4-pyridinecarboxaldehyde, 2-chloro-3-methyl-

4-Ethyl-2-bromo-3-methylpentane is an organic compound with a wide range of uses in the field of organic synthesis.
First, this compound can act as a key intermediate in the construction of complex organic molecular structures. Its unique carbon chain structure and associated specific functional groups enable chemists to further modify and expand it with the help of various organic reactions. For example, bromine atoms have good departure properties and can interact with many nucleophiles through nucleophilic substitution reactions. Nucleophiles such as alcohols and amines can replace bromine atoms, and then build new carbon-oxygen bonds, carbon-nitrogen bonds, etc., laying the foundation for the generation of different types of organic compounds, and assisting in the synthesis of complex molecules with specific biological activities or material properties.
Second, in the construction of carbon-carbon bonds, the carbon atoms connected by ethyl and methyl groups have certain reactivity due to the electronic and spatial effects of surrounding groups. It can be reacted with halogenated hydrocarbons, carbonyl compounds, etc., through methods such as Grignard reaction, to achieve the growth of carbon-carbon bonds and the expansion of molecular skeletons. For example, after it is made into Grignard reagent, it can be added with carbonyl compounds such as aldons and ketones to form alcohols, which is of great significance for building a polyfunctional carbon skeleton in organic synthesis.
Third, in the field of medicinal chemistry, 4-ethyl-2-bromo-3-methylpentane can be used as a structural fragment of a lead compound. By modifying and optimizing its structure, functional groups with specific biological activities can be introduced, or the spatial configuration of molecules can be adjusted to enhance the interaction between compounds and biological targets, improve the activity, selectivity and pharmacokinetic properties of drugs, and provide a key structural basis for the development of new drugs. Fourth, in the field of materials science, using this compound as a starting material, through subsequent reactions, polymers or functional materials with special properties can be synthesized. For example, through polymerization, it is introduced into the main chain or side chain of the polymer to endow the material with unique solubility, thermal stability, optical properties, etc., to meet the diverse needs of different fields for material properties.

The physical properties of 4-ethylhexanonitrile and 2-bromo-3-methyl-ethyl are as follows:
##4-ethylhexanonitrile
1. ** Properties **: This is a colorless to light yellow liquid, which is relatively stable at room temperature and pressure. In its molecular structure, cyano (-CN) is connected to hexyl, and ethyl is used as a substituent on hexyl.
2. ** Boiling point **: The boiling point will be affected by air pressure, and at standard atmospheric pressure, it is roughly in a certain temperature range. Due to the existence of a certain van der Waals force between molecules, including dispersion force, inducing force, etc., the relative mass of molecules and intermolecular forces determine their boiling point. Usually, the boiling point of such compounds containing nitrile groups is relatively high, and the specific value can be accurately determined by experiments.
3. ** Melting point **: Its melting point is also determined by the molecular structure and force. The presence of cyanide groups makes it possible to form a certain interaction between molecules, which affects the melting point. In the solid state, the molecules are arranged in an orderly manner, and their melting point is at a specific temperature, which is the critical temperature for a substance to transform from a solid state to a liquid state.
4. ** Solubility **: In organic solvents such as ethanol and ether, 4-ethylhexanonitrile has a certain solubility due to the principle of similar miscibility. Organic solvent molecules and 4-ethylhexanonitrile molecules can form a weak interaction, which promotes their dissolution. In water, because water is a highly polar solvent and the force between 4-ethylhexanonitrile molecules is weak, its solubility in water is small.
5. ** Density **: Density is closely related to molecular weight and molecular accumulation. The molecular weight of 4-ethylhexanitrile and the arrangement of molecules determine its density. The density value is a constant at a specific temperature and can be accurately measured by density measurement instruments.
##2-bromo-3-methyl-ethyl
1. ** Properties **: Most appear as colorless to slightly yellow liquids, and bromine atoms are connected to methyl-containing ethyl groups in the molecular structure. The introduction of bromine atoms makes the molecules have a certain polarity, and at the same time changes the interaction between molecules.
2. ** Boiling point **: Due to the relatively large mass of bromine atoms and the ability to enhance intermolecular forces, its boiling point is higher than that of similar compounds without bromine atoms. Under standard conditions, it has a specific boiling point value, which is the temperature at which a liquid boils into a gas, which is related to the energy required to overcome the interaction force between molecules.
3. ** Melting point **: The electronegativity of bromine atoms is large, which has a significant impact on intermolecular forces, which in turn affects the melting point. The solid-state time division is affected by the position of bromine atoms and methyl groups, and its melting point is the specific temperature at which a substance changes from solid to liquid.
4. ** Solubility **: In organic solvents, such as dichloromethane, chloroform, etc., due to the similar polarity and interaction between molecules, 2-bromo-3-methyl-ethyl has good solubility. In water, it is difficult to overcome strong interactions such as hydrogen bonds between water molecules due to the force between molecules and water molecules, so the solubility in water is low.
5. ** Density **: The relative mass of bromine atoms is large, which increases the molecular weight and affects the way of molecular accumulation, thus determining the density of the compound. At a specific temperature, the density is a fixed value, reflecting the mass of a substance per unit volume.

