5-Methoxy-2-pyridinecarboxylic acid

5-Amino-2-hydroxybenzoic acid, that is, 5-aminosalicylic acid, is a key pharmaceutical ingredient in the treatment of inflammatory bowel diseases, such as ulcerative colitis. In the era of "Tiangong Kaiwu", although there is no modern precise chemical understanding, from the perspective of traditional medicine, it may be possible to explore its traces from natural medicinal plants.
In traditional Chinese medicine, many plants contain similar functional ingredients. In ancient medicine, natural plants are often used as medicines, which are processed and matched to treat various diseases. If you explore the efficacy of 5-aminosalicylic acids, or involve many plants that clear heat, dryness, cool blood and detoxify.
In traditional medicine books, Coptis chinensis, Scutellaria baicalensis, and Phellodendron chinensis all have the power to clear away heat and dry dampness. Coptis chinensis contains berberine and other ingredients, which can be antibacterial and anti-inflammatory, and may relieve intestinal inflammation; Scutellaria baicalin contains baicalin, etc., which has the effect of anti-inflammatory and immune regulation. Although 5-aminosalicylic acid has not been precisely refined at that time, such plant compounds may relieve intestinal inflammation symptoms.
Another example is ground elm, which has the ability to cool blood and stop bleeding, detoxify and restrain sores, or improve intestinal ulcers and bleeding. Traditional Chinese medicine is based on the overall concept, syndrome differentiation and treatment, and the medication is mostly a compound prescription, which works synergistically to If modern chemical analysis is used to find similar structural components containing 5-aminosalicylic acid, or metabolized into similar active substances in vivo.
Although 5-aminosalicylic acid is not detailed in "Tiangong Kaiwu", traditional medical practice may find its application prototype, and use natural plant compounds to relieve intestinal inflammation-related diseases, laying the foundation for the development of later medicine.

5-Amino-2-hydroxybenzoic acid, also known as o-aminosalicylic acid, is an organic compound. Its physical properties are as follows:
Looking at its properties, it usually appears white to light yellow crystalline powder under normal circumstances. This color state is similar to the purity of early winter snow, and the yellowish color of light autumn leaves, giving people a sense of simplicity and purity visually.
As for the melting point, it is about 144-146 ° C. When the temperature gradually rises, the compound is like ice and snow meeting warm sun, gradually melting from the solid state to the liquid state, completing the transformation of the state. The characteristics of the melting point, like the identification of its identity, provide an important basis for identifying this compound. < Br >
In terms of solubility, it is slightly soluble in cold water, but has better solubility in hot water. This characteristic is just like the choice of the wise. Cold water is like adversity, and its integration is limited; if hot water is prosperous, it can be more harmonious. In organic solvents such as ethanol and ether, it also has a certain solubility, showing mutual affinity with different solvents.
Furthermore, its density is about 1.481g/cm ³. This density value determines its floating and sinking situation in the material world. In related research and applications, it is of great significance to consider its mass and volume. The physical properties of 5-amino-2-hydroxybenzoic acid are of key value in many fields such as chemical research and pharmaceutical manufacturing, which lays the foundation for its rational application and in-depth exploration.

