2-aminopyridine-3-thiol

2-Hydroxypyridine-3-sulfonic acid is an important organic compound with a wide range of main uses.
In the field of medicine, this compound is often a key intermediate for the synthesis of many drugs. Due to its unique chemical structure, it can participate in various reactions, and then construct molecular structures with specific physiological activities. For example, in the synthesis pathway of some antibacterial and antiviral drugs, 2-hydroxypyridine-3-sulfonic acid can undergo a series of chemical transformations, introducing key structural fragments, giving drugs the ability to target specific pathogens and inhibit their growth and reproduction, making great contributions to human health.
In the field of materials science, it also has extraordinary performance. It can be used as a functional monomer to prepare high-performance polymer materials. With its reactivity of hydroxyl groups and sulfonic acid groups, it can polymerize with other monomers to generate polymers with special properties. Such as adsorption materials with adsorption selectivity for specific substances, which can be used in wastewater treatment, environmental monitoring, etc., to effectively remove harmful impurities in water and accurately detect environmental pollutants; or electrolyte materials with good ion conductivity, which play an important role in energy storage devices such as batteries, improving the charging and discharging efficiency and service life of batteries.
In the dye industry, 2-hydroxypyridine-3-sulfonic acid also plays an important role. It can be used as a raw material for the synthesis of new dyes, because its structure can endow dyes with unique color and stability. The synthetic dyes have bright colors, good light resistance and washable properties, and are widely used in textile, printing and dyeing industries to meet people's requirements for the beauty and durability of fabrics.
Furthermore, in the field of organic synthetic chemistry, it is a powerful tool in the hands of organic synthetic chemists. As an important intermediate, it participates in the construction of many complex organic molecules. Through ingenious design of reaction routes, with the help of the reaction characteristics of its functional groups, it realizes the precise synthesis of target molecules, promotes the continuous development of organic synthetic chemistry, and provides important support for the creation of new compounds.

2-Hydroxypyridine, also known as 2-pyridyl phenol, is an important organic synthesis intermediate, which is widely used in the fields of medicine, pesticides, dyes and so on. Its synthesis method is as follows:
1. ** Skraup synthesis method **: Acrylic aldehyde, glycerol and o-aminophenol are used as raw materials, in the presence of concentrated sulfuric acid and oxidants (such as nitrobenzene), through cyclization, dehydration and oxidation steps to generate 2-hydroxypyridine. This reaction has gone through many steps, the conditions are relatively harsh, and the concentrated sulfuric acid is highly corrosive, so careful operation is required. During the reaction, glycerol is dehydrated under the action of concentrated sulfuric acid to produce acronaldehyde. Acronaldehyde and o-aminophenol undergo addition and cyclization reactions, and then dehydroaromatization under the action of nitrobenzene and other oxidants to obtain the target product.
2. ** Hantzsch Synthesis Method **: React diethyl ethoxymethylmalonate with ammonia or amine compounds to generate 2-hydroxypyridine-3,5-dicarboxylate, and then hydrolyze and decarboxylate to obtain 2-hydroxypyridine. This method has relatively many steps, but the conditions are relatively mild, and the raw materials are relatively easy to obtain. First, diethyl ethoxymethylmalonate undergoes nucleophilic addition reaction with ammonia or amine to construct a pyridine ring skeleton. The generated 2-hydroxypyridine-3,5-dicarboxylate is hydrolyzed under acidic or basic conditions to obtain the corresponding carboxylic acid. Finally, heat decarboxylation to obtain 2-hydroxypyridine.
3. ** Oxidation method using pyridine as raw material **: In the presence of a catalyst (such as a metal oxide), pyridine is oxidized with oxygen or other oxidants, and the nitrogen atom on the pyridine ring can be introduced into the hydroxyl group to obtain 2-hydroxypyridine. This method has good atomic economy and environmental friendliness, but the choice of catalyst and the control of reaction conditions are crucial. Appropriate catalysts can improve the selectivity and yield of the reaction, and the reaction temperature, pressure and oxidant dosage need to be precisely regulated to avoid side reactions such as excessive oxidation.
3-nitropyridine, as an important nitrogen-containing heterocyclic compound, is synthesized by:
1. ** Pyridine nitrification method **: Pyridine is used as a raw material to carry out nitrification in a mixed acid system composed of concentrated sulfuric acid and concentrated nitric acid. The electronic effect of nitrogen atoms on the pyridine ring makes the nitrification reaction regioselectivity special, and mainly produces 3-nitropyridine. It is necessary to strictly control the temperature during the reaction. Due to the high temperature, side reactions such as polynitrification are prone to occur, which reduces the purity and yield of the product. Concentrated sulfuric acid not only acts as a dehydrating agent, but also enhances the nitrification ability of nitric acid, promotes the generation of nitro-positive ions (NO 2), and thereby undergoes an electrophilic substitution reaction with pyridine.
2. ** Halogenated pyridine nitrification method **: Pyridine is first halogenated to obtain halogenated pyridine (such as 3-chloropyridine, 3-bromopyridine, etc.), and then the nitrification reaction is carried out under appropriate nitrification conditions. The localization effect of halogen atoms helps to guide nitro groups into specific positions of the pyridine ring and For example, in the nitration reaction of 3-chloropyridine, the electron cloud density of the ortho and para-position of the chlorine atom is relatively high, but due to factors such as steric hindrance, the nitro group mainly enters the interposition of the chlorine atom, that is, 3-nitro-3-chloropyridine is obtained, and the chlorine atom can be removed by an appropriate method to obtain 3-nitropyridine.
3. ** Conversion method using 2-methyl-3-nitropyridine as raw material **: The methyl group in 2-methyl-3-nitropyridine is removed by a suitable reaction and converted into 3-nitropyridine. For example, methyl is oxidized to carboxyl group by oxidation reaction, and then the target product is obtained by decarboxylation reaction. This method requires the selection of appropriate oxidants and reaction conditions to ensure the selective oxidation of methyl and subsequent decarboxylation reactions proceed smoothly, avoiding the impact on nitro and other groups.

