Benzene,2-Bromo-1-Iodo-3-Methyl-

This compound is called "Dansha", which is the spiritual object of creation in heaven and earth, and was bred in the intersection of yin and yang, and the transportation and transformation of the five elements.
"Shentong Agreement" says: "Dansha wood essence, get gold is combined." In Dansha, the sulfide of mercury is also red like blood, and its nature is yang. It is born between mountains and rivers, and it collects the pure yang qi of heaven and earth, gathers the light of the essence of the sun and the moon, and is a thing of the ultimate yang.
Dansha is used in health preservation, and the sages and sages of ancient times are often mentioned. Ge Hong's "Baopuzi" said: "Cinnabar is gold, and the sergeant who serves the ascended immortals is also." Gai because it can nourish the spirit, understand the gods, If a person is restless, terrified and sleepless, and uses elixir as medicine, it can calm the mind, return the heart and soul, and restrain the air.
In the art of alchemy, elixir is also the most important thing. "The Seven Signs of Yungui" states: "The one of elixir, the master of all spirits, resides in the sky of the clear spirit, and is in Taixuan." The alchemist is based on elixir, and is matched with various spiritual medicines. According to the wonder of the heat, after the ninth revolution, you can obtain elixir. This elixir can prolong life and be otherworldly. Although this may be said to be mysterious, it can also be seen that elixir is respected in alchemy.
And in the theory of warding off evil spirits and exorcising ghosts, elixir is also valued by the people. " Shennong Materia Medica Scripture calls it "killing the spirit and enchanting the evil ghost". In ancient times, Dan Sha was often applied to the door and utensils, and by virtue of its pure yang power, it drove away evil spirits and avoided filth, and kept the house peaceful. Therefore, Dan Sha is a wonderful use of health preservation, alchemy, and warding off evil spirits. It is actually a strange compound between heaven and earth, and a treasure of traditional Chinese medicine and culture.

A certain stone has all kinds of physical properties. Its quality is firm, and it is not fragile when hit. It is like the bones of a strong man, and it will not be bent by the force of thousands of miles. Looking at its shape, it is mostly in the shape of blocks, or square or round, or with edges and corners, all of which have a natural state, without any carving marks, like the random shape of heaven. Its colors are different, or blue and gray like twilight clouds, or brown and yellow like autumn soil, or white like winter snow. Although the color is not dazzling, it has its own rustic beauty.
As for its weight, it is even more than ordinary earth and stone. In the hand, there is a heavy feeling, and it can be known that its density is quite large. If you touch it with your hand, the surface may be rough like sand, or smooth like a mirror, and the touch is different. And its nature is cold, summer touches it, and a trace of coolness seeps into the skin, as if it can dispel the heat.
The heat conduction of stones is also different from other things. It is heated by fire, and the heating is slow. After the fire is withdrawn, the cooling is also slow, just like the warm elderly, not arrogant or impatient. And because of its dense texture, water is difficult to penetrate. When placed in water, although it is immersed for a long time and does not rot, it can still maintain its own integrity. It can be said to be tenacious. All kinds of physical properties of this stone are endowed by heaven, showing the magical mysteries of nature.

Fudan sand, its chemical properties are unique. Dansha, that is, mercury sulfide (HgS), is red in color, and is often heavy by the ancients.
Its properties are stable, and it is difficult to combine with many substances under normal temperature and pressure. If exposed to air, it rarely changes under normal conditions. When calcined by fire, a wonderful change occurs. Dansha is thermally decomposed, mercury escapes from it, and sulfur also melts into other things. This change was often seen when the ancients refined alchemy.
And Dansha is in the realm of acid and alkali, and it also shows different properties. In case of strong acids, such as aqua regia, although it can gradually dissolve, the process is slow and not urgent. In case of strong alkali, there is little reaction, and it is safe.
And because it contains mercury, mercury, and highly toxic substances, Dan sand is also toxic. However, the ancients did not understand this reason, and they often used it as medicine, or used it for alchemy to seek longevity, which is actually a risk.
The conductivity of Dan sand is very small, almost none, and it is a good insulator. In terms of optical properties, it has a special refractive index, so its appearance is unique and eye-catching.
In summary, the chemical properties of Dan sand, stable changes in China and Tibet, show different states in different environments, which were studied and explored by the ancients, and also left many valuable clues for the development of later chemistry.

