3-Amino-5-pyridinecarboxylic acid

3-Amino-5-nitrobenzoic acid is an important raw material for organic synthesis and is widely used in the fields of drugs, dyes, pesticides, etc. Although it is not directly recorded in "Tiangong Kaiwu", its use can be explained in the style of ancient classical Chinese:
This 3-amino-5-nitrobenzoic acid can be used as the cornerstone of exquisite medicines in the way of medicine. Doctors who treat diseases and save people often rely on the combination of various medicinal materials. This compound has been prepared by skilled craftsmen, and may be a good prescription for treating diseases, relieving suffering and restoring health to those who are suffering from pain.
In the way of dyes, its role should not be underestimated. Dyeing craftsmen are always looking for bright and long-lasting pigments. 3-Amino-5-nitrobenzoic acid is skillfully treated, or it can produce a dye with a unique color. It can dye silk and satin, making it gorgeous and radiant. Whether it is the fine clothes of officials and nobles, or the cloth shirts of ordinary people, it adds color.
As for the field of pesticides, it is also very useful. Farmers are often infested by pests, and grain production is reduced. Based on this compound, it may be able to make anti-insect and anti-pest drugs. Sprinkling on the field can protect crops from insect devour, and the grain is abundant and the warehouse is full, which is a move that benefits the country and the people.
In short, although 3-amino-5-nitrobenzoic acid is invisible in ancient books, in many fields today, it is like a skilled craftsman hidden behind the scenes, silently playing a key role and benefiting all people.

3-Hydroxy-5-pentenoic acid is an organic compound with special physical properties.
Looking at its shape, under room temperature and pressure, this substance is mostly colorless to light yellow liquid, with a texture like light oil, warm to the touch and flowing freely, like smart water, but with a bit more thick texture.
When it comes to smell, it exudes an elegant and unique smell, not pungent, but with a hint of freshness and softness, like being in the midst of spring flowers, smelling the faint fragrance, but it is unique.
As for the boiling point, in a specific pressure environment, its boiling point is within a certain range. The value of this boiling point is the key node for the substance to change from liquid to gaseous state, just like a door to different states. When the temperature gradually rises to the boiling point, the thermal movement of 3-hydroxy-5-pentenoic acid molecules becomes more intense, breaking free from the liquid state, turning into a gaseous state and floating in the air.
In terms of melting point, it also has its inherent value. When the temperature drops to the melting point, the substance gradually solidifies from liquid state to solid state, as if time has stopped, and the molecular arrangement has changed from disorder to order, forming a stable structure.
Solubility is also one of its important physical properties. In many common organic solvents, such as ethanol, ether, etc., 3-hydroxy-5-pentenoic acid exhibits good solubility, just like a fish entering water, it can mix with solvent molecules and disperse them evenly. However, in water, its solubility is relatively limited, just like a drop of oil falling into water. Although some molecules try to get close to water, it is difficult to completely blend, and can only show a delicate state of disintegration.

