3-bromo-2-chloro-4-methylpyridine

3-Hydroxy-2-chloro-4-methylpyridine is an organic compound. This compound has specific physical properties. It is mostly solid under normal conditions, with a certain melting point and boiling point. The melting point is related to the temperature at which a substance melts from a solid state to a liquid state, and the boiling point is the temperature at which a substance changes from a liquid state to a gaseous state. Both of these are critical to the determination of its physical state under specific conditions.
Looking at its solubility, its solubility in water may be limited, but in some organic solvents, such as ethanol, ether, etc., the solubility may be different. This is due to the principle of similarity compatibility, that is, polar solutes are easily soluble in polar solvents, and non-polar solutes are easily soluble in non-polar solvents. The molecular structure characteristics of 3-hydroxy- 2-chloro-4-methylpyridine cause differences in its interaction with different solvents.
When it comes to appearance, or white to light yellow powder or crystal, this appearance characteristic is of great significance in the identification and initial determination of purity of the substance.
Furthermore, its density is also an important physical property. Density reflects the mass of the substance per unit volume, which is helpful for the space occupied by it in practical application and the proportion consideration when mixed with other substances.
In addition, the stability of the compound also belongs to the category of physical properties. Under specific temperature, humidity and light conditions, its chemical structure is prone to change, which affects its storage and use. If the stability is not good, special measures should be taken during storage, such as low temperature, dark storage, etc.

3-Bromo-2-chloro-4-methylpyridine is an organic compound with unique chemical properties and a wide range of uses in the field of organic synthesis. Its chemical properties are described in detail below:
1. ** Nucleophilic Substitution Reactivity **: In this compound, both bromine and chlorine atoms are good leaving groups. The electron cloud distribution of the pyridine ring is affected by these halogen atoms, which reduces the electron cloud density on the ring. Therefore, in the presence of nucleophiles, halogen atoms are easily replaced by nucleophilic reagents. For example, with sodium alcohol as the nucleophilic reagent, under appropriate solvents and temperatures, bromine or chlorine atoms can be replaced by alkoxy groups to form corresponding alkoxy-containing pyridine derivatives.
2. ** Basic **: The nitrogen atom of the pyridine ring has a lone pair of electrons, making it alkaline to a certain extent. However, due to the electron-absorbing effect of the halogen atom, the alkalinity of the compound is weakened compared with that of the pyridine. Under acidic conditions, it can combine with protons to form a pyridine salt. If it is dissolved in dilute hydrochloric acid, the corresponding pyridine hydrochloride will be formed.
3. ** Redox properties **: The pyridine ring can undergo oxidation reaction under specific conditions. For example, using a strong oxidant, the pyridine ring may be oxidized to open the ring to form oxidation products containing carboxyl groups and the like. At the same time, the halogen atom in the molecule can participate in the reduction reaction. Under the action of a suitable reducing agent, the halogen atom can be reduced to the corresponding hydrogen atom ** Electrophilic Substitution Reaction **: Although the electron cloud density of the pyridine ring decreases due to the electron-withdrawing action of the halogen atom, the electrophilic substitution reaction can still occur under specific conditions. The reaction mainly occurs at the relatively high electron cloud density position on the pyridine ring, such as the 3-position of the pyridine ring (relative to the nitrogen atom). When there is an electrophilic reagent, the hydrogen atom at this position can be replaced to form a new substituted product.
5. ** Reaction with metal-organic reagents **: 3-bromo-2-chloro-4-methylpyridine can react with metal-organic reagents, such as Grignard reagent or organolithium reagent. Taking Grignard reagent as an example, carbon anions in Grignard reagent can attack pyridine rings, form new carbon-carbon bonds, and construct more complex organic molecular structures. This reaction is often used for carbon chain growth and structural modification in organic synthesis.

