2-CHLORO-3-PICOLINE 2-CHLORO-3-METHYLPYRIDINE

2-Chloro-3-methylpyridine (2-CHLORO-3-PICOLINE and 2-CHLORO-3-METHYLPYRIDINE are different expressions of the same substance) has a wide range of uses.
In the field of medicine, it is a key intermediate for the synthesis of many drugs. For example, some antibacterial drugs, using 2-chloro-3-methylpyridine as the starting material, through a series of chemical reactions, can construct molecular structures with specific antibacterial activities, contributing to the fight against bacterial infections.
In the pesticide industry, it is also an important synthetic building block. It can be used to prepare high-efficiency insecticides, fungicides and other pesticide products. By chemically modifying it, compounds with high selectivity and activity to specific pests or pathogens can be obtained, which can help agricultural harvest and reduce the damage of pests and diseases to crops.
In the field of materials science, 2-chloro-3-methylpyridine can participate in the synthesis of functional materials. For example, some organic materials with special optical and electrical properties, in the synthesis process, it acts as a key component, giving the material unique properties and meeting the specific needs of electronic devices, optical instruments and other fields.
In addition, in the study of organic synthetic chemistry, as a commonly used basic raw material, it provides an important starting material for chemists to explore new reaction paths and construct complex organic molecular structures, and promotes the continuous development and progress of organic chemistry.

2-Chloro-3-methylpyridine (2-CHLORO-3-PICOLINE and 2-CHLORO-3-METHYLPYRIDINE are different expressions of the same substance), its physical properties are as follows:
This substance is mostly colorless to light yellow liquid at room temperature, and it is clear and transparent. Smell it, there is a special smell, but this smell is not obviously fragrant, but has a certain irritation, and it is slightly uncomfortable to smell. Its boiling point is within a certain range, between 195 ° C and 197 ° C. At this temperature, the liquid 2-chloro-3-methylpyridine will be converted into a gaseous state. The melting point is relatively low, about -30 ° C. When the ambient temperature drops below the melting point, the substance condenses from liquid to solid.
Its density is slightly higher than that of water, about 1.16g/cm ³. If it is placed in one place with water, it will sink underwater because of its high density. And the solubility of 2-chloro-3-methyl pyridine in water is not good, and the two are difficult to melt and exist separately. However, in organic solvents, such as ethanol, ether, etc., it has good solubility and can be mixed uniformly with it. < Br >
The vapor pressure of 2-chloro-3-methylpyridine is relatively small at room temperature, but with the increase of temperature, the vapor pressure will also increase accordingly. Its flash point is about 78 ° C. When exposed to open flames and hot topics, it is easy to cause combustion. When using and storing, special attention should be paid to fire and explosion protection.
The physical properties mentioned above are of important guiding significance in many fields such as chemical production and scientific research experiments, and are related to key links such as operation safety and reaction condition control.

2-Chloro-3-methylpyridine (2-CHLORO-3-PICOLINE and 2-CHLORO-3-METHYLPYRIDINE are different expressions of the same substance), is an organic compound with unique chemical properties.
In terms of physical properties, it is a colorless to light yellow liquid under normal conditions, has an irritating odor, and can be volatile in air. Boiling point is about 175-177 ° C, density is nearly 1.15 g/cm ³, slightly soluble in water, easily soluble in most organic solvents, such as ethanol, ether, acetone, etc. This solubility is due to the characteristics of pyridine ring, chlorine atom and methyl group in its molecular structure. The chemical properties of
are active, the pyridine ring is aromatic, and the density distribution of the ring electron cloud is uneven due to the presence of nitrogen atoms, which is nucleophilic and electrophilic. The 2-position chlorine atom has high activity and is prone to substitution reactions. For example, when reacting with nucleophilic reagents such as sodium alcohol and amines, the chlorine atom can be replaced by corresponding groups to generate new nitrogen-containing organic compounds. It is often used as an intermediate in organic synthesis for the construction of complex molecular structures. The 3-position methyl group of
also participates in the reaction and can be oxidized, such as being converted into carboxyl groups and other functional groups under the action of appropriate oxidizing agents, which expands the reaction path and derivatization possibility of the compounds. It can also participate in the electrophilic substitution reaction on the pyridine ring, because the methyl group is the power supply group, the electron cloud density of the pyridine ring is relatively high, and the electrophilic reagent is more likely to attack these positions to achieve the functionalization of the pyridine ring. It is widely used in drug synthesis, material preparation and other fields.

