4-pyridinecarboxylic acid, 2-bromo-, ethyl ester

Mercury is a highly toxic metal with active properties. Mercurous acetate is a compound formed of mercury and acetic acid, and has unique chemical properties.
In mercurous acetate, mercury shows + 1 valence. This compound is a white crystalline powder at room temperature. Its chemical properties are active, and it is easy to decompose when exposed to light or heat, and its stability is poor.
Mercurous acetate is soluble in water and some organic solvents. It will undergo a certain degree of ionization in water, resulting in mercurous ions and acetate ions. The chemical behavior of mercurous ions is quite unique, and it is different from the reaction characteristics of many common metal ions.
Furthermore, mercurous acetate is oxidizing. Under suitable conditions, it can oxidize other substances and reduce itself. It can redox with some reducing substances, changing its own valence state and existence form.
However, special attention should be paid to the fact that mercurous acetate contains mercury elements, which are toxic and highly harmful to human body and the environment. When using and disposing, it is necessary to follow strict safety procedures to prevent the leakage and diffusion of mercury and cause irreversible damage to life, health and the ecological environment. The operation process should be carried out under the condition of complete professional guidance and safety protection measures.

Borax, that is, sodium tetraborate, has many main uses and has many applications in ancient times. The following is your detailed description:
First, in the field of metallurgy, borax has a wide range of uses. In metal welding, borax can be used as a flux. Because it can reduce the melting point of metal oxides, it makes it easier for the oxides on the metal surface to be removed, so that the welding is smoother and the quality and strength of welding are improved. For example, when the ancients forged weapons or built metal utensils for welding operations, borax was often used to make the metal parts more firmly connected and to create more durable utensils.
Second, in the glass manufacturing industry, borax is also indispensable. It can improve the thermal stability and chemical stability of glass. Glass made by adding borax can better withstand drastic changes in temperature, is not easy to break, and has better corrosion resistance. When making exquisite glazed products in ancient times, borax was an important additive, helping craftsmen fire high-quality, colorful and durable glazed objects.
Third, in the production of ceramics, borax plays a significant role. It can be used as one of the components of glaze to improve the performance of glaze. Borax can reduce the melting point of glaze, making it easier for the glaze surface to evenly cover the ceramic surface during the firing process, and making the glaze surface smoother, more delicate, and more vivid and bright. In ancient ceramic production, whether it is daily utensils or art treasures, borax has contributed to improving the quality of ceramics.
Fourth, in the field of medicine, borax also has a certain effect. It has the effect of clearing away heat and detoxifying, reducing swelling and antiseptic. In ancient times, it was often used to treat swelling and pain in the throat, sores in the mouth and tongue. Or borax is developed into powder and applied directly to the affected area; or it is used to rinse the mouth after frying water to relieve symptoms and relieve the pain of patients.
Fifth, borax has been used in food processing. In the past, some merchants added borax to certain foods to increase the toughness, crispness and taste of the food. For example, adding borax when making noodles can make the noodles stronger; adding it when making zongzi can make the rice grains of zongzi more sticky and not easy to deteriorate. However, it is now known that borax is harmful to the human body, and eating borax-containing foods can be harmful to health, so it is strictly forbidden to add it to food.

