3-Pyridinecarboxylic acid, 2-bromo-

3-Dicarboxylic acid, 2-hydroxylic acid, is widely used in the field of engineering.
First and the industry of medicine. In the manufacture of various medicines, these two are often essential materials. For example, in the preparation of an antipyretic and analgesic agent, 2-hydroxy- or can be used as a starting material. After multi-step reaction, 3-Dicarboxylic acid is added to form a molecule with specific pharmacological effect. Due to the characteristics of the two structures, they can participate in diverse chemical reactions and help form pharmacologically active structures.
Furthermore, it is also crucial in the manufacture of chemical products. 3 - The carboxylic acid has certain moisturizing and antibacterial properties, and can be added to creams, lotions, etc., to protect the skin from moisturizing and prevent bacterial invasion. 2 - Hydroxy - can change the texture and stability of the chemical, make it feel better when applied, and maintain long-term quality.
In the fragrance industry, the two also develop their growth. 2 - Hydroxy - can be used as an intermediary for fragrance synthesis, giving the fragrance a unique fragrance. 3 - The carboxylic acid may help the fragrance to stabilize and extend, so that the aroma can last for a long time.
In agriculture, pesticides can be prepared. The combination of the two, through suitable changes, can obtain pesticides with insecticidal and bactericidal effects. For example, based on 3-carboxylic acid, the structure of 2-hydroxy- is introduced, the activity and targeting of drug enhancement, precise pest control, and the health of crops.
And in the field of polymer materials, it is also possible. 2-hydroxy- and 3-carboxylic acid can be used as polymerized monomers to form polymers with specific properties. Such as polyester materials, or with good mechanical properties and chemical resistance, used in the production of packaging materials, engineering plastics, etc.

3 - to its carboxyl group, 2 - hydroxyl - The physical properties are as follows:
This substance is hydrophilic, because both carboxyl and hydroxyl groups can form hydrogen bonds with water. In the carboxyl group, the carbonyl group is connected to the hydroxyl group, which changes the electron cloud density of the oxygen atom, and the hydroxyl hydrogen is easy to dissociate, so it is acidic and can neutralize with bases to form corresponding carboxylic salts and water. The hydroxyl group, as a polar group, enhances the interaction between molecules and water molecules, resulting in a certain solubility in water.
Furthermore, in terms of melting point, because carboxyl and hydroxyl groups can form intermolecular hydrogen bonds, it requires higher energy to destroy the intermolecular force to melt or vaporize the substance, so the melting boiling point is relatively high.
Its solubility is characterized by being soluble in some polar organic solvents, such as ethanol. This is because the molecular polarity is similar to that of organic solvents and follows the principle of "similar miscibility". At the same time, because of its acidity, it can be soluble in alkaline solutions and chemically reacts to form soluble salts.
In addition, the appearance of the substance is usually colorless to slightly yellow liquid or solid, depending on the specific structure and purity. Stable at room temperature and pressure, but when encountering specific substances such as strong oxidants, chemical reactions such as oxidation may occur, changing its physical and chemical properties.

The chemical properties of the 3-hydroxyl group and the 2-aldehyde group are as follows:
Let's talk about the 3-hydroxyl group first. The hydroxyl group has active hydrogen and can undergo a substitution reaction. For example, when reacting with sodium metal, the hydrogen atom in the hydroxyl group is replaced by a sodium atom to generate sodium alcohol and release hydrogen gas. The reaction formula is:\ (2R - OH + 2Na\ longrightarrow 2R - ONa + H_ {2}\ uparrow\). Under certain conditions, the hydroxyl group can also undergo esterification reaction with the acid. For example, when reacted with acetic acid, the hydroxyl group and the carboxyl group of acetic acid dehydrate to form an ester compound. This reaction requires concentrated sulfuric acid as a catalyst and heating. The reaction formula is:\ (CH_ {3} COOH + R - OH\ underset {\ Delta} {\ overset {concentrated sulfuric acid} {\ rightleftharpoons}} CH_ {3} COOR + H_ {2} O\). In addition, if the carbon atom connected to the hydroxyl group has a hydrogen atom on the adjacent carbon atom, it can be heated under the action of concentrated sulfuric acid to produce a compound containing carbon-carbon double bonds.
Looking at the 2-aldehyde group again, the aldehyde group has strong reductivity. It can be oxidized by weak oxidants, such as silver mirror reaction with silver ammonia solution, aldehyde group is oxidized to carboxyl group, silver ammonia complex ion is reduced to metal silver, attached to the inner wall of the container to form a bright silver mirror, the reaction formula is:\ (R - CHO + 2Ag (NH_ {3}) _ {2} OH\ overset {\ Delta} {\ longrightarrow} R - COONH_ {4} + 2Ag\ downarrow + 3NH_ {3} + H_ {2} O\). The aldehyde group is also oxidized to carboxyl group, and the copper hydroxide is reduced to the red precipitate of cuprous oxide brick. The reaction formula is:\ (R - CHO + 2Cu (OH) _ {2} + NaOH\ overset {\ Delta} {\ longrightarrow} R - COONa + Cu_ {2} O\ downarrow + 3H_ {2} O\). The aldehyde group can also be oxidized by strong oxidants such as acidic potassium permanganate solution. At the same time, aldehyde groups can also undergo addition reactions, such as addition with hydrogen under the action of catalysts, to generate alcohols. The reaction formula is:\ (R - CHO + H_ {2}\ underset {\ Delta} {\ overset {catalyst} {\ longrightarrow}} R - CH_ {2} OH\).
In summary, the structural characteristics of 3-hydroxy and 2-aldehyde genes show their own unique chemical properties and have important applications in many fields such as organic synthesis.

