3,7-Dibromodibenzo[b,d]thiophene

3,7-Dihydroxydibenzo [b, d] furan, although this substance did not have such modern knowledge in the era covered by Tiangong Kaiwu, its function can still be deduced from the perspective of traditional pharmacy and technology.
In the way of pharmacy, the characteristics of traditional herbal medicine are explored. This furan substance may have the effect of clearing away heat and reducing fire. In ancient books, there are many herbs and wood medicines, compounds containing hydroxyl groups often have the effect of clearing away heat and cooling blood. Such as Rehmannia, which is rich in hydroxyl components and can clear heat and generate fluid. In this analogy, 3,7-dihydroxydibenzo [b, d] furan may relieve heat toxicity in the body and soothe fever, getting angry and other diseases.
The process of manufacturing, which may involve the field of dyeing. Ancient dyeing, relying on natural plants and minerals. Some compounds containing such structures can be used as dyes or mordants. Like some phenolic hydroxy compounds, they can complex with fabrics and mordant metal ions to make dyeing firmer and brighter. The hydroxyl structure of 3,7-dihydroxydibenzo [b, d] furan, or endow it with similar dyeing or dyeing characteristics, plays a role in the fabric dyeing process, helping craftsmen obtain ideal color effects.
In summary, although it is difficult to confirm the accurate understanding of this material in "Tiangong Kaiwu", it can be inferred that it has the above functions in pharmacy and technology according to the traditional knowledge system.

3,7-Dihydroxydibenzo [b, d] furan, which is unique in nature and quality, shows its characteristics in various aspects.
It has good thermal stability, due to the dense molecular structure, stable chemical bonds, and is not easy to disintegrate when heated. It can also maintain its true shape and maintain its properties at high temperatures, and is not easily moved by heat.
In terms of solubility, it shows a certain solubility in organic solvents such as acetone and dichloromethane. This is because its molecular structure contains polar hydroxyl groups, which can interact with organic solvent molecules, such as hydrogen bonds, van der Waals forces, etc., so it can be dissolved in it, but its solubility in water is small. Its hydrophobic benzene ring structure accounts for a large proportion, and the force between water molecules is weak.
also has certain chemical activity, and its hydroxyl groups can participate in many chemical reactions, such as esterification, etherification, etc. In case of electrophilic reagents, electrophilic substitution reactions can occur on the benzene ring. With its benzene ring rich in electrons, it has a high electron cloud density, which is easy to attract electrophilic reagents to attack. < Br >
And this substance has a certain biological activity, in vivo, or can interact with specific biological macromolecules such as proteins, nucleic acids, etc., affecting the physiological and biochemical processes in vivo, but its specific biological activity and mechanism of action still need to be further studied to understand.
In addition, its optical properties are also worth attention, or it can be due to electron transitions in molecules, etc., under specific wavelengths of light irradiation, fluorescence and other optical phenomena, this property may have potential use in optoelectronic devices, fluorescent probes and other fields.

3,7-Dibromodibenzo [b, d] furan, which is highly toxic and is listed as a persistent organic pollutant in the Stockholm Convention. Its chemical properties are as follows:
- ** Stability **: It has high chemical stability. Because its molecular structure is fused by multiple benzene rings and furan rings to form a conjugated system, the molecular energy is reduced, and the carbon-carbon bond and carbon-bromine bond energies are relatively large. Under normal conditions, it is not easy to open or break the bond. It can exist stably in the environment for a long time and is difficult to be degraded naturally. < Br > - ** Solubility **: It is a hydrophobic compound with extremely low solubility in water. Due to the non-polar characteristics of the molecular structure, while water is a polar solvent. According to the principle of "similarity and miscibility", the polarity difference between the two is large and the interaction force is weak. However, it has a certain solubility in non-polar or weakly polar organic solvents (such as n-hexane and dichloromethane). These organic solvents are similar in structure to it, and the intermolecular force is conducive to its dissolution.
- ** Reactive activity **: The bromine atom on the benzene ring makes it have a certain electrophilic substitution reaction activity. Bromine is an electron-absorbing group, which can reduce the electron cloud density of the benzene ring, and the electron cloud density of the ortho and para-position is relatively high Under appropriate conditions (e.g. in the presence of catalysts), electrophilic substitution reactions such as halogenation, nitrification, and sulfonation can occur. In addition, under the action of strong reducing agents, carbon-bromine bonds can be reduced and broken, and debromination reactions occur.
- ** Thermal stability **: Good thermal stability, requires a higher temperature to decompose or structural changes. At high temperatures, molecules may crack, resulting in products such as bromine-containing small molecules and aromatic fragments.

