PYRAZINE-2,5-DICARBOXYLIC ACID

Carbuncle is also used. The second condition of carbuncle, as referred to in "2,5", what is the main use of acid in the second condition?
The second condition of carbuncle is used in medical medicine and has a wide range of uses. First, it can be tested for the state of qi and blood. "Lingshu · Carbuncle" says: "If the cold evil guest is in the meridians, the blood will cry, and the blood will not be blocked. If it is not passed, the defense qi will return, and it cannot be reversed, so the carbuncle is swollen." If the qi and blood are not smooth, it will accumulate and produce carbuncle. And the feeling of acid is often the first sign of qi and blood blockade. If the acid in the affected area is not heavy, or because the qi and blood are still fighting, the blockade is not deep; if the acid feeling is strong and long-lasting, the qi and blood According to this, the doctor can determine the severity and depth of the disease, as the basis for treatment.
Second, the location of the disease is related to the meridians. Human meridians, internal connection viscera, outer collaterals limb nodes. Carbuncle in different parts is accompanied by acidity, often related to the corresponding meridians. If the outer carbuncle of the upper limb is acidic, it is mostly related to the large intestine meridian of Yangming; carbuncle acid on the inner side of the lower limb may be related to the spleen meridian of Foot Taiyin. Knowing this connection, you can follow the meridians and the relationship between the viscera and the inside, and investigate the root cause of the disease, so as to accurately use medicine. If the disease is in the Yangming meridian, you can use medicine such as Baizhi and cohosh to introduce the meridian, so that the medicinal
Third, it helps to judge the prognosis. If the acidity of carbuncle gradually lightens, accompanied by redness, swelling, heat and pain also slow down, this is the sign of qi and blood gradually passing through, and the evil poison gradually dissipates, and the prognosis is better; on the contrary, if the acidity intensifies, and the carbuncle becomes harder, or the acid remains persistent after collapse, it indicates that the evil poison is not clear, the qi and blood have not recovered, and the prognosis is worrisome. According to this, doctors can adjust the treatment method in time, or correct it, or remove the evil, so as to promote the recovery of the disease.
The second syndrome of carbuncle is of great significance in diagnosis, treatment and prognosis judgment, and is the key that doctors cannot ignore.

Dicarboxylic acids, organic acids containing dicarboxylic groups are also. Oxalic acid, malonic acid, succinic acid, etc. are common. Its physical properties are unique, and I will describe them in detail today.
First words Melting point. The melting point of dicarboxylic acids is often higher than that of monocarboxylic acids containing the same number of carbon atoms. This is because more hydrogen bonds can be formed between dicarboxylic acid molecules to enhance the intermolecular force, so higher temperatures are required to overcome it, resulting in an increase in the melting point. For example, the melting point of oxalic acid is about 189.5 ° C, while the melting point of monocarboxylic acid containing the same number of carbon atoms is only 8.6 ° C.
Second and solubility. Lower-grade dicarboxylic acids have high solubility in water. The intra-molecular carboxylic groups can form hydrogen bonds with water molecules, enhancing their affinity with water. Such as oxalic acid and malonic acid, both can be miscible with water in any ratio. However, with the increase of the number of carbon atoms, its solubility in water gradually decreases, and the hydrophobic effect is enhanced due to the increase of the hydrocarbon group part.
Furthermore, the boiling point. Dicarboxylic acids also have a higher boiling point. Except for the hydrogen bonding between molecules, their relative molecular weight is larger than that of monocarboxylic acids, and the van der Waals force is also stronger, which requires more energy for gasification, so the boiling point increases.
has a state. At room temperature, lower dicarboxylic acids are mostly crystalline solids and have certain stability. However, higher dicarboxylic acids have complex intermolecular forces due to the growth of carbon chains, and their states may change. < Br >
Dicarboxylic acids have important applications in chemical, pharmaceutical, biological and other fields because of their unique physical properties.