Phosphorus is a collection of materials containing phosphorus.

The first word is that the color of phosphorus is light. The color of phosphorus is often white, gray, brown, and other colors, and the content is different. Its light, many glass light or grease light, especially for those who are hard on the ground, is especially grease light, just like the pearl jade, the heart of the eye.
Second hardness cleavage. The hardness of phosphorus, generally between 3.5 and 5, is not hard. Its cleavage is also special, and some phosphorus has a good cleavage surface, which can be easily cleaved in a specific direction. This characteristic is important in the material. With the help of hand, the cleavage surface is smooth, but there are also those whose cleavage is not very good, and the surface is rough.
Furthermore, the specific gravity also depends on the physical properties of phosphorus. The specific gravity of phosphorus is usually between 2.9 and 3.2. When placed in the hand, it feels like a hand. This is due to the density of the phosphorus surface and the high content of the composition of the phosphorus.
In addition, the mouth of the phosphorus also shows a lot of strength. Often, there is a mouth of the phosphorus, just like the shape of the mouth, which is smooth and curved, and the surface of the mouth must be smooth. There are also uneven mouths, with high and low surface undulations and uneven surfaces. This is due to the difference in the surface of the material.
Therefore, the physical rationality of phosphorus, such as color, light, hardness, cleavage, specific gravity, and mouth, etc., each have their own characteristics. In terms of land exploration and material development, they are all important judgments. Only by clarifying its nature can we make good use of it and make it beneficial to the world.

The second is aminobenzene, and the third is boric acid. They are all chemical substances, each with its own characteristics.
Aminobenzene, the color is often close to nothing, it is liquid, and the smell has a special gas. It is active and has a wide range of uses in the field of organic synthesis. It can be used in the production of dyes, which make the color gorgeous and fixed by virtue of its structure. It is also used in the research of medicinal stones, because it can be involved with the biochemical path of the body and help the formation of medicinal power. However, this substance is toxic. If you accidentally touch it, smell it, or eat it, it can harm the human body, damage the viscera, and disrupt qi and blood. Be careful when using it.
Boric acid, white in color and powdery or crystalline, has a peaceful nature. It is often found in the glass industry, increasing its heat resistance and transparency, making the utensils exquisite and practical. In the way of medicine, it can be used as a disinfectant and antiseptic agent, which can clear sores, prevent ulcers, and protect the health of the skin. In agriculture, it also has its function, which can make up for the lack of boron in the soil, help the growth of crops, improve their yield, and improve their quality. However, excessive use of it can also be harmful, or cause soil compaction and crop growth to be blocked.
Both are of great use in industry, medicine, and agriculture. Those who use them must know their properties in detail, and use them according to regulations. Avoid harm and seek profit, so that they can obtain their benefits and avoid their troubles. Just like the good ruler of ancient times, who used the bridle to get the law, and controlled the horse to walk the right path, reaching far and safe.

In today's market, the price of phosphorus powder varies between high and low, often depending on its quality, supply and demand conditions. Crude phosphorus is slightly cheaper, per catty or tens of dollars; refined and pure, the price is high, up to hundreds of dollars per catty. If you buy in huge quantities, the price may be concessional. In addition, the supply and demand of the market change, and the current price fluctuates accordingly. When the year is sorry, agriculture seeks fertilizer, and phosphorus needs to be prosperous and the price is high; if the production is abundant and the supply is excessive, the price may drop. Therefore, if you want to know the exact price, when you check the real-time news of the city and visit the people of Jia, you can get its details.