The common synthesis methods of 3-bromo-2-chloro-4-methylpyridine include the following:
One is halogenation. First, a suitable pyridine derivative is used as the starting material, and the methyl group is halogenated under specific reaction conditions. For example, 4-methylpyridine is used as the substrate, and bromine and chlorine atoms can be introduced under the action of appropriate halogenation reagents and catalysts. Brominating agents such as N-bromosuccinimide (NBS) are usually used, which can replace the hydrogen atom of the methyl group with the bromine atom in the presence of light or initiators to form intermediates such as 4-bromomethylpyridine. Then select a suitable chlorinating agent, such as chlorine gas or other chlorinating reagents, under suitable reaction conditions, introduce chlorine atoms at a specific position on the pyridine ring, and through careful regulation of reaction conditions such as temperature, reagent ratio, reaction time, etc., the chlorine atoms are precisely introduced to the target position, and finally 3-bromo-2-chloro-4-methylpyridine is generated.
The second is the pyridine ring construction method. Starting from the basic raw materials, the pyridine ring is constructed through multi-step reaction and the required substituent is introduced synchronously. For example, a suitable nitrogen-containing and carbon-containing compound is used as the starting material to construct the pyridine ring through a series of reactions such as condensation and cyclization. In the process of building the pyridine ring, bromine, chlorine and methyl are introduced in specific steps according to the reaction design. For example, β-ketone esters, ammonia and halogenated hydrocarbons are used as raw materials to form pyridine ring precursors through condensation reaction, and then in subsequent reaction steps, bromine, chlorine and methyl are introduced into the corresponding positions of the pyridine ring in a predetermined order by halogenation reaction and methylation reaction, so as to achieve the synthesis of 3-bromo-2-chloro-4-methylpyridine.
The third is the metal catalytic coupling method. Pyridine derivatives containing some substituents are prepared first, and then bromine, chlorine and methyl groups are introduced by means of metal catalysts, such as palladium, nickel and other metal complexes. For example, chloropyridine derivatives are used as substrates to react with bromine-containing reagents and methylating reagents under suitable reaction conditions through palladium-catalyzed Suzuki coupling reaction or other similar coupling reactions. Under the action of metal catalyst, the bromine atom in the bromine-containing reagent is coupled to a specific position on the pyridine ring, and the methylation reagent introduces methyl. The reaction conditions are optimized, such as selecting suitable ligands, bases and reaction solvents, etc., to improve the reaction selectivity and yield, and complete the synthesis of 3-bromo-2-chloro-4-methylpyridine.

3-Bromo-2-chloro-4-methylpyridine, this substance is useful in the fields of medicine, pesticides and materials.
In the field of medicine, it is a key pharmaceutical intermediate. It can be converted into a compound with specific pharmacological activity through a series of reactions. If it is used as a starting material, it can be replaced, condensed and other steps, or antibacterial drugs can be prepared. Because of its specific chemical structure, it can precisely act on specific targets of bacteria, interfere with the normal physiological process of bacteria, and then achieve antibacterial effect.
The field of pesticides is also indispensable. Through rational molecular design and synthesis, it can be converted into high-efficiency pesticides. For example, for the nervous system or growth and development mechanism of some pests, pesticides based on 3-bromo-2-chloro-4-methylpyridine are designed and synthesized, which can specifically act on pest-related receptors or enzymes, inhibit the growth and reproduction of pests, achieve pest control, and have a relatively small impact on the environment, which is in line with the development of green pesticides.
In the field of materials, it can participate in the synthesis of high-performance materials. Because it contains active halogen atoms and methylpyridine structures, it can be used as a functional monomer for polymerization reactions. After polymerization, it is introduced into the main chain or side chain of polymer materials to endow the material with unique properties, such as improving the thermal stability and mechanical properties of the material, or endowing the material with specific optical and electrical properties, expanding the application of the material in the fields of electronics and optical devices.

3-Hydroxy-2-chloro-4-methylpyridine is a fine chemical intermediate that is widely used in the fields of pesticides and pharmaceutical synthesis. Its market price is determined by many factors such as raw material cost, production process, market supply and demand.
From the perspective of recent market conditions, due to fluctuations in raw material prices, stricter environmental protection policies, and changes in market demand, its prices also fluctuate. Generally speaking, the market price for high quality and high purity is about 500 to 1,000 yuan per kilogram; for slightly lower purity, the price may be 200 to 500 yuan per kilogram.
If the supply of raw materials is abundant, and the production process is mature and the cost is controllable, the price may stabilize, or even decrease slightly due to market competition. However, if there is a shortage of raw materials, or the increase in production costs due to environmental protection requirements, coupled with strong market demand, the price will easily rise.
Furthermore, different manufacturers have different product prices due to their own technical level and scale benefits. Large manufacturers may be able to provide more cost-effective products by virtue of their scale advantages and advanced technology; small manufacturers are limited by cost, and the price may be slightly higher.
Market prices are difficult to be accurate and constant. Those who are interested in purchasing or selling should pay attention to market dynamics in real time and communicate closely with relevant manufacturers and distributors to obtain accurate price information.