3-cyanopyridine

3-Hydroxypyridine is an important class of organic compounds with key uses in many fields. Although this compound is not directly mentioned in Tiangong Kaiji, its main uses are as follows based on current chemical knowledge and research:
First, in the field of pharmaceutical chemistry, 3-Hydroxypyridine is a key drug synthesis intermediate. Many biologically active drug molecules contain 3-Hydroxypyridine fragments. With its special chemical structure and reactivity, chemists can transform it into drugs with specific pharmacological activities through a series of chemical reactions. For example, some drugs used to treat cardiovascular diseases use 3-hydroxypyridine as the starting material in the synthesis process, and through carefully designed reaction steps, the core structure of the drug molecule is established, which in turn gives the drug the effect of regulating blood pressure and improving cardiac function.
Second, in the field of materials science, 3-hydroxypyridine can be used to prepare functional materials. Because of its coordination ability and electronic properties, it can form complexes with metal ions, and these complexes often exhibit unique optical, electrical or magnetic properties. For example, when preparing luminescent materials, the complexes formed by 3-hydroxypyridine and specific metal ions can emit specific wavelengths of light under specific conditions, which is expected to be applied to display technologies such as organic Light Emitting Diode (OLED) to improve display effects and performance.
Third, in the field of organic synthetic chemistry, 3-hydroxypyridine is an extremely useful synthetic building block. The hydroxyl groups and pyridine rings in its molecules can participate in a variety of chemical reactions, such as nucleophilic substitution reactions, oxidation reactions, and reduction reactions. Chemists can use these reactions to introduce different functional groups into molecules to build complex and diverse organic compounds. Through ingenious design of reaction routes, a series of organic molecules with special structures and functions can be synthesized based on 3-hydroxypyridine, providing a rich material basis for the development of organic synthetic chemistry.

3-Hydroxypyridine, its physical properties can be studied. Looking at its appearance, at room temperature, it is often white to light yellow crystalline powder, delicate and textured.
When it comes to the melting point, its melting point is about 107-110 degrees Celsius. The value of this melting point makes it gradually melt from solid to liquid when heated moderately, showing a wonderful process of material state transformation. The boiling point data is about 270-273 degrees Celsius, indicating that a higher temperature is required to make it boil into a gaseous state.
In terms of solubility, 3-Hydroxypyridine can exhibit certain solubility properties in water. Due to the hydroxyl groups contained in its molecular structure, it can interact with water molecules through hydrogen bonds, so it has moderate solubility in water. In addition, it also has good solubility in common organic solvents such as ethanol and acetone. This solubility property is of great significance in many chemical experiments and industrial applications, making it convenient to participate in various chemical reactions or play a role in specific solution systems.
Its density is also one of the important physical properties, about 1.31 g/³ cm. This density value reveals its mass distribution compared with common substances, and is a key reference for practical operations such as material mixing and separation.
In addition, 3-hydroxypyridine still has a certain odor, although not strong and pungent, it also has its own unique smell. The characteristics of this odor are also a distinguishable feature in the process of recognizing and operating it.

3-Hydroxypyridine is an organic compound with many unique chemical properties. It is weakly acidic, because the hydrogen atoms in the hydroxyl group can be partially ionized, and it can react with bases to form corresponding salts. For example, when reacted with sodium hydroxide, 3-hydroxypyridine sodium salt and water can be formed.
This compound is also nucleophilic, because there are lone electrons on the nitrogen atom and the hydroxyl oxygen atom. Under suitable conditions, it can attack the electrophilic reagent and undergo a nucleophilic substitution reaction. For example, when reacting with halogenated hydrocarbons, the lone pair electrons on the nitrogen atom or the oxygen atom will attack the carbon atom connected to the halogen in the halogenated hydrocarbon, and the halogen atom will leave to form a substitution product.
3-hydroxypyridine can also participate in redox reactions. Hydroxyl groups are easily oxidized, and can be converted into other functional groups such as carbonyl groups under the action of specific oxidants. On the contrary, under certain reduction conditions, the double bonds on the pyridine ring may be reduced, resulting in changes in its structure and properties.
In addition, 3-hydroxypyridine can form intramolecular or intermolecular hydrogen bonds because it contains nitrogen heterocycles and hydroxyl groups. Intramolecular hydrogen bonds affect the stability and spatial structure of compounds; intermolecular hydrogen bonds affect their physical properties, such as melting point, boiling point, solubility, etc. Because it can form hydrogen bonds with water molecules, it has a certain solubility in water. In the field of organic synthesis, these chemical properties make 3-hydroxypyridine an important intermediate, which is widely used in the preparation of many compounds such as drugs, pesticides and materials.

