3-chloro-2-iodopyridine

3-Bromo-2-chloropyridine is an organic compound with the following chemical properties:
1. ** Nucleophilic Substitution Reaction **: Its halogen atom has high activity of bromine and chlorine, and is vulnerable to attack by nucleophilic reagents. Due to the electron-absorbing effect of the pyridine ring, the electron cloud density of the carbon atom connected to the halogen atom is reduced. Nucleophilic reagents such as hydroxyl negative ions (OH) and amino negative ions (NH ²) can replace bromine or chlorine atoms to form corresponding derivatives such as alcohols and amines. For example, when co-heating with sodium hydroxide aqueous solution, chlorine or bromine atoms can be replaced by hydroxyl groups to obtain hydroxyl-containing pyridine derivatives.
2. ** Electrophilic substitution reaction **: The electron cloud density distribution on the pyridine ring is uneven, the electron cloud density of the adjacent and para-sites of the nitrogen atom is relatively low, and the meta-site is relatively high. Electrophilic reagents are more inclined to attack the meta-site of the pyridine ring. However, due to the blunt action of halogen atoms bromine and chlorine, the electrophilic substitution reaction conditions are more severe than those of benzene. For example, under specific catalyst and reaction conditions, electrophilic substitution reactions such as nitrification and sulfonation can occur, and nitro and sulfonic acid groups are introduced into the meta-site of the pyridine ring.
3. ** Metal-organic reagent reaction **: 3-bromo-2-chloropyridine can react with metal-organic reagents such as Grignard reagent (RMg Halogen atoms react with metal reagents to form carbon-metal bond intermediates. This intermediate can further react with other electrophilic reagents to achieve the construction of carbon-carbon bonds, which can be used to synthesize organic compounds with complex structures. For example, react with alcaldes and ketones to generate alcohols containing different substituents.
4. ** Reduction Reaction **: Halogen atoms in molecules can be reduced and removed under the action of appropriate reducing agents. For example, in the presence of certain metal catalysts and hydrogen, bromine and chlorine atoms can be gradually reduced to hydrogen atoms to obtain pyridine derivatives.
5. ** Basic **: The pyridine ring nitrogen atom has a lone pair of electrons, which makes 3-bromo-2-chloropyridine appear alkaline and can react with acids to form salt compounds. This property can be used in organic synthesis to separate and purify the compound, or to regulate the pH of the reaction system, affecting the reaction process and selectivity.

The common synthesis methods of 3-bromo-2-iodobenzoic acid are as follows:
###With benzoic acid as the starting material
1. ** Halogenation reaction **:
- The benzoic acid is first brominated, and liquid bromine and iron powder can be used as catalysts. Under the catalysis of iron powder, the electrophilic substitution reaction of benzoic acid and liquid bromine occurs, and bromine atoms are mainly introduced at the ortho and para-positions of the benzene ring to generate a mixture of bromophthalic acid and p-bromobenzoic acid. By controlling the reaction conditions and separation means, bromobenzoic acid can be enriched. The reaction equation is:\ (C_ {7} H_ {6} O_ {2} + Br_ {2}\ xrightarrow [] {Fe} C_ {7} H_ {5} BrO_ {2} + HBr\).
- Then the o-bromobenzoic acid is iodized. Since the bromine atom is an ortho-para-site group and the carboxyl group is an meta-site group, the comprehensive action makes the iodine atom mainly introduced into the ortho-site of the bromine atom (relative to the carboxyl group is an meta-site). Generally, iodine elements, oxidants (such as hydrogen peroxide, periodate acid, etc.) can be used to react in an appropriate solvent (such as glacial acetic acid). Taking hydrogen peroxide as an example, the reaction equation is:\ (C_ {7} H_ {5} BrO_ {2} + I_ {2} + H_ {2} O_ {2}\ xrightarrow [] {HAc} C_ {7} H_ {4} BrIO_ {2} + 2H_ {2} O\).
2. ** Introduction of carboxyl groups **:
- Bromine and iodine atoms can also be introduced into the benzene ring first, and then carboxyl groups can be introduced. For example, using bromobenzene as a raw material, it reacts with lithium metal at low temperature to form phenyl lithium, and then reacts with iodine to form o-iodine bromobenzene. Then through Grignard reaction, o-iodobromobenzene reacts with magnesium to form Grignard reagent, then reacts with carbon dioxide, and finally acidifies to obtain 3-bromo-2-iodobenzoic acid. The reaction process is as follows:
-\ (C_ {6} H_ {5} Br + 2Li\ xrightarrow [] {cryogenic} C_ {6} H_ {5} Li + LiBr\)
-\ (C_ {6} H_ {5} Li + I_ {2}\ xrightarrow [] {} C_ {6} H_ {4} BrI + LiI\)
-\ (C_ {6} H_ {4} BrI + Mg\ xrightarrow [] {anhydrous ether} C_ {6} H_ {4} BrMgI\)
-\ (C_ {6} H_ {4} BrMgI + CO_ {2}\ xrightarrow [] {} C_ {6} H_ {4} BrCOOMgI \)
-\ (C_ {6} H_ {4} BrCOOMgI + H_ {3} O ^ {+}\ xrightarrow [] {} C_ {7} H_ {4} BrIO_ {2} + Mg ^ {2 +} + I ^{-}\)
###Starting with other aromatic derivatives
1. ** Starting with o-xylene **:
- Brominating of o-xylene first, selectively introducing bromine atoms at an ortho-position of methyl to produce 2-methyl-3-bromotoluene. For example, free radical substitution reactions are carried out using N-bromosuccinimide (NBS) in the presence of light or initiators. The reaction equation is:\ (C_ {8} H_ {10} + NBS\ xrightarrow [] {hv or initiator} C_ {8} H_ {9} Br + succinimide\).
- Then 2-methyl-3-bromotoluene is iodized, and under suitable conditions, an iodine atom is introduced at the ortho-position of the bromine atom to generate 2-methyl-3-bromo-4-iodotoluene.
- Finally, two methyl groups are oxidized to carboxyl groups, and a strong oxidant such as potassium permanganate can be used for oxidation to obtain 3-bromo-2-iodobenzoic acid. The reaction equation is:\ (C_ {8} H_ {7} BrIO_ {2} + 2KMnO_ {4}\ xrightarrow [] {basic condition} C_ {7} H_ {4} BrIO_ {2} + 2MnO_ {2} + 2KOH\), and then acidify to obtain the target product.

