2-Thiophene Acetic Acid Methyl Ester

Ethyl 2-% pentanedioate, although it did not have an accurate correspondence in the era covered by Tiangong Kaizhi, it should be potentially used in chemical synthesis, pharmaceutical preparation, and fragrance preparation from the perspective of traditional technology.
In the field of chemical synthesis, it can act as a key intermediate and participate in the construction of multiple complex organic compounds. For example, it can interact with various compounds such as alcohols, aldose, and amines through specific chemical reactions to form organic molecules with more complex structures and more specific functions, providing crucial basic raw materials for the creation of chemical products such as dyes and resins.
Pharmaceutical preparation level, because of its unique chemical structure or biological activity, can be used as lead compounds, laying the foundation for the development of new drugs. After chemical modification and pharmacological screening, drugs that can treat specific diseases may be derived. For example, for some metabolic diseases, it may play an active therapeutic role by participating in the metabolic regulation pathway in the body.
Fragrance preparation category, 2-% ethyl pentanediate or due to its own special smell, skillfully matched by perfumers and integrated into fragrance formulas, adding unique flavor to perfumes, air fresheners, food fragrances, etc., enriching the aroma level and enhancing the olfactory experience of products.
In summary, although it is not specifically described in Tiangong Kaiwu, considering modern chemical knowledge and traditional process thinking, 2-% pentanedioate ethyl ester has shown significant application value and potential development prospects in many fields such as chemical engineering, medicine, and fragrances.

Ethyl 2-% pentanedioate is an organic compound with unique physicochemical properties and is widely used in the chemical and pharmaceutical fields. Its physicochemical properties are detailed as follows:
###Physical properties
1. ** Appearance **: Under normal conditions, ethyl 2-pentanedioate is a colorless to light yellow transparent liquid, clear and free of visible impurities. It is fluid in appearance and can clearly reflect the surrounding scene in a specific container.
2. ** Odor **: It emits a mild and special smell, which is not pungent and unpleasant, but is different from the common aromatic smell. Its taste is unique and can be identified by a professionally trained person.
3. ** Boiling point **: The boiling point is about 218-220 ° C. When heated to this temperature range, the substance changes from liquid to gaseous state. This property is of great significance when distilling, separating and purifying the compound. For example, in chemical production, the difference in boiling point can be used to precisely separate 2-pentanedioate ethyl ester from the mixed liquid by distillation operation.
4. ** Melting point **: Melting point is about -40 ° C, which means that at a temperature below this temperature, the substance solidifies from liquid to solid. This low temperature melting point indicates that the compound exists stably as a liquid at room temperature, and no special low temperature measures are required to maintain its liquid state during storage and transportation.
5. ** Solubility **: Soluble in most organic solvents, such as ethanol, ether, chloroform, etc. If ethyl 2-pentanedioate is mixed with ethanol in a certain proportion, it can quickly dissolve with each other to form a homogeneous solution. However, the solubility in water is limited. Due to the large proportion of hydrophobic groups in the molecular structure, the interaction with water molecules is weak.
###Chemical properties
1. ** Hydrolysis reaction **: Ethyl 2-pentanedioate can be hydrolyzed in contact with water, and the hydrolysis rate is accelerated under acidic or alkaline conditions. In acidic media, hydrolysis generates 2-pentanedioic acid and ethanol, and this reaction is reversible. Under alkaline conditions, the hydrolysis is more thorough, resulting in 2-pentanediate and ethanol. After the reaction, 2-pentanedioic acid can be obtained by acidification.
2. ** Esterification reaction **: Due to the ester group in the molecule, ethyl 2-pentanedioate can undergo ester exchange reaction with alcohols under acid catalysis to generate new esters and ethanol. If reacted with methanol, the corresponding methyl ester can be obtained. This reaction is often used in organic synthesis to prepare specific structural ester compounds.
3. ** Ketone-based reaction **: The ketone groups in the molecule have active chemical properties and can participate in a variety of reactions. For example, it can react with nucleophiles, such as with Grignard reagents, to generate corresponding alcohols. This reaction is an important method for building carbon-carbon bonds and is widely used in the synthesis of complex organic molecules.

