2-(3-Bromophenyl)pyridine

"Tiangong Kaiwu" records that calamine (the main component is zinc carbonate\ (ZnCO_ {3}\)) in the process related to metal smelting, its main use is as a source of zinc for zinc smelting.
In ancient times, people mastered the technology of using calamine to smelt zinc. The general principle is: calamine will decompose under high temperature conditions, and zinc carbonate will decompose to form zinc oxide (\ (ZnO\)) and carbon dioxide (\ (CO_ {2}\)). The chemical equation is\ (ZnCO_ {3}\ stackrel {high temperature }{=\!=\!=} ZnO + CO_ {2}\ uparrow\). In the process of zinc smelting, carbon (\ (C\)) is usually added, and carbon is reductive. It will react with the generated zinc oxide to reduce the zinc in the zinc oxide. The chemical equation is\ (2ZnO + C\ stackrel {high temperature }{=\!=\!=} 2Zn + CO_ {2}\ uparrow\).
Zinc has a unique position in ancient metal smelting. The nature of zinc is more active, and the refined zinc can be used to make alloys such as brass (copper-zinc alloy). Brass has better mechanical properties than pure copper, increased hardness, more wear resistance, and to a certain extent, corrosion resistance has also improved. The utensils made by it were widely used in life and production, such as building various utensils, weapons, etc., and played an important role in the economy and military aspects of ancient society. Therefore, calamine, as an important raw material for zinc smelting, was of key significance to the development of ancient metal smelting technology and the progress of related industries.

To prepare the compound of di- (tri-hydroxymethyl) propane, there are many methods, each with its own advantages, as follows:
One is the method of aldehyde-alcohol condensation. First, n-butyraldehyde and formaldehyde are carried out in the environment of alkali catalyst. In this process, the α-hydrogen of n-butyraldehyde is activated by the action of base, and the carbonyl group of formaldehyde is added to generate 3-hydroxy-2-methylpropanaldehyde. This step requires precise control of the reaction temperature and catalyst dosage. If the temperature is too high, side reactions will occur frequently, and if it is too low, the reaction rate will be slow. Then, 3-hydroxy-2-methylpropanal is hydrogenated and reduced, and the aldehyde group is converted into a hydroxyl group, then di- (tri-hydroxymethyl) propane is obtained. The raw material of this route is easy to obtain, but the reaction steps are slightly complicated and the reaction conditions are strict.
The second is the method of disproportionation reaction. Butyraldehyde and formaldehyde are still used as raw materials, but under special catalysts and specific reaction conditions, the two undergo disproportionation reaction. Part of formaldehyde is oxidized to formic acid, while n-butyraldehyde is reduced to hydrogen, and at the same time, it is added to formaldehyde to gradually build the structure of di- (tri-hydroxymethyl) propane. The advantage of this method is that the reaction steps are relatively simple, but the requirements for catalysts are extremely high, and the product separation and purification process is also difficult.
The third is the way of transesterification reaction. First, the transesterification reaction is carried out with a suitable alcohol and an ester containing the corresponding structure. Through careful selection of reactants and catalysts, and fine regulation of reaction temperature, time and other parameters, the ester group and the alcohol hydroxyl group are exchanged, and then hydroxymethyl groups are introduced, and finally di- (tri-hydroxymethyl) propane is synthesized. The reaction conditions of this method are relatively mild, but the selection of raw materials is relatively narrow, and efficient transesterification catalysts need to be found to improve the reaction efficiency.
All these synthesis methods have advantages and disadvantages. In practical application, it is necessary to comprehensively consider the cost of raw materials, the difficulty of reaction conditions, product purity, and production scale, and carefully choose the most suitable synthesis path to achieve the goal of efficient, economical, and environmentally friendly synthesis.

