4-Fluoro-3-bromopyridine

4-Fluoro-3-bromopyridine is also an organic compound. It has a wide range of uses and has important applications in medicine, pesticides, materials science and other fields.
In the field of medicine, it is often the key intermediate for the synthesis of drugs. The development of many new drugs relies on it to build a specific molecular structure and endow the drug with unique pharmacological activity. For example, in the synthesis of some anti-arrhythmia drugs and antibacterial drugs, 4-fluoro-3-bromopyridine can be the starting material or key structural fragment. After a series of chemical reactions, drug molecules with precise pharmacological effects can be prepared, which help treat corresponding diseases and benefit patients.
In pesticides, it is also indispensable. On this basis, high-efficiency, low-toxicity and environmentally friendly pesticides can be synthesized. Its structural characteristics enable it to participate in the synthesis of pesticides with high selective inhibition or killing effect on specific pests or pathogens, help agricultural harvest, ensure crop yield and quality, and reduce the adverse impact on the environment, which is in line with the current needs of green agriculture.
In the field of materials science, 4-fluoro-3-bromopyridine can be used to prepare functional materials. For example, organic photovoltaic materials, through appropriate chemical modification and polymerization, can obtain materials with special optical and electrical properties, which can be used in the fields of organic Light Emitting Diodes (OLEDs), solar cells, etc., to promote the progress of related material technologies and provide new material options for the development of electronic devices and energy fields.

The synthesis method of 4-fluoro-3-bromopyridine has existed in ancient times, and it has changed with time, and the technology has become more and more exquisite.
First, pyridine is used as the starting material. Bromine atoms are introduced into the pyridine ring first, and liquid bromine and pyridine are often reacted with appropriate catalysts such as iron powder. This reaction needs to be carried out in a low temperature and anhydrous environment to prevent side reactions from breeding. The electron cloud density of the bromine atom in the pyridine ring is characteristic, and it is mostly substituted at the 3 position. After the bromination reaction is completed, 3-bromopyridine is obtained after separation and purification. Then, 3-bromopyridine is heated with fluorinating reagents such as potassium fluoride in a high-boiling organic solvent such as dimethyl sulfoxide. In this process, the reaction temperature and time need to be strictly controlled. Due to high temperature or long time, it is easy to cause excessive fluorination or other side reactions. After these two steps, 4-fluoro-3-bromopyridine can be obtained.
Second, 3-aminopyridine is used as the starting material. Shilling 3-aminopyridine reacts with brominating reagents such as N-bromosuccinimide (NBS) in suitable solvents such as carbon tetrachloride to introduce bromine atoms at the amino ortho-position, or the 4-position, to generate 4-bromo-3-aminopyridine. Then, through the diazotization reaction, the amino group is converted into a diazonium salt, and then reacts with fluoroboronic acid to form a fluoroboronic acid diazonium salt. Finally, the diazonium salt of fluoroboronic acid is decomposed by heating to obtain 4-fluoro-3-bromopyridine. Although this route is a little complicated, the reaction selectivity is good and the product purity is quite high.
Third, the cross-coupling reaction with halogenated aromatics as raw materials and catalyzed by palladium. First, the bromoaryl halide and fluoropyridine derivatives react in an organic solvent in the presence of palladium catalyst, ligand and base. This reaction condition is relatively mild, the equipment requirements are relatively low, and the selectivity and yield of the reaction can be effectively improved by selecting suitable ligands and reaction conditions. However, palladium catalysts are expensive and costly, which slightly hinders large-scale production.
The above synthesis methods have their own advantages and disadvantages. In practical application, the choice needs to be weighed according to specific needs, raw material availability, cost considerations and other factors.

