chloride, and the solvent toluene and incompletely reacted chloromethyl ether were evaporated by a rotary evaporator to obtain an oily liquid intermediate (II).

The peak of the alkyl chain connected to the N of the imidazole ring appears at the H on the methyl ethyl ether group. Methyl H peak 3Hδ=2.5416～2.6186.

3. Synthesis of the target product

Add intermediate (II) 1-methylethyl ether-2-methylbenzimidazole, dodecane bromide, and solvent acetonitrile into a 50 mL three-necked flask, heat to 80°C, and react for 8-12 hours. After cooling, a white precipitate was obtained, and the unreacted raw material and solvent were removed by suction filtration to obtain a light yellow primary product. Recrystallized three times with acetonitrile to obtain white flaky crystals, and the product was obtained by suction filtration.

In the ¹ H NMR spectrum of benzimidazole salt, the H peak 2Hδ=3.2654～3.5783 in the dodecyl group connected to the imidazole ring N, the adjacent H peak 2Hδ=1.5205～1.6015, and the H peak 2Hδ on C ₃ ～C ₁₁ =1.2014～1.3530, 3Hδ=0.8945～0.9566. H on the benzene ring, 2Hδ=6.4051～6.5124, Hδ=6.5135～6.5895, Hδ=6.5746～6.6621.

Claims (4)

1. quaternary ammonium salt Biocidal algae-killing agent is characterized in that: be 1-the first and second ethers shown in the following chemical formula-2-methyl-3-R base benzimidazole quaternary ammonium salt:

In the formula: X :-CH ₂OCH ₂CH ₃, R is selected from C ₃-C ₁₆The alkyl of carbon.

2. Biocidal algae-killing agent according to claim 1, it is characterized in that: R is selected from C ₈-C ₁₆The alkyl of carbon.

3. the preparation method of the Biocidal algae-killing agent shown in claim 1, take o-phenylenediamine as initiation material, comprise the synthetic of the preparation of intermediate and target product and separate, washing and each unit process of purifying, it is characterized in that: to be o-phenylenediamine with acetic acid separated after 110-130 ℃ of stirring reaction 8-12 hour in mass percentage concentration 80-90% phosphoric acid and mass percentage concentration 80-90% polyphosphoric acids solvent obtains intermediate (I) 2-tolimidazole in the preparation of described intermediate; The volume ratio of phosphoric acid and polyphosphoric acids is 2:1-1:2; Intermediate (I) and chloromethyl ether obtain intermediate (II) 1-the first and second ethers-2-tolimidazole take mass percentage concentration 35-45% sodium hydroxide solution as solvent, separating under the phase transfer catalyst tetrabutyl ammonium bromide existence condition after 80-100 ℃ of stirring reaction 8-12 hour; The addition of phase transfer catalyst is the 1-2% of intermediate (I) quality; Described target product synthetic is that intermediate (II) separated after 75-85 ℃ of stirring reaction 8-12 hour in acetonitrile solvent with bromoalkane and obtains 1-the first and second ethers-2-methyl-3-R base benzimidazole quaternary ammonium salt target product.

4. the purposes of a Biocidal algae-killing agent as claimed in claim 1 is characterized in that: 1-the first and second ethers-2-methyl-3-R base benzimidazole quaternary ammonium salt in industrial circulating cooling water as the application of Biocidal algae-killing agent.