2-chloro-4-iodopyridine

The main uses of 2-%-4-imidazole are in the synthesis of compounds, in the field of bacteria and weeds, in the field of materials, it can be used in functional materials, and it is also important in chemical catalysis.
In the synthesis of compounds, 2-%-4-imidazole can be used as a catalyst. Due to the presence of imidazole, it has a specific biological activity. For some antifungal compounds, the synthesis process requires the help of 2-%-4-imidazole, which is specific and anti-fungal, and the introduction of other functional molecules with specific biological activities, for the purpose of inhibiting or inhibiting fungi.
In this field, 2-%-4-imidazole can be used to develop new types of fungus and weed control. Through rational chemical modification, it can be used to target specific crop disease bacteria or herbicide inhibition or effect. For example, the modification allows the fungus to target a specific enzyme that acts on a common crop fungal pathogen, dry its normal generation, and has high efficiency and low toxicity. The fungal effect is friendly to the environment, which meets the needs of the development of the color of the plant.
In terms of materials, 2-%-4-imidazole can be used in functional materials. Because of its certain coordination ability, it can be used to coordinate the formation of gold-containing frame materials (MOFs). This material has the characteristics of high specific surface area, high pore size, etc., and shows good application prospects in various fields such as adsorption, catalysis, and energy.
In addition, in the catalytic reaction, 2-% 4-imidazole can be used as a catalyst to form a complex, and the catalytic activity of the catalyst can be improved. By changing the atom and the substituent on the imidazole, it can precisely control the molecular efficiency and air efficiency, so as to meet the needs of different catalytic reactions and improve the catalytic reaction efficiency.

2-Bromo-4-chloropyridine is an important intermediate in organic synthesis, and its synthesis methods are rich and diverse. The following are detailed for you:
###Halogenation method
1. ** Direct halogenation **: Pyridine is used as the starting material, and the brominating agent and the chlorinating agent act in sequence or simultaneously. In the presence of appropriate catalysts, such as iron powder and iron trichloride, pyridine undergoes electrophilic substitution reaction with bromine and chlorine gas. Due to the electron-absorbing effect of nitrogen atoms on the pyridine ring, the reaction mainly occurs at the 2nd and 4th positions. However, this method has poor regioselectivity and produces a variety of halogenated pyridine isomers, which is cumbersome to separate and purify. For example, under the catalysis of ferric chloride, pyridine reacts with bromine and chlorine in a suitable organic solvent (such as dichloromethane), and various products such as 2-bromo-4-chloropyridine and 2-chloro-4-bromo-pyridine are obtained.
2. ** Guide group-directed halogenation **: First introduce a guide group on the pyridine ring to enhance the electron cloud density at a specific location, thereby improving the regioselectivity of the halogenation reaction. Common guide groups such as amino, hydroxyl, etc. Taking 2-aminopyridine as an example, the amino group is an ortho-para-position locator. Under appropriate conditions, the bromine atom will selectively enter the 4 position, and then the amino group will be converted into a chlorine atom through diazotization and other reactions to obtain 2-bromo-4-chloropyridine. Although this method has many steps, it has good regioselectivity and high product purity.
##palladium-catalyzed cross-coupling method
1. ** Coupling of halopyridine with halides **: Using halopyridine (such as 2-bromopyridine or 4-chloropyridine) as a substrate, under the action of palladium catalysts (such as tetra (triphenylphosphine) palladium, etc.), ligands (such as tri-tert-butylphosphine, etc.) and bases (such as potassium carbonate, sodium carbonate, etc.), cross-coupling reactions occur with halogenated reagents (such as copper bromide, zinc chloride, etc.). By selecting suitable reaction conditions and ligands, efficient synthesis of 2-bromopyridine can be achieved. For example, 2-bromopyridine and zinc chloride are heated in N, N-dimethylformamide (DMF) solvent under the action of palladium catalyst and appropriate ligands to obtain the target product.
2. ** Coupling of pyridyl boronic acid with halides **: Pyridyl boronic acid is coupled with halogenated reagents under palladium catalysis. Pyridyl boronic acid is prepared first, and then reacts with bromide and chloride under basic conditions. This method has relatively mild reaction conditions and high yields. For example, 2-bromo-4-chloropyridine can be successfully synthesized by refluxing 4-pyridyl boronic acid with 2-bromochlorobenzene in a toluene-water mixed solvent under the action of palladium catalyst, potassium carbonate and suitable ligands.
##Other methods
1. ** Conversion of pyridine derivatives as raw materials **: Some pyridine derivatives containing specific substituents undergo functional group conversion under suitable reaction conditions. Such as 2-hydroxy-4-methylpyridine, methyl is first oxidized to a carboxyl group, and then a series of reactions such as halogenation and decarboxylation can be obtained 2-bromo-4-chloropyridine. This method requires precise control of the reaction conditions. The steps are more complicated, but it has certain advantages for the situation where the specific raw material sources are abundant.
2. ** Electrochemical Synthesis Method **: Under electrochemical conditions, pyridine or its derivatives are used as raw materials, and the selective introduction of bromine atoms and chlorine atoms on the pyridine ring is realized by controlling the electrode potential, electrolyte composition and other conditions. This method is green and environmentally friendly, and the reaction conditions are relatively mild, but it requires high equipment. It has not been widely industrialized at present. For example, 2-bromo-4-chloropyridine can be synthesized by electrochemical halogenation from pyridine in a specific ionic liquid electrolyte.

