3-Hydroxypyridine-5-boronic acid pinacol ester

3-Hydroxypyridine-5-boronic acid pinacol ester is an important chemical substance in the field of organic synthesis. Its chemical properties are unique and of great significance to organic synthesis reactions.
Looking at its structure, the pyridine ring system is connected to the boronic acid pinacol ester group, and this specific structure endows the substance with many characteristics. In terms of physical properties, it is usually in a solid state and has certain solubility in organic solvents. Organic solvents such as common dichloromethane and tetrahydrofuran can provide a good solubility environment for it.
In terms of chemical properties, the boronic acid pinacol ester group is very active and can participate in a variety of classical organic reactions. For example, in the coupling reaction of Suzuki (Suzuki), it can be coupled with halogenated aromatics or halogenated olefins under the action of palladium catalyst, thereby forming carbon-carbon bonds, and then realizing the construction of complex organic molecules. This reaction condition is mild and highly selective, and it is widely used in drug synthesis, materials science and other fields.
Furthermore, the hydroxyl group of 3-hydroxypyridine-5-boronic acid pinacol ester is also reactive. The hydroxyl group can undergo esterification reaction and react with acyl chloride or acid anhydride under appropriate conditions to form corresponding ester derivatives. At the same time, the hydroxyl group can also participate in the nucleophilic substitution reaction and react with suitable nucleophiles to modify the molecular structure.
In addition, the nitrogen atom of the pyridine ring has lone pair electrons, which can form coordination bonds with metal ions, which has potential applications in the field of metal-organic chemistry, or can be used to prepare specific metal complexes. These complexes may exhibit unique properties in catalysis, materials, etc.
3-hydroxypyridine-5-boronic acid pinacol esters play a key role in many fields of organic synthesis due to their unique chemical properties, providing an effective way for the construction of organic molecules and the preparation of functional materials.

The common synthesis methods of 3-hydroxypyridine-5-boronic acid pinacol ester are as follows:
The starting material is mostly 3-hydroxypyridine. First, 3-hydroxypyridine can be halogenated first, and halogen atoms (such as bromine or iodine) are introduced at the 5 position of the pyridine ring. Commonly used halogenation reagents include N-bromosuccinimide (NBS) or iodine, etc., and react under the action of suitable solvents (such as dichloromethane, etc.) and catalysts (such as peroxides, etc.) to generate 5-halo-3-hydroxypyridine. Subsequently, 5-halide-3-hydroxypyridine is coupled with the diphenol borate in a metal-catalyzed coupling reaction. Palladium (Pd) complexes (such as tetra (triphenylphosphine) palladium (0), that is, Pd (PPh)) are often used as catalysts, potassium carbonate is used as a base, and the reaction is heated in an organic solvent (such as toluene, dioxane, etc.) to obtain 3-hydroxypyridine-5-boronic acid phenol esters. In this process, the metal catalyst can activate the carbon-halide bond and promote its coupling with the borate ester.
Second, 3-hydroxypyridine can also be properly protected first to avoid hydroxyl interference during the reaction. For example, the hydroxyl group is protected with a protective group such as tert-butyldimethylsilyl (TBS), and then the halogenation and coupling reaction similar to the above are carried out. Finally, the protective group is removed to obtain the target product. The deprotection step selects the appropriate reagent according to the nature of the protective group. For example, the TBS protective group can be removed by tetrabutylammonium fluoride (TBAF). These methods have their own advantages and disadvantages. In the actual synthesis, the selection needs to be comprehensively considered according to the availability of raw materials, cost, reaction conditions and other factors.