The physical properties of 3-hydroxymethylglutaric acid are as follows:
This substance is mostly a crystalline solid at room temperature and has a certain melting point. Usually the melting point is between 106 and 108 ° C. When heated to this temperature range, it melts from a solid to a liquid state. This property can be used for identification and purification.
It has a certain solubility in water. Because there are hydrophilic hydroxyl and carboxyl groups in the molecule, it can form hydrogen bonds with water molecules and then dissolve. However, the solubility is not very large. With the increase of temperature, the solubility in water will increase. In organic solvents, polar organic solvents such as ethanol and acetone have greater solubility than in water. Due to the principle of similar miscibility, it interacts strongly with polar organic solvent molecules.
In appearance, pure 3-hydroxymethylglutaric acid presents a white crystal shape, with pure color, uniform texture, and a certain luster under light. From the particle morphology, the crystals are relatively regular and relatively uniform in size.
Its density has a specific value. Under standard conditions, the density is about 1.31 g/cm ³, which indicates that under the same volume, it has a slightly larger mass than water. If placed in water, it will slowly sink.
3-hydroxymethylglutaric acid also has some volatility, but the volatility is weak. Under normal temperature and pressure, only a very small amount of molecules can overcome intermolecular forces and evaporate from the solid surface into the air, but if the temperature is increased, the volatilization rate will be accelerated.

3-Hydroxybenzyl group has the following chemical properties:
This group contains a hydroxyl group and a benzyl group structure. Hydroxyl groups have active chemistry and can participate in a variety of reactions. One is a substitution reaction. The hydrogen atom in the hydroxyl group is active and can be replaced by other atoms or groups. For example, when reacting with hydrogen halide, the hydroxyl group will be replaced by halogen atoms to form halogenated hydrocarbons.
The second is an esterification reaction. Under acid catalysis, the hydroxyl group can react with carboxylic acids to remove a molecule of water to form an ester group. This reaction is commonly used in the preparation of ester compounds in organic synthesis.
The third is an oxidation reaction, and the hydroxyl group is easily oxidized. Under the action of a suitable oxidant, it can be gradually oxidized to aldehyde groups, carboxyl < Br >
The benzyl moiety also has its own characteristics. The methylene group connected to the benzene ring in the benzyl group has a certain activity of hydrogen atoms due to the influence of the benzene ring. Halogenation reactions can occur, and hydrogen atoms on the methylene can be replaced by halogen atoms under light or specific catalyst conditions. Moreover, the large π bond structure of the benzene ring makes the benzyl group as a whole stable and aromatic, and can participate in electrophilic substitution reactions, like introducing other groups on the benzene ring.
In addition, there is an interaction between the hydroxyl group and the benzyl group in the 3-hydroxybenzyl group. The electron cloud density of the benzene ring can be increased by the electron supply effect of the hydroxyl group, which affects the activity and positional selectivity of the electrophilic substitution reaction of the benzyl group part; while the benzene ring has an effect on the acidic properties of the hydroxy group, which makes it more acidic than the hydroxy group in simple fatty alcohols.

Today there are two subtracts (triminus cyanyl), what is the price in the market?
Guanfu's "Tiangong Kaiwu", when it comes to prices, it is often related to various factors. The price of this (triminus cyanyl) thing depends first on the difficulty of making it. If the method of making it is complicated, and rare materials and exquisite techniques are required, the price will be high; if it is simple to make, and all the things used are ordinary, the price will be low.
Furthermore, the supply and demand of the city is also the key. If the world's demand for (tri- cyanide) is strong, but output is limited, the supply is in short supply, the price will rise; if demand is weak, output is excessive, supply exceeds demand, and the price will fall.
And the origin is far away and the transportation is difficult, which can also affect its price. If the origin is close and the transportation is easy, the cost is not much, and the price may be close to the people; if the origin is far away, the transportation is difficult, and the freight is added, etc., the price will also increase.
And the chaos in the past and the apology in the past also have an impact on the price. The world is prosperous, all industries are prosperous, and trade circulates, and the price may be stable; if it is a troubled and desolate year, everything is difficult, and the price may fluctuate greatly. < Br >
However, only two minus (triminus cyanyl) is mentioned, without specifying what it is, and without knowing the current world conditions and market conditions, it is difficult to determine its price in the market. Only when we carefully study the method of production, supply and demand, and production and marketing can we obtain a more accurate price.