2-Fluoropyridine-Boronic Acid

2-%E6%B0%9F%E5%90%A1%E5%95%B6-%E7%A1%BC%E9%85%B8, that is, borax, its main use is quite extensive.
In the field of medicine, borax has the effect of clearing away heat and detoxifying. "Compendium of Materia Medica" contains: "Borax, sweet taste, slightly salty, cold in nature, non-toxic." It can be used for swelling and pain in the throat, sores in the mouth and tongue, etc. Borax is often used as medicine, formulated as a powder, and applied externally to the affected area, which can clear away heat and reduce swelling, prevent corrosion and build muscle. Such as Bingboron powder, containing borax and other medicines, treating sore throat, swollen gums, and sores in the mouth and tongue, with significant efficacy.
In industry, borax has many uses. In glass manufacturing, the addition of borax can improve the thermal stability, chemical stability and mechanical strength of glass. " Although Tiangong Kaiwu does not detail the application of borax in glass manufacturing, the glass manufacturing process continues to develop, and the role of borax is prominent. For example, in the production of heat-resistant glass, borax can reduce the coefficient of expansion of the glass, making it able to withstand sudden changes in temperature, and is widely used in laboratory instruments and kitchen cookware. In the ceramic industry, borax is used as a flux to reduce the firing temperature of ceramics, improve the gloss and hardness of ceramics, and make ceramic products more beautiful and durable.
In the field of food processing, borax has been used in the past to increase food toughness, brittleness and preservation. However, due to borax toxicity, excessive intake can endanger human health, and it is now strictly prohibited to add it to food.
In agriculture, borax can be used as a trace element fertilizer. Boron is important for plant growth and development, and can promote the development of plant reproductive organs, pollen germination and pollen tube elongation. Reasonable application of borax can improve crop yield and quality, and prevent diseases caused by boron deficiency in crops.

To prepare 2-hydroxybutyric acid, there can be various synthesis methods.
First, acetaldehyde is used as the starting material, and hydroxybutyric acid is condensed by hydroxyaldehyde. First, acetaldehyde is condensed under the catalysis of dilute base to generate 3-hydroxybutyraldehyde. This reaction is that the α-hydrogen of the aldehyde group is active and can form a carbon anion, which can be nucleophilic addition to the carbonyl group of another molecule of aldehyde. Then, 3-hydroxybutyraldehyde is carefully oxidized to carboxylic groups with a suitable oxidizing agent, such as manganese dioxide or TEMPO, to obtain 2-hydroxybutyric acid.
Second, acrylate is used as the raw material. Acrylate is first added to magnesium ethanol and other reagents by Michael, and a group containing active hydrogen is introduced. This step is the conjugated addition of nucleophilic agents to α, β-unsaturated esters. Subsequently, hydrolysis, acidification and reduction steps. Hydrolysis can change the ester group to carboxyl group, acidification adjusts the pH of the system, and then reducing the carbonyl group of the intermediate product to hydroxyl group with reducing agents such as aluminum lithium hydride, and finally 2-hydroxybutyric acid.
Third, ethyl acetoacetate is used as the starting point. Ethyl acetoacetate reacts with ethyl haloacetate under basic conditions, performs nucleophilic substitution, and introduces carboxyl-related groups at the α-position of ethyl acetoacetate. After hydrolysis and decarboxylation, the hydrolysis of ethyl acetoacetate is used to heat the characteristics of easy decarboxylation to remove unnecessary carbonyl groups, while retaining the desired carboxyl group and another α-position activity. After appropriate reduction, 2-hydroxybutyric acid can be obtained. These methods all depend on the reaction mechanism of organic chemistry, and each has its own advantages and disadvantages and applicable scenarios. They need to be used according to the actual situation.

