2 Chloro 4 Iodopyridine

The main use of 2-%-4-pyridone is in "Tiangong Rubber", and it is mostly used in the fields of medicine, dyeing and chemical raw materials.
The use of pyridone, with its characteristics, can be used for many purposes. Those in ancient times knew the wonders of the compatibility of pyridone, and 2-%-4-pyridone can help the disease because of its specialization. For example, in the case of poison, the family used the prescription containing this substance, applying it or taking it, with its ability to treat diseases, relieve pain, and promote the combination.
Dyeing together is also indispensable. In the past, dyeers used various media to fix the color, and 2-% 4-pyridone can be used for this purpose. The dye is immersed in the dye solution, which can interact with the dye molecules to make the dye firmly adhere to the dye. In this way, the color of the dye will last for a long time, and it will not fade for a long time. The color of the dye will increase a lot, and it will be able to show the color of the dye. It will be used for daily use by the rich and the poor.
As for chemical raw materials, their uses are more extensive. In the early days of ancient chemical industry, metallurgy, paint making, etc. can be used to help it in many ways. Metallurgy can be used as a melting aid, reducing the melting of gold, making metallurgy easier to operate, and the proposed gold quality has also been improved. Paint making can improve the performance of paint, increase its adhesion and durability, and the paint made can protect the utensils and make them new for a long time. It plays an important role in furniture, construction, etc.
Of course, 2-%-4-pyridone is not well known to many people. However, in ancient times, dyeing, chemical industry and other fields, it is important to promote the development of the industry.

The synthesis methods of 2-% -4-nitropyridine are as follows:
First, pyridine is used as the starting material. First, the nitrification of pyridine, such as the mixed acid of nitric acid and sulfuric acid, is carried out under a specific degree of nitrification. In this case, the nitro group first replaces the β position (ie, the 4-position) on the pyridine to generate 4-nitropyridine. However, the reactive phase of pyridine is low, and the reactivity may not be very ideal. It may be accompanied by the formation of nitrification byproducts at other positions. Therefore, it is necessary to precisely control the reactivity, such as the reactivity, ratio, and reactivity, in order to improve the reactivity of 4-nitropyridine.
Second, pyridine derivatives can be used. If the starting material is 2-alkyl pyridine, the first alkyl group can be used to protect the alkyl group, so as to prevent it from drying in the nitrification and reverse reaction. The same nitrification is carried out with nitrification to obtain 4-nitro-2-alkyl pyridine derivatives. Then, the specific alkyl group is removed from the alkyl group to obtain 2-alkyl-4-nitropyridine, and then the alkyl group is reduced to the atom, such as the alkyl group, to obtain 2-alkyl-4-nitropyridine. In this way, the alkyl group-preserving strategy can be used to improve the inverse property, but the step-by-step propagation requires multi-step inverse and reverse operations.
Third, the gold catalyst is used to improve the inverse strategy. For example, a pyridine derivative containing alkyl element, such as 2-pyridine, is nitrogenated in gold catalysis, such as in the presence of gold catalysis. Gold catalysis can activate the substrate and promote the substitution of nitro atoms to form 4-nitropyridine derivatives. If the 2-position atom is replaced by gold, the target 2-nitropyridine can be obtained. This method has the characteristics of high neutralization and high neutrality, but the cost of gold catalysis and catalytic recovery need to be considered.

2-% -4- is a special thing, and its physical properties are special. It is a small density. Under normal conditions, the density is less than 0.0899g/L. It is so high that it can often float in the air. And it is soluble in water, which makes it very little soluble in water. In addition, it is flammable, and the oxygen is mixed in an appropriate proportion. In case of open flame, it will burn intensely, releasing a large amount of energy, and its combustion and reaction equation is 2H 2O + O 2O + 2H 2O O.
As low as 4-O, it is a radioactive heavy metal. The density is very high, large 18.95g/cm ³, and the ground is hard. Its outer surface is white, with golden light, not in the air, easy to be oxidized, and the color is not good. The most well-known characteristic of the atom is its radioactivity, which can self-emit alpha, beta and gamma radiation. The penetration ability of alpha radiation is weak, and it can be blocked by one atom; the penetration ability of beta radiation is slightly lower, and it can penetrate a millimeter thick plate; the penetration ability of gamma radiation is low, and it needs a thick concrete or atom to be effectively blocked. It is because of the radioactivity of the atom that it plays an important role in the nuclear reactor. Through nuclear fission, it can release huge energy and use it in multiple domains such as the atom. However, its radioactivity also poses certain hazards to organisms and the environment. If accidentally exposed to the radioactivity of the atom, it may cause damage to the cells and genes of the organisms.

