3-Hydroxybutyric acid is an organic compound. It is a colorless, odorless oily liquid that can be mixed with water, ethanol and ether solvents, and has unique chemical properties.
First, acidic. 3-Hydroxybutyric acid contains carboxyl (-COOH), which is an acidic functional group that can dissociate hydrogen ions (H 🥰) in water and is acidic. In case of alkali, it can be formed into salt and water. If it reacts with sodium hydroxide (NaOH), the hydrogen in the carboxyl group is combined with hydroxide (OH) to form water, and the rest is formed into a salt bound by 3-hydroxybutyrate and sodium ion (Na 🥰). The reaction formula is: $C_ {4} H_ {8} O_ {3} + NaOH\ rightarrow C_ {4} H_ {7} O_ {3} Na + H_ {2} O $.
second, it has the characteristics of a hydroxyl group. It also contains a hydroxyl group (-OH), which can cause many reactions. The esterification reaction can occur. When catalyzed by acetic acid ($CH_ {3} COOH $) and heated with concentrated sulfuric acid, the hydroxy group dehydrates and condenses with the carboxyl group of acetic acid to form an ester and water. The product is ethyl 3-hydroxybutyrate and water. The reaction formula is: $C_ {4} H_ {8} O_ {3} + CH_ {3} COOH\ underset {\ triangle} {\ overset {concentrated sulfuric acid} {\ rightleftharpoons}} C_ {6} H_ {10} O_ {4} + H_ {2} O $. And the hydroxyl group can be oxidized. Under the action of an appropriate oxidizing agent such as potassium permanganate ($KMnO_ {4} $), it can be oxidized to an aldehyde group or a carboxyl group according to different reaction conditions. If the conditions are mild, the hydroxyl group can be oxidized to an aldehyde group. If the conditions are strong, it can be further oxidized to a carboxyl group.
Furthermore, 3-hydroxybutyric acid can undergo a substitution reaction. Because the hydrogen atom in the molecule can be replaced by other atoms or groups. Such as halogen atoms ($X $, $X = Cl $, $Br $, $I $, etc.), under specific conditions, halogen can replace the hydrogen atom in the molecule that is connected to the hydroxy group. Substitution reactions occur.
In addition, 3-hydroxybutyric acid is also of great significance in the body and is one of the components of the ketone body. Under normal physiological conditions, the human body can produce a small amount and play a role in energy metabolism. However, in some pathological conditions, such as diabetic ketoacidosis, the production of 3-hydroxybutyric acid in the body increases sharply, which can cause its concentration in blood and urine to increase significantly, affecting the acid-base balance and physiological functions of the human body.

3-Hydroxybutyric acid, also known as gamma-hydroxybutyric acid, is a drug category and has no beneficial application in various legitimate fields. It is mostly used by criminals for illegal acts, which is very harmful to personal health and social order.
Guanfu's "Tiangong Kaiwu", although it contains many technical techniques in detail, 3-hydroxybutyric acid and other drugs should not be involved in any beneficial environment. 3-hydroxybutyric acid is highly addictive, and once contaminated, it is harmful to the body of the user. It can cause depression of the central nervous system, initially showing drowsiness, dizziness, nausea, vomiting, etc. For a long time, it seriously affects cardiopulmonary function and endangers life.
And at the social level, 3-hydroxybutyric acid is often involved in illegal trade and abuse, which deteriorates public security and breaks down families. Therefore, it should never be used for any so-called "application". We should be aware of its harm, strictly reject it, and keep the peace of society and personal health. In any situation, we should be vigilant against such drugs, so as not to let them flow into society and cause harm.

