pyridine-2-carboxaldoxime

The chemical structure of pyridine-2-formaldehyde oxime can be regarded as the condensation of aldehyde and hydroxylamine on the second carbon of the pyridine ring. The pyridine ring is a nitrogen-containing six-membered heterocycle, which is composed of five carbon atoms and one nitrogen atom connected by a conjugated double bond. It presents a planar hexagonal structure and is aromatic. When the aldehyde group is condensed with hydroxylamine, a carbon-nitrogen double bond (C = N) is formed between the carbonyl carbon of the aldehyde group and the nitrogen atom of the hydroxylamine, and a hydroxyl group (-OH) is attached to the nitrogen atom. In this way, the structure of pyridine-2-formaldehyde oxime can be constructed. Its structural expression can be written as C H N 2O O, with a relative molecular weight of about 122.13. This compound is alkaline due to the existence of pyridine ring, and its chemical properties of C = N double bond and hydroxyl group are active. It has shown unique uses in organic synthesis and coordination chemistry. It can be used as a ligand to form complexes with metal ions, and can also participate in various organic reactions. It is an important intermediate in organic synthesis chemistry.

Pyridine-2-formaldehyde oxime has a wide range of uses. In the field of chemical synthesis, it is often used as a key intermediate. Due to its special structure, it can be combined with various reagents through various chemical reactions to form complex organic compounds. For example, in the synthesis of some biologically active heterocyclic compounds, pyridine-2-formaldehyde oxime can be used as a starting material. After ingeniously designed reaction routes, substances with specific pharmacological activities can be generated, laying the foundation for drug development.
In the field of analytical chemistry, pyridine-2-formaldehyde oxime also has important functions. It can form stable complexes with specific metal ions, and this complex often has unique physicochemical properties. Due to this property, pyridine-2-formaldehyde oxime can be used to detect and quantitatively analyze some metal ions. For example, when measuring the content of heavy metal ions in environmental water samples, the concentration of heavy metal ions can be accurately determined by the color change or other detectable signal changes of the complexes formed by pyridine-2-formaldehyde oxime and heavy metal ions.
In addition, in the field of materials science, the materials prepared by pyridine-2-formaldehyde oxime show special properties. Introducing it into polymer materials can improve some properties of materials, such as thermal stability, mechanical properties, etc. The principle is that the functional groups of pyridine-2-formaldehyde oxime can interact with the polymer chain to adjust the microstructure and macroscopic properties of the material, providing an effective way for the development of new functional materials.

Pyridine-2-carboxyaldoxime is also an organic compound. Its physical properties are quite elusive.
Under normal temperature and pressure, it is mostly white to light yellow crystalline powder, which is easy to store and use.
As for the melting point, it is about 140-143 ° C. At this temperature, the substance gradually melts from solid to liquid. This phase transition temperature is one of the important markers for identifying and purifying the substance.
In terms of solubility, it has a certain solubility in water, but it can also be soluble in organic solvents such as ethanol and acetone. This property makes it possible to participate in a variety of chemical reactions and separation processes in different solvent systems. < Br >
Looking at its density, although there is no exact literature detailing it as a fixed value, but analogous to similar nitrogen-containing heterocyclic aldoxime compounds, its density should be higher than that of water, and it varies slightly with external conditions such as temperature and pressure.
Its smell is also different, with a slightly special smell. Although it is not strongly pungent, it is still recognizable. This smell originates from the synergistic effect of the pyridine ring and the aldoxime group in the molecular structure.
In addition, pyridine-2-carboxyaldoxime is stable at room temperature, but in case of high temperature, open flame or strong oxidant, there may be a risk of chemical reaction or even combustion or explosion, so when storing and using it, be careful and follow safety procedures.

The synthesis method of pyridine-2-formaldehyde oxime has been known in ancient times, and the above numbers are given below.
First, pyridine-2-formaldehyde and hydroxylamine hydrochloride are used as raw materials. First, place pyridine-2-formaldehyde in a suitable reaction vessel, add an appropriate amount of solvent, such as ethanol or methanol, etc., and stir well. Then, slowly add hydroxylamine hydrochloride, and at the same time add an appropriate amount of base, such as sodium acetate, to adjust the pH of the reaction system. At an appropriate temperature, generally between 50 and 80 ° C, when the reaction number is carried out. After the reaction is completed, the crude product of pyridine-2-formaldehyde oxime can be obtained through cooling, filtration, washing and other steps, and then purified by recrystallization, etc., to obtain the pure product.
Second, 2-methylpyridine is used as the starting material. First, 2-methylpyridine is oxidized to pyridine-2-carboxylic acid under the action of appropriate oxidants, such as potassium permanganate or potassium dichromate. Then, pyridine-2-carboxylic acid reacts with thionyl chloride to convert to pyridine-2-formyl chloride. Then pyridine-2-formyl chloride is reacted with hydroxylamine to obtain pyridine-2-formaldehyde oxime. In this process, the conditions of each step of the reaction need to be carefully controlled. The oxidation reaction temperature may be 80-100 ° C, the chlorination reaction needs to be in an anhydrous environment, and the pH and temperature should also be paid attention to when reacting with hydroxylamine, about 20-40 ° C.
Third, using pyridine as the raw material, a suitable substituent is introduced at the 2-position of pyridine first, and through multi-step reaction, pyridine-2-formaldehyde is finally formed. Although this route is complicated, it is also one of the synthesis methods. It is necessary to pay attention to the selectivity and yield of each step of the reaction. When introducing substituents, appropriate reagents and conditions need to be selected to ensure that the reaction mainly occurs at the 2-position. After each step of the reaction, it needs to be separated and purified to ensure the purity of the product, and then smoothly advance the subsequent reaction.

For pyridine-2-carboxyaldoxime, many matters must be paid attention to when using it.
Safety is the first priority. This is the foundation of the use. Pyridine-2-carboxyaldoxime has certain toxicity and irritation, so when using it, it is necessary to wear suitable protective equipment, such as gloves, goggles, gas masks, etc., to avoid contact with the skin, eyes and respiratory tract. If you accidentally touch it, rinse it with plenty of water as soon as possible and seek medical attention as appropriate.
Furthermore, it is related to storage. It should be placed in a cool, dry and well-ventilated place, away from fire and heat sources. It is unstable due to its nature or due to changes in temperature and humidity. If it is improperly stored or deteriorated, it will affect its effectiveness and even cause safety risks.
And operation. During experiments or production operations, it should be done in a fume hood to ensure smooth ventilation of the operating environment to dissipate harmful gases that may escape. And the operation must be fine, and it must be done according to the standard process. Do not act hastily to avoid accidents.
Repeat the dosage. It needs to be precisely controlled, depending on the specific use and reaction needs. If the dosage is too small, or the expected effect is not achieved; if the dosage is too large, it will cause material waste or lead to other side reactions, which will increase the difficulty of subsequent treatment.
Furthermore, the waste after use should not be discarded at will. It must be properly disposed of in accordance with relevant environmental regulations to prevent pollution to the environment.
In short, the use of pyridine-2-carboxyaldoxime, safety, storage, operation, dosage and waste disposal should not be ignored, so as to ensure smooth use and avoid accidents.