The physical properties of 2-% of the boric acid are very specific. Boric acid, often in the form of white crystalline powder or colored flakes, is not easy to dissolve. Its melting is very specific, and it is around 169 ° C. At this temperature, boric acid will self-solidify and melt the liquid, and this process is smooth and orderly.
In terms of solubility, the degree of solubility of boric acid in water depends on the degree of solubility. Under normal conditions, boric acid can dissolve in water to a certain amount, but the solubility is not high; however, if the water's solubility increases, the solubility of boric acid increases. This is because the degree of solubility increases, and the activity of water molecules increases, which can more effectively break the force of boric acid molecules and make it easier to disperse in water.
The density of boric acid is also one of its important physical properties. Its density is determined, which is 1.435g/cm ³. This density makes boric acid exhibit different sinking or floating characteristics of other substances under normal conditions.
Furthermore, boric acid has a certain hardness, which is not a hard material, but its crystals make it have a certain resistance. And boric acid also has a performance in light, and its crystals show a specific law of refraction and scattering of light, which may have its uses in some light materials. In addition, the general physical properties of boric acid make it useful in many fields such as chemical industry, technology, materials, etc. It has a wide range of uses, and it is an indispensable one for the development of world-class materials.

The most important place to hide. It must be placed in a dry and refreshing place to avoid water. If it comes into contact with water, it is easy to dissolve and dissolve, so it is hidden in the house, and the walls are closed, so there is a risk of rain leakage. And the bottom should be high, so as to separate the ground, so that the ground should not be connected with the tide. In addition, it is convenient to pass through the building well, but it is also necessary to prevent soil, flocs and other substances from being mixed into the building, so as not to dye it.
Furthermore, it is easy to absorb moisture, so it is also necessary to pack it. It is often stored in a tight bag, such as a burlap bag or a cloth bag, and the seal must be sealed. In this way, the intrusion of external tides can be blocked and the dryness of the environment can be guaranteed. If the packaging is not good, the tide will enter, and it will be easy to use. It is not easy to sell outside.
It is also difficult to obtain and sell.
There are also general studies. The flat and solid equipment should be placed first, and the ship should be placed safely, so that it should not be overturned or collided. It is necessary to use the material to prevent the bag from breaking. The ship should pay attention to whether the ship leaks, and the pile should be properly supported to prevent the ship's hull from shaking and shifting.
The management on the way should not be ignored. In case of rain, snow, and other bad weather, it must be covered with cloth and other materials, so that it will not be soaked in the rain. And the process of transportation should also be carefully arranged, so as not to expose it to moisture-prone environments.
Therefore, it is necessary to be careful when hiding, and pay attention to the general situation, so as to ensure that the amount of food is not damaged, so that the land can be used from the ground to the hands of the people, for the needs of people's livelihood.

The water is close to it, and the acid phase is safe. First, it is corrosive. Acids are often corrosive. If you are not careful, the skin will be damaged, the muscles will be damaged, and the skin will sting, leaving scars. If they enter the eyes, they will be damaged, or even cause blindness. If they are connected to clothing and utensils, they will also be corrosive. Second, toxic. Some acids, such as fluoric acid, are more toxic in addition to rotting. If the skin is absorbed or eaten, toxins will enter the body, damaging the organs and endangering life. Third, the disease of the reaction. When the acid is exposed to gold, it is often damaged, and the dense air will gather. In case of open fire or high temperature, the explosion will rise. Mixing, neutralization and reaction will be strong, fast, causing liquid damage. Fourth, the harm of the body. Acids such as acid and nitric acid are easy to burn, causing pungent and rotten, entering the respiratory tract, throat, tubes, and lungs, causing cough, respiratory distress, and exposure during the period, and the rate of respiratory diseases increases greatly. Fifth, it is important to know. Due to the dangerous characteristics of acid, special containers and environments are required. If the container is not resistant to corrosion or poor density, leakage will cause pollution in the surrounding environment, endangering the safety of humans and animals, and collision in the middle of the accident will also increase leakage. In addition, when it comes to acid, it must be followed to prevent the same safety and ensure the safety of people, things and the environment.