7-Chlorobenzo[b]thiophene

Borax is an important compound of boron. It has a long history of medicinal use and has been used in alchemy, medicine, porcelain and many other fields. In the situation described in Tiangong Kaiwu, borax has unique chemical properties.
Borax, chemically called sodium tetraborate decahydrate ($Na_2B_4O_7 · 10H_2O $), is a colorless translucent crystal or a white crystalline powder. Its taste is salty and easily soluble in water. Under heating conditions, borax will gradually lose its crystalline water and eventually turn into anhydrous sodium borate.
Borax will undergo hydrolysis in water and exhibit alkaline properties. This alkaline property is significant in many processes. Take metallurgy as an example, borax can act as a flux. Because it can react with oxides on the metal surface at high temperatures to form fusible borates, which can remove impurities on the metal surface, help the metal to better integrate, and improve the quality of metal products.
In ancient alchemy, borax also has unique uses. Because it has certain chemical activity, it can react with other minerals, metals, etc. under specific conditions, change the properties and morphology of the material, and meet the needs of alchemy.
In the field of ceramic firing, borax can be used as a flux and glaze additive. As a flux, it can reduce the melting point of ceramic bodies, reduce the energy consumption and time of firing; as a glaze additive, borax can improve the gloss, hardness and wear resistance of the glaze surface, making ceramic products more beautiful and durable. < Br >
Borax also has buffering properties. In some chemical reaction systems, it can maintain the relative stability of the pH of the system and ensure the smooth progress of the reaction. Although this property was not explained in modern scientific terms in ancient times, it was reflected in practical applications. In short, borax played a key role in many ancient technological fields due to its diverse chemical properties.

Borax is an important compound of boron, and its unique physical properties have attracted much attention in ancient times. The appearance of borax is often colorless translucent crystals or white crystalline powder, which is soft and delicate to the touch. Its solubility in water is quite special, and it increases significantly with the increase of temperature. In hot water, borax can dissolve well, but after cooling, some crystals will precipitate, just like the hidden things in water gradually appear.
The melting point of borax is relatively low, and it is easy to melt into glassy substances when heated. This property makes it important in many fields. And borax has a certain toxicity. Although the degree of toxicity may not be accurately known in ancient times, it should be used with caution.
In alchemy and early process practice, the fusibility of borax plays a key role. Due to its low melting point, it is easy to turn into a liquid state when heated, which can reduce the melting point of other minerals and promote the fusion reaction of different substances at relatively low temperatures. It is like building an invisible bridge, allowing substances that were originally difficult to coalesce to gather in one place, undergo wonderful chemical changes, and then produce the desired things.
In ancient dyeing and other processes, borax may also be used as a mordant. Thanks to its special chemical properties, borax can make the dye adhere more firmly to the fabric, making the dyed color more vivid and lasting, just like a layer of fabric that will never fade, so that the fabric can still be colorful after years. The many physical properties of borax played an important role in the exploration and development of ancient crafts, opening up new directions for many fields and promoting technological progress and innovation.

Borax is a blind traditional Chinese medicine. Although its main use is not detailed in "Tiangong Kaiwu", according to the relevant knowledge of traditional Chinese medicine and past literature records, borax is widely used.
Borax can be used externally to clear away heat and detoxify, and is often used to treat swollen throat, sores on the mouth, and blindness. In throat diseases, such as laryngeal paralysis, borax can relieve redness, swelling and pain in the throat by its ability to clear away heat and detoxify. In terms of oral diseases, it also has a good effect on oral ulcers and swollen gums. The ancients often combined borax with other drugs to make a powder and applied it to the affected area to achieve the purpose of clearing away heat and reducing swelling, generating muscle and astringent sores.
Borax can be taken internally to clear the lungs and reduce phlegm, and can be used to treat phlegm-hot cough. When the human body is invaded by the evil of phlegm heat, and symptoms such as cough and thick phlegm appear, borax can exert its effect of reducing phlegm and clearing heat, making phlegm easy to cough up and reducing cough symptoms. However, it should be noted that borax has certain toxicity, and it should be used with caution when taken internally, and the dosage must also be strictly controlled.
In addition, in some ancient alchemy or process production, borax may also be used. For example, in some metal smelting or ceramic firing processes, borax can be used as a flux to reduce the melting point, making metal or ceramic materials easier to process and improve their properties. However, these applications are not detailed in "Tiangong Kaiwu", and are mostly found in other technical books or practical experience.