5-Amino-2-hydroxybenzoic acid, which can be called o-aminosalicylic acid, has many synthesis methods, each with its own advantages and disadvantages. Under the rhyme of "Tiangong Kaiwu", it is described in the text as follows:
First, salicylic acid is used as a group, and it is prepared by nitration and reduction sequence. First take salicylic acid, add nitrifying reagents in an appropriate solvent, such as mixed acid of concentrated nitric acid and concentrated sulfuric acid, and nitrate salicylic acid to obtain 5-nitro-2-hydroxybenzoic acid under temperature control and control. This step needs to be careful. Due to the violent nitrification reaction, improper temperature control can easily lead to side reactions and impure products. After that, the nitro group is reduced to an amino group by a suitable reducing agent, such as iron powder and hydrochloric acid, or by catalytic hydrogenation, and 5-amino-2-hydroxybenzoic acid is obtained. The raw materials of this method are easy to obtain, but the nitrification step requires fine operation, and the waste acid treatment is complicated.
Second, start with catechol. Catechol is first condensed with diethyl oxalate under alkali catalysis to form 2-hydroxy-3-formylbenzoate ethyl ester, and then goes through various steps such as oximation, rearrangement, and hydrolysis. When condensing, choose a suitable base, such as sodium ethyl alcohol, precisely control the temperature, and promote the reaction in the desired direction. Oximation uses hydroxylamine as an agent, and the target product is hydrolyzed under suitable conditions for rearrangement. This method has a long route, but the reaction selectivity of each step is still possible, and a purer product can be obtained.
Third, 2-aminobenzoic acid is used as a raw material and prepared by hydroxylation. In a specific reaction system, hydroxylation reagents, such as hydrogen peroxide and catalyst, are added to introduce hydroxyl groups under mild conditions. This approach is simple, but the selectivity of the hydroxylation position needs to be fine-tuned, otherwise it is easy to produce by-products and affect the yield and purity.
All these synthetic methods have their own advantages and disadvantages. In practice, when considering factors such as raw material availability, cost, and product purity, carefully weigh and choose the best strategy to efficiently obtain 5-amino-2-hydroxybenzoic acid.

5-Amino-2-hydroxybenzoic acid, in the market, its price range is difficult to determine. The change in its price depends on many reasons.
First, it is related to the technology of production. If there is a new and clever method that can greatly increase the yield and reduce the labor-consuming materials, the price may decline. On the contrary, if the production is difficult, the required materials are expensive, and the labor is abundant, the price will be high.
Second, it depends on the state of supply and demand. If there are many applicants in the market, and there are few suppliers, the price will rise. If there are few applicants, and the supply exceeds the demand, the price will fall.
Third, the price of raw materials is also a major factor. If the price of raw materials is high, the price of this acid will not be low; if the price of raw materials decreases, the price may decrease accordingly.
Fourth, changes in the current situation, such as tax increases and decreases, trade regulations, natural and man-made disasters causing damage to the place of origin, etc., can cause prices to fluctuate.
According to common sense, the price of this acid may be between tens and hundreds of dollars per gram. However, this is only a rough number, and the actual price must be based on the current market conditions, the quality of the goods, and the amount purchased. If you want to get a definite price, you must look at the market in detail and ask the merchants to know the details.

5-Methoxy-2-hydroxybenzoic acid, the storage conditions depend on its quality and storage time. This compound is delicate in nature, and the environment needs to be carefully selected during storage to avoid unfavorable causes.
It should be placed in a cool and dry place. If the temperature is high, the molecule is easy to move, causing structural changes, and its properties are also different. In the hot sun of summer, the temperature is often more than 30 degrees. If this substance is exposed to the outside or in a warm room, it may gradually change, and its efficacy or chemical properties are not initial. Therefore, it is better to be in a cool place to keep it stable, usually below 20 degrees. < Br >
It is also necessary to avoid moisture. Water is the medium for the transformation of all things. When this thing encounters water, it may hydrolyze and cause impure quality. In the land of the south, it is wet and heavy in season and summer, and the water vapor in the air is nearly 80%. If this thing is stored here, it will not be protected by desiccant, and it will soon be deliquescent. When it is sealed with a built-in desiccant to eliminate water vapor, it can keep its quality for a long time.
And it is protected from light. Light has energy, which can promote the change of things. This thing is exposed to light, especially ultraviolet light, or has a photochemical reaction, causing the structure to break. Therefore, it is appropriate to use an opaque device, such as a brown bottle, to hide in a dark corner to avoid light disturbance.
In summary, 5-methoxy-2-hydroxybenzoic acid needs to be kept cool and protected from light to ensure its purity and stability for future use.