2,8-Dichloroquinoline-3-carbaldehyde

"Tiangong Kaiwu" states that ethanol, which is commonly known as alcohol, has many main uses.
One is used in medicine. Ancient healers mostly used ethanol as a disinfectant and sterilizer. Cleaning wounds with wine can prevent infection and promote healing. Such as war wounds in the army, it is often washed with wine, which can remove saprophysis and regenerate new ones and help the wounded recover. The Compendium of Materia Medica also says: "Wine is the beauty of the sky. The wine of noodle music, if you drink less, it will be combined with blood and qi, strengthen the spirit and keep out the cold, and relieve worries and rejuvenation; if you drink it hard, it will hurt the spirit and consume blood, damage the stomach and kill the essence, and generate phlegm and fire." It can be seen that in medicine, it is beneficial to health when used in moderation.
Second, it is used as a drink Since ancient times, ethanol has been favored by the world. Every New Year's festival, banquets and guests, wine is a must-have. Different production methods and raw materials produce different flavors of wine. There is a mellow rice wine made from millet, and there is a strong shochu made from sorghum. When drinking, you can write poems and express your will, or you can express your friendship, adding a lot of fun to life. Such as "Green Ant New Grains Wine, Red Clay Small Stove. Come late to the sky for snow, can you drink a cup?" It vividly depicts the warm scene of friends drinking around the stove.
Third, it is also used in industry. In some processes, ethanol can be used as a solvent to help dissolve many substances and facilitate processing. For example, in the production process of pigments, fragrances, etc., ethanol can better integrate various ingredients and improve product quality.

The synthesis of dioxypropane and ethylene covers the key techniques of chemical industry. Dioxypropane is unique and widely used, and the synthesis method is very difficult to study.
One method starts with propylene and is co-placed with chlorine in an appropriate environment to perform an addition reaction. The chlorine atom attaches to the double bond of propylene to form 1,2-dichloropropane. Then, 1,2-dichloropropane is heated with an alcohol solution of sodium hydroxide, and the chlorine atom and the adjacent hydrogen atom leave to produce dichloropropene. Then with an appropriate catalyst, such as palladium carbon, dichloropropene is reacted with hydrogen, and the chlorine atom is gradually replaced by hydrogen, and finally dioxypropane is obtained. Although this step is complicated, the raw materials are easy to obtain and the reaction is controllable. It is quite commonly used in industrial production.
Another method uses propanol as the source. First, propanol is catalyzed and oxidized to obtain acetone. Acetone and formaldehyde are in an alkaline environment, and the reaction of hydroxyaldehyde condensation is carried out to produce hydroxymethylacetone. Continued with the dehydration method, the hydroxyl group of the dehydroxymethyl group and the adjacent hydrogen form methacrylic aldehyde. Then methacrylic is oxidized to obtain methacrylic acid. Methanol is esterified with it to obtain methyl methacrylate. After a series of reactions, dioxypropane can finally be obtained. The raw materials of this method are common, but the reaction conditions are harsh, and precise temperature control and pressure control are required. The choice of catalyst is crucial.
As for ethylene, there are many ways to prepare it. The most common one is the cracking of petroleum. Hydrocarbon raw materials such as naphtha and light diesel oil are split into short URL olefins at high temperature (about 750-900 ° C) and in a short time, and ethylene is produced. This is the main way to obtain ethylene in industry, with huge output and high efficiency.
Another method of ethanol dehydration. Ethanol is heated to an appropriate temperature (about 170 ° C) with the help of catalysts such as concentrated sulfuric acid or alumina, and ethylene is obtained by removing a molecule of water in the ethanol molecule. When the raw materials are pure, the product is relatively pure, but the cost is higher, and it is mostly used in laboratory production.
Each of these synthesis methods has its own advantages and disadvantages. Chemists should choose them according to the availability of raw materials, cost calculation, and product requirements.

