"Tiangong Kaiwu" says: "Where plants and trees have flowers, the majority of them are harvested every year, and the few are harvested every year, and even those who start harvesting every year at the age of three or four. Its profit is also thin, and the labor force is a hundred times that of grain food." In various products, this 1,4-dibromo-2,5-dibromobenzene has unique uses.
1,4-dibromo-2,5-dibromobenzene is often a key raw material in the field of organic synthesis. The delicacy of cover organic synthesis lies in the use of various basic raw materials, through clever reactions, to construct complex organic molecules. This compound contains bromine atoms, which have active chemical properties and can participate in many key reactions. Such as nucleophilic substitution reaction, bromine atoms can be replaced by other functional groups, thereby introducing the required groups, paving the way for the synthesis of organic compounds with specific structures.
In materials science, 1,4-dibromo-2,5-dibromobenzene also has extraordinary uses. Today's material research strives for new and high-performance materials. This compound can be used as an important monomer for constructing high-performance polymer materials. After polymerization, it can integrate its own structure into the polymer chain, giving the material unique properties. Such as improving the heat resistance and mechanical properties of the material. Because of its regular structure, it helps to arrange the polymer molecular chain in an orderly manner and improve the overall performance of the material.
Furthermore, in the field of medicinal chemistry, although it is not a direct drug, it is an intermediate in synthesis, and its role cannot be ignored. Pharmaceutical synthesis often requires complex organic molecular structures to conform to human physiological mechanisms and exert drug effects. 1,4-dibromo-2,5-dibromobenzene can be converted into bioactive compounds through multi-step reactions, providing an important material basis for the development of new drugs.
In summary, although 1,4-dibromo-2,5-dibromobenzene may seem ordinary, it plays an important role in many fields such as organic synthesis, materials science, and medicinal chemistry, and has made great contributions to promoting the development of various fields.

The objects referred to by 1% 2C4 and 2% 2C5 are both Erzhuhu, which is a rare mineral in ancient times. Its physical properties are unique and have many records in ancient books.
Looking at its color, it is warm and crystal clear, like jade but not jade, with a soft luster, just like the warm sun on the lake in spring, sparkling but not restrained. "Tiangong Kaiwu" says: "The color of Erzhuhu is elegant and elegant, with hidden treasure light." This color is accessible to unusual minerals, so it is important for the world.
In terms of its texture, it is delicate and hard. With your finger to touch it, it is smooth without leaving your hand, just like touching high-quality silk, and the delicate feeling reaches the heart. Its hardness can resist ordinary grinding, just like a rock in the mountains, which can stand firmly for thousands of years without damage. Ancient books contain: "The quality of Erzhuhu is as strong as gold stone, and it is as delicate as fat." Such a texture makes it elegant and luxurious in carving utensils or decoration.
As for its density, it is larger than that of common stones. When placed in the hand, it has a feeling of sinking, just like holding the precipitation of time. "Tiangong Kaiwu" also says: "Erzhuhu is heavy because of its density." This characteristic is also an important basis for distinguishing the authenticity of Erzhuhu.
Second, Hu's physical properties are unique, and its color, texture, and density are all extraordinary. It is a treasure of heaven and earth creation. It is of high value in many fields such as ancient craftsmanship and decoration, adding luster to the bright pearl of Chinese civilization.

The substances involved in 1% 2C4 and 2% 2C5 are suspected to be dibromobenzene and dibromobenzene. Dibromine is a halogen element compound with strong oxidizing properties, red-brown color, liquid at room temperature, pungent and foul odor, corrosive and highly toxic. If accidentally touched, it can cause skin burns, and if inhaled its vapor, it is also harmful to respiratory organs.
Dibromobenzene, depending on the substitution position of bromine atoms, has three isomers of o-dibromobenzene, m-dibromobenzene, and p-dibromobenzene. All three are colorless liquids with a special odor. Its chemical properties are more stable than dibromine, but it can also be flammable. It can be burned in open flames and hot topics. In the field of organic synthesis, dibromobenzene is often used as an intermediate in the preparation of fine chemicals such as medicines, pesticides, and dyes.
Although the characteristics of dibromine and dibromobenzene are not detailed in "Tiangong Kaiwu", the logic can be deduced according to the ancient people's cognition of halogen element compounds and aromatic compounds. The ancient people's cognition of chemical substances often began with their appearance, smell, and reaction with common substances. For example, for strongly oxidizing substances, or to observe their corrosion to metals, for flammable substances, or to observe their combustion phenomenon. If the ancient people encountered the strong oxidizing, corrosive, and pungent odor of dibromobenzene, they would have been deeply impressed; the flammability and special smell of dibromobenzene should also be perceived by the ancient people. In addition, the ancient people often started from practice in the application of substances. If the characteristics of dibromine and dibromobenzene were observed, they might try to use them in certain processes, such as dyeing and corrosion protection.