To prepare a 3-amino, 2-aldehyde compound, the method is as follows:
Take a suitable starting material first. If an aromatic hydrocarbon is used as the starting point, it can be reached through several steps of reaction. The first step is to make the aromatic hydrocarbon react with halogenated reagents such as bromine or chlorine under specific conditions, and introduce halogen atoms on the aromatic ring. This reaction requires a suitable catalyst and reaction temperature. If iron or iron salt is used as the catalyst, under appropriate heating conditions, the aromatic hydrocarbon and bromine undergo electrophilic substitution reaction to obtain halogenated aromatics.
Second step, the halogenated aromatics are converted into Grignard reagents. With anhydrous ether as the solvent and in the presence of magnesium chips, halogenated aromatics react with it to form Grignard reagents. This process must ensure that the reaction system is anhydrous and oxygen-free. Because Grignard's reagent is extremely active, it is easy to react with water or oxygen and fails.
Furthermore, Grignard's reagent is reacted with carbon dioxide. The obtained Grignard's reagent is passed into carbon dioxide gas to generate carboxylic salts, and then acidified to obtain aryl carboxylic acids.
Then, the aryl carboxylic acid is reduced, and strong reducing agents such as lithium aluminum hydride can be used to reduce the carboxyl group to an aldehyde group to obtain an aldehyde-containing aromatic compound.
The last step is to convert the aldehyde group compound into 3-amino group and 2-aldehyde. The desired 3-amino and 2-aldehyde compounds can be obtained by introducing suitable nitrogen-containing reagents, such as an amine compound, under specific reaction conditions, through a series of nucleophilic addition and elimination reactions, and introducing amino groups at the ortho-position of the aldehyde group, while ensuring that the aldehyde group is not affected. However, each step of the reaction requires precise control of the reaction conditions, such as temperature, reagent dosage, reaction time, etc., to obtain products with higher yield and purity.

In today's market, the price range of 3-carboxylic acid and 2-alkyne is quite popular. However, in order to clarify the scope of its price, it is necessary to look at all the reasons.
As far as 3-carboxylic acid is concerned, its price depends first on quality. Those who are of high quality will have a high price; those who are of average quality will have a low price. And the difficulty of its production is also the key. If the production of complex techniques requires a lot of materials and requires a lot of labor, the price will also increase. Furthermore, the supply and demand of the market will affect its price. If supply exceeds demand, the price will automatically decline; if demand exceeds supply, the price will rise. In the market, the price of 3-carboxylic acid depends on the quality, source, etc., or in the range of [X1] to [X2], but this is only an approximate number. The actual price varies with the market, and it is difficult to determine.
As for 2-alkyne, the price is determined according to various reasons. The purity of 2-alkyne is the cornerstone of the price. Those with high purity have a wide range of uses and good efficiency, and the price is high. The way of its preparation, if it is a common method, the price is stable; if a new method is used, or due to the cost of research and development, the price varies. In addition, the needs of the market are the guidance of the price. At a specific time, if industrial use suddenly increases, the demand is too much and the supply is not enough, the price will rise. Usually, the price of 2-alkyne, according to its situation, is between [Y1] and [Y2]. However, the market situation is variable, and this is not a definite number.
In short, the prices of 3-carboxylic acid and 2-alkyne in the market are not static. Factors such as quality, production, and demand interact. To know the exact price, when you carefully observe the real-time market conditions, you cannot generalize.