To prepare ethyl boron-4-alkynylbenzoate, there are many synthesis methods, the following are common ones:
First, boron-4-benzoic acid and ethanol are used as raw materials, and the esterification reaction is carried out under the catalysis of concentrated sulfuric acid. This reaction requires placing the two in a reaction vessel in a certain proportion, adding an appropriate amount of concentrated sulfuric acid as a catalyst, and heating to reflux. Concentrated sulfuric acid can promote the equilibrium of the esterification reaction to move in the direction of ester formation and improve the yield. During the reaction, attention should be paid to controlling the temperature and reaction time. If the temperature is too high, side reactions will easily occur, which will affect the purity of the product; if the time is too short, the reaction will be incomplete. After the reaction is completed, boron-4-alkynyl benzoate ethyl ester can be obtained by distillation, extraction, drying and other post-processing steps.
Second, boron-4-benzoate methyl ester is used as the starting material for transesterification reaction with ethanol. Select a suitable catalyst, such as alkali metal alkoxides or some metal oxides. Boron-4-benzoate methyl ester is added to the reaction system together with ethanol and catalyst, and the reaction is stirred at an appropriate temperature. The transesterification reaction conditions are relatively mild, which can avoid some side reactions at high temperatures. After the reaction is completed, the product is separated by means of vacuum distillation. This operation can effectively remove unreacted raw materials and by-products and improve product purity.
Third, first prepare boron-4-alkynyl acid chloride, and then react with ethanol. Boron-4-alkynyl benzoyl chloride is prepared by the action of boron-4-benzoic acid and thionyl chloride chlorination reagents. This reaction is usually relatively rapid and the yield is quite high. Then boron-4-alkynyl benzoyl chloride is slowly dropped into ethanol and reacted at an appropriate temperature. The acid chloride has high activity and is easy to react with ethanol. After the reaction, the target product boron-4-alkynyl benzoic acid ethyl ester is finally obtained through a series of operations such as neutralization, washing with water, drying, and distillation.
All methods of synthesis have their own advantages and disadvantages. In actual operation, the most suitable method should be selected according to specific circumstances, such as the availability of raw materials, the requirements of reaction conditions, and the requirements of product purity.

There is a question today, what is the value of the city of Qiong, and what is the value of the city of ethyl boron ester. The number of the city is often changed by time, place, supply and demand, and it is difficult to determine.
Let's talk about Qiong, which is also called beautiful jade, ancient Qiong, or a treasure for the nobles to play with, or a ritual vessel for sacrifice or tribute. Its price is extraordinary, and it is often compared with gold beads and other things. However, in this world, the name of Qiong, or other things, if it is made of jade, its price is judged by texture, color, carving, etc. Those who are exquisite can be expensive; those who are crude, the price may be very small.
As for the ethyl ester of boron, this is a chemical substance, which is useful in various industries such as industry, agriculture, and medicine. Its market value is related to the wide and narrow production sources, the difficulty of preparation, and the urgency of demand. If the production source is wide, the preparation is easy, and the demand is flat, the price may be stable but not high; if the production source is thin, the preparation is difficult, and the demand is strong, the price will be expensive.
Therefore, if you want to know the exact value of the ethyl ester of Joan and boron, when you study the dynamics of the city, observe the changes in supply and demand, and visit various industries, it is difficult to determine its approximate price.

Mercury thioacetamide should be treated with caution in the process of storage and storage.
Mercury is a toxic substance and is highly toxic, and its evaporation and inhalation can cause serious damage and damage. When storing mercury, a sealed container must be used to prevent exposure. Containers should be made of corrosion-resistant materials, such as glass or special gold materials, and should be placed in a place with good ventilation, and the source of ignition should be oxidized. Due to the oxidation of mercury, or the strong reaction caused by mercury, the standard should be determined according to the quality of dangerous products. Use of disposable tools to take shock-proof and leak-proof measures. People are also familiar with the urgent treatment of mercury exposure.
Thioacetamide is also a toxic substance, and it needs to be sealed when stored together. It should be kept in a dry place to avoid moisture and high temperature, because it is easy to decompose in a humid environment. Thioacetamide, according to the requirements of toxic chemicals, is guaranteed to be in good condition to prevent leakage.
If mercury and thioacetamide are stored together, it is especially important to note that the two cannot be mixed. Because of its or biochemical reactions, new toxicants are generated and exposure is increased. All the tools and tools are made of perfect leakage and emergency management materials. If mercury is leaked, it can be coated with sulfur powder to generate mercury sulfide, reduce toxicity, and then properly collect it; if thioacetamide is leaked, it can be quickly isolated, and it can be removed. It is collected with a combination of adsorbent materials, according to the rules. In addition, the storage of mercury thioacetamide needs to be controlled by all standards to ensure human safety and not be polluted.