The synthesis method of 1,4-diol-2,5-diethylfuran has existed in ancient times, and has changed over the years, and various methods have gradually proliferated. The details are as follows:
First, furfural is used as the starting material and prepared by multi-step reaction. Furfural can be first reduced to obtain furfuryl alcohol. This step requires the selection of a suitable reducing agent, such as sodium borohydride, etc., under appropriate reaction conditions, the aldehyde group in furfural can be reduced to hydroxyl groups. Next, furfuryl alcohol can be converted into 2,5-dimethylfuran through dehydration reaction. This dehydration reaction requires the selection of a suitable catalyst, such as an acidic catalyst, to promote the removal of hydroxyl groups to form double bonds at a certain temperature. Then, 2,5-dimethylfuran can be oxidized and hydrolyzed to obtain the target product 1,4-diol-2,5-diethylfuran.
Second, biomass is also used as the starting material. Many biomass are rich in carbohydrates and can be converted into carbohydrate derivatives after pretreatment. For example, through specific enzymatic or acid hydrolysis reactions, complex carbohydrate structures in biomass can be degraded. The obtained carbohydrate derivatives can construct the basic skeleton of 1,4-diol-2,5-diethylfuran through a series of functional group transformation reactions, such as oxidation, reduction, etherification, etc. This path has gradually attracted attention due to the wide range of biomass sources and renewable sources.
Third, there is a synthesis strategy using halogenated hydrocarbons and alcohols as raw materials. Under the action of bases, halogenated hydrocarbons and alcohols can undergo nucleophilic substitution reactions. The structure of halogenated hydrocarbons and alcohols is cleverly designed, so that the two can gradually build the carbon chain structure of the target molecule after substitution reaction. Subsequently, the functional groups are adjusted through oxidation, reduction and other reactions to achieve the synthesis of 1,4-diol-2,5-diethylfuran. This method requires precise control of the reaction conditions to ensure the selectivity and yield of each step.
There are many methods for synthesizing 1,4-diol-2,5-diethylfuran, and each method has its own advantages and disadvantages. In practical application, it is necessary to comprehensively consider the availability of raw materials, cost, and difficulty of reaction conditions to choose the optimal synthesis path.

1% 2C4 and 2% 2C5 refer to the "two-way thistle", when storing and transporting, pay attention to many matters.
First, it is related to storage. The two-way thistle likes a cool and dry environment, and is afraid of high temperature and humidity. If stored in a high-temperature and humid place, it is prone to mildew and decay, resulting in a significant decrease in its quality. Therefore, it should be stored in a cool, ventilated, dry and moisture-free place. And it needs to be placed at intervals with other sundries to prevent odor infection and damage its original taste and medicinal properties. Furthermore, when storing, it is advisable to use a clean container, such as a crock pot, a wooden box, etc., and the container needs to be well sealed to avoid air and moisture intrusion.
Second, about transportation. During transportation, the first thing is to ensure the integrity of the thistle and avoid extrusion and collision. Due to its fragile texture, external extrusion can easily cause crushing and damage its quality. Therefore, soft objects, such as hay, cotton cloth, etc., should be used to properly wrap the thistle and place it in a sturdy transport container. At the same time, the temperature and humidity of the transportation environment also need to be controlled. Do not make the temperature too high to prevent it from being heated and deteriorated; do not make the humidity too high to avoid moisture and mildew. If long-distance transportation, it is necessary to closely monitor the temperature and humidity and adjust it in a timely manner. In addition, the transportation tool should also be clean and odorless to prevent other odors from contaminating the thistle. If the transportation vehicle has carried odorous objects, it needs to be thoroughly cleaned before it can be used for the transportation of the thistle. Therefore, the quality and efficacy of the thistle can be maintained to the maximum extent during storage and transportation.