2-% -4-A cannon, its physical nature is rational, and it has a lot of special characteristics. The element is also, depending on its color, color, odor. Its density is as small as that of the air, more than ten times. This characteristic makes it easy to rise. If it is filled with a ball, its energy is higher than that of the air. And it is flammable. When mixed with oxygen, it will explode in case of fire. Its reaction is strong, capable of generating high energy and producing a huge amount of energy.
As for the 4-cannon, this instrument is also exquisitely shaped, made of gold, with a long ruler, a front end such as a hole, and a hollow end. Its materiality is important, the first is the weight, and the metal material is used, so there is a relative weight. It is in the hand, and it feels heavy. The second is hard, and the metal is made, so that it can withstand high temperatures without breaking down.

The gun can be fired, and the fire can be ignited. The fire can be ignited, and the height of the gun can be generated in an instant. This effect is on the cannon's high-speed pellets and pushes them out quickly. When the pellets are out, they are advanced due to their performance. Their speed is very fast, and they can be used in short distances, high-speed, and high-speed.
The cannon seems to be involved, but if it is used for fuel, it may have new uses for equipment. For example, it is impossible to explore how to generate energy to supply the energy required for artillery shooting. And burning materials and water, cleaning and dyeing, if we can make good use of it, we may be able to change the force mode of general equipment, which is also one way of physical application.

2-%-4-pyridine should pay attention to the following general things in the storage and storage:
First, it is not suitable for storage. Because of its chemical activity, it is suitable for transportation, dryness and good communication. This is due to the fact that the tide environment or its water will react, resulting in sexual change; and high temperature may improve its reaction activity and increase safety. It is necessary to store oxidized materials, acids and other materials separately, and must not be mixed. Due to the oxidation of 2-%-4-pyridine, it is easy to cause oxidation reaction, or cause combustion or even explosion; the mixing of acid may also cause strong reaction, endangering safety. In addition, the storage place has a combined containment material, so that the leakage can be quickly dealt with in the process, to prevent its dispersion from causing greater harm.
Second, it is necessary to ensure that the container is well sealed before transportation to prevent its leakage and leakage. During the transportation process, it is necessary to prepare and measure the amount of firefighting equipment and leakage emergency management. Chargeants need to be trained and well-versed in the dangerous characteristics and emergency management methods of 2-%-4-pyridine. On the way, it is necessary to prevent exposure, rain, and high. If you are in densely populated areas or other sensitive areas, you need to be extra careful, follow the established route, and do not stop inadvertently. In the event of a leak, immediately evacuate the surrounding crowd, cut off the fire source, and deal with it quickly according to the case. Use clean materials to contain the leakage to avoid its inflow into the territory and cause pollution.

2-% -4-pyridine which has the following phases is safe:
1. ** Fire explosion **: This compound is flammable. In case of open flame or high temperature, it is like a dry wood in case of fire, and it is easy to be burned. It may even form an explosive mixture due to evaporation. At a certain degree, once it encounters a fire source, it will instantly cause a strong explosion, such as a fixed explosion hidden in the body, which will affect the lives and safety of people around the world.
2. ** Health Hazards **: First, breathing and inhalation, like a human being, quietly enters the respiratory tract, irritates the mucosa of the respiratory tract, causing cough, respiratory distress and other diseases. Inhalation during the period may even damage lung function. Second, the skin is connected to the skin, it may act as a rot, breaking the protective barrier of the skin, causing skin damage, pain, burning, etc. Third, if you accidentally eat, it will cause "waves" in the mouth, throat, stomach, etc., causing severe pain, vomiting and other serious consequences.
3. ** Environmental Hazards **: Once it enters the environment, it is like a harmful "invader", causing pollution such as water and soil. In water, it may affect the survival of aquatic organisms and break the balance of aquatic life; in soil, it may change the sex of the soil, the fertility of plants, and the characterization of the whole biological system.