There are many methods for the synthesis of 7-cyanoindolo [b] quinoline, which are described in detail below:
** 1. Using indole derivatives as the starting material **
1. ** Classical synthesis method **: Select the appropriate substituted indole, first functionalize its specific position, and introduce key groups such as cyanyl. For example, under the appropriate base catalysis, the indole is reacted with cyanyl-containing reagents, such as potassium cyanide, in a specific solvent (such as dimethylformamide), so that the cyanyl group is smoothly connected to the indole ring. After that, the quinoline structure is constructed through a clever cyclization reaction. The Friedländer condensation reaction can be used to successfully synthesize 7-cyanoindolo [b] quinoline in the presence of aldehyde compounds (such as o-aminobenzaldehyde) and indole derivatives in an acid or base catalyzed environment through a series of reactions such as nucleophilic addition and dehydration. This method has a long history and the reaction conditions are relatively mature, but there may be problems such as complicated steps and the yield needs to be improved.
2. ** Improved one-pot method **: The traditional step-by-step reaction is optimized, and the cyano group introduction and the quinoline ring construction step are integrated into the same reaction system. For example, under the synergistic action of metal catalysts (such as copper catalysts) and ligands, indole derivatives, cyanide sources, and o-aminobenzaldehyde and other raw materials can react simultaneously under mild conditions. This method is simple to operate, and can effectively reduce the separation of intermediates, reduce losses, and improve the overall yield. However, the control requirements for reaction conditions are more stringent, and the selection of metal catalysts and ligands is crucial.
* Second, Synthesis Based on Quinoline Derivatives **
1. ** Cyanylation Reaction Strategy **: With a suitable quinoline derivative as the starting material, a cyanide group is introduced directly at the target location through cyanylation reaction. Under the catalysis of transition metals, such as palladium catalysis systems, quinoline derivatives react with cyanide reagents (such as zinc cyanide) in the presence of suitable bases and ligands. This method route is relatively direct, and the selectivity of quinoline derivatives is high. It is necessary to precisely design the starting material structure.
2. ** Cyclization in tandem with cyanylation **: Quinoline precursors containing potential cyclization check points are first constructed, and then the target product is synthesized by means of the strategy of intramolecular cyclization and cyanylation at the same time. For example, by designing quinoline derivatives containing alkenyl or alkynyl groups, cyanide is introduced in a suitable catalytic system to form 7-cyanoindolo [b] quinoline. The strategy has good atomic economy and simple steps, but the regioselectivity and stereoselectivity of the reaction are challenging.

In the storage and transportation of halogenated [b] mercury sand, many matters need to be paid attention to.
When storing, choose the first environment. When placed in a cool, dry and well-ventilated place, avoid direct sunlight and high temperature. Hot sunlight, or the variation of the properties of halogenated [b] mercury sand, affects its quality and utility. High temperature can also easily cause its chemical changes, such as volatilization, decomposition, etc., which damage its inherent characteristics.
Furthermore, attention should be paid to the tight packaging. Halogenated [b] mercury sand may be toxic and volatile, and tight packaging can prevent its leakage and ensure the safety of the surrounding environment and personnel. In a special container, the lid must be tight to prevent the intrusion of air and water vapor, so as not to react with external substances.
During transportation, it is important to drive steadily and slowly. Due to the fragile nature of halogen [b] mercury sand, the road is bumpy and severe, and it is easy to cause damage to the container and cause it to spill. The transportation vehicle also needs to be clean, and there are no other chemical residues to prevent cross-contamination.
In addition, the transportation personnel must be professionally trained and familiar with the characteristics of halogen [b] mercury sand and emergency treatment methods. In case of emergencies such as leakage, it can be disposed of quickly and properly to minimize the harm. And the whole transportation process should have complete records, indicating the start and end times, and the location of the passage to ensure that the whole process can be traced back. In case of any situation, the records can be traced back to the source and properly handled.