4-Bromopyridine hydrochloride

4-Bromopyridine hydrochloride, this is an organic compound. Its properties are white to light yellow crystalline powder, which is quite stable in air.
From the perspective of chemical properties, first, because it contains a pyridine ring, it is weakly basic and can form a salt with an acid. This compound is the salt of 4-bromopyridine and hydrochloric acid. Second, the bromine atom is an important functional group and has high activity. In nucleophilic substitution reactions, bromine atoms are easily replaced by nucleophiles. For example, in reaction with sodium alcohol, bromine atoms can be replaced by alkoxy groups to form 4-alkoxy pyridine derivatives. Third, the presence of the pyridine ring allows the compound to participate in many reactions involving aromatic rings, such as electrophilic substitution reactions under specific conditions, but the reaction check point is related to the distribution of the pyridine ring electron cloud. Due to the electronegativity of nitrogen atoms, the electron cloud density of the pyridine ring is not uniformly distributed, so the electrophilic substitution reaction often occurs at the β-position of the pyridine ring (relative to the nitrogen atom).
Furthermore, 4-bromopyridine hydrochloride has different solubility in organic solvents, and generally has a certain solubility in polar organic solvents such as methanol, ethanol, and dichloromethane. This property is extremely critical in the separation and purification steps of organic synthesis. In a chemical reaction system, its chemical properties are also affected by reaction conditions, such as temperature, reaction time, reactant concentration, and the presence or absence of catalysts, which all affect the reaction process and product selectivity.

4-Bromopyridine hydrochloride is a common raw material in organic synthesis. It is widely used and has important uses in the fields of medicine, pesticides and materials science.
It is often a key intermediate in the synthesis of medicine. For the preparation of specific antihistamine drugs, 4-bromopyridine hydrochloride can introduce a pyridine structure through a series of reactions. This structure is crucial for the interaction between drugs and targets, and is related to drug activity and selectivity. Because the nitrogen atom of the pyridine ring has lone pairs of electrons, it can form hydrogen bonds or other non-covalent interactions with biological macromolecules.
In the process of pesticide creation, 4-bromopyridine hydrochloride is also indispensable. For example, in the synthesis of new insecticides, the active chemistry of bromine atoms can react with other organic groups to construct molecular structures with high insecticidal activity. The presence of bromine atoms may enhance the binding force between molecules and targets in pests, achieving good insecticidal effect.
In the field of materials science, 4-bromopyridine hydrochloride can be used to prepare functional materials. If a conductive polymer is prepared, it can participate in the polymerization reaction, or it can regulate the electronic structure and electrical conductivity of the polymer. Pyridine rings can provide electron transport channels, and bromine atoms may affect the crystallinity and solubility of materials, optimizing the physical and chemical properties of materials.
Furthermore, 4-bromopyridine hydrochloride is also used in organic synthesis methodological studies. Chemists use it as a substrate to explore novel reaction pathways and catalytic systems, expand the chemical boundaries of organic synthesis, and provide the possibility to create more complex and functional organic compounds.

