4-Quinolinecarbaldehyde

4-Quinolinecarbaldehyde, that is, 4-quinoline formaldehyde, has the following chemical structure. Quinoline, a nitrogen-containing heterocyclic compound, is formed by fusing a benzene ring with a pyridine ring. In the quinoline ring system, each atom is numbered according to a specific rule. In 4-quinoline formaldehyde, aldehyde (-CHO) is attached to the carbon atom numbered 4 of the quinoline ring.
From a structural perspective, the quinoline ring endows this compound with a rigid planar structure, which has a significant impact on its physical and chemical properties. As an active functional group, aldehyde groups have unique chemical properties and can participate in many organic reactions, such as oxidation reactions, reduction reactions, and nucleophilic addition reactions. Due to its special structure, 4-quinoline formaldehyde is widely used in the field of organic synthesis, and is often used as a key intermediate to prepare various drugs, dyes and functional materials.

4-Quinolinecarbaldehyde, Chinese name 4-quinoline formaldehyde, is an important compound in organic chemistry. Its main physical properties are as follows:
- ** Appearance properties **: At room temperature, 4-quinoline formaldehyde mostly appears as a light yellow to yellow crystalline powder, which has a unique appearance. This morphology not only reflects the orderly arrangement of its molecular structure, but also affects its stability and reactivity in different environments. Powder-like substances have a large specific surface area and can more fully contact with other reactants when participating in chemical reactions, which may accelerate the reaction rate.
- ** Melting point **: Its melting point is between 102-104 ° C. As an important physical constant of a substance, the melting point is a key basis for identification and purity judgment. For 4-quinoline formaldehyde, the melting point range indicates that the intermolecular force is at a specific strength. When this temperature range is reached, the lattice structure begins to disintegrate, and the substance changes from solid to liquid. Accurate determination of the melting point helps to determine the purity of the substance. If it contains impurities, the melting point tends to decrease and the melting range becomes wider.
- ** Solubility **: 4-quinoline formaldehyde is slightly soluble in water. As a common solvent, the solubility of water implies the polar characteristics of the compound. Because water is a polar solvent, 4-quinoline formaldehyde is slightly soluble in it, indicating that its polarity is relatively weak and its molecular structure may contain more non-polar groups. However, it is easily soluble in organic solvents such as ethanol and chloroform. Organic solvents such as ethanol and chloroform have different polarities and molecular structures, and can interact with 4-quinoline formaldehyde through van der Waals forces, hydrogen bonds, etc., to achieve good dissolution. This solubility facilitates its application in organic synthesis and related fields.
- ** Odor **: has a weak special odor. The odor originates from the volatilization of molecules into the air, which stimulates the olfactory receptors. The weak special odor reflects the unique role of its volatility and molecular structure on olfactory perception. In practical operation and application, the odor can be used as a reference basis for preliminary judgment of its existence and purity.

4-Quinoline formaldehyde is a key intermediate in organic synthesis and is widely used in the fields of medicine, pesticides, materials and other fields. Common synthesis methods are as follows:
First, quinoline is used as the starting material and synthesized by Vilsmeier-Haack reaction. In this reaction, quinoline is co-heated with N, N-dimethylformamide (DMF) and phosphorus oxychloride (POCl 🥰). POCl 🥰 interacts with DMF to generate an active electrophilic reagent, which attacks a specific position on the quinoline ring, and then hydrolyzes to obtain 4-quinoline formaldehyde. The advantage of this method is that the reaction conditions are relatively mild and the yield is acceptable; however, the disadvantage is that the use of more toxic POCl 🥰 is not friendly to the environment and the post-treatment is complicated.
Second, it is synthesized by palladium-catalyzed cross-coupling reaction. For example, 4-haloquinoline and formaldehyde derivatives are used as raw materials and react in the presence of palladium catalyst, ligand and base. Commonly used haloquinoline is 4-bromoquinoline or 4-ioquinoline, and formaldehyde derivatives such as formaldehyde dimethanol. This method has good selectivity and can efficiently construct carbon-carbon bonds; but its disadvantage is that palladium catalysts are expensive, and the reaction requires strict anhydrous and anaerobic conditions, which requires high equipment and operation.
Third, it is prepared by oxidation of 4-methylquinoline. A mild oxidizing agent, such as manganese dioxide (MnO _ 2), active manganese dioxide, etc., can be used to oxidize 4-methylquinoline in a suitable solvent. The raw materials of this method are easy to obtain and the operation is relatively simple; however, the amount of oxidizing agent is large, and the separation and purification of the product requires fine operation, otherwise the purity and yield will be affected.
The above synthetic methods have their own advantages and disadvantages. In practical application, it is necessary to consider the cost of raw materials, reaction conditions, product purity and environmental protection according to specific needs, and carefully select the appropriate method.