It is widely used, and it may be applied in various fields.
In the field of agricultural affairs, it can be used to fertilize the field and raise seedlings. In the past, farmers nourished the land with natural fertilizers, but when the land's strength was eventually exhausted. Today's chemical fertilizers, such as nitrogen fertilizers, phosphorus fertilizers, potassium fertilizers, etc., are made according to scientific formulas, which can accurately replenish the lack of land, so that the crops are strong and lush, and the actual yield is abundant, so as to provide food for all people.
In the world of engineering, the things of harmony are also indispensable. In the production of building materials, various chemical mixtures make the material stronger and more resistant, such as the improvement of cement, adding chemical and chemical substances, making it coagulate faster and stronger, building houses and bridges, as stable as Mount Tai. In the textile industry, chemical and chemical materials are used for printing and dyeing, with bright and long-lasting colors, and ready-to-wear is beautiful and durable.
In the road of medicine, chemical and chemical products have made outstanding achievements. Many drugs are chemically synthesized and delicately proportioned to heal diseases. Or antibacterial and anti-inflammatory, so that patients can avoid the pain of illness; or conditioning the viscera and helping the human body recover.
Furthermore, in daily use, chemical and chemical products can also be seen everywhere. Plastics, the product of chemical and chemical, are lightweight and widely used. They are made into appliances, or contents, or supplies, which is convenient for life. Cleaning products, such as detergents, contain chemical and chemical substances, can remove dirt and scale, and keep the environment clean.
As for the field of transportation, fuel additives are also chemical and chemical substances, which can make fuel burn more fully, improve power, and reduce exhaust pollution, which is conducive to environmental protection.
All of these can be seen in many fields such as agriculture, industry, medicine, daily use, transportation, etc., and are of great use. They are actually essential for promoting the development of the world and improving people's livelihood.

There are many methods for synthesizing a chemical compound, each according to its own reason, and follows a different path. Now let's describe the common methods to clarify their importance.
One of them is the method of addition. If there are unsaturated bodies, such as alkenes and alkynes, they can be added with other substances to cause structural changes and form new compounds. For example, ethylene meets bromine, and the double bond is opened, and the bromine atom is added separately to obtain dibromoethane. This is because the unsaturated bond is active and easy to interact with electrophilic reagents. The addition reaction is initiated. The process is relatively straight and the yield is often considerable.
The second is the method of substitution. The atom or group in the compound can be replaced by other atoms or groups. If halogenated hydrocarbons are in alkali, halogen atoms can be replaced by hydroxyl groups and alcohols. This reaction depends on the nucleophilicity of the reagent. The nucleophilic reagent attacks the carbon-halogen bond of the halogenated hydrocarbon, and the halogen atom leaves, and a new bond is formed. The key lies in choosing the appropriate nucleophilic reagent and reaction conditions to promote the reaction.
The other is the method of condensation. Two molecules or multiple molecules are reacted to remove small molecules and form larger molecules, that is, condensation reaction. The hydroxyl-aldehyde condensation of aldosterone and ketone, the α-hydrogen of one molecule of aldehyde or ketone, under the catalysis of base, is added to the carbonyl group of another molecule, and α, β-unsaturated aldosterone is obtained after water loss. This reaction increases the carbon chain of molecules, which is crucial in organic synthesis and can form complex structures.
There is also a method of oxidation and reduction. The oxidizer increases the valence state of an element in the compound, such as alcohol, which can be oxidized to form an aldehyde or acid; the principle is the opposite, the valence state is reduced, such as nitro compounds can be reduced to obtain amines. These two methods are often used to convert functional groups. Depending on the desired change of the compound, the appropriate oxidation or reducing agent is selected to control the degree of the reaction.
The above methods have their own uses in the synthesis of compounds. In practice, according to the structure and properties of the target compound, we should carefully review the raw materials and conditions, and choose the synthesis strategy, or use it alone, or apply a combination of methods to achieve the purpose of synthesis.