The physical properties of ethane are as follows:
- ** State of matter **: Under normal temperature and pressure, ethane is in a gaseous state, but it can be liquefied with a little pressure or cooling, making it easy to store and transport. At extremely low temperatures, it can also solidify into a solid state. "Tiangong Kaiwu" has a saying: "The state of all things changes with temperature and pressure. Gas can be liquid, and liquid can be solid. This is also true." The state change of ethane is also true.
- ** Color and odor **: Ethane is colorless and odorless, as if an invisible thing is hidden between heaven and earth. This characteristic makes it difficult for people to directly detect its existence by their senses, and it is necessary to use special equipment and methods to detect it. "Tiangong Kaiwu" talks about various things in the world, often describing their shapes, colors and odors, and ethane is colorless and odorless, which is its unique feature.
- ** Density **: The density of ethane is slightly smaller than that of air, about 1.356kg/m ³ (standard condition). Therefore, if it leaks in the open space, the ethane gas will slowly rise and concentrate at a high place. This characteristic is crucial for safe production and protection. In case of ethane leakage, the high area needs to be carefully guarded. " Although Tiangong Kaiwu does not directly describe the density of ethane, in the discussion of various substances, the principle of light, weight and density is often involved. The density of ethane is smaller than that of air, and it is also one of such properties.
- ** Solubility **: Ethane is extremely insoluble in water, but it can be miscible with organic solvents such as ethanol and ether. This solubility is related to the molecular structure of water and organic solvents. Water is a polar molecule, while ethane is a non-polar molecule. According to the principle of "similar miscibility", ethane is insoluble in water. Organic solvents are mostly non-polar or weakly polar, so they are miscible with ethane. " Although there is no clear record on the solubility of ethane in Tiangong Kaiwu, it is often operated according to the difference in solubility during the extraction and separation of various substances, which is the same as the solubility of ethane.

Ethane is a genus of alkanes and is a colorless and odorless gas. Its chemical properties are quite stable. Under normal temperature and pressure, it is usually difficult to react with strong acids, strong bases, strong oxidants, etc. However, under certain conditions, ethane can also exhibit several typical chemical properties.
First, ethane can undergo combustion reactions. When ethane is fully mixed with enough oxygen, it can burn violently in an open flame, generating carbon dioxide and water, and releasing a lot of heat. The chemical equation for combustion is: $2C_ {2} H_ {6} + 7O_ {2}\ stackrel {ignited }{=\!=\!=} 4CO_ {2} + 6H_ {2} O $. This reaction is widely used in life and industry, and is often used as a fuel to provide energy.
Second, ethane can undergo substitution reactions. Under light conditions, hydrogen atoms in ethane molecules can be gradually replaced by halogen atoms. For example, when ethane and chlorine are illuminated, the following series of reactions will occur: $C_ {2} H_ {6} + Cl_ {2}\ stackrel {light }{=\!=\!=} {2} H_ {5} Cl + HCl $, the generated monochloroethane can continue to react with chlorine to generate various chlorinated ethanes such as dichloroethane and trichloroethane. The substitution reaction is one of the typical reactions of alkanes, and this reaction can be used to prepare a variety of organic compounds.
Third, high temperature cracking reaction. Under the condition of high temperature and air isolation, ethane will be cracked and decomposed into ethylene and hydrogen, that is, $C_ {2} H_ {6}\ stackrel {high temperature }{=\!=\!=} C_ {2} H_ {4} + H_ {2} $. This reaction is of great significance in the petrochemical industry, and the ethylene produced is an extremely important basic chemical raw material, which is widely used in synthetic plastics, rubber, fibers and many other fields.

In today's city, the price of propane varies according to the situation, supply and demand. If you want to study the actual price, you should consider all things in detail.
In the past, propane was in the city, and its price often moved with the season. In winter, when the weather is cold, the people's need for heating increases greatly. Propane is widely used, and its price tends to rise. In summer and summer, when it needs to be slightly reduced, the price may drop.
Also found in different places, the supply and demand are different everywhere, and the price is also different. In the vicinity of the source of production, the supply is more and the demand is slow, and the price may be slightly lower; if in remote places, the transportation cost increases, the price will increase.
And the international situation is also related to the price of propane. Global supply and demand, changes in oil prices, are the cause of the impact. When oil prices rise, the production and transportation costs of propane rise, and its price rises; on the contrary, when oil prices fall, the price of propane may also fall.
In summary, the price of propane fluctuates between 3,000 yuan and 5,000 yuan per ton. However, this is only an approximate number. The actual price is often high and low due to various reasons, and it cannot be restrained. Businesspeople can obtain the price and seek the benefits of business when they are in the market, when they review the situation, observe the changes in supply and demand, and understand the international situation.