3-pyridinecarboxylic acid, 6-chloro-5-fluoro-

3-Amino, 6-bromo-5-hydroxy groups are mainly used in the fields of medicinal chemistry and organic synthesis.
In medicinal chemistry, such compounds are often key intermediates for the creation of new drugs. With their unique chemical structure, they can be modified and derived to obtain substances with specific pharmacological activities. For example, for specific disease targets, carefully designed and synthesized compounds containing this structure are expected to develop new drugs with good efficacy and few side effects. In this structure, amino groups can participate in the formation of hydrogen bonds and interact with proteins, hydroxyl groups can enhance molecular hydrophilicity and participate in various enzymatic reactions, and bromine atoms can adjust the lipid solubility and spatial structure of molecules, which have a great impact on the pharmacokinetic properties and biological activities of drugs.
In the field of organic synthesis, 3-amino groups, 6-bromo-5-hydroxyl groups are also very important starting materials or synthetic building blocks. Chemists can use the nucleophilicity of amino groups, the replaceability of bromine atoms, and the reactivity of hydroxyl groups to construct more complex organic molecular structures through various classical organic reactions, such as nucleophilic substitution, coupling reactions, etc. For example, the construction of polycyclic aromatic hydrocarbons and heterocyclic compounds provides an effective path for the synthesis of materials with special functions and the total synthesis of natural products. In the design of organic synthesis routes, it is like a cornerstone, which can derive many organic compounds with novel structures and unique functions, and promote the development of organic synthesis chemistry.

The physical properties of 3-hydroxy, 6-bromo-5-aldehyde are as follows:
This substance may be solid at room temperature. Due to the interaction of hydrogen bonds and van der Waals forces between molecules, the molecular arrangement is relatively regular and tight, so it tends to be solid. Looking at its appearance, it may be white to light yellow powder. The formation of this color is related to the electron transition and conjugate system in the molecular structure. The existence of the conjugate system causes the molecule to absorb light of a specific wavelength, and then exhibit a specific color.
Its melting point may be within a certain range. When the outside world provides energy enough to overcome the intermolecular force, the substance changes from solid to liquid. The specific value of this melting point is closely related to the regularity of the molecular structure and the strength of the hydrogen bond. The more regular the structure and the stronger the hydrogen bond, the higher the melting point.
In terms of solubility, because it contains polar groups such as hydroxyl and aldehyde groups, it may have a certain solubility in polar solvents such as water and alcohols. Hydroxy and aldehyde groups can form hydrogen bonds with water molecules to promote the dissolution process. However, because they also contain non-polar parts such as bromine atoms, the solubility in non-polar solvents such as alkanes may be lower.
As for the density, it may be slightly higher than that of common organic solvents, or due to the type and relative mass distribution of atoms in the molecule. The relative mass of the bromine atom in the molecule is relatively large, resulting in an increase in the overall mass. Under the same volume, the mass increases and the density increases.
Its volatility is weak, and due to the strong intermolecular forces, especially the hydrogen bond action, the binding molecule makes it difficult to break away from the liquid or solid surface and enter the gas phase. To make it volatilize, more energy needs to be provided to overcome the intermolecular interaction.
In summary, 3-hydroxy, 6-bromo-5-aldehyde exhibit the above physical properties due to their unique molecular structure, which is of great significance for their applications in chemical, pharmaceutical and other fields.

