5-chloro-6-oxo-1,6-dihydropyridine-3-carboxylate

5-Ammonia-6-oxo-1,6-dihydropyridine-3-carboxylic anhydride, which is widely used in many fields.
In the field of medicinal chemistry, it is often a key intermediate. Through organic synthesis, its structure can be ingeniously modified and transformed, and then compounds with diverse biological activities can be synthesized. Many anti-cancer drugs have been developed using it as a starting material. Through a series of fine chemical reactions, specific functional groups can be introduced to obtain drug molecules that inhibit the growth of cancer cells, providing a powerful boost for the fight against cancer.
In the field of materials science, it also has unique contributions. Due to its specific chemical structure and properties, it can participate in the synthesis of polymer materials. After polymerization with suitable monomers, polymers with special properties can be prepared. Such polymers may have good thermal stability and mechanical properties, and have potential application value in aerospace, automobile manufacturing and other fields that require strict material properties. They can be used to manufacture high-performance components and improve product quality and performance.
In biochemical research, it can act as a bioactive probe. Using its specific interaction with biological macromolecules, scientists can deeply explore complex biochemical processes in living organisms. For example, when studying the structure and function of proteins and nucleic acids, they can use this substance to mark biomolecules, so as to clearly observe the dynamic changes of biomolecules, providing key clues and tools for revealing the mysteries of life.

To prepare 5-bromo-6-oxo-1,6-dihydropyridine-3-carboxylic acid esters, the following methods can be followed:
First, a pyridine derivative containing a suitable substituent is used as the starting material. Choose a group that can be converted into the target functional group, such as a hydrogen atom on the pyridine ring that can be replaced by bromine, and a functional group that can be converted into carbonyl and carboxyl ester groups. By halogenation reaction, with suitable brominating reagents, such as bromine, N-bromosuccinimide (NBS), etc., under suitable reaction conditions, the bromine atom is substituted for the hydrogen atom at a specific position to achieve the introduction of 5-bromine. Then, through the oxidation step, a suitable oxidizing agent, such as potassium permanganate, potassium dichromate, etc., is selected to convert the specific group into a carbonyl group to form a 6-oxo structure. Finally, by esterification, the corresponding alcohols are reacted with carboxylic acids in the presence of catalysts to obtain 3-carboxylic acid esters.
Second, a cyclization reaction strategy is adopted. Chain compounds containing multiple reactive functional groups are selected to undergo cyclization reactions in their molecules. For example, chain compounds with bromine atoms, carbonyl precursors, and functional groups required to form pyridine rings are used as raw materials. Under suitable reaction conditions, by heating, catalysts, etc., the cyclization of molecules is promoted to build a pyridine ring structure, and the intermediate of 5-bromo-6-oxo-1,6-dihydropyridine-3-carboxylate is formed at the same time. After subsequent modification and transformation, the target product is obtained.
Third, a multi-step reaction combination is used. Starting from simple compounds, the target molecular structure is gradually constructed. First, the intermediate containing part of the target structure is prepared by common organic reactions, such as nucleophilic substitution, electrophilic substitution, etc. For example, a compound containing a bromine atom and a partial structure of a pyridine ring is first synthesized, and then an oxo group and a carboxylic acid ester group are introduced in sequence through a functional group conversion reaction. After a multi-step carefully designed reaction, each step ensures high yield and high selectivity, and finally synthesizes 5-bromo-6-oxo-1,6-dihydropyridine-3-carboxylic acid esters.
All synthesis methods have their own advantages and disadvantages. It is necessary to carefully select the appropriate synthesis path according to the availability of starting materials, the difficulty of controlling the reaction conditions, and cost considerations, so as to efficiently prepare the target compound.

