Although 1,3-dibromo-5-chlorobenzene is not directly recorded in "Tiangong Kaiwu", it is deduced from the ancient chemical industry, medicine, dyeing and weaving industries, and its uses may have the following ends.
In chemical synthesis, it can be an important intermediate. Ancient alchemy and early pharmaceuticals were often based on various minerals and plants, and new products were prepared through complex reactions. 1,3-dibromo-5-chlorobenzene has active chemical properties, or involves aromatic ring substitution, addition and other reactions. For example, ancient pigments may need to be made from them, and through multi-step transformation, fresh and stable pigments can be obtained for calligraphy, painting, dyeing and weaving.
In the field of medicine, there is also potential value. Ancient healers treated diseases, and often used herbs and golden stones as medicine. 1,3-Dibromo-5-chlorobenzene or after processing and compatibility, has the effects of sterilization and anti-inflammation. Although the ancients did not have modern precise pharmacological knowledge, they found in practice that compounds containing such structures are effective for some diseases. Such as swelling of sores and toxins, the external application of the agent participated in the preparation may inhibit the growth of bacteria and help the wound heal.
Dyeing and weaving industry, or as a mordant. In ancient dyeing cloth, in order to make the color firm and uniform, mordants were often used. 1,3-Dibromo-5-chlorobenzene may be able to combine with fabric fibers and dyes to enhance the adhesion of dyes, so that dyed fabrics can be washed in the sun without fading, and meet the needs of the ancients for the beauty and durability of clothing and fabrics.
In summary, although 1,3-dibromo-5-chlorobenzene is not detailed in "Tiangong Kaiwu", it is still based on the development of ancient technologies and the commonality of chemical substances. It may have important uses in chemical, pharmaceutical, dyeing and weaving industries, etc., adding luster to the life and production of the ancients.

1% 2C3-dibromo-5-pentyne is an organic compound with special physical properties. Although "Tiangong Kaiwu" does not directly describe this substance, it can be described in Chinese according to the method of the ancients.
Under normal temperature and pressure, it is a colorless to light yellow liquid. It has a clear state, like morning dew condensation, and its luster is restrained. Smell it, there is a pungent smell, like being in a foreign land, its smell is unique and has penetrating power, making people instantly alert.
The density of this substance is greater than that of water. If it is dumped in water, such as a stone sinking abyss, it goes straight down and is decisively layered with water. The upper water is still clear, and the lower layer is the stable state of the substance. Its boiling point is quite considerable, and it needs a higher temperature to boil it into a gaseous state. Just like to sublimate it, it needs to be tested by fire. The melting point is in a specific low temperature range, and it is easy to condense when cold. It is like water in a cold winter turning into hard ice, and the form changes from flow to solidification.
Furthermore, 1% 2C3-dibromo-5-pentyne has good solubility in organic solvents, like a duck to water. It can be mixed with many organic solvents, and it is seamless and indistinguishable from each other. This solubility is like mixing fine sand into water, which is evenly distributed after stirring, making it difficult to trace.
However, this thing is also dangerous, because it is flammable, in case of open flames and hot topics, it will be like dry firewood in case of fire, instantly exploding, with amazing power. When operating, you need to be very careful, like walking on thin ice in the abyss, you must not take it lightly, so as not to cause a disaster.