2-Bromo-4-nitropyridine is an organic compound with many unique chemical properties and has a wide range of uses in the field of organic synthesis.
First, the activity of nucleophilic substitution reaction is significant. The nitrogen atom on the pyridine ring has an electron-absorbing effect, which reduces the electron cloud density on the ring. The bromine atom of 2-bromo-4-nitropyridine is connected to the nitro group. Affected by the electron-absorbing action of the two, the electron cloud density of the carbon site where the bromine atom is located further decreases, and it is highly vulnerable to attack by nucleophilic reagents. For example, using sodium oxide as a nucleophilic reagent, the anion of alcohol and oxygen can attack the carbon connected to the bromine atom and replace the bromine to form corresponding ether compounds. This reaction is widely used in the construction of carbon-oxygen bonds.
Second, the reduction reaction has distinct characteristics. Its nitro group can be reduced under specific conditions. In a system composed of metals and acids, such as iron and hydrochloric acid, or under the condition of catalytic hydrogenation, the nitro group can be gradually converted into an amino group. After the nitro is reduced to an amino group, the chemical properties and reactivity of the compound change, and it can be used to prepare amino-containing pyridine derivatives. These derivatives are important intermediates in medicine, pesticides and other fields.
Third, the halogenation reactivity also has characteristics. Although the electron cloud density of the pyridine ring is low, the electrophilic substitution reaction is more difficult than that of benzene, but under appropriate conditions, the halogenation reaction of 2-bromo-4-nitropyridine can still occur. For example, under specific catalysts and reaction conditions, halogen atoms can be introduced into other positions of the pyridine ring to further enrich its chemical structure, expand its application range in organic synthesis, and provide the possibility for the synthesis of complex pyridine derivatives.
Fourth, the basicity and coordination ability cannot be ignored. The nitrogen atom of the pyridine ring has a lone pair of electrons, so that 2-bromo-4-nitropyridine has a certain alkalinity and can react with acids to form salts. At the same time, the lone pair of electrons of the nitrogen atom can be used as a ligand to form coordination compounds with metal ions. Such coordination compounds may exhibit unique catalytic properties in the field of catalysis and provide a new catalytic pathway for organic synthesis reactions.

There is a medicine of two-nitrate and four-sulphur today, what is the market value? This medicine is described in "Tiangong Kaiwu". "Tiangong Kaiwu" was written by Song Yingxing in the Ming Dynasty, and it records all kinds of technological techniques, including such drugs.
Although the book does not directly state the exact market value of the medicine of two-nitrate and four-sulphur. However, looking at the value of various materials at that time, it is inferred that the price of nitrate and sulphur is related to the difficulty of obtaining, the distance of the place of origin, and the state of supply and demand. Nitrate, or mined in soil walls or caves, is mostly from sulfur ore. If the place of origin is close and the output is abundant, the price may be slightly flat; if it is far away and difficult to mine, and there are many people in need, the price will
And at that time, such drugs were mostly used in the military, fireworks and other industries. In the military, guns and gunpowder are needed; fireworks are used during festivals and entertainment. When the military needs it, the imperial court and the government must levy widely, and the price may rise because of it. The use of civilian fireworks also increases the demand during festivals, but the scale is slightly smaller than that of the military.
At that time, the situation of commercial circulation also affects the price. In places with convenient transportation, the goods are easy to gather and disperse, and the price may be stable and reasonable; in remote places, transportation is difficult, the cost increases, and the price is also high. To sum up, in order to determine the value of the medicine of two nitrate and four sulphur in the market, it is necessary to carefully examine the situation of origin, supply and demand, transportation and so on at that time, in order to get a clue.