4-Quinolinecarbaldehyde, Chinese name 4-quinoline formaldehyde, has wonderful uses in many fields such as medicine, materials, and scientific research.
In the field of medicine, it is a key intermediate for the synthesis of many drugs. The structure of 4-quinoline exists widely in many bioactive molecules, and 4-quinoline formaldehyde can be introduced into specific functional groups through a series of chemical reactions to construct compounds with unique pharmacological activities. For example, in the research and development of anti-tumor drugs, researchers use 4-quinoline formaldehyde as the starting material, and through ingenious design and reaction, synthesize new compounds that have the effect of targeting tumor cells and inhibiting tumor growth and spread. Another example is in the development of antibacterial drugs, the use of its synthetic derivatives shows a good inhibitory effect on specific bacteria, paving the way for the development of new antibacterial drugs.
In the field of materials science, 4-quinoline formaldehyde also plays an important role. First, it can be used to prepare materials with special optical properties. After reacting with other organic molecules, a conjugated system is constructed, so that the obtained material has fluorescence emission characteristics, which is widely used in fluorescent sensors, Light Emitting Diode, etc. Second, in the synthesis of organic semiconductor materials, 4-quinoline formaldehyde participates in the formation of the structure, which can optimize the electrical properties of materials and contribute to the development of organic electronic devices.
At the scientific level, 4-quinoline formaldehyde is a commonly used reagent for organic synthesis chemistry research. Chemists use various functional group reactions to explore novel synthesis methods and strategies, expand the structural diversity of organic compounds, and lay the foundation for discovering new chemical phenomena and laws. At the same time, in the preparation of metal-organic frameworks (MOFs) materials, 4-quinoline formaldehyde can be used as an organic ligand to coordinate with metal ions to construct MOFs materials with specific topological structures and functions, with great potential in gas adsorption, separation, catalysis and other fields.

4 - Quinolinecarbaldehyde, Chinese name 4 - quinoline formaldehyde, its market price range varies due to many factors. This compound is often used in medicine, chemical industry and other fields, and its price is affected by purity, market supply and demand, and preparation process complexity.
In terms of purity, high purity is expensive. For example, for pharmaceutical research and development, strict requirements for impurity content, more than 99% purity products, due to the need for fine purification and high cost, the price per gram may be hundreds or even thousands of yuan. If the purity requirements for chemical production are slightly lower, such as 95% purity, the price per gram may drop to tens of yuan.
Market supply and demand also affect the price. If the pharmaceutical industry has a large increase in demand for drugs containing 4-quinoline formaldehyde during a certain period, the supply will exceed the demand, and the price will rise significantly; on the contrary, the demand will be sluggish, the supply will exceed the demand, and the price will decline.
The complexity of the preparation process is also critical. If the preparation requires multi-step reactions, special reagents or harsh conditions, the cost will increase and the price will increase accordingly; if the process is relatively simple, the cost will be controllable, and the price will also be reduced.
Overall, the market price of 4-quinoline formaldehyde fluctuates greatly, with low-purity products reaching tens of yuan per gram, and high-purity products can reach hundreds to thousands of yuan per gram. Buyers should weigh price and quality according to their own needs.