The synthesis of 4-bromopyridine hydrochloride is a key research point in the field of organic synthesis. Its synthesis pathways are diverse, and the following are described in detail by Jun.
One of them can be started from pyridine. Pyridine can be brominated to introduce bromine atoms at position 4. In this process, suitable brominating reagents, such as bromine (Br ²), are often required, and assisted by suitable catalysts, such as iron powder (Fe) or iron tribromide (FeBr ²). Under specific reaction conditions, such as suitable temperature and solvent environment, bromine and pyridine undergo electrophilic substitution. The solvent can be selected from halogenated hydrocarbons such as dichloromethane, because of its good solubility to the reaction system and relatively stable properties. The reaction temperature usually needs to be controlled between low temperature and room temperature to prevent the occurrence of side reactions such as excessive bromination. After this reaction, 4-bromopyridine can be obtained, and then it can be reacted with hydrochloric acid to obtain 4-bromopyridine hydrochloride.
Second, 4-aminopyridine is also used as the starting material. First, 4-aminopyridine is converted into diazonium salts through diazotization reaction. This process requires sodium nitrite (NaNO 2) and hydrochloric acid to be carried out in a low temperature environment. After the formation of the diazonium salt, it is treated with cuprous bromide (CuBr) and other reagents to achieve the substitution of the diazonium group by the bromine atom to form 4-bromopyridine, and then the target product 4-bromopyridine hydrochloride is also reacted with hydrochloric acid. The advantage of this route is that the starting material 4-aminopyridine is relatively easy to obtain, and although the reaction steps are slightly complicated, the reaction selectivity of each step is acceptable.
Furthermore, using pyridine N-oxide as the raw material is also a method. Pyridine N-oxide reacts with the brominating reagent under suitable conditions, and the bromine atom preferentially replaces the No. 4 position. After reduction, the oxygen on the nitrogen is removed, and then it is salted with hydrochloric acid to obtain 4-bromopyridine hydrochloride. This approach can take advantage of the unique electronic effect of pyridine N-oxide to make the bromination reaction more selective. However, the reduction step requires the selection of a suitable reducing agent and the control of the reaction conditions to ensure the purity and yield of the product.
When synthesizing 4-bromopyridine hydrochloride, the fine regulation of the reaction conditions is extremely important, including temperature, ratio of reactants, reaction time, etc., all of which are related to the yield and purity of the product. At the same time, the separation and purification operations of each step cannot be ignored, such as extraction, distillation, recrystallization, etc., to obtain high-purity target products.

4-Bromopyridine hydrochloride is a chemical substance. When storing, many aspects need to be paid attention to.
First, temperature is very important. This substance should be stored in a cool place. If the temperature is too high, it is easy to change its chemical properties or cause decomposition. For example, in the extreme heat of summer, if the storage temperature exceeds the appropriate range, it may cause the substance to deteriorate and affect the subsequent use effect.
Second, the humidity should not be underestimated. The storage environment should be ensured to be dry, because it is exposed to water or high humidity environment, and reactions such as hydrolysis may occur. Like the southern plum rain season, the air humidity is high. If stored improperly, 4-bromopyridine hydrochloride is prone to moisture absorption and quality damage.
Third, keep away from fire sources and oxidants. 4-Bromopyridine hydrochloride may be flammable to a certain extent, and it is dangerous to burn in case of open flames and hot topics; and in contact with oxidants, it is easy to react violently, and even explode, threatening storage safety.
Fourth, storage containers should be properly selected. Containers with good sealing performance should be used to prevent excessive contact with air, causing oxidation or absorption of air components and deterioration. Common such as glass bottles or specific plastic containers, but make sure that the material does not react with the substance.
Fifth, the storage place should be well ventilated. Avoid the accumulation of volatile gases and the formation of dangerous environments, and also prevent local temperature and humidity abnormalities caused by lack of air circulation, which affect material stability.
In short, when storing 4-bromopyridine hydrochloride, it is necessary to pay more attention to temperature, humidity, fire source, container and ventilation, so as to ensure its quality and storage safety.

The market price range of 4-bromopyridine hydrochloride often changes due to a variety of reasons. This compound is widely used in the chemical raw material market, such as in pharmaceutical synthesis, fine chemicals and many other fields. Its price is then influenced by factors such as supply and demand, production costs, and market competition.
In the past few years, according to the example of material price fluctuations recorded in the "Tiangong Kaiwu", the price of 4-bromopyridine hydrochloride, if the common industrial-grade quality is considered, may be around a few hundred yuan per kilogram. However, if it is high purity and suitable for high-end uses such as pharmaceutical research and development, its price will be even higher.
Looking at the market supply and demand, if the demand is strong and the supply is limited, such as the demand of pharmaceutical companies increases greatly, if the manufacturer fails to expand the production capacity in time, the price will rise. On the contrary, if the supply is abundant and the demand is flat, the price may decline. Production costs are also key. The price of raw materials, the complexity of the production process, and energy consumption will all affect the final selling price. If the price of 4-bromopyridine hydrochloride rises due to the scarcity of raw materials, or the cost is reduced due to new processes, the price of 4-bromopyridine hydrochloride will change accordingly. Furthermore, the market competition situation should not be underestimated. If there are many manufacturers and the competition is fierce, the price may be lowered in order to compete for market share; conversely, if the market monopoly is strong, the price may be high. Overall, its market price ranges from a few hundred to several thousand yuan per kilogram, making it difficult to determine a fixed figure.