Dicarboxylic acids are a class of compounds containing two carboxylic groups (-COOH). Common are oxalic acid (oxalic acid), malonic acid, succinic acid, etc. Its chemical properties are unique and play a key role in many chemical reactions and life processes.
First, it is acidic. The carboxyl group of dicarboxylic acid can ionize hydrogen ions and exhibit acidity. Its acidity is slightly stronger than that of monocarboxylic acid, which is caused by the electron-absorbing effect of another carboxylic group, which makes the carboxylic group more susceptible to ionization. In water, dicarboxylic acids are ionized step by step according to the ionization constant. Taking oxalic acid as an example, the first step ionization generates hydrogen oxalate ion and hydrogen ion, and the second step ionization of hydrogen oxalate ion and oxalate ion and hydrogen ion. This acidic property allows it to neutralize with bases to form corresponding carboxylic salts and water.
Second, esterification can occur. Under catalysts such as concentrated sulfuric acid and heating conditions, the carboxylic group of dicarboxylic acid can be esterified with the hydroxyl group of alcohol to form esters and water. For example, succinic acid reacts with ethanol to form diethyl succinate. This reaction is extremely important in organic synthesis and can be used to prepare many organic compounds such as fragrances and plasticizers.
Third, dehydration can be carried out. Under specific conditions, dicarboxylic acids can undergo intramolecular or intermolecular dehydration. During intramolecular dehydration, if the two carboxylic groups of dicarboxylic acid are separated by an appropriate number of carbon atoms, a cyclic anhydride can be formed. When glutaric acid is heated, intramolecular dehydration forms glutaric anhydride. Intermolecular dehydration can form polyanhydride, which lays the foundation for the preparation of some polymer materials.
Fourth, the reduction reaction is also characteristic of dicarboxylic acids. Partial dicarboxylic acids can be reduced to alcoholic hydroxyl groups under the action of suitable reducing agents. For example, succinic acid (succinic acid) can be reduced to 1,4-butanediol under specific conditions. This reaction provides a way to obtain polyols in organic synthesis.
The many chemical properties of dicarboxylic acids make them widely used in many fields such as chemical industry, medicine, biology, etc., and become an indispensable and important category of compounds in chemical research and industrial production.

Dihydroxylic acid is an important class of substances in organic compounds. There are three ways to synthesize it.
First, start with the oxidation method. Choose suitable starting materials, such as alcohols or aldehyde compounds, and convert them into dihydroxylic acid by oxidation. If it is based on ethylene glycol, it can be gradually oxidized to oxalic acid by the action of strong oxidants, such as potassium permanganate. This process requires attention to the reaction conditions. Temperature, pH, etc. have a great impact on the yield and purity of the product. If the temperature is too high, it is easy to cause excessive oxidation, product or decomposition; if the pH is not suitable, the reaction rate is also blocked.
Second, hydrolysis is used. Some esters or halogenated hydrocarbons and other compounds can form dihydroxylic acids under suitable hydrolysis conditions. For example, diester compounds, in the hydrolysis environment catalyzed by acids or bases, ester bonds are broken, hydroxyl groups are introduced, and dihydroxylic acids are finally obtained. Taking diethyl oxalate as an example, hydrolyzed under basic conditions and then acidified, oxalic acid can be obtained. Among these, the choice of hydrolysis reagents and the control of reaction time are very critical. The concentration of bases is too high, or the hydrolysis time is too long, or side reactions occur, which affects the quality of the product.
Third, by the method of condensation reaction. Select small molecule compounds containing specific functional groups to undergo condensation reactions to construct a carbon skeleton of dihydroxylic acids. If formaldehyde and acetaldehyde are used as raw materials, under the action of an alkaline catalyst, the second hydroxy acid with the corresponding structure can be prepared by subsequent steps such as hydroxyaldehyde condensation reaction and oxidation. In this path, the type and amount of catalyst, the reaction sequence and other factors are all related to whether the reaction can proceed smoothly and the structure and purity of the product.
Where this synthesis method has its own advantages and disadvantages, it is necessary to consider the availability of raw materials, cost, difficulty of reaction conditions and purity of the product according to actual needs, and choose carefully to achieve the best synthesis effect.

I look at what you are asking, but I am inquiring about the price range of Epimedium - 2,5 - secondary acid in the market. Epimedium, a medicinal herb, also has many medicinal effects, but the price of its secondary acid varies with many factors.
First, the season has a great impact. If the supply is full during the peak harvest season, the price may decrease; if the supply is scarce when the green and yellow are not available, the price will rise easily. Second, quality is also the key. High-quality Epimedium - 2,5 - secondary acid has few impurities and high active ingredients, and the price is higher than that of ordinary ones. Third, the price varies depending on the region. In the vicinity of the place of origin, the price is often lower due to less transportation costs and transit benefits; and in the place of export, the price will increase due to the addition of freight and layers of commercial benefits.
According to past market conditions and market conditions, the price per catty of Epimedium-2,5-secondary acid, if the quality is average, or between tens of dollars and more than 100 dollars; if the quality is high, it can reach 200 dollars or even higher. However, this is only an approximate number. The actual price also needs to refer to the current market supply and demand, the quality of medicinal materials, and the state of commerce in various places. The market is fickle, and the price changes at any time. If you want to know the exact price, you should consult the pharmacist, market or people in the relevant industry in person to get the exact number.