The chemical properties of 3-amino group and 6-chloro-5-hydroxyl group are quite stable.
Looking at the structure of these three groups, the nitrogen atom in the amino group (-NH ²) has a lone pair of electrons, which can show a certain alkalinity and can react with acids to form corresponding salts. However, in many common environments, if there is no strong acid material intrusion, the amino group is still stable.
6-chlorine, although the chlorine atom is a halogen element, has some activity, but in this compound, it forms a strong chemical bond with the surrounding atoms. Usually, if there is no specific reagent, such as nucleophiles, to attack, the chlorine atom is not easy to leave or change on its own. < Br >
5-Hydroxy (-OH). The oxygen atoms in the hydroxyl group are quite electronegative, and the hydrogen-oxygen bond has a certain polarity. However, the structure formed by the hydroxyl group and its adjacent atoms gives it a relatively stable situation. Under normal conditions, the hydroxyl group will not be dehydrated for no reason or react with other substances at will, unless it encounters special chemical reagents such as strong oxidants and dehydrators.
As a whole, 3-amino groups and 6-chloro-5-hydroxyl groups form a relatively stable structure due to the mutual influence and restraint between the groups in the conventional chemical environment. If there is no external specific stimulation, the chemical properties are stable and it is not easy to have significant chemical reactions.

To prepare 3-pentenoic acid and 6-bromo-5-hexenal, the following method can be used:
1. ** Preparation of 3-pentenoic acid **
- ** Using diethyl malonate as raw material **: Diethyl malonate and 1-bromoethylene under the action of strong bases such as sodium ethyl alcohol undergo nucleophilic substitution, and the alkenyl group replaces the α-hydrogen of an ester group in diethyl malonate. After basic hydrolysis, re-acidification and heating decarboxylation, 3-pentenoic acid can be obtained. The reason is that diethyl malonate α-hydrogen is acidic, and it forms carbon negative ions under strong bases, and nucleophilic attacks 1-bromoethylene. Hydrolysis causes the ester group to form a carboxyl group, and heating decarboxylates to obtain the target acid.
- ** Using ethyl acrylate as raw material **: Ethyl acrylate reacts with vinyl format reagents (such as vinyl magnesium bromide), first through nucleophilic addition to obtain intermediates, and then hydrolyzes to obtain 3-pentenoic acid. This is the nucleophilic addition of ester carbonyl by format reagents, and the product is obtained by subsequent hydrolysis.
2. ** Preparation of 6-bromo-5-hexenal **
- ** Using 1,3-butadiene as raw material **: 1,3-butadiene and N-bromosuccinimide (NBS) underwent an allyl bromination reaction in the presence of light or an initiator to obtain 3-bromo-1-butene. 3-bromo-1-butene and 3-butenal under alkali catalysis were allylated to obtain 6-bromo-5-hexenal. Because NBS can selectively brominate allyl hydrogen, allyl halogen and aldehyde can be allylated in alkali catalysis.
- ** Using cyclohexene as raw material **: Cyclohexene is first added to bromine to obtain 1,2-dibromocyclohexane, and then debrominated under the action of strong bases such as sodium ethanol to obtain 1,3-cyclohexadiene. 1,3-cyclohexadiene is ozonized and then reduced hydrolyzed to obtain 6-bromo-5-hexenaldehyde. Ozonation can break the carbon-carbon double bond into carbonyl groups, and the target product can be obtained by controlling the reaction conditions.

In today's market, the price of 3-carboxylic acid and 6-bromo-5-hydroxyl is different, depending on the category, quality, supply and demand conditions.
The price of goods in the market is not constant, and often changes with various factors. If the 3-carboxylic acid is of the highest quality, it is pure and net, suitable for all kinds of fine industries, and the price is high in the market. Its price per catty may reach tens of gold, or even hundreds of gold. If the quality is slightly inferior, it is suitable for ordinary services, and the price may be halved, ranging from more than ten gold to tens of gold per catty.
As for 6-bromo-5-hydroxyl, the same is true. If it is refined, impurities are rare, and it is indispensable in medicine and chemical industry, and the price must be high. The price per catty, or nearly 100 gold, or even higher. If its product is average, it can be used for general use, and the price hovers between tens of gold.
And 5-hydroxyl products also vary in price according to quality. The better is expensive, and the worse is cheap. Its price is often between the number of gold per catty and tens of gold.
However, these are all approximate numbers. When the market conditions change, when merchants buy and sell, they should carefully observe their situation, evaluate the situation, and know the exact price in order to make a transaction. It is not enough to keep this saying, but when the time is appropriate according to local conditions, consider it in detail to achieve reality.