6-Methoxypyridine-3-boronic acid pinacol ester

6-Methoxypyridine-3-boronic acid pinacol ester is an important intermediate in organic synthesis. It has a wide range of uses and is often a key structural block in the field of medicinal chemistry. Many bioactive compounds rely on it to build a pyridine skeleton structure during the synthesis process. Due to the unique electronic properties and spatial structure of pyridine rings, the introduction of methoxy and boronic acid pinacol ester groups can precisely regulate the physicochemical properties and biological activities of molecules.
In the field of materials science, it has also attracted much attention. It can be introduced into polymer materials or functional materials through specific chemical reactions, giving materials unique photoelectric properties, self-assembly properties, etc. For example, in the synthesis of some organic luminescent materials, 6-methoxypyridine-3-boronic acid pinacol esters can participate in the construction of luminescent core structures and improve the luminescent efficiency and stability of materials.
In addition, in the methodological study of organic synthetic chemistry, as borate esters, they can participate in a variety of classic coupling reactions, such as Suzuki-Miyaura coupling reaction. This reaction condition is mild and highly selective. By coupling with substrates such as halogenated aromatics or halogenated olefins, carbon-carbon bonds can be efficiently formed, thus realizing the synthesis of complex organic molecules, which greatly enriches the strategies and means of organic synthesis.

The synthesis method of 6-methoxypyridine-3-boronic acid pinacol ester has been known for a long time. Its methods are diverse and have their own strengths. Several common methods are described in detail below.
First, 6-methoxy-3-halopyridine is used as the starting material. Palladium-catalyzed cross-coupling reaction between 6-methoxy-3-halopyridine and pinacol borate occurs in organic solvents in the presence of palladium catalysts, bases and ligands. Common palladium catalysts such as tetra (triphenylphosphine) palladium (0), bases can be selected from potassium carbonate, sodium carbonate, etc., ligands such as 2,2 '-bipyridine, etc. Organic solvents such as toluene, dioxane, etc. During the reaction, the system is heated to maintain a certain temperature, usually between 80 and 120 ° C. After several hours of reaction, the halogen atom and the borate ester group are exchanged to form the target product 6-methoxypyridine-3-boronic acid pinacol ester. This reaction condition is mild and the yield is quite high, but the palladium catalyst is expensive and the cost is slightly higher.
Second, 6-methoxypyridine is used as the raw material. First, 6-methoxypyridine is lithiated. Usually at low temperature, such as -78 ° C, it is treated with a strong base such as n-butyllithium to lithium at a specific position of the pyridine ring. Subsequently, the boric acid ester is added, and the lithium atom is combined with the borate group to form 6-methoxypyridine-3-boronic acid boronyl alcohol ester. This process requires strict control of the reaction temperature and the amount of reagents. Although the use of expensive palladium catalysts can be avoided, the reaction conditions are harsh and the operation requirements are very high.
Third, there are also those who use 6-methoxy-3-nitropyridine as the starting material. The nitro group is first reduced to an amino group, which can be reduced under acidic conditions by iron powder, zinc powder, etc., or catalyzed by hydrogenation. After 6-methoxy-3-aminopyridine is obtained, the amino group is converted into a diazonium salt by diazotization reaction, and then reacts with pinacol borate to form the target product. This route has a little more steps, but the raw materials are relatively easy to obtain, and the cost may be advantageous.
The above synthesis methods have advantages and disadvantages. According to actual needs, factors such as raw material cost, reaction conditions, yield and purity requirements should be considered, and the most suitable method should be selected.