3-Hydroxy-5-pentenoic acid is a class of organic compounds. Its chemical properties are interesting and unique.
When it comes to acidity, the carboxyl group in this compound can release protons, showing acidity. Due to the high electronegativity of oxygen atoms in the structure of carboxyl groups, the hydrogen-oxygen bond electron cloud is biased towards oxygen atoms, and hydrogen atoms are easily dissociated in the form of protons, showing acidic characteristics. However, compared with some strong acids, its acidity is weaker. After all, carboxyl groups are not very easy to completely ionize.
In nucleophilic substitution reactions, both hydroxyl and carboxyl groups in molecules are active check points. The oxygen atom of the hydroxyl group is rich in lone pair electrons and has nucleophilicity. Under appropriate conditions, it can undergo nucleophilic substitution reactions with electrophilic reagents. For example, under acid catalysis, it can react with halogenated hydrocarbons. The oxygen atom of the hydroxyl group attacks the carbon atom of the halogenated hydrocarbon, and the halogen ion leaves to form the corresponding ether compound. The carbonyl carbon in the carboxyl group is electrophilic and can be attacked by nucleophilic reagents, but the reactivity of the carboxyl group is changed due to the conjugation effect. For example, in the esterification reaction, alcohol attacks the carbonyl carbon of the carboxyl group as a nucleophilic reagent, and undergoes a series of intermediate transformations, eventually forming esters.
Looking at the addition reaction, the carbon-carbon double Carbon-carbon double bonds are rich in electrons and can undergo addition reactions with electrophilic reagents. For addition to hydrogen halide, the hydrogen atom of hydrogen halide first binds to one of the carbon atoms in the double bond to form a carbon cation intermediate, and then the halogen ion attacks the carbon cation to form halogenated hydrocarbon derivatives. If a suitable catalyst is present, it can also undergo addition reaction with hydrogen, and the double bond is reduced to a single bond to form a saturated carboxylic acid derivative.
The chemical properties of 3-hydroxy-5-pentenoic acid are rich and diverse. Based on the functional groups it contains, these properties provide many possibilities for the field of organic synthesis, which can be used to prepare various organic compounds with specific structures and functions.

There are many methods for the synthesis of 3-amino-5-nitrobenzoic acid, which can be selected and described here.
First, benzoic acid can be initiated. The nitration reaction of schilling benzoic acid occurs. Under appropriate conditions, the mixed acid of nitric acid and sulfuric acid can introduce benzoic acid into a specific position. However, this reaction requires precise control of conditions. Because different conditions will cause differences in the introduction position of nitro groups, after optimizing the conditions, the main nitro group can be introduced into the target 5-position. Afterwards, the obtained 5-nitrobenzoic acid is aminated. Usually, the carboxyl group can be converted into an easy-to-leave group, such as acyl chloride, and then reacted with an ammonia source to introduce an amino group; or by reducing the nitro group to an amino group, but the reduction process also needs to be carefully regulated to prevent excessive reduction or side reactions.
Second, m-nitrotoluene is used as a raw material. M-nitrotoluene is oxidized, and methyl groups can be converted into carboxyl groups to obtain 5-nitrobenzoic acid. The oxidizing agents commonly used in this oxidation step include potassium permanganate, etc., and the reaction temperature, time and amount of oxidizing agent need to be controlled to obtain a high yield product. Then, the same method is used to convert 5-nitrobenzoic acid into 3-amino-5-nitrobenzoic acid.
Third, starting from aniline. Aniline is first acetylated to protect the amino group, and then nitrified, so that the nitro group can be mainly introduced into the para-position of the amino group, that is, the 5-position. After that, the deacetyl group is released by water, and the ortho-methyl group of the amino group is oxidized to the carboxyl group. Suitable strong oxidizing agents can be selected for this oxidation process. Finally, the target product 3-amino-5-nitrobenzoic acid can be obtained.
Although there are many ways to synthesize, each method has its own advantages and disadvantages. It needs to be weighed according to actual needs, such as the availability of raw materials, cost, and difficulty of reaction conditions.

Today there is 3-hydroxy-5-pentenoic acid, want to know its price range in the market. This acid, organic compounds are also used in chemical, pharmaceutical and other fields.
However, its price often varies due to quality, purity, supply and demand. If it is of ordinary purity, the price per kilogram may be hundreds of yuan. If the purity is extremely high, reaching pharmaceutical grade, the price will be high, or to thousands of yuan per kilogram.
Looking at the trading of chemical raw materials in the market, when the supply and demand are high, the price may be slightly flat; if the supply is less and the demand is more, the price will rise. And different origins and manufacturers have different prices due to differences in production methods and costs.
Generally speaking, the price of ordinary industrial grade 3-hydroxy-5-pentenoic acid is about 500 yuan to 1,500 yuan per kilogram; while high purity is suitable for pharmaceutical developers, ranging from 2,000 yuan to 5,000 yuan per kilogram. However, this is only a rough estimate, and the actual price should be subject to the current market conditions and the merchant's decision.