2-Pyridinecarboxylicacid, 4-chloro-

4-Alkane-2-pentenoic acid is (E) -4-methyl-2-pentenoic acid, the main use of this substance, covering the field of fragrances and pharmaceutical chemicals, with extraordinary use.
In terms of fragrances, it is widely used to prepare various edible and daily flavors with its unique odor characteristics. In edible flavors, it can create a special flavor and add a unique aroma to food, such as for baked goods, candies, etc., it can increase its aroma level, give products a unique flavor, and enhance consumers' appetite and sensory enjoyment. In daily flavors, its aroma can be integrated into perfumes, air fresheners and other products to give a fresh and unique fragrance and create a pleasant atmosphere.
In the field of medicine and chemical industry, 4-alkane-2-pentenoic acid is an important intermediate in organic synthesis. It can be converted into a variety of biologically active compounds through a series of chemical reactions and used in the synthesis of drugs. Because its structure contains active groups such as double bonds and carboxyl groups, it can participate in many organic reactions, providing a basis for the construction of complex drug molecular structures, assisting the development and production of new drugs, and playing an important role in promoting the development of the pharmaceutical field.
In summary, 4-alkane-2-pentenoic acid plays a key role in the field of fragrance and medicine and chemical industry, and plays an important role in the development of related industries.

4-Bromo-2-pentenyl acetate is an organic compound with the following physical properties:
Under normal conditions, it is mostly a colorless to light yellow transparent liquid with a clear texture, which can be seen as refracting luster under light. Smell it, or emit the smell of specific organic compounds, which is not pungent and unpleasant, but has a unique odor, which can be preliminarily judged in analysis and identification.
Its boiling point is quite critical, related to separation, purification and application. It has been experimentally determined that the boiling point is within a certain range, which is determined by intermolecular forces. Factors such as chemical bonds within the molecule and intermolecular van der Waals forces make it require specific energy to boil, giving it a specific boiling point value.
Melting point is also an important physical property. The value of the melting point of this compound can help to determine its physical state under different temperature conditions. The melting point is established. When it is lower than this temperature, it may be in a solid state and have an orderly structure; when it is higher than the melting point, it will gradually transform to a liquid state.
In terms of solubility, 4-bromo-2-pentenyl acetate has good solubility in organic solvents such as ethanol, ether, and dichloromethane. Due to the principle of "similar miscibility", its organic structure is similar to that of an organic solvent, and intermolecular forces can interact to cause it to dissolve. However, the solubility in water is poor, and water is a solvent with strong polarity. The structure difference with this compound is large, and it is difficult to form effective forces between molecules, so it is not easily soluble in water.
Density is also a significant physical property. Its density value is specific and may be different from that of water. When it comes to a mixed system, the density difference determines its position in the system. If the density is greater than that of water, it will sink at the bottom after mixing with water; if it is less than water, it will float on the water surface. This property has important applications in separation, storage, and other aspects.

4-Alkane-2-pentenoic acid, an organic compound, has unique chemical properties and is of great research value.
In terms of acidity, it is acidic because it contains a carboxyl group (-COOH). Hydrogen atoms in the carboxyl group can dissociate under certain conditions, releasing hydrogen ions (H 🥰), thus exhibiting acidic properties. This acid can neutralize with bases to form corresponding salts and water. For example, when reacted with sodium hydroxide (NaOH), a sodium salt of 4-alkane-2-pentenoic acid and water are formed, which is a typical example of acid-base neutralization. 4-Alkane-2-pentenoic acid also has a double bond (C = C) structure, which gives it the ability to add reactions. For example, it can react with hydrogen (H _ 2) under the action of a catalyst, one of the double bonds is broken, and two hydrogen atoms are added to the two carbon atoms of the double bond, resulting in saturated 4-alkane-2-pentanoic acid. It can also be added with halogens (such as bromine Br _ 2) to form bromine-containing halogenated hydrocarbons.
In addition, due to the interaction between the carboxyl group and the double bond, the hydrogen atom on the α-carbon atom connected to the carboxyl group has a certain activity, and the substitution reaction can occur under appropriate conditions. For example, under specific catalysts and reaction conditions, α-hydrogen atoms can be replaced by halogen atoms.
At the same time, 4-alkane-2-pentenoic acid can also participate in the esterification reaction. In the presence of a catalyst such as concentrated sulfuric acid and under heating conditions, its carboxyl group can react with the hydroxyl group (-OH) of alcohols to remove a molecule of water and generate corresponding ester compounds and water, which is an important reaction path for the preparation of esters.
In summary, 4-alkane-2-pentenoic acid has important applications in many fields such as organic synthesis due to its unique structure, which combines various chemical properties such as acidity, addition reaction, substitution reaction, and esterification reaction.

