3-PHENYLPYRIDINE-4-CARBOXYLIC ACID

The chemical structure of 3-benzyl group to its 4-carboxyl group is the content that needs to be investigated in detail in the field of organic chemistry. In this structure, benzyl group is called benzyl group, which is formed by connecting a phenyl group to methylene group, and has unique electronic effects and steric resistance characteristics. As an aromatic hydrocarbon group, phenyl group has a high electron-rich cloud density due to the conjugation system, which shows a certain stability and electron delocalization ability; methylene is the bridge connecting phenyl group to other groups.
As for 4-carboxyl group, it is composed of a carbonyl group and a hydroxyl group, which has a great influence on the properties of organic compounds. The carboxyl group is acidic. Because the oxygen atom of the hydroxyl group has a lone pair of electrons, it is easy to combine electrons with protons, so that the compound can release protons under appropriate conditions and exhibit acidic characteristics.
These two interact in a specific molecular structure, and the electronic effect of benzyl group may affect the acidity of the carboxyl group. If benzyl group has an electron charge effect, or increases the electron cloud density of the carboxyl group, the oxygen atom in the hydroxyl group increases the binding force to the proton, and the acidity is weakened; conversely, if benzyl group has an electron-absorbing effect, the electron cloud density of the carboxyl group decreases and the acidity is enhanced.
Furthermore, in terms of steric resistance, the size and shape of the benzyl group may affect the reactivity of the car If the benzyl steric barrier is large, or the carboxyl group is hindered from participating in some reactions, the reaction rate will be slowed down or the reaction selectivity will be changed. In general, the chemical structure of 3-benzyl to its 4-carboxyl group, due to the interaction between the two, endows the compound with unique physical and chemical properties, which are of great significance in the fields of organic synthesis, medicinal chemistry and so on.

The main purpose of borax is to disinfect and prevent corrosion. In ancient times, borax was often used to make powder and paste, which was used for poisoning, sore throat, and mouth. Borax has the effect of clearing, detoxifying, and anti-corrosion, which can reduce pain and promote healing of the mouth.
In the industrial field, borax is also indispensable. In ceramic manufacturing, the addition of borax can reduce the temperature of the ceramic, make the ceramic floor denser, surface light, and improve its mechanical properties. And it can give ceramics a characteristic color light, so there are many ceramic craftsmen. In glass manufacturing, borax can be used to help melt, reduce the degree of glass melting, and save energy. It can also improve the mechanical quality of glass, and it can be used in the production of high-quality glass and light glass.
In the printing and dyeing industry, borax can be used as a mordant dye. Help dyes better adsorb on the material, so that the dyeing is firm and the color is long-lasting. Dyeing workshop craftsmen follow this technology to dye out beautiful products.
Furthermore, in metallurgical engineering, borax can be used for melting. Metallurgical engineering, can remove the gold in the gold, improve the gold, and increase the amount of gold. In welding, borax can prevent the oxidation of the surface of the gold, making the welding stronger.
Among the fields, borax is also wonderful. It can be used as boron fertilizer, and plants provide the necessary boron element. Boron is very important for plant reproduction and growth, can promote pollen germination and pollen tube extension, improve fruit setting rate, increase plant stress resistance, and increase crop income.

Borax is a very important mineral traditional Chinese medicine, and its main chemical composition is sodium tetraborate. The following is a detailed description of its physical properties:
1. ** Morphology **: Borax crystals are usually short columnar or thick plate-like, and the aggregates are mostly granular, soil-like or skin-shell-like. Among the various mineral forms depicted in "Tiangong Kaiwu", the crystal morphology of borax is also unique. Although it has not been described in detail, it is compared with common mineral forms. Its short columnar and thick plate-like forms are unique in the mineral world, unlike many long or flaky minerals.
2. ** Color and Luster **: Pure borax is mostly colorless and transparent, but it often appears white, gray, yellow, blue, green and other colors due to impurities. Its luster is as bright as glass, and when the light shines on it, it will refract warm and bright light, like the luster of an ancient mirror, but it has a sense of transparency. This feature makes it quite eye-catching in minerals. Among the many mineral colors mentioned in Tiangong Kaiwu, the color and luster of borax also occupy a unique position.
3. ** Hardness **: Borax has a lower hardness, with a Mohs hardness of about 2-2.5. This means that its texture is relatively soft, and scratches can be left on its surface with fingernails. Just like the description of some softer minerals in Tiangong Kaiwu, the low hardness of borax gives it unique properties during processing and identification.
4. ** Cleavage and Fracture **: Borax has good cleavage and can be split into smooth thin slices along the cleavage surface. Its fracture is shell-like or jagged, which distinguishes it from the cleavage and fracture characteristics of other minerals. When ancient craftsmen identified borax, the shape of cleavage and fracture was also an important basis.
5. ** Density **: Borax has a smaller density, about 1.69 - 1.72g/cm ³. Compared with many metal minerals with higher density, borax is lighter. When weighed in the hand, it can clearly sense its light weight. This physical property also plays a certain auxiliary role in judging the authenticity and purity of borax in ancient mineral mining and application.
6. ** Solubility **: Borax is easily soluble in water, and its aqueous solution is alkaline. When dissolved in water, the speed is relatively fast. This solubility makes it unique in ancient medicine and industrial applications. For example, in the liquid formula of traditional Chinese medicine processing and some traditional processes, the solubility of borax allows it to be quickly fused with other ingredients.

