3-Pyridinecarboxylicacid,4-fluoro-(9CI)

The article about "Jiang-3-Xiangqi carboxylic acid (9CI) " in "Tiangong Kaiwu", although "Tiangong Kaiwu" is an ancient scientific and technological masterpiece, the chemical concept at that time was very different from today, and there may be no exact corresponding expression in the book. But according to today's chemical knowledge, it can be analyzed.
"Jiang-3-Xiangqi carboxylic acid (9CI) ", "9CI" refers to the name of the 9th revised edition of "Chemical Abstracts". This carboxylic acid should have a specific structure and properties. Carboxylic acid compound containing carboxyl group (-COOH) functional group. Its chemical properties are active and acidic. Because the hydroxy hydrogen in the carboxyl group has a certain tendency to dissociate, it can neutralize with bases, such as reacting with sodium hydroxide to form carboxylate and water. < Br >
And carboxylic acids can undergo esterification reaction. Under the catalysis of concentrated sulfuric acid and heating conditions, they can react with alcohols to form esters and water. This reaction is widely used in the fields of fragrance and drug synthesis. At the same time, carboxylic acids can be reduced, such as aluminum lithium hydride, which can be reduced to alcohols with a strong reducing agent. If this "Jiang-3-to-its carboxylic acid (9CI) " contains special substituents, there will be unique reactions. If the substituent has an unsaturated bond, an addition reaction can occur; if it contains a halogen atom, a nucleophilic substitution reaction can occur. In short, such carboxylic acids exhibit diverse chemical properties due to carboxylic groups and possible substituents, which are of great significance in many fields of modern chemistry.

9-Ene-3-nonenoic acid (9CI) is an organic compound that has important uses in many fields.
In the field of medicinal chemistry, it may be a key intermediate for the synthesis of specific drugs. Due to its unique chemical structure, it can be chemically modified to construct molecular structures that fit biological targets, or participate in the synthesis of active pharmaceutical ingredients, laying the foundation for the development of innovative drugs for the treatment of specific diseases. Gu Yun: "Medicine is subtle, the synthesis of drugs is based on structure." The structure of this compound may be the cornerstone of drug creation.
In the field of materials science, 9-Ene-3-nonenoic acid can be used as a functional monomer. Can participate in the polymerization reaction, giving polymer materials unique properties, such as improving material flexibility, chemical resistance, etc. Just as "Kaogong Ji" said: "The material is beautiful, the workmanship is skillful, and then it can be good." This compound can be used as a raw material, or materials with excellent performance can be prepared.
In the fragrance industry, because of its own structure or special smell, or chemically converted to produce substances with pleasant aroma, it is used as a fragrance formulation ingredient to add unique flavor to perfumes, flavors and other products. The ancient saying: "Fragrance is a pleasant thing." This compound may play a key role in the preparation of fragrances, bringing a good olfactory experience to the world.
In the agricultural field, it may have potential biological activity. It may be used as a plant growth regulator to affect plant growth, development and stress resistance. "Qi Min Yao Shu" has a saying: "When the weather is smooth, the amount of land is used, and the force is less and the success is more." If this compound can be used properly to regulate plants, it may help agricultural production and improve crop yield and quality.

To prepare 4-alkenyl-3-ketocarboxylic acid (9CI), the following ancient method can be used:
First take the appropriate starting material and start with the enol ether method. Choose a compound containing alkenyl groups and make it react with carboxylic acid derivatives with ketone groups and suitable substituents. In this reaction, mild reaction conditions are required to maintain the structural stability of alkenyl and ketone groups. Organic solvents such as dichloromethane and tetrahydrofuran are commonly used to create a suitable reaction environment.
During the reaction, it is crucial to control the temperature and reaction time. If the temperature is too high, it may cause a cluster of side reactions; if the temperature is too low, the reaction rate will be slow. Usually, the reaction temperature can be maintained in the range of low temperature to room temperature, and it can be fine-tuned according to the specific reactant activity. The reaction time may take several hours to several days. The reaction process is monitored in real time by thin-layer chromatography and other methods. When the raw materials are fully converted, the reaction is stopped.
Next, if a protective group is formed in the reaction, it needs to be removed with caution. Choose the right conditions for deprotection, which not only removes the protective group, but also does not damage the structure of the target product. This step involves the use of acid-base conditions, or requires specific reagents, depending on the type of protective group.
Post-treatment should not be ignored. The product is purified by conventional methods such as extraction and column chromatography. During extraction, choose a suitable solvent to effectively separate the target product from impurities. According to the polarity difference between the product and the impurity, the appropriate silica gel and eluent were selected to obtain pure 4-ene-3-keto carboxylic acid (9CI). The whole process, the experimenter should be careful operation, pay attention to the details of the reaction and control the conditions, can be effectively obtained.

In today's market, the quality of this product is simple.
As far as the three beams of acupuncture (9CI) are concerned, if it is a common product sold by Changfang, its price may be between 10 and 120. However, if it is well-made, it is used with high-quality rice, and it is old, its price will be high. It may be as high as three or four hundred, or even higher.
If this is from a famous place, there is a special method, and it is broadcast by a famous place, and the price is not often comparable. It is unknown whether the rich or the rich are seeking the best, and they do not hesitate to spend a lot of money on it.
Furthermore, the market is also affected by supply and demand. If the demand for a certain product increases greatly and the supply is limited, its price must be reduced. On the contrary, if the supply is limited, the price may decline.
Therefore, the price of three beams (9CI) in the market is low, less than 10%, more than 500%, and it is determined in one case.

Mercury is a highly toxic substance, and trivalent arsenic (9CI) is also very harmful. The use of both is life-threatening and requires extreme caution.
Let's talk about mercury first. It is liquid at room temperature and is volatile, forming mercury vapor. This vapor is very toxic. Once inhaled, it can cause serious damage to the nervous system, kidneys and other organs. Light cases can cause headaches, dizziness, fatigue, insomnia, memory loss, etc.; severe cases may cause life-threatening diseases such as limb tremors, mental disorders, and kidney failure. Therefore, when exposed to mercury, it is necessary to operate in a well-ventilated place, preferably equipped with professional ventilation equipment to drain mercury vapor. And wear protective clothing, protective gloves and masks to avoid skin contact and inhalation. If mercury is accidentally sprinkled, ventilation should be turned on immediately and quickly covered with sulfur powder to generate mercury sulfide and reduce mercury volatilization.
Besides trivalent arsenic (9CI), its compounds are many toxic and can enter the human body through the respiratory tract, digestive tract and skin. Long-term exposure or ingestion of trivalent arsenic-containing substances can cause damage to the skin, liver, nervous system, etc., causing skin lesions, abnormal liver function, peripheral neuropathy, etc., and may even cause cancer. When using, the operating procedures must be strictly followed and carried out in a special experimental site to prevent the leakage and spread of trivalent arsenic. Once a leak occurs, effective measures should be taken immediately to collect and dispose of it to avoid polluting the environment.
In short, for mercury and trivalent arsenic (9CI), every step of the way from storage, handling to use must be strictly followed. A little negligence can lead to catastrophe, endangering the safety of oneself and others, and must not be taken lightly.