6-Methoxypyridine-3-boronic acid pinacol ester is an important reagent commonly used in organic synthesis. Its physical and chemical properties are particularly critical, and it is related to the process and effect of many chemical reactions.
Looking at its physical properties, under normal circumstances, this substance is mostly in the form of a white to off-white solid. Its melting point is quite specific, about [X] ° C. This property is very important for the purity identification and separation and purification of the substance. The melting point is stable and accurate, which can be one of the important characteristics of its quality. In addition, its solubility is also characterized, and it exhibits good solubility in common organic solvents such as dichloromethane and toluene. This is due to the synergistic effect of methoxy, pyridine ring and boric acid pinacol ester groups contained in the molecular structure. Such solubility makes it well mixed with many reactants in organic synthesis reactions, thereby promoting the smooth progress of the reaction.
As for chemical properties, the reactivity of boric acid pinacol ester groups in 6-methoxypyridine-3-boronic acid pinacol ester is quite high. In transition metal-catalyzed coupling reactions, such as the Suzuki-Miyaura coupling reaction, this group can react with halogenated aromatics or halogenated olefins to form carbon-carbon bonds. The mechanism of this reaction is based on metal-catalyzed oxidative addition, metallization, and reduction elimination. At the same time, methoxy groups and pyridine rings also affect their chemical properties. Methoxy groups are the power supply groups, which can enhance the electron cloud density of the pyridine ring, which in turn affects the electrophilic substitution reaction activity on the pyridine ring. Pyridine rings are alkaline due to the presence of nitrogen atoms, and can react with acids to form corresponding salts. In addition, the substance is sensitive to air and moisture, and it needs to be properly sealed during storage to prevent deterioration and affect its effectiveness in various reactions.

6-Methoxypyridine-3-boronic acid pinacol ester is a commonly used reagent for organic synthesis. When storing and transporting, pay attention to the following things:
First, the storage environment should be dry and cool. This compound is prone to moisture hydrolysis, causing it to deteriorate and its effectiveness is impaired. Therefore, it should be stored in a dryer or placed in a storage place with a desiccant to keep the environment dry. Excessive temperature will also accelerate its decomposition. Usually, the storage temperature should be controlled at 2-8 ° C.
Second, be sure to avoid contact with oxidants, acids, and alkalis. The chemical properties of 6-methoxypyridine-3-boronic acid pinacol ester are lively, and it is easy to react chemically when encountering the above substances, or cause danger such as combustion and explosion. When storing, it should be stored separately from such substances and kept at a certain distance.
Third, pay attention to the tightness and stability of the packaging during transportation. This compound may damage the packaging due to vibration and collision, and then leak. Suitable packaging materials, such as glass bottles, plastic bottles, etc., must be used, and reinforced with fillers to prevent collisions during transportation. At the same time, warning signs should be clearly marked on the outside of the package to remind the transportation personnel to pay attention.
Fourth, strictly follow relevant regulations and operating procedures. Whether it is storage or transportation, it must comply with national and local chemical management regulations. Operators need to undergo professional training to familiarize themselves with their characteristics and safe operation methods to ensure the safety of the entire process.

6-Methoxypyridine-3-boronic acid pinacol ester, this product is in the market, and its price is difficult to determine. The price in the market often changes due to many reasons, and it cannot be held together.
Its price may vary depending on the place where it is produced. If it comes from a place where the craftsmanship is sophisticated and the materials are easy to produce, the yield is abundant, and the price may be slightly cheaper; if the place of origin is remote, the materials are difficult to collect, and the production is difficult, the price will increase.
It is also related to the quality. Those who are refined and pure have few impurities, and their price is high; if the quality is inferior, the price should be reduced. This principle is like the ancient goods, the refined ones are expensive, and the coarse ones are cheap. < Br >
And the supply and demand of the city is also the main reason. If there are many people who want it, the price will increase; if the supply exceeds the demand, the price will be suppressed. Just like the ancient city, if the goods are rare, they will be expensive, and if the goods are abundant, they will be cheap.
And the route of trade also affects its price. Through the tedious journey, the hands of many people are transferred, and the value is added layer by layer, and the price will be high; if the route is sold in the city, the cost in the middle will be saved, and the price may be appropriate.
Looking at the past, the price of such chemical products often fluctuated. According to past examples, the price per gram may fluctuate between tens of yuan and hundreds of yuan. However, this is only a rough figure, not an exact value. If you want to know the real-time price, you must consult the chemical market and suppliers before you can get it. Although it is difficult to determine the exact price, the reasons for all the effects have been stated by you. I hope it is helpful to speculate on the price.