"Tiangong Kaiwu" was written by Song Yingxing in the Ming Dynasty. Its literary style is simple and plain, and it focuses on practical description. The following answers this question in a style similar to ancient proverbs:
The application of Fu 3-ammonia-2-chloropyridine is found in various fields. In the field of medicine, it is often the key raw material for synthetic drugs. Due to its special chemical structure, it can participate in many reactions to produce antibacterial, anti-inflammatory, analgesic and other drugs, which is an important help for healing diseases and saving people.
In the field of pesticides, it is also indispensable. It can be made into high-efficiency pesticides, fungicides and other pesticide products through specific processes. It can precisely act on pests, inhibit their growth and reproduction, protect crops from pests and diseases, help agricultural harvests, and be a food for people's livelihood.
In the field of materials science, it also shows its unique value. It can be used to prepare materials with special properties, such as materials with excellent stability, conductivity or optical properties. These materials are widely used in electronic devices, optical instruments, etc., to promote the progress of science and technology, and have far-reaching impact on industrial manufacturing, communications and many other industries.
In the field of organic synthesis, 3-ammonia-2-chloropyridine is an important intermediate, which can open a variety of reaction pathways and synthesize complex and special functional organic compounds. Provide possibilities for chemical research to explore new substances, expand knowledge boundaries, and lead the development trend of organic chemistry.
It can be seen that 3-ammonia-2-chloropyridine plays a key role in the fields of medicine, pesticides, materials science, organic synthesis, etc., and has far-reaching influence, contributing to the development of various industries.

Wen Jun inquired about the market price of trichlorodipyridine. This unusual substance has unique uses in the field of chemical industry, so the price depends on multiple reasons.
One is related to the price of raw materials. If the price of all kinds of raw materials required for the synthesis of the two fluctuates, the price of trichlorodipyridine will also change. If the source of raw materials is wide and the price is flat, the cost will decrease, and the market price may also decrease; on the contrary, the raw materials are scarce and expensive, and the cost is high, so the price must rise.
Second, the difficulty of production. The complexity of the synthesis process and the high technical requirements all affect the cost. If you need high-end equipment, harsh conditions, or skills are difficult to find, and the production consumes huge manpower and material resources, the price will be high; if the process is mature, the operation is convenient, and the cost is controllable, the price may be stable at a lower position.
Third, the market supply and demand. If the demand for trichlorodipyridine in various industries is strong, but the supply is limited, the demand exceeds the supply, and the price will rise; if the market demand is weak, and the output is too large, the supply will exceed the demand, and the price will fall.
Fourth, the system of policies and regulations. The chemical industry is strictly regulated, and changes in policies such as environmental protection may cause production to be limited and costs to increase, which in turn will cause price fluctuations.
However, it is difficult for me to determine the current market price, because the market situation is changing rapidly. To know the exact price, when consulting the chemical raw material trading field, manufacturer, or relevant market survey agency, he can tell you the detailed price according to the real-time situation.

"Tiangong Kaiwu" is a scientific and technological masterpiece written by Song Yingxing in the Ming Dynasty. The records of mercury (that is, mercury) involve a lot of related content. However, it is not specifically expressed in modern terms such as "What are the storage conditions of mercury-2 mines?". However, based on the knowledge and ancient relevant operating habits, the outline of mercury storage conditions can be inferred.
Mercury, which is a liquid metal at room temperature, has volatile properties and is highly toxic. Although the ancients did not have modern precise chemical understanding, they also explored certain storage methods in practice. In the era of "Tiangong Kaiwu", mercury was mostly stored in sealed containers. If you use a thick and well-sealed ceramic container, its material can prevent the volatilization of mercury to a certain extent, and it is not easy to chemically react with mercury. The sealing method is crucial, which can greatly slow down the rate of mercury volatilization into the air and reduce the harm to the environment and human body.
In addition, the storage place should be cool and dry. Due to the increased volatilization of mercury by heat, the volatilization rate of mercury increases greatly in the high temperature environment, which not only causes mercury loss, but also increases the concentration of mercury in the surrounding environment, endangering personal safety. The dry environment can avoid the contact of mercury with too much water vapor, and prevent other complex chemical reactions caused by water vapor from affecting the purity and properties of mercury.
Furthermore, the ancients may have stored mercury in a relatively stable place to avoid frequent vibration and collision. Because mercury is a liquid, vibration and collision can easily cause it to spill. Once spilled, mercury will quickly disperse into small droplets, which are extremely difficult to collect and evaporate faster, polluting the surrounding environment. Therefore, choosing a safe place is of great significance for the proper storage of mercury.