5-鈥婥hloro-鈥?H-鈥媝yrrolo[2,鈥?-鈥媌]鈥媝yridine

In the category covered by "Tiangong Kaiwu", [2,5-b] pyridine composed of mercury (mercury) and hydroxide, its most common use is mainly related to alchemy and medicine.
In the matter of alchemy, the ancients believed that through special refining methods, mercury and other substances could be used to refine miraculous medicinal pills, hoping to achieve immortality. Mercury is an important material in the eyes of alchemists because of its unique chemical properties. Although [2,5-b] pyridine substances are not explicitly mentioned in ancient books, they are speculated from the perspective of chemical connection and the exploration of complex substances at that time, or participate in some special reaction links in the process of alchemy, which helps to change the composition and characteristics of alchemy pills.
In medicine, mercury has been used in medicine since ancient times. Mercury compounds are believed to have special curative effects on some diseases, such as skin diseases such as scabies, and small amounts of mercury preparations can be used externally or sterilized to relieve itching. [2,5-b] Pyridine-like structural substances or also due to their own chemical activity, were explored in ancient medicine attempts to adjust the medicinal properties of drugs, enhance the efficacy or change the way drugs act in the body. However, the ancients had limited knowledge of these substances, and they used them based on experience. At that time, it was difficult to accurately grasp the dosage and safety, and there were always risks. But in any case, in the process of ancient alchemy and medicine exploration, mercury and related similar structural substances played an important role in a specific historical stage, which was part of the ancients' exploration of material properties and applications.

"Tiangong Kaiwu" says: "Mercury, also known as mercury. Its essence is one, but its rheology is special. If the shape of the hardware is one, and the constant change is only mercury." This "5 + -mercury-5-H-to-stirrup [2,5-b] has various physical properties.
Mercury, at room temperature, is a silver flowing liquid, like a smart silver flow, shining. Its density is quite high, heavier than ordinary things, and if the utensils are placed on mercury, they can float more. And mercury has good thermal and electrical conductivity, similar to other metals, which is its physical property.
The melting point of mercury is very low, about -38.87 ° C, so it is a liquid at room temperature. Its boiling point is 356.6 ° C. When heated to the boiling point, it turns into a curl of mercury vapor. Its surface tension is quite large, and it can be gathered into silver beads in a flat place. It is like pearls and jade in heaven, rolling freely and not easy to disperse.
As for the thing [2,5 - b] to which it belongs, although the book does not specify the relationship between this thing and mercury, it is inferred from common sense that it may be a new substance formed by the combination of mercury and other things under specific conditions, or it may be other substances similar to mercury. However, to know the details, more investigation and research are needed.

In the context of "Tiangong Kaiwu", I will explain this about mercury (mercury) for you.
Mercury, at room temperature, is a liquid metal with a silver-white color and a metallic luster. It flows like water, so it is also known as mercury. Its properties are special, and many physical and chemical properties are different from others.
In terms of its chemical properties, mercury has certain reactivity. In case of sulfur, the two are very easy to combine to form mercury sulfide. The speed of this combination is quite amazing, and the ancients have long noticed it. Mercury is often collected by this method to prevent its volatilization and dissipation.
Mercury can also interact with metals to form amalgam. If it meets with metals such as gold and silver, it can form amalgam with it. This property is often used in metallurgy, and it can be used to extract precious metals such as gold and silver.
However, mercury is also toxic. Its volatile gas, inhaled into the human body, can cause poisoning, damage the organs, nerves, etc. When the ancients used mercury, although they did not know its toxicology, they knew its harm and often handled it with caution.
When heated, mercury can react with oxygen to form mercury oxide. This reaction shows that mercury can combine with oxidation under certain conditions, showing its chemical change state. < Br >
Mercury has unique chemical properties and is important in many processes and experiments. However, its toxicity should not be underestimated, so be careful when using it.

To prepare "5 + - 5 - H - to [2,5 - b] to it", you can do it according to the following method.
First, start with the raw material containing
. Common compounds containing
, such as a hydrate, use it as the starting material, and through a multi-step reaction, the purpose of introducing the desired group is achieved. First, the raw material containing
is reacted with a specific reagent under suitable conditions, or under the condition of heating and the catalyst is present in between, so that it undergoes a substitution reaction, and some atoms or groups are replaced with those related to the target product. Then, by adjusting the reaction conditions, such as changing temperature, pH, etc., the reaction proceeds in the expected direction, and the basic skeleton of the target product is gradually constructed.
Second, a specific compound containing H is used as the starting point. Select a compound containing an active H atom and make it react with another substance containing a specific functional group. For example, a compound containing H and a compound containing a carbonyl group undergo a condensation reaction under the catalysis of a base, thereby forming a new carbon-carbon bond or a carbon-hetero bond. Subsequent reaction steps such as oxidation and reduction are used to modify the obtained intermediate, so that each group is gradually converted into the desired structure of the target product "5 + -P-5-H-to-P [2,5-b]".
Third, use organic synthesis strategies, such as reverse synthesis analysis. First analyze the structure of the target product and disassemble it into several simple fragments or precursors. Then consider what common raw materials and reaction paths each precursor can be made from. For example, the target product can be disassembled into several smaller molecules by chemical bond breaking, and then consider the synthesis method of each small molecule separately. Then, according to the synthesis route of each small molecule, the overall synthesis plan from the raw material to the target product is designed. After multi-step reactions, each fragment is gradually spliced, and finally "5 + - 5 - H - [2,5 - b] is synthesized". In this process, the conditions of each step of the reaction need to be carefully controlled to ensure the selectivity and yield of the reaction, so as to achieve the purpose of efficient synthesis.

Now there is a business question to ask Yu Wu: "'5 + -
Looking at its expression," 5 + -
- 5 - H - Xiangyang and [2,5 - b] ", it is difficult to determine its true meaning. Or "5 + -
- 5 - H -" is some kind of obscure logo, and "to the turnip and [2,5 - b]", if it is deduced from common sense, "to the turnip and" or to a certain type of object, "[2,5 - b]" or to set the parameters related to this object, "2,5" or the range limit, "b" or a variable.
However, if you want to know its price range in the market, there is not enough information to rely on. If this is a rare product, it may be necessary to consider its material, process, use, supply and demand and many other reasons. If "[2,5 - b]" is its key attribute, and the value of "b" is not known, it is also difficult to determine the price.
Let this be an ordinary thing. Without more explanation, it is difficult to determine its price range in the market if it is only expressed in the existing confusion. Or it is necessary to discuss the properties, sources, uses, qualities and other things of this thing in detail before it is possible to estimate the price range for it.