4-N-1-amino-2-carboxylbenzene, or p-aminobenzoic acid, has a wide range of main uses. In the field of medicine, it is a key raw material for the synthesis of many drugs. For example, in the synthesis of local anesthetics, p-aminobenzoic acid can be converted into common local anesthetics such as procaine through a series of chemical reactions. By blocking nerve impulse conduction, it can achieve the effect of local anesthesia, so that patients can avoid pain during medical operations such as surgery.
In the dye industry, p-aminobenzoic acid can be used to prepare a variety of dyes. Because its structure contains specific functional groups, it can react with other compounds to generate dyes with different colors and properties. It is widely used in textile, leather and other industries to give rich colors to fabrics and leather.
In the cosmetics industry, p-aminobenzoic acid also plays an important role. It has the property of absorbing ultraviolet rays and is often added to sunscreen products to resist ultraviolet damage to the skin, prevent sunburn, tanning and photoaging problems, and protect skin health.
In addition, p-aminobenzoic acid is also an important intermediate in the field of organic synthesis. It can react with other reagents to construct complex organic compounds, providing important support for the development of organic synthetic chemistry and promoting technological progress and product innovation in many fields.

The physical properties of 4-Jiang-1-amino-2-carboxylbenzene are as follows:
The appearance of this substance may be white to light yellow crystalline powder, and the smell is light. In terms of solubility, it is slightly soluble in water, because although there are polar groups amino and carboxyl groups in its molecular structure, the hydrophobicity of the benzene ring makes the overall solubility in water limited. However, it is easily soluble in some polar organic solvents, such as ethanol, acetone, etc., because these organic solvents can form hydrogen bonds or other intermolecular forces with the molecules of the substance, thereby promoting dissolution.
Its melting point is within a certain range, and the specific value varies slightly due to factors such as purity, roughly around [X] ° C. The existence of the melting point is because when the temperature rises to a certain extent, the molecule obtains enough energy, the lattice structure is destroyed, and the substance changes from a solid state to a liquid state.
The density of this substance is relatively stable, about [X] g/cm ³, and the density depends on the way its molecules are deposited and the relative molecular mass. At room temperature and pressure, its chemical properties are relatively stable, but under certain conditions such as high temperature, strong acid and alkali environment, amino groups and carboxyl groups may react. For example, amino groups can react with acids to form salts, and carboxyl groups can neutralize with bases. Its stability is derived from the conjugated system of the benzene ring and the electronic effect between the amino and carboxyl groups, which makes the molecular structure stable to a certain extent. When storing, it should be placed in a cool and dry place to avoid contact with strong acids and bases to prevent chemical reactions and deterioration.

The chemical properties of 4-N-1-amino-2-carboxylbenzene are as follows:
This compound has amino and carboxyl groups, each with its own unique chemical properties. The amino group is basic and can react with acids to form salts. In the case of hydrochloric acid, the lone pair electrons of the nitrogen atom in the amino group will combine with the hydrogen ion in the hydrochloric acid to form the corresponding ammonium salt. This is an acid-base neutralization reaction, reflecting the alkaline characteristics of the amino group.
The carboxyl group is acidic and can neutralize with bases. Taking sodium hydroxide as an example, the carboxyl group will react with sodium hydroxide to form carboxylate and water. This reaction is often used in organic synthesis to adjust pH and prepare carboxylate compounds.
In addition, the amino group and the carboxyl group can also undergo condensation reactions. Under appropriate conditions, the amino group of the compound dehydrates and condenses with the carboxyl group of another molecule to form a peptide bond. This reaction is of great significance in the field of peptide and protein synthesis, and is one of the key reactions in the construction of biological macromolecules.
From the perspective of the benzene ring, the benzene ring of the compound has a certain stability due to the existence of a conjugated system. The benzene ring can undergo substitution reactions, such as halogenation reactions. Under the action of suitable catalysts, halogen atoms can replace hydrogen atoms on the benzene ring.
The presence of 4--1-amino-2-carboxyphenylbenzene amino, carboxyl and benzene rings is rich in chemical properties and plays an important role in many fields such as organic synthesis, medicinal chemistry and biochemistry. It provides a diverse chemical reaction basis for research and application in related fields.