The chemical properties of 4-ethylhexanonitrile and 2-bromo-3-methyl-pentanitrile are as follows:
###Halogenated hydrocarbon characteristics
2-bromo-3-methyl-pentanitrile has halogenated hydrocarbon properties due to the bromine atom. When heated in an aqueous sodium hydroxide solution, the bromine atom will be replaced by a hydroxyl group, and a hydrolysis reaction will occur to form 2-hydroxy-3-methyl-pentanamide, which will continue to hydrolyze to form 2-hydroxy-3-methyl-pentanoic acid and ammonia. When heated in a sodium hydroxide alcohol solution, an elimination reaction occurs. The bromine atom is removed from the hydrogen atom on the adjacent carbon atom to form an unsaturated nitrile compound containing carbon-carbon double bonds.
###Nitrile group characteristics
1. ** Hydrolysis reaction **: Both 4-ethylhexanonitrile and 2-bromo-3-methyl-valeronitrile contain nitrile groups, which can be hydrolyzed under acid or base catalysis. Under acidic conditions, such as heating in an aqueous solution of sulfuric acid, the nitrile group is first hydrolyzed to amides, which can then form carboxylic acids and ammonium salts; under alkaline conditions, such as heating in an aqueous sodium hydroxide solution, carboxylate and ammonia are formed, and the corresponding carboxylic acids can be obtained after acidi ** Reduction reaction **: The two nitrile groups can be reduced to primary amines under the action of strong reducing agents such as lithium aluminum hydride. Taking 4-ethylhexanonitrile as an example, 4-ethylhexylamine is reduced by lithium aluminum hydride; 2-bromo-3-methyl-pentanonitrile is reduced to 2-bromo-3-methyl-pentamide.
3. ** Nucleophilic substitution reaction **: 2-bromo-3-methyl-pentanonitrile has high bromine atom activity and is vulnerable to attack by nucleophilic reagents. If it reacts with sodium alcohol, the bromine atom is replaced by an alkoxy group to form a corresponding ether compound; when it reacts with thiols, it forms a compound containing thioether bonds.
####Hydrocarbyl Characteristics
The hydrocarbyl moiety of 4-ethylhexanonitrile and 2-bromo-3-methyl-pentanitrile affects its physical and chemical properties. Longer carbon chain 4-ethylhexanitrile is relatively more hydrophobic, and its solubility in organic solvents may be better than that of short carbon chain 2-bromo-3-methyl-pentanitrile. The two hydrocarbon groups can undergo free radical substitution reaction. Under the action of light or initiator, the hydrogen atom on the hydrocarbon group reacts with the halogen element, and the hydrogen atom is replaced by the halogen atom.

To prepare 4-aminopyridine, 2-chloro-3-methylpyridine, the method is as follows:
First, 2-chloro-3-methylpyridine is used as the starting material, and the conversion can be achieved by aminolysis reaction. When aminolysis, suitable reaction conditions need to be selected. Generally speaking, the reaction is preferably carried out under high temperature and high pressure environment. 2-chloro-3-methylpyridine and liquid ammonia can be placed in an autoclave, an appropriate amount of catalyst is added, such as copper catalyst, etc., the temperature is raised to 150-250 ° C, and the pressure is controlled at 3-8 MPa. Under these conditions, the chlorine atom can be replaced by an amino group to form a mixture of 4-aminopyridine and 2-amino-3-methylpyridine.
Because the target product is 4-aminopyridine, subsequent separation and purification are required. The difference in physical properties between the two can be achieved. The boiling point and solubility of 4-aminopyridine and 2-amino-3-methylpyridine are slightly different. It can be separated by vacuum distillation first according to the difference in boiling point, and then the difference in solubility in different solvents can be used for recrystallization. After multiple recrystallization, a relatively pure 4-aminopyridine can be obtained.
Another strategy may be to perform functional group conversion of 2-chloro-3-methylpyridine first. For example, it is first reacted with a nucleophilic reagent to convert chlorine atoms into functional groups that are more susceptible to amino substitution, and at the same time, the position of the methyl group on the pyridine ring is properly protected to prevent it from interfering with the amino group substitution in subsequent reactions. After the introduction of suitable functional groups, the aminolysis reaction can be carried out. This process can optimize the reaction conditions so that the amino group is more inclined to replace the atom at the target position, thereby increasing the yield of 4-aminopyridine. After the reaction is completed, the protective group is removed, and then the separation and purification step can also obtain pure 4-aminopyridine.

There are four things today, the names are 4-Yang Epimedium, 2-
, 3-methyl, what is the market median price?
Hearing it, the price of various things often varies with time, place and quality. 4-Yang Epimedium, a product that uses both medicine and food, is mild in nature, and has a good effect on regulating qi and blood, dissipating cold and dampness. Its price, if the quality is good and fresh, may be worth tens of dollars per catty; dry products are also different due to processing and storage, or about a hundred dollars.
2-
Those who are brewed from water and grain, fragrant and mellow, are good in drinking. The price is very different, the usual
As for 3-methyl, it is a chemical substance with a wide range of uses, involving medicine and chemical industries. The change in its price is related to purity, supply and demand. If the purity is ordinary, it costs two or tens of dollars; if the high purity is difficult to make, the price may be several times higher, and the market fluctuates, the price will follow.
However, the market does not have a constant price. If you want to know the exact number, you should go to the market and ask the merchants in person.