To prepare 4-cyano2-pentenylacetic acid, there are three methods.
First, 2-pentene is used as the beginning, and it is first added with hydrogen bromide to obtain 2-bromopentane. After sodium cyanide, 2-cyanopentane is obtained. After elimination, 2-pentenylnitrile is obtained. Subsequently, 2-pentenylnitrile reacts with formaldehyde under alkali catalysis to obtain 4-cyano2-pentenylaldehyde. Finally, the aldehyde group is reduced with lithium aluminum hydride, and then treated with dilute acid to hydrolyze the nitrile group into a carboxyl group, then 4-cyanogen-2-pentenylacetic acid is obtained. This path step is slightly complicated, but the reaction conditions of each step are relatively mild and easy to control.
Second, 3-pentanone is used as the starting material. First, 3-pentanone is heated with triethyl orthoformate and acetic anhydride for condensation reaction to obtain 2-ethoxymethylene-3-pentanone. This product is then reacted with hydroxylamine hydrochloride to convert into oxime. Subsequently, under the catalysis of acid, the oxime undergoes a Beckmann rearrangement reaction to generate the corresponding amide. Next, phosphorus pentachloride is used to treat amide to obtain nitrile. Finally, the nitrile is hydrolyzed and acidified under basic conditions, and the enol tautomerism is a stable alkenyl structure, so as to obtain 4-cyano2-pentenylacetic acid. This approach cleverly uses rearrangements and other reactions, but some of the reaction conditions are relatively harsh and the operation requirements are quite high.
Third, diethyl malonate and 1,3-dibromoacrylic are used as the starting materials. Under the action of sodium alcohol, the nucleophilic substitution reaction occurs to form an intermediate containing alkenyl groups and ester groups. After that, potassium cyanide replaces the halogen atom on one of the ester groups and introduces a cyano group. After hydrolysis and decarboxylation, 4-cyano2-pentenylacetic acid can be prepared. The raw materials of this method are relatively easy to obtain, and the reaction is relatively direct, but attention should be paid to the selective reaction and control of each group during the reaction process.

I look at your question, but I am inquiring about the price of 4-bromo-2-pentenylacetic acid in the market. However, this price is not constant and often changes for many reasons.
First, the price of raw materials is the key. If the raw material for preparing 4-bromo-2-pentenylacetic acid is difficult to obtain and the amount of production varies, the price of this chemical will also move accordingly. If raw materials are scarce and difficult to find, the price will rise; if raw materials are abundant and easy to obtain, the price may decline.
Second, the complexity and simplicity of the process also have an impact. If the preparation method requires delicate equipment, cumbersome steps, or energy consumption is huge, the cost is high, and the price is also expensive; if the manufacturing process is simple, the cost is controllable, and the price may be relatively low.
Third, the supply and demand of the city is related to the ups and downs of the price. If the market demand for this product is strong, but the supply is limited, the price will rise; if the demand is weak and the supply is excessive, the merchant will sell its goods or reduce the price.
Fourth, the price varies depending on the region. In different places, the price varies due to different transportation costs and taxes. If it is shipped from a distance, the transportation cost is high, and the price may be higher than that of the place of origin.
And the price of this chemical is also different under different purity and packaging specifications. The price of high purity is expensive, and the price of ordinary purity is low; the price is also divided between large and small packages.
Therefore, to know the exact market price of 4-bromo-2-pentenylacetic acid, you should consult chemical raw material suppliers, chemical reagent sellers, or the relevant chemical product trading platform to obtain the current actual price.