To prepare 4-alkynyl-1-amino-2-formylnaphthalene, there are three methods.
First, naphthalene is used as the starting point, and α-bromonaphthalene is brominated first, and then reacts with acetyllithium to obtain alkynyl naphthalene. After nitration and reduction, 4-alkynyl-1-aminonaphthalene is obtained. Finally, it is treated with a suitable acylating agent, such as formyl chloride and aluminum trichloride catalysis, 2-formyl group can be introduced, and the target is formed. This step is slightly complicated, but the raw materials are easy to obtain, and the reaction conditions of each step are relatively smooth and easy to control.
Second, starting from 2-formylnaphthalene, the formyl group is first protected to prevent disturbance in the reaction. Then the amino group is introduced at the 1-position of the naphthalene ring, which can be achieved by nitrification and reduction. After that, the alkynyl group is introduced at the 4-position, which can be achieved by the coupling reaction of halogenate and alkynyl fund reagent. Finally, the formyl protecting group is removed to obtain 4-alkynyl-1-amino-2-formylnaphthalene. This method focuses on protection and deprotection strategies, and can precisely control the order of introduction of each group, improving the yield and purity.
Third, the target molecule is constructed by the catalytic coupling reaction of transition metals with alkynyl and amino precursors and naphthalene derivatives as raw materials. For example, a suitable halogenated naphthalene derivative is coupled with alkynyl boronic acid and amination reagents under the catalysis of transition metals such as palladium under the "one-pot method". This method is simple in steps and has excellent atomic economy. However, it requires strict reaction conditions and catalysts, and requires fine regulation of reaction parameters to improve yield and selectivity.
All methods have advantages and disadvantages. In actual preparation, the optimal way should be selected according to the trade-off of raw material availability, reaction conditions, cost and yield, so as to achieve the purpose of efficient synthesis of 4-alkyne-1-amino-2-formylnaphthalene.

4-Hydroxy-1-methoxy-2-acetylbenzene should pay attention to the following matters during storage and transportation:
** Storage **:
First, it should be placed in a cool and dry place. If this substance is in a warm and humid environment, it is prone to chemical reactions due to humidity and temperature, causing its chemical properties to change. For example, when the humidity is high, it may cause hydrolysis reactions, destroy its molecular structure, and reduce purity and quality.
Second, it needs to be stored in a well-ventilated place. Good ventilation can avoid the accumulation of its volatile gases to prevent danger caused by excessive concentration. If the storage space is closed, the volatile gas may reach a certain concentration, which may cause combustion or even explosion in case of open fire or static electricity.
Third, it should be stored separately from oxidants, acids, bases, etc. The chemical properties of 4-hydroxy-1-methoxy-2-acetylbenzene determine that it is prone to violent chemical reactions when it comes into contact with these substances. If it comes into contact with strong oxidants, it may initiate an oxidation reaction, which not only changes its own properties, but also may generate a lot of heat and pose a safety hazard.
Fourth, the storage container should be well sealed. The seal can prevent external factors such as air and moisture from entering and maintain material stability. If the container is poorly sealed, the oxygen in the air may cause it to oxidize slowly, and the entry of moisture may lead to problems such as deliquescence.
** Transportation **:
First of all, the transport vehicle should ensure that it is clean and dry, and avoid other residual chemicals from reacting with it. At the same time, good protective measures should be taken, such as sun shading and rain protection equipment. If it is exposed to direct sunlight or rain during transportation, it may affect the properties of the substance.
Secondly, severe bumps and collisions should be avoided during transportation. 4-Hydroxy-1-methoxy-2-acetylbenzene may cause damage to the package due to violent vibration. If the package is damaged, the leakage of the substance may not only cause losses, but also pose a threat to the environment and the safety of the transportation personnel.
Furthermore, the transportation personnel need to understand the basic properties of the substance and emergency treatment methods. In the event of an accident, such as a leak, it can be dealt with in a timely and correct manner to reduce the harm. For example, if a leak occurs, you should know how to contain, clean up, and take protective measures to avoid self-harm.