There are many methods for the synthesis of 3-benzylpyridine-4-carboxylic acids, each with its own advantages. The details are as follows:
###Synthesis of pyridine-based
1. ** Direct benzylation-carboxylation method **: Pyridine is used as the starting material, and benzyl is introduced at the 3-position of pyridine through benzylation reaction. In this step, benzyl halide can be selected to achieve nucleophilic substitution under the catalysis of base. Then, carboxylation is performed on the 4-position. The side chain of pyridine 4-position can be oxidized to carboxyl by using strong oxidants, such as potassium permanganate. This approach is simple, but the reaction conditions are harsh. The amount of oxidant and the reaction temperature need to be precisely controlled, otherwise it is easy to cause oxidative damage to the pyridine ring.
2. ** Metal Catalytic Coupling Method **: The pyridine is modified first, and a functional group that can interact with the metal catalyst, such as a halogen atom, is introduced at the 3-position. Subsequently, under the action of a metal catalyst (such as a palladium catalyst), it is coupled with benzylboronic acid or its derivatives to form a 3-benzylpyridine structure. Then, under specific reaction conditions, a carboxyl group is introduced at the 4-position through a suitable carboxylating agent, such as carbon dioxide. This method has good selectivity, but the metal catalyst is expensive, the reaction system is relatively complex, and the reaction equipment and operation requirements are quite high.
###Synthesis with carboxylic acid as the group
1. ** Esterification-benzylation-hydrolysis method **: With 4-pyridinecarboxylic acid as the starting material, the carboxyl group is first converted into an ester group to enhance its stability. Then, under appropriate reaction conditions, the benzylation reaction is carried out at the 3-position. The benzylation reagent can be selected from benzyl halide or benzyl alcohol, etc., with the help of a suitable catalyst and base, the reaction is promoted. Finally, through hydrolysis, the ester group is re-converted into a carboxyl group. The reaction conditions of this method are relatively mild, but the steps are more cumbersome, and the yield of each step will affect the yield of the final product.
2. ** Acyl chloride method **: 4-pyridinecarboxylic acid is converted into acyl chloride to enhance its reactivity. Then, the acyl chloride is reacted with benzyl Grignard reagent or benzyl lithium reagent to generate 3-benzyl-4-pyridinecarbonone intermediates. Methyl ketone groups are converted into carboxyl groups through oxidation reaction. This method has high reactivity, but Grignard reagent or lithium reagent has strict requirements on the reaction environment and needs to be operated under anhydrous and oxygen-free conditions, and the preparation and use of acyl chloride need to be particularly cautious, because it is highly corrosive and irritating.

In today's world, what is the market prospect of 3-pyridyboronic acid? Let me tell you in detail.
Guanfu 3-pyridyboronic acid, in the field of organic synthesis, has extraordinary functions. This is an important organic synthesis intermediate, which is widely used in medicine, pesticides, materials and other industries.
In the field of medicine, the preparation of many drugs depends on it. Gein 3-pyridyboronic acid has unique chemical properties and can participate in various key chemical reactions to help build the structure of drug active molecules. Today's pharmaceutical research and development is increasingly advanced, and the demand for new drugs is eager. 3-Pyridyl boronic acid is an indispensable factor in this process. Therefore, with the vigorous development of the pharmaceutical industry, the demand for 3-pyridyl boronic acid will also rise.
As for pesticides, in order to ensure the robust growth of crops and resist the invasion of pests and diseases, the research and development of high-efficiency pesticides is crucial. 3-Pyridyl boronic acid can be used as a key raw material in the creation of pesticides to help synthesize new, efficient and low-toxic pesticides. Today, the world's growing attention to food safety and environmental protection has prompted the pesticide industry to move towards a green and environmentally friendly direction. Under this trend, pesticides prepared with 3-pyridyl boronic acid as raw materials meet the needs of the times, and their market prospects are quite promising.
On the material industry again, with the rapid development of science and technology, the demand for high-performance materials is increasing day by day. 3-pyridyl boronic acid can be used to synthesize special polymer materials, optoelectronic materials, etc. Such materials have important applications in frontier fields such as electronics and optics. Therefore, with the continuous innovation of the materials industry, 3-pyridyl boronic acid will also usher in a broader market space.
In summary, 3-pyridyl boronic acid plays a pivotal role in the pharmaceutical, pesticide, material and other industries. And with the continuous development and progress of various industries, its market prospects are promising, and demand is expected to rise rapidly. It is a chemical product with great potential.