4-Fluoro-3-bromopyridine is one of the organic compounds. Its physical properties are quite important and are listed below:
Looking at its appearance, under room temperature and pressure, 4-fluoro-3-bromopyridine is mostly colorless to light yellow liquid, which is the first characteristic visible to the naked eye. Its color and state are the keys to a preliminary understanding of this substance.
As for the boiling point, it is about 180-185 ° C. The boiling point is the specific temperature at which a substance changes from liquid to gaseous state. This value indicates that 4-fluoro-3-bromopyridine will undergo a phase change in this temperature range. It is of great significance for the study of its separation, purification and stability under a specific temperature environment.
The melting point is about -20 ° C. The melting point is the temperature at which a solid substance melts into a liquid state. This value reveals that 4-fluoro-3-bromopyridine will exist in solid form when it is below this temperature, and will gradually transform into a liquid state when it is above this temperature, which is related to its physical state during storage and transportation.
The density is about 1.72 - 1.75 g/cm ³. This value reflects the mass of the substance per unit volume and is an indispensable parameter when it comes to the measurement, mixing and distribution of the substance in different media.
In terms of solubility, 4-fluoro-3-bromopyridine is slightly soluble in water. Water is a common solvent, and its solubility in water affects the behavior of the substance in the aqueous environment, such as whether it is easy to diffuse in water and interact with water-soluble substances. However, it is easily soluble in common organic solvents such as ethanol, ether, dichloromethane, etc. Organic solvents are widely used in organic synthesis, extraction and other fields. This solubility characteristic provides a basis for the selection of suitable reaction media and separation methods in organic chemistry experiments and industrial production.
In addition, 4-fluoro-3-bromopyridine has a certain volatility and will slowly evaporate into the air in an open environment. Volatility not only affects its storage conditions, but also is related to the environmental safety of the workplace. It needs to be properly handled to avoid the accumulation of harmful gases.
The above physical properties are the basis for the understanding and application of 4-fluoro-3-bromopyridine. In many fields such as organic synthesis and medicinal chemistry, accurate grasp of its properties will help to carry out related work more effectively.

4-Fluoro-3-bromopyridine is also an organic compound. Its molecule contains fluorine, bromine and pyridine rings, and this structure gives it unique chemical properties.
In terms of its reactivity, the pyridine ring is electron-deficient. Because the electronegativity of nitrogen atom is greater than that of carbon, the electron cloud density on the ring decreases. Therefore, the electrophilic substitution reaction is more difficult than benzene and often requires more severe conditions. However, the reactivity varies in specific positions.
In the nucleophilic substitution reaction, 4-fluoro-3-bromopyridine behaves quite interestingly. Both fluorine and bromine atoms can leave, but it is difficult for fluorine atoms to leave due to the large carbon-fluorine bond energy; bromine atoms have small carbon-bromine bond energy and are relatively easy to leave. In the case of strong nucleophiles, bromine atoms are preferentially replaced. For example, when reacting with sodium alcohol, bromine can be replaced by alkoxy groups, and pyridine derivatives can be replaced accordingly.
In terms of basicity, pyridine nitrogen atoms have lone pairs of electrons and are weakly basic. However, due to the electron-withdrawing action of fluorine and bromine, the electron cloud density of nitrogen atoms decreases, and the basicity is weaker than that of pyridine. In acidic media, it can be combined with protons to form salts
In addition, 4-fluoro-3-bromopyridine can participate in metal-catalyzed coupling reactions, such as palladium-catalyzed coupling with borate esters to form carbon-carbon bonds for the synthesis of complex organic molecules. This reaction requires strict conditions and requires suitable ligands and bases to promote.
Due to the presence of fluorine and bromine atoms, 4-fluoro-3-bromopyridine can undergo halogenation and conversion, expanding its use in the field of organic synthesis, providing the possibility for the preparation of a variety of compounds containing pyridine structures.

The price range of 4-fluoro-3-bromopyridine in the market is difficult to determine. This change in price depends on many reasons.
First look at its supply and demand. If there are many people who want it, but the supply is small, the price will tend to increase; on the contrary, if the supply exceeds the demand, the price will drop automatically. And the difficulty of its preparation is also the main reason. The system of 4-fluoro-3-bromopyridine, or the complicated method, the expensive material, or the special setting and strict environment, all of which increase the cost and cause the price to be high. If the method of preparation is gradually simplified, the material is also easy, and the price may drop.
Furthermore, the competition of the market also affects the price. If there are many people in the market, each competes to attract customers and profit, or there is a price reduction; if there are few people in the market, it is almost monopolized, and the price must be controlled by them, often high.
And the regulations and political guidelines of the chemical industry can also affect the price. Regulations are tight, production is limited, costs may rise, and prices change accordingly.
Looking at the examples of past transactions, it is difficult to find a definite number. Its price may vary greatly depending on time and place. Some land or 100 yuan per gram, and some land is sold at a higher price.
To sum up, 4-fluoro-3-bromopyridine is available in the market, and the price may range from tens of yuan per gram to hundreds of yuan per gram. For real-time price confirmation, please consult the chemical raw material supplier to obtain the approval letter.