2-pyridinecarboxylic acid methyl ester

What are the main uses of 2-% glutaric anhydride? It is described in "Tiangong Kaiwu" and has a wide range of uses.
glutaric anhydride is used in the chemical industry as an important raw material for organic synthesis. It can be used to prepare polyester resins. This resin has excellent physical properties and chemical stability, and is often used in the manufacture of coatings, adhesives, composites, etc. In coatings, it can make the coating have good wear resistance, corrosion resistance and gloss, adding protection and beauty to the object; in adhesives, it can give good bonding strength and durability, so that the object is firmly connected.
In the field of medicine, glutaric anhydride also has key uses. It can be used as a pharmaceutical intermediate and participate in the synthesis process of various drugs. Drugs made from it, or have specific therapeutic effects, such as positive effects on the treatment or relief of certain diseases.
In the fragrance industry, glutaric anhydride can be used to synthesize fragrances. Because it can impart a unique aroma to fragrances, it is often used to prepare various flavors, add a pleasant fragrance to perfumes, cosmetics, food, etc., and improve the sensory quality of products.
In addition, glutaric anhydride is also used in plastic additives, lubricants and other industries. In plastic additives, it can improve the processing and physical properties of plastics; in lubricants, it can improve the lubrication effect, reduce the wear of mechanical parts, and prolong the service life of equipment.
To sum up, glutaric anhydride plays an important role in many industries such as chemicals, pharmaceuticals, and fragrances, and is indispensable to the development of various industries.

Dipentene, limonene, is a terpenoid compound widely found in nature. Its physical properties are as follows:
Looking at its properties, at room temperature and pressure, dipentene is a colorless to light yellow transparent liquid, clear and has a special lemon aroma, fresh and pleasant smell, just like the fragrance emitted by lemons, and the smell is refreshing.
When it comes to boiling point, the boiling point of dipentene is about 175-177 ° C. At this temperature, dipentene gradually changes from liquid state to gaseous state, and the molecules can break free from each other's attractive forces and escape into space.
Its melting point is about -74.3 ° C. When the temperature drops below the melting point, dipentene solidifies from liquid to solid, and the molecular movement slows down and the arrangement tends to be orderly.
The density of dipentene is small, about 0.84 g/cm ³, which is lighter than water, so if it is mixed with water, dipentene will float on the water surface, and the two layers are clear.
And dipentene is insoluble in water. Due to the characteristics of its molecular structure, it is difficult to form an effective interaction with water molecules. However, it is soluble in organic solvents such as ethanol and ether. Due to the principle of "similarity and compatibility", it has a certain similarity with the molecular structure of organic solvents and can be miscible with each other.
Furthermore, dipentene has optical activity, and there are dextrorotopes and levorotopes. Dextrorotopes exist in lemon oil, neroli oil, etc., while levorotopes exist in turpentine and other substances. Different optical isomers may have differences in some chemical reactions and biological activities.

Ethyl 2-% pentenoate is an organic compound. It has various chemical properties, which are described as follows:
First, it has the general properties of esters. Hydrolysis can occur under acid or base catalysis. When catalyzed by acid, the reaction formula is: 2-ethyl pentenoate + water $\ underset {\ triangle} {\ overset {acid} {\ rightleftharpoons}} $2-pentenoic acid + ethanol. This reaction is reversible and can reach equilibrium under moderate conditions. In alkali catalysis, the reaction is more thorough, resulting in 2-pentenoate and ethanol, such as 2-ethyl pentenoate + sodium hydroxide $\ overset {\ triangle} {\ longrightarrow} $2-sodium pentenoate + ethanol. This hydrolytic property can be used to prepare corresponding acids and alcohols in organic synthesis.
Second, it contains carbon-carbon double bonds, so it has the characteristics of olefins. Addition reactions can occur, such as addition with bromine water, to form dibromo substitutes. The reaction formula is: 2-ethyl pentenoate + $Br_2 $\ longrightarrow $2,3-ethyl dibromovalerate. This reaction can break the carbon-carbon double bond, and the bromine atom can be added to it. And it can be added with hydrogen under the action of the catalyst to obtain a saturated ester. That is, ethyl 2-pentenoate + $H_2 $\ underset {catalyst} {\ overset {\ triangle} {\ longrightarrow}} $valerate ethyl ester, which is one of the ways to prepare saturated esters.
Third, it can participate in the substitution reaction. Because the hydrogen on the carbon atom connected to the ester group in the molecule has a certain activity, it can be replaced by other atoms or groups under appropriate conditions. For example, under the action of light or a specific catalyst, it can be replaced with halogen elements to form halogenated products. < Br >
Fourth, it has a certain stability. At room temperature and pressure, if there is no specific reagent or condition to initiate, its chemical properties are relatively stable and can be stored for a certain period of time. In case of extreme conditions such as high temperature and open flame, violent reactions such as combustion may occur, because it is an organic compound and flammable.