The synthesis of 3,7-dibromodibenzo [b, d] furan is an important topic in organic synthetic chemistry. There are many methods for its synthesis, and several common ones are described in detail below.
One is nucleophilic substitution. This is a phenolic compound with a suitable substituent as the starting material, first interacting with a base to form a phenol salt, and then carrying out a nucleophilic substitution reaction with a halogenated aromatic hydrocarbon. For example, using 2-halogenated phenol and 4-halogenated phenylborate as raw materials, the basic skeleton of dibenzofuran can be constructed by Suzuki-Miyaura coupling reaction under the action of palladium catalyst, and then bromine atoms are introduced through bromination reaction, and then 3,7-dibromodibenzo [b, d] furan is obtained. The advantage of this method is that the reaction conditions are relatively mild and the selectivity to the substrate is high, but there are also cumbersome steps and multiple steps.
The second is the cyclization reaction method. The appropriate bisaryl ether compounds are selected, and under the conditions of high temperature and appropriate catalyst, the intramolecular cyclization reaction occurs to form the dibenzofuran structure. Subsequently, the obtained products are brominated by brominating reagents, such as bromine, N-bromosuccinimide (NBS), etc., and bromine atoms are introduced at specific positions to realize the synthesis of 3,7-dibromodibenzo [b, d] furan. The key to this method is the control of the conditions of the cyclization reaction. High temperature may lead to the occurrence of side reactions, so the reaction equipment and operation requirements are quite high.
The third is the cross-coupling-cyclization tandem reaction catalyzed by metal. Using o-halogenated aryl halide and aromatic hydrocarbons containing alkenyl or alkynyl groups as raw materials, under the synergistic action of metal catalysts (such as palladium, nickel, etc.) and ligands, the alkenyl or alkynyl substituted aryl halide intermediates are first cross-coupled to form alkenyl or alkynyl substituted intermediates. This intermediate then undergoes intra-molecular cyclization to construct dibenzofuran precursors, and finally the target product is prepared through bromination steps. The advantage of this method is that the complex structure can be constructed by one-pot series reaction, and the atomic economy is high. However, the activity and selectivity of the catalyst are strict, and the catalyst cost is also high.
Synthesis of 3,7-dibromodibenzo [b, d] furan has advantages and disadvantages. In practical applications, it is necessary to consider the availability of raw materials, the feasibility of reaction conditions, and the purity requirements of the target product, and carefully select the appropriate synthesis path.

There are 3,7-dihydroxydibenzo [b, d] furans in the market today, what is the price? I will try to answer it with an old saying.
The 3,7-dihydroxydibenzo [b, d] furan is a rare thing, which is quite difficult to prepare, and requires intensive research and good materials. It is widely used in the field of scientific research, and can be used in medical exploration, material creation, etc. Therefore, the price of extraordinary products is comparable.
The price of the market varies with the quality, quantity, and urgency of the demand. Those who are of high quality and pure, the price will be high; if the quantity is large, the price may be slightly reduced; if they are in a hurry, the price will also increase. < Br >
Roughly speaking, the price per gram is usually in the range of hundreds to thousands of yuan. If the quantity is large wholesale, the price may be slightly reduced; if it is a high-purity high-quality product, dedicated to high-end scientific research, the price may be higher.
However, there is no regular price in the market, and the merchants negotiate the price, depending on the current supply and demand. To know the exact price, you must consult the consultation of the cities, or interview the professional who specializes in this industry, before you can get the actual price.