4-chloro-3-hydroxy-pyridine

4-Chloro-3-hydroxypyridine has a wide range of uses. In the field of medicine, it is often a key intermediate for the synthesis of many drugs. For example, in the development of antimicrobial drugs, its unique chemical structure can be incorporated into drug molecules through specific reactions to give the drug antibacterial activity, or to enhance the targeting of the drug to specific bacteria and improve the therapeutic effect. In the field of pesticides, it also plays an important role. It can be used as a raw material for the synthesis of new pesticides. With its chemical properties, it can be used to produce pesticide products with high insecticidal and bactericidal properties, contributing to crop protection. In addition, in the field of materials science, 4-chloro-3-hydroxypyridine can participate in the synthesis of some functional materials. For example, some organic materials with special optical and electrical properties can be added to regulate the molecular structure of the material, which in turn affects the properties of the material to meet the special needs of materials in different scenarios. Furthermore, in organic synthetic chemistry experiments, it is often used as an important reagent for researchers to explore new chemical reaction paths, synthesize organic compounds with unique structures and properties, and contribute to the development of chemistry.

4-Chloro-3-hydroxypyridine is one of the organic compounds. Its physical properties are considerable.
Looking at its appearance, under normal conditions, it is mostly white to light yellow crystalline powder, fine and uniform. This form is easy to store and use, and in many chemical reaction systems, because of its good dispersibility, it can make the reaction more sufficient.
The melting point is about 130-135 ° C. The characteristics of the melting point are of key guiding value in the identification, purification and setting of specific reaction conditions. Based on this melting point, the experimenter can accurately determine the purity of the substance by means of melting point determination. If the purity is high, the melting point should approach the theoretical value with little fluctuation; if impurities are present, the melting point may be offset, and the melting range will also become wider.
Solubility is also an important physical property. 4-chloro-3-hydroxypyridine is slightly soluble in water, but it exhibits good solubility in polar organic solvents such as methanol, ethanol, and dichloromethane. This difference in solubility is very useful in the separation, extraction, and construction of solution systems. For example, to separate this compound from a mixed system, a suitable solvent can be selected for extraction according to its solubility in different solvents to achieve efficient separation.
Furthermore, its stability is also a consideration of physical properties. Under normal temperature and pressure, protected from light and dry environments, 4-chloro-3-hydroxypyridine can maintain a relatively stable state, and its chemical properties are not prone to significant changes. However, if environmental conditions change, such as high temperature, high humidity or strong light exposure, its structure may gradually change, which in turn affects its physical properties and chemical activity.

The chemical stability of 4-chloro-3-hydroxypyridine depends on many factors and cannot be generalized.
Under normal conditions, the stability of 4-chloro-3-hydroxypyridine may be acceptable. The hydroxyl group is connected to the pyridine ring, and the presence of the hydroxyl group can participate in the formation of hydrogen bonds through its active hydrogen, which affects the intermolecular interaction to a certain extent, or enhances its stability. The chlorine atom is connected to the pyridine ring. Although the chlorine atom has an electron-absorbing effect, the conjugated system of the pyridine ring itself will also affect the distribution of its electron cloud. Under the interaction of the two, the overall structure can be maintained under common conditions.
However, if the environment changes, its stability is another matter. In the case of high temperature, the thermal motion of the molecule intensifies, or the vibration of the chemical bond increases. When the energy reaches a certain threshold, the chemical bond may break, causing the material to decompose. If it is placed in a strong acid-base medium, the acidity of the hydroxyl group in the 4-chloro-3-hydroxypyridine molecule and the alkaline check point of the pyridine ring, or the chemical reaction with the acid and base, thereby destroying the original structure, the stability is impossible. Another example is under light conditions, if the light energy is absorbed by the molecule and the excited state molecule is generated, it may also trigger a series of photochemical reactions, which affects its stability.
Therefore, the chemical stability of 4-chloro-3-hydroxypyridine depends on the specific environmental conditions, and it cannot be simply asserted whether it is stable or not.

The synthesis method of 4-chloro-3-hydroxypyridine has been recorded in many books in the past, and the main one is selected to describe it.
First, pyridine is used as the initial substance, and it goes through the sequence of halogenation and hydroxylation. First, pyridine meets the halogenating reagent, and at a suitable temperature, pressure and catalytic environment, the chlorine atom enters the fourth position of the pyridine ring to form 4-chloropyridine. Later, it is used as a hydroxylating reagent to induce the hydroxyl group to the third position, and then 4-chloro-3-hydroxypyridine is obtained. However, the reagents and conditions need to be carefully selected to prevent paraphysis and impure products. < Br >
Second, starting from a pyridine derivative containing a specific substituent group. If there is a pyridine derivative with a group that can be converted into a hydroxyl group at the 3rd position and a group that can be substituted as a chlorine atom at the 4th position, the two groups can be converted successively by suitable reactions. For example, 3-alkoxy pyridine derivatives, the 4-position is first substituted for chlorine, and then the alkoxy group is converted to a hydroxyl group. However, the reaction steps are cumbersome and need to be carefully controlled.
Third, it is formed by cyclization. A chain-like compound with an appropriate functional group is used as a raw material, and the pyridine ring is formed by intramolecular cyclization. At the same time, chlorine and hydroxyl groups are introduced. The design of this route is exquisite, but the raw materials are rare, the reaction conditions are harsh, and it is difficult for those who are not familiar with organic synthesis.
There is also a method of metal catalysis. With the help of metal catalysts, the reagents containing chlorine and hydroxyl precursors react with pyridine or its derivatives through coordination, insertion, reduction and elimination to form 4-chloro-3-hydroxypyridine. This approach relies on high-efficiency metal catalysts, and the recovery and reuse of catalysts are essential to meet the purpose of green chemistry.
All kinds of synthesis methods have advantages and disadvantages. When implementing, when the availability of raw materials, cost considerations, product purity and yield factors, careful choices can be made to achieve the purpose of synthesis.

In today's world, business conditions are unpredictable, and it is not easy to determine the price range of 4-chloro-3-hydroxypyridine in the market. This compound is used in many fields such as chemical industry, pharmaceutical research and development, and its price fluctuates depending on quality, purity, supply and demand, purchase quantity, and even the place and season where it is sold.
Looking at the price trajectory of chemical raw materials in the past, if the quality is ordinary and the purity is about 95%, the batch is small, such as only a few dozen grams, at ordinary chemical reagent suppliers, the price per gram may be in the tens of yuan. If the purity is increased to more than 98%, the price of a single gram may rise to around 100 yuan.
However, if the purchase volume is quite large, reaching several kilograms or even several tons, due to the scale effect, the unit price should drop significantly. At that time, the price per kilogram may be between a few hundred and a thousand yuan.
Furthermore, the market supply and demand situation is particularly important. If there are many people who demand at a time, but the supply is small, the price will rise; on the contrary, if the supply exceeds the demand, the price may be downward.
And different regions, due to different transportation costs and tax policies, the price also varies. Prosperous commercial ports, convenient logistics, or due to fierce competition, the price is slightly flat; remote places, or due to difficult transportation, the cost is superimposed, and the price is high. Therefore, in order to obtain the exact price range of 4-chloro-3-hydroxypyridine, it is necessary to carefully investigate the current market supply and demand, consult multiple suppliers, and compare the quotations of different specifications in order to obtain a relatively accurate number.