To make ethyl 2-hydroxypropionate, there are three methods.
First, lactic acid and ethanol are used as raw materials and obtained by esterification. This is a common method. Lactic acid has active carboxyl groups and ethanol contains hydroxyl groups. Under the action of catalysts, esterification can occur. Sulfuric acid is usually used as a catalyst. Under heating conditions, the carboxyl group of lactic acid and the hydroxyl group of ethyl alcohol dehydrate and condensate to form ethyl 2-hydroxypropionate. During the reaction, attention should be paid to temperature control. If it is too high, side reactions will increase, and if it is too low, the reaction rate will be slow. And sulfuric acid is corrosive, and the post-treatment needs to be careful. The product needs to be purified through neutralization, washing with water, and distillation.
Second, acetaldehyde is used as the starting material, and 2-hydroxypropionitrile is first prepared by cyanohydration reaction, then hydrolyzed into 2-hydroxypropionic acid, and finally esterified with ethanol. Acetaldehyde and hydrocyanic acid are cyanohydrated under alkaline conditions to generate 2-hydroxypropionic nitrile. This step requires attention to control the reaction conditions, because hydrocyanic acid is highly toxic. The subsequent hydrolysis step can be carried out under acidic or alkaline conditions to convert the cyanyl group into a carboxyl group. Finally, the target product can be obtained by esterification with the same method. This route step is slightly complicated, but the raw material acetaldehyde has a wide range of sources and may have advantages in cost.
Third, ethylene oxide and ethyl propionate are used as raw materials. Ethylene oxide has a ternary ring structure and is active in nature. Under the action of basic catalyst, ethyl propionate is stripped of its α-hydrogen, forming carbon negative ions, attacking ethylene oxide to undergo ring-opening reaction, resulting in 2-hydroxypropionate ethyl ester. This reaction condition is relatively mild and the selectivity is good. However, ethylene oxide is flammable and explosive, and special attention should be paid to safety during operation. And the reaction equipment and process requirements are high to ensure the smooth progress of the reaction and the purity of the product.

For methyl hydroxy acetate, many precautions should be kept in mind during storage and transportation.
Bear the brunt of storage. This substance should be stored in a cool and ventilated warehouse. Because a cool environment can slow down the rate of its chemical change, and good ventilation can avoid the risk of its accumulation. Do not place it in a high temperature place, high temperature can easily promote its decomposition and cause accidents. The temperature of the warehouse should be controlled within a certain range to prevent danger caused by excessive temperature. And it is necessary to stay away from fire and heat sources. Open flames and hot topics are taboos. If you are not careful, it may cause ignition and explosion.
Furthermore, when storing, it should be stored separately from oxidizing agents, reducing agents, acids, alkalis, etc., and should not be mixed. This is because of its active chemical properties, and it is easy to chemically react with the above-mentioned substances, or cause serious consequences such as combustion and explosion. There are also requirements for storage containers, and it must be ensured that they are well sealed to prevent leakage. Leakage will not only cause material loss, but also accidents may occur due to contact with air, moisture, etc.
As for transportation, it should not be underestimated. Be sure to ensure that the packaging is complete and the loading is secure before transportation. Packaging materials should have good sealing and impact resistance to resist bumps and vibrations during transportation. During transportation, pay close attention to weather conditions and avoid transportation in bad weather such as high temperature and heavy rain. High temperature easily makes the properties of the substance unstable, and heavy rain may cause damage to the packaging and the material to react with water.
Transport vehicles must be equipped with the corresponding variety and quantity of fire-fighting equipment and leakage emergency treatment equipment. If a leak occurs unfortunately on the way, it can be dealt with in time to reduce the harm. The speed of the vehicle during transportation also needs to be reasonably controlled to avoid violent operations such as sudden braking and sharp turning to prevent the packaging from breaking. And transport personnel should be familiar with the characteristics of the substance and emergency treatment methods. In case of emergencies, they can respond calmly to ensure transportation safety.