3-Hydroxyanhydride, that is, a compound containing a carboxyl group and an acid anhydride group. The interaction between the two gives the substance unique physical and chemical properties. The following details:
- ** Physical Properties **:
- ** State and Solubility **: At room temperature and pressure, the lower 3-hydroxyanhydride is mostly liquid, and the higher ones are solid. Because it contains carboxyl groups and acid anhydride groups, it has a certain affinity for water. Small molecules are soluble. Large molecules have reduced solubility due to the growth of hydrophobic carbon chains. However, they have good solubility in polar organic solvents such as ethanol and acetone.
- ** Melting Point and Boiling Point **: There are hydrogen bonds and dipole-dipole interactions between molecules, resulting in higher melting points and boiling points. As the relative molecular mass increases, the intermolecular force increases, and the melting boiling point also increases.
- ** Chemical Properties **:
- ** Hydrolysis Reaction **: 3-Hydroxyacid anhydride encounters water, the acid anhydride group is easy to hydrolyze, and the carboxylic group is formed into a carboxylic acid. If the conditions are suitable, the carboxylic group is further reacted to form the corresponding salt or ester. For example, in an alkaline aqueous solution, hydrolysis is accelerated to form carboxylic salts and alcohols or phenolic salts.
- ** Esterification Reaction **: The carboxylic group is active and can be esterified with alcohols under acid catalysis to form esters and water. This reaction is reversible. By removing the product water or increasing the concentration of the reactants, the equilibrium can be shifted to the right and the ester yield can < Br > - ** Ring-opening reaction **: The acid anhydride ring has a certain tension. When encountering nucleophilic reagents such as amines and alcohols, a ring-opening reaction is prone to occur, resulting in the formation of corresponding amides or esters. Taking amine as an example, the nitrogen atom in the amine nucleophilic attacks the acid anhydride carbon, causing the acid anhydride ring to open, forming amides and carboxylic acids.
- ** Dehydration reaction **: Under specific conditions, especially in the presence of heating and dehydrating agents, the intramolecular carboxyl group and the acid anhydride group can be dehydrated to further generate more complex acid anhydrides or cyclic compounds. This reaction is often used in the cyclization step of organic synthesis.

"Tiangong Kaiwu" has a saying: "All nitrate, fire nitrate, mirabilite two categories. Fire nitrate is flame nitrate, a potassium saltpeter, produced in various places in Shanxi and Shandong, which is condensed by frost over time, and has also been dug from the earth cellar. Glauberite is simple nitrate, produced in Shu and Jin provinces, all of which produce salt, scraped halogen land, and fried."
Today I want to know the market price range of 3-hydroxy-6-oxo-1,6-dihydropyridine-5-nitrile, but it is not included in Tiangong Kaiwu, and at that time most chemical substances were not present in the world. Today, prices in the city often vary according to changes in time, place, quality and supply and demand. This compound is mostly used in fields such as medicine and chemical industry, and its price may vary due to purity and mass production.
If the purity is ordinary, buy it in small quantities, or in the tens of yuan per gram. If it is high purity and used in fine chemical and high-end pharmaceutical research and development, it can reach more than 100 yuan per gram. Large purchases, due to economies of scale, the unit price may drop. If the origin is different, the transportation cost is different, which also affects the price. The eastern coast, with developed chemical industry, has sufficient supply, and the price is slightly lower; the inland is remote, and the transportation is inconvenient, and the price may be slightly higher. Therefore, the exact price should be consulted from the supplier of chemical raw materials, combined with real-time market conditions, to get the quasi-price.

Mercury, a vulgar water, is of great use in Chinese and ancient science and technology. Mercury is used in the fields involved in "Tiangong".
The first example is "Dan". The ancients' communication and communication of Dan can prolong the aging and become immortals. Mercury is wanted by Dan because of its specialization. Such as Ge Hong and other Dan families, the main source of mercury is mercury, accompanied by sulfur, sulfur and other substances, hoping to create miraculous pills. This is a recipe for life that has not yet been obtained, and to a certain extent, the knowledge of the ancients' transformation and transformation.
The world is also often filled with mercury. In ancient books, water can be used to treat, poison, and poison. For example, to treat the disease of scabies, water can be used to form an ointment for external use, with its toxicity. Another example is the treatment of mercury, water can detoxify and go out, and promote the combination of the mouth. However, due to the toxicity of mercury, it needs to be used with caution, and it is important to control the amount of mercury.
Furthermore, mercury has a place in metallurgy. The use of mercury can form mercury in many metals, and it can extract gold, gold and other metals. The ancients mixed gold, stone and mercury, and the gold and mercury were dissolved in mercury to form mercury, and then the mercury was removed by steaming to obtain high-density gold. This method was widely used in ancient gold extraction to help metallurgical technology develop.
In addition, mercury played an important role in ancient metals. When gold such as mercury is mixed into mercury, it solidifies on the surface of glass or billets to form a bright reflection, making the image clear. This is an important work in ancient times.