There are several common methods for the synthesis of 1% 2C3-dibromo-5-chlorobenzene:
One is the halogenation reaction method. Benzene can be taken as the starting material first, and under specific reaction conditions, benzene and bromine can be substituted. Because the hydrogen atom on the benzene ring has a certain activity, the bromine atom can replace the hydrogen on the benzene ring in the presence of suitable catalysts such as iron or iron tribromide. Controlling the reaction conditions and the amount of bromine, the bromine atom can be introduced preferentially to the specific position of the benzene ring to obtain a bromobenzene product. Subsequently, by re-halogenating the bromobenzene, by regulating the reaction conditions, the second bromine atom can selectively enter the ortho or meta position to obtain 1,3-dibromobenz Finally, 1,3-dibromo-5-chlorobenzene is obtained by introducing chlorine atoms at the 5th position of 1,3-dibromobenzene with chlorine reagents such as chlorine gas or chlorination agents under appropriate catalyst and reaction conditions.
The second is to use other compounds containing benzene rings as starting materials for conversion. For example, select a specific substituted benzene derivative whose benzene ring already has some transformable groups. First, these groups are converted into bromine atoms through a series of reactions by organic synthesis. This process may involve various reaction steps such as substitution, oxidation, and reduction. After two bromine atoms are successfully introduced into the benzene ring and the positions meet the requirements, chlorine atoms are introduced at the 5th position through a specific reaction. This method requires careful design of the reaction route according to the structure of the starting compound to ensure the selectivity and yield of each step.
The third is the cross-coupling reaction using metal catalysis. First prepare benzene derivatives with bromine atoms and suitable leaving groups, as well as chlorine-containing nucleophiles. Under the action of metal catalysts such as palladium catalysts, the two are cross-coupled. This reaction can achieve the breaking of carbon-halogen bonds and the formation of new carbon-carbon bonds or carbon-halogen bonds under relatively mild conditions. Through rational selection of reaction substrates, catalysts and reaction conditions, bromine atoms can be introduced at the 1,3 positions and chlorine atoms at the 5 positions of the benzene ring to achieve the synthesis of 1,3-dibromo-5-chlorobenzene. This method has the advantages of mild reaction conditions and high selectivity, but the catalyst cost is higher and the reaction operation requirements are stricter.

1% 2C3-dibromo-5-chlorobenzene requires attention to many matters during storage and transportation.
One is related to storage. This substance should be placed in a cool, dry and well-ventilated place, and must not be close to fire or heat sources to prevent its chemical properties from changing and causing danger due to excessive temperature. Because it has certain chemical activity, high temperature or decomposition reactions. And should be stored separately from oxidants, strong bases, etc., to avoid chemical reactions in contact with them. If the two are mixed, or react violently, it will cause serious consequences such as fire and explosion. The storage place should also be equipped with suitable containment materials. In the event of leakage, it can be collected in time to prevent the spread of pollution.
Second, about transportation. Before transportation, it is necessary to ensure that the packaging is intact. Packaging materials must be able to effectively prevent the leakage and volatilization of the substance. Containers with good sealing performance are commonly used and properly fixed to avoid packaging damage due to bumps and collisions during transportation. During transportation, relevant hazardous chemical transportation regulations must be strictly followed, and transportation vehicles must be equipped with corresponding fire protection equipment and emergency treatment equipment. Escorts also need to be familiar with the characteristics of the substance and emergency disposal methods. In case of emergencies, they can respond quickly and correctly. At the same time, transportation routes should try to avoid densely populated areas and environmentally sensitive areas to prevent leakage from causing serious harm to people and the environment.

The market price of 1% 2C3-dibromo-5-chlorobenzene fluctuates due to a variety of factors, making it difficult to give an exact value.
In the market, the price of this compound is first affected by the cost of raw materials. If the starting material required to synthesize the substance is difficult to obtain and the production is limited, the price increase will drive up the cost of 1% 2C3-dibromo-5-chlorobenzene, which in turn will increase the market price.
The complexity of the production process is also crucial. If the preparation process requires multi-step reactions, special reaction conditions (such as high temperature, high pressure, strict anhydrous and anaerobic environment) or the use of expensive catalysts, the production cost will increase, which will be reflected in higher market prices.
The market supply and demand relationship is also critical. If the demand for 1% 2C3-dibromo-5-chlorobenzene increases sharply during a certain period of time, such as the explosion of demand in the synthesis of some pharmaceutical and pesticide intermediates, and the supply cannot keep up in time, the price will rise; conversely, if the market demand is low and the supply is sufficient, the price may fall.
In addition, the purity of the product has a significant impact on the price. The preparation of high-purity 1% 2C3-dibromo-5-chlorobenzene is difficult and can meet high-end application scenarios, such as for precision chemical synthesis and high-end pharmaceutical research and development, and the price will be much higher than that of ordinary purity products.
Generally speaking, in the chemical raw material market, the price per kilogram of ordinary purity 1% 2C3-dibromo-5-chlorobenzene may range from hundreds to thousands of yuan; if it is a high-purity product that meets the strict standards of a specific industry, the price may be higher. However, the specific price needs to pay attention to the dynamics of the chemical raw material trading market in real time and consult relevant suppliers to know the exact value.