The production methods of 3-carboxypyridine are roughly as follows:
One is a chemical synthesis method. Using an appropriate pyridine derivative as the starting material, a carboxyl group is introduced through a specific chemical reaction step. For example, a specific substituted pyridine can be selected and acted on with a specific reagent under suitable reaction conditions. Common reagents include compounds with carboxylation ability. In the presence of a suitable catalyst and a specific temperature and pressure environment, the reagent reacts with the pyridine derivative and undergoes a series of complex chemical changes, resulting in the successful introduction of carboxyl groups on the pyridine ring to achieve the synthesis of 3-carboxypyridine. This method requires precise control of reaction conditions, such as temperature, reaction time, and the dosage ratio of reagents. A slight deviation may affect the purity and yield of the product.
The second is biosynthesis. 3-carboxypyridine is synthesized with the help of microbial metabolic activities. Specific microorganisms can convert specific precursor substances into 3-carboxypyridine through their own complex metabolic pathways under suitable medium and culture conditions. It is necessary to carefully select suitable microbial strains, taking into account factors such as their utilization efficiency of substrates and tolerance to products. At the same time, the composition of the medium, such as carbon source, nitrogen source, inorganic salts, etc., as well as the environmental conditions such as culture temperature, pH value, dissolved oxygen, etc., need to be carefully optimized to promote the efficient synthesis of 3-carboxypyridine by microorganisms. This method is relatively green and environmentally friendly, but the microbial culture process is prone to contamination by bacteria, which requires high production environment.
The third is the extraction method of natural products. Some natural plants or organisms may contain trace amounts of 3-carboxypyridine. Through a specific extraction process, the target product is obtained from these natural sources. First, it is necessary to select natural raw materials rich in 3-carboxypyridine, and then use separation techniques such as solvent extraction, distillation, chromatography, etc., to gradually separate and purify 3-carboxypyridine from complex natural mixtures. The raw materials in this method are natural, but the content of 3-carboxypyridine in natural raw materials is often low, the extraction process is cumbersome, the cost is high, and a large number of natural raw materials are obtained or have a certain impact on the ecological environment.

When storing and transporting 3-hydroxypyridine, there are a number of urgent precautions that need to be taken with caution.
When storing it, choose the first environment. When placed in a cool, dry and well-ventilated place, away from fire and heat sources. Because of its certain chemical activity, high temperature is prone to chemical reactions or dangerous. As described in "Tiangong Kaiwu", everything follows natural principles, and this is no exception. It should be stored separately from oxidizing agents, acids, bases, etc., and must not be mixed. It is easy to react chemically with such substances. Once mixed, it may cause violent reactions, endangering safety.
The choice of storage container is also crucial. A well-sealed container should be used to prevent it from evaporating or reacting with components in the air. Just as properly sealed items can be stored for a long time, tight containers can protect 3-hydroxypyridine from external interference.
When transporting, ensure that the packaging is complete and the loading is secure. The packaging should be in accordance with relevant standards to resist certain external shocks and environmental changes and prevent its leakage. During driving, it should be protected from sun exposure, rain exposure and high temperature. If transporting in hot summer, appropriate protective measures, such as sun shading and cooling, are required.
Transportation vehicles should also be carefully selected and should not be mixed with contraband items. Escort personnel must be familiar with their characteristics and emergency treatment methods, pay attention all the way, and if there is any abnormality, deal with it immediately.
In short, during the storage and transportation of 3-hydroxypyridine, it is necessary to observe various precautions according to its chemical properties in order to ensure safety. As advocated in "Tiangong Kaiwu", everything is based on fine and compliance.