The preparation method of 2-chloro-3-methylpyridine (2-CHLORO-3-PICOLINE and 2-CHLORO-3-METHYLPYRIDINE are different expressions of the same substance) has been different throughout the ages.
First, 3-methylpyridine is used as the starting material. The 3-methylpyridine is added with an appropriate amount of chlorination agent, such as phosphorus oxychloride and phosphorus pentachloride, in an appropriate reaction vessel. The amount of chlorination agent needs to be precisely prepared according to the reaction mechanism and expected yield. In the reaction system, appropriate solvents are often diluted, such as dichloromethane, chloroform and other organic solvents, in order to facilitate the full mixing of the reactants and improve the reaction efficiency. The reaction temperature is also a key factor, usually controlled within a certain range, between about 50 ° C and 100 ° C, depending on the specific chlorinating agent and reaction conditions. In this temperature range, the chlorinating agent fully reacts with 3-methyl pyridine, and through substitution reaction, chlorine atoms are introduced into the second position of the pyridine ring to obtain 2-chloro-3-methyl pyridine. However, in this process, the reaction process needs to be closely monitored. The degree of reaction can be detected by thin-layer chromatography, gas chromatography and other analytical methods, and the reaction can be stopped in time to prevent side reactions such as excessive chlorination.
Second, it can be started from 2-hydroxy-3-methylpyridine. First contact 2-hydroxy-3-methylpyridine with appropriate halogenating reagents, such as phosphorus oxychloride, thionyl chloride, etc. The halogenating reagent reacts with the hydroxyl group and replaces the hydroxyl group with a chlorine atom. This reaction process also requires attention to the reaction environment. The choice of solvent is very important, such as pyridine, N, N-dimethylformamide, etc., which can provide a suitable medium for the reaction. The reaction temperature should also be properly regulated, generally at room temperature to about 80 ° C, so that the reaction can proceed smoothly. Similarly, by means of analysis and detection methods, ensure that the reaction evolves in the expected direction to obtain high-purity 2-chloro-3-methylpyridine products.
Furthermore, using 2-amino-3-methylpyridine as raw material, the target product can also be prepared by diazotization and Sandmeier reaction. 2-amino-3-methylpyridine is reacted with an appropriate amount of sodium nitrite and inorganic acids (such as hydrochloric acid, sulfuric acid, etc.) at low temperatures (usually 0 ° C to 5 ° C) to form diazonium salts. After that, the diazonium salt is reacted with a catalyst such as cuprous chloride and an appropriate amount of hydrogen chloride, and the diazonium group is replaced by a chlorine atom to obtain 2-chloro-3-methylpyridine. This method requires strict reaction conditions, and the temperature and reagent dosage need to be carefully controlled to improve the yield and purity of the product.

2-Chloro-3-methylpyridine (2-CHLORO-3-PICOLINE and 2-CHLORO-3-METHYLPYRIDINE are different expressions of the same substance) are organic compounds. When storing and transporting, the following points should be noted:
First, the storage place must be cool and well ventilated. This is because it is volatile, high temperature or poor ventilation, or causes it to accumulate in the air. First, it increases the risk of fire and explosion, and second, it is harmful to the health of people around.
Second, it must be kept away from fire and heat sources. 2-Chloro-3-methylpyridine is a flammable substance. It is easy to burn when exposed to open flames and hot topics. Therefore, fireworks are strictly prohibited in the place of storage and transportation, and all electrical equipment and tools should have explosion-proof functions.
Third, it should be stored separately from oxidants, acids, alkalis, etc., and should not be mixed in storage and transportation. Because of its active chemical properties, contact with the above substances, or cause violent chemical reactions, causing fire, explosion or toxic substances.
Fourth, the storage container must be well sealed. To prevent it from volatilizing and leaking, polluting the environment and endangering the human body. If a leak occurs, the personnel in the leaked contaminated area should be quickly evacuated to a safe area and quarantined to strictly restrict access. Cut off the source of fire. It is recommended that emergency personnel wear self-contained positive pressure respirators and anti-toxic clothing. Cut off the source of leakage as much as possible. Prevent it from flowing into restricted spaces such as sewers and flood drains. Small leaks: mix with sand, dry lime or soda ash. It can also be scrubbed with emulsion made of non-flammable dispersants, and the lotion is diluted and placed into the wastewater system. Large leaks: build a dike or dig a pit for containment. Cover with foam to reduce vapor disasters. Transfer to a tanker or a special collector with an explosion-proof pump for recycling or transportation to a waste treatment site for disposal.
Fifth, when transporting, follow the specified route and do not stop in residential areas and densely populated areas. Because of its potential danger, once an accident occurs in a densely populated area, it will cause serious consequences.