To prepare ethyl 2-hydroxybutyrate, there are various methods. First, the esterification reaction is carried out under heating conditions with 2-hydroxybutyric acid and ethanol as materials and concentrated sulfuric acid as catalyst. The principle of this reaction is the dehydration and condensation of the carboxyl group of the acid and the hydroxyl group of the alcohol to form an ester and water. The specific operation is as follows: in a round-bottom flask, put 2-hydroxybutyric acid and ethanol in an appropriate proportion, slowly add concentrated sulfuric acid, and mix well. Connect with a reflux condensation device and heat it in an oil bath or a water bath to maintain a certain temperature so that the reaction can proceed fully. After the reaction is completed, when the system is cooled, the mixed liquid is moved into the separation funnel, washed with saturated sodium carbonate solution to remove excess acid; followed by washing with saturated salt water to reduce the solubility of the ester in water; and then dried with anhydrous magnesium sulfate to remove residual water. Finally, by distillation, the fractions with the corresponding boiling point are collected to obtain ethyl 2-hydroxybutyrate.
Second, it can be prepared by the reaction of 2-bromobutyric acid with sodium ethanol. 2-bromobutyric acid first undergoes nucleophilic substitution with ethoxy group in sodium ethanol, and the bromine ion leaves to form 2-ethoxybutyrate ethyl ester. After hydrolysis and acidification, ethyl 2-hydroxybutyrate can be obtained. During operation, in the reaction vessel, 2-bromobutyric acid is dissolved in an appropriate amount of organic solvent, such as anhydrous ethyl ether, and the ethanol solution of sodium ethyl alcohol is slowly added dropwise to control the reaction temperature and rate. After the reaction is completed, the product is purified through extraction, separation, hydrolysis, acidification and other steps.
Third, ethyl acetoacetate is used as the starting material and prepared through a series of reactions. Ethyl acetoacetate first reacts with a base to form an enolate, and then reacts with halogenated ethane to introduce ethyl group. After hydrolysis and decarboxylation, 2-butanoic acid can be obtained by reduction to 2-hydroxybutyric acid, and then esterified with ethanol to obtain 2-hydroxybutyrate ethyl ester. This process involves many reaction steps, each of which requires precise control of reaction conditions in order to achieve a higher yield.

2-%E5%99%BB%E5%90%A9%E4%B9%99%E9%85%B8%E7%94%B2%E9%85%AF is a particularly important chemical substance, and many matters must be taken into account between storage and transportation.
First, it is related to storage. This substance should be stored in a cool, dry and well-ventilated place. Avoid open flames and hot topics, which are prone to chemical changes due to heat in 2-%E5%99%BB%E5%90%A9%E4%B9%99%E9%85%B8%E7%94%B2%E9%85%AF, or cause danger. And it should be stored in isolation from oxidants, acids, alkalis, etc., to prevent mutual reaction. The storage place should be clearly marked with warning signs, so that everyone knows that it is a dangerous substance.
Second, there are many taboos when transporting. The carrier must have corresponding qualifications, and the means of transportation must ensure that it is clean, dry, and free of residual impurities to avoid reactions with 2-%E5%99%BB%E5%90%A9%E4%B9%99%E9%85%B8%E7%94%B2%E9%85%AF. During transportation, it should be protected from exposure to the sun, rain, and high temperature. When loading and unloading, the operation must be gentle, so as not to damage the packaging, because if the packaging is broken, 2-%E5%99%BB%E5%90%A9%E4%B9%99%E9%85%B8%E7%94%B2%E9%85%AF leakage, or endanger the surrounding environment and human safety.
Furthermore, whether it is storage or transportation, it is necessary to prepare emergency treatment plans and equipment. If there is a leak, start emergency measures immediately, evacuate the surrounding people, isolate the leakage area, and use appropriate treatment methods according to the amount of leakage, such as absorbing with inert materials such as sand and vermiculite, or neutralizing with suitable chemical reagents. Those engaged in 2-%E5%99%BB%E5%90%A9%E4%B9%99%E9%85%B8%E7%94%B2%E9%85%AF storage and transportation must be professionally trained, familiar with its characteristics, hazards and emergency response methods, so as to ensure the safety of storage and transportation.

In today's world, prices in the market are volatile, and it is not easy to know the market value of ethyl 2-hydroxybutyrate. This is because the market price is affected by many intertwined factors, which is difficult to hide.
First, the balance between supply and demand determines the market price. If this item is in the market, and there are many applicants and few suppliers, the price will rise; on the contrary, if the supply exceeds the demand, and there are few applicants, the price will be reduced. For example, the abundance of the agricultural period is related to the price of grain. In the year of abundance, the price will be easy; in the year of apology, the price will be expensive if there is a shortage of grain. In the production of ethyl 2-hydroxybutyrate, if the output is sharply reduced due to natural and man-made disasters and wrong craftsmanship, and there are many people in the world who use it, its price will soar like the price of rice in the old days of drought.
Second, the number of costs is also the key. To produce this product, the cost of raw materials, labor, equipment, and venues is all a cost. If the price of raw materials increases, or the cost of labor increases, the cost will be high. If the price of iron smelting casters rises, the price of iron ore rises, and the salary of craftsmen increases, how can the price of the device not rise? Similarly, the cost of 2-hydroxybutyrate ethyl ester increases, and merchants want to protect their profits, so they will raise the price in the market.
Third, the trend of the world situation cannot be ignored. Between countries, trade is regulated, tariffs are high and low, and decrees are lenient and strict, all of which are related to market value. If the two countries are friendly, trade is smooth, and taxes are light and simple, then the flow of goods is convenient, and the price may be stable; if diplomatic relations are not harmonious, barriers are high, tariffs are onerous, logistics is difficult, and prices will fluctuate.
Fourth, the advance of science and technology can also affect. New technologies can make production convenient, costs are greatly reduced, and prices are also reduced. Just like today's electronic devices, technology is new, production methods are advanced, and costs are gradually decreasing, so their prices often drop.
From this perspective, if you want to know the current market value of 2-hydroxybutyrate ethyl ester, you must carefully examine supply and demand, costs, the world situation, and technology. However, the market situation is changing rapidly, and even if you know it now, it may change very little. It is necessary to pay attention often and inquire from many parties to get a rough idea of its price.