3-Hydroxypyridine-5-boronic acid pinacol ester is used in many fields. In the field of medicinal chemistry, it is a key intermediate in organic synthesis and can be used to construct biologically active compounds. Due to its borate ester structure, it can participate in a variety of coupling reactions, such as the Suzuki-Miyaura coupling reaction, through which carbon-carbon bonds can be precisely formed, and then complex drug molecules can be synthesized. For example, when developing anti-inflammatory or anti-tumor drugs, using this as a raw material and carefully designing the reaction route can obtain the target product with specific pharmacological activity.
In the field of materials science, this compound also plays an important role. It can be used to prepare functional materials because its unique structure can endow materials with specific optical and electrical properties. For example, in the preparation of organic optoelectronic materials, it can be introduced into the polymer skeleton after appropriate chemical modification, which can adjust the energy level structure of the material, improve the luminous efficiency or charge transport performance of the material, and provide the possibility for the optimization of materials such as organic Light Emitting Diode (OLED) or organic solar cells.
In the field of organic synthetic chemistry, as a common reagent, its borate ester has good partial stability, and the hydroxyl group can be further derivatized. In the total synthesis process of complex natural products, it can be used to participate in multi-step reactions to gradually construct the complex structure of the target molecule. At the same time, when constructing new pyridine derivatives, it can be used as a key building block to expand the substitution mode of pyridine rings and enrich the structural diversity of organic compounds by reacting with different halogens or electrophilic reagents. In short, 3-hydroxypyridine-5-boronic acid pinacol esters play an indispensable role in many frontier scientific fields due to their unique structure and reactivity.

3-Hydroxypyridine-5-boronic acid pinacol ester, the price of this product in the market varies with time, place and quality, and it is difficult to know for sure. If it is stated in the ancient style of "Tiangong Kaiwu", it is said:
Now I want to know the geometry of 3-hydroxypyridine-5-boronic acid pinacol ester in the city, but its price is not the same, often due to changes in supply and demand, differences in origin, and differences in quality. In the prosperous capital of Dayi, merchants gather, and the supply of goods is abundant, but the price is slightly flat; in remote places, the material is thin and difficult to produce, and the price may be expensive. < Br >
And the quality is also the key to the price. Those who are refined and pure, the price must be higher than those who are crude and miscellaneous. And the times are different, and the price also fluctuates. In a year of plenty of goods, the price may stabilize; in a year of famine, when things are scarce, the price will rise.
To get a definite price, you need to consult the people of Sijia in various cities, or visit the homes of chemical materials brokers. They are often involved in the trade of this product, and they should be well known at the current price. However, roughly speaking, the price per gram, or ranging from a few gold to dozens of gold, is difficult to determine quickly. You need to visit in person and consult many parties to get a more accurate price.

3-Hydroxypyridine-5-boronic acid pinacol ester is a commonly used reagent in organic synthesis. Its storage conditions are crucial, which affect the stability and activity of this reagent, and also affect the effectiveness of subsequent chemical reactions.
This reagent should be stored in a low temperature, dry and dark place. For low temperatures, about -20 ° C is preferred. This temperature can slow down the thermal movement of molecules, reduce the rate of chemical reactions, inhibit the decomposition of reagents themselves or react with substances in the environment, and maintain the integrity of their chemical structure. A dry environment is indispensable. Borate esters are prone to hydrolysis with water. If the ambient humidity is high and moisture invades, 3-hydroxypyridine-5-boronic acid pinacol esters will be hydrolyzed to form boric acid and corresponding alcohols, which will damage their original chemical properties and cannot be used in organic synthesis.
As for avoiding light, because light can provide energy and cause photochemical reactions, unnecessary chemical changes will occur in the reagent. Therefore, it can be avoided in a brown bottle or a container wrapped in dark materials.
In addition, the storage place should also be kept away from oxidants, acids, bases and other substances. The oxidizing agent may react with the reagent to change its chemical structure; the acid and base can catalyze its hydrolysis or other chemical reactions, which are not conducive to its storage. When taking it, it is advisable to open and close the container quickly to reduce its contact time with the external environment and maintain its quality. In this way, 3-hydroxypyridine-5-boronic acid pinacol ester can maintain good chemical properties during storage for organic synthesis.