The synthesis of 3-hydroxybutyric acid has been around since ancient times. In the past, the warlocks of the Fang family wanted the transformation of gold and stone and the method of longevity, and they explored the transformation of various substances in the cauldron of the alchemy furnace. Although many involved falsehood, there was also no lack of exploration of the beginning of chemistry, or inadvertently, by analogy, occasionally similar to the beginning of synthesis.
In later generations, the study of matter was gradually emerging, and wise people used empirical methods to study the properties and changes of substances. Synthesis of 3-hydroxybutyric acid can be obtained by hydrolysis of corresponding esters. First take a suitable ester, put it in the kettle, add an appropriate amount of water, and add a specific catalyst. Catalyst, can promote the speed of the reaction, and itself does not participate in the change of its final product. Common catalysts include acids or bases. When an acid is used as a catalyst, hydrogen ions in the acid can polarize the ester bond, making the carbonyl carbon of the ester more positive. The oxygen atom of water is rich in electrons, so nucleophilic attack carbonyl carbon, and then after a series of proton transfer, bond fracture and recombination, the final product is 3-hydroxybutyric acid.
If a base is used as a catalyst, the hydroxyl ion of the base has strong nucleophilicity, directly attacking the carbonyl carbon of the ester to form a tetrahedral intermediate, and then the alkoxy group leaves. After the acidification step, 3-hydroxybutyric acid can also be obtained. These two methods have their own advantages and disadvantages. In the method of acid catalysis, the conditions may be milder, but the reaction rate may be slightly slower; although the alkali catalysis is fast, the follow-up treatment may need to be cautious to prevent the product from being further acted by the base and causing side reactions.
In addition, there are also those who use aldosterone as the starting material to synthesize 3-hydroxybutyric acid through multi-step reactions such as addition and redox. First, the aldosterone is added with a suitable nucleophilic reagent, the required functional group is introduced, and then the oxidation state is adjusted by oxidation or reduction, and the carbon frame and functional group of the target molecule are gradually constructed to eventually form 3-hydroxybutyric acid. Although this approach is complicated, it can be flexibly adjusted according to the availability of raw materials and the controllability of the reaction, which is an important means of synthesis.

In today's world, business conditions are unpredictable, and the price of 3-hydroxybutyric acid in the market is also variable. This is due to the intertwining of many factors such as its use, supply and demand, system and regulations, which makes it difficult to determine its price.
Looking at its uses, 3-hydroxybutyric acid is used in medicine, chemical industry and other fields. In medicine, or involved in research, it is related to disease treatment and health maintenance; in chemical industry, it can be used as a raw material to help other things synthesize. Different uses, the needs of different people, and the price fluctuates accordingly. Those who use it widely and urgently, the price may be high; those who use it narrowly and slowly, the price may be inferior.
The trend of supply and demand is also the main reason. If there are many people who produce, but there are few who want it, and the goods are in the market, the price will inevitably decline; if the production is limited, and the seekers flock, the goods are rare and expensive, and the price will rise. The weather, geographical location, human resources, capital, etc., can all affect the output; and the changes of the world and the needs of people can also move the heart of the seeker.
The difference between the production method also involves cost. Simple and efficient methods, the cost is low, and the price is also easy and cheap; complicated and difficult techniques, the cost must be high, and the price is difficult to suppress. The emergence of new technologies, often reform the system, so that the cost changes, and the price is also due to it.
Furthermore, the regulations are strictly controlled. Because of its particularity, it is related to safety and health, so the law is strict. Compliance of production and sales, the cost increases and the price rises; illegal actions, although the price is low for a while, the risk is huge, and it disrupts the market, which is not a long-term state.
To sum up, the price of 3-hydroxybutyric acid in the market changes with various factors, and it is difficult to be sure. Businesses and seekers need to judge the situation and distinguish the reasons before they can know the direction of the price and respond to changes in the market.

3-Hydroxybutyric acid has various physical properties. Its color is as pure as water, like a transparent liquid, odorless and light in taste. It often exists in a colorless and invisible state, and it is flowing at room temperature. It is slightly similar to ordinary water, but its properties are different.
Its melting point is about -90 ° C. Under this low temperature, it condenses into a solid state, and it looks like ice, crystal clear. The boiling point is between 207-208 ° C. When heated to this point, it turns into a gaseous state and rises.
The density of 3-hydroxybutyric acid is slightly heavier than that of water, about 1.101g/cm ³. If placed in water, it sinks slowly. And it has good solubility, in common solvents such as water, ethanol, ether, etc., it can be miscible with each other, as if it is in perfect harmony. Due to its molecular structure, it contains hydroxyl and carboxyl groups, which can be connected with water molecules by hydrogen bonds, so it can be evenly dispersed in water to form a uniform and stable system.
And because of its active hydroxyl and carboxyl groups in the molecule, it is chemically active and can participate in many chemical reactions. For example, it can react with alcohols to form esters and emit a unique aroma; it can react with bases to form corresponding salts, which are caused by the characteristics of functional groups in its molecules. And in the body, 3-hydroxybutyric acid is also an important metabolite, which participates in the process of energy metabolism and is related to the physiological function of the organism. Its physical properties have an impact in many fields, and it has its uses in chemical, pharmaceutical and other industries. It is a compound with unique properties.