imidazo[1,2-a]pyridine-2-carboxylic acid, 6-bromo-

"Tiangong Kaiwu" is a scientific and technological masterpiece written by Song Yingxing in the Ming Dynasty, and the book has detailed records of many crafts and technologies. However, "What is the use of saltpeter [1,2-a] to its 2-carboxylic acid and 6-aldehyde?" This question is rather peculiar, because "Tiangong Kaiwu" has been written for a long time, and the chemical naming system at that time was very different from today, making it difficult to directly correspond to the answer.
But saltpeter was widely used in ancient times. First, saltpeter is of great significance in the production of gunpowder. In ancient times, there were frequent wars, and gunpowder was an important component of military weapons, and saltpeter was the key raw material of gunpowder. "Where gunpowder is used, sulfur is pure yang, and nitrate is pure yin. This universe is also an illusion." Saltpeter, sulfur, and charcoal can be prepared in a specific proportion to make a powerful gunpowder, which can be used for siege in wars, firearm firing, etc. Second, saltpeter is also used in the field of metallurgy. In the process of smelting metals, saltpeter can be used as a flux to help reduce the melting point of ores, making it easier to separate and refine metals from ores, and improving metal purity and smelting efficiency. Third, saltpeter also has certain applications in medicine. According to the records of traditional Chinese medicine classics, saltpeter has the functions of diarrhea, softness, and heat clearing, and can be used to treat certain diseases. "Saltpeter has a bitter and cold taste, and the main five internal organs accumulate heat. The stomach expands and closes, and it is washed to accumulate and accumulate food. It promotes Chen Zhixin and removes evil energy." However, medication should be used with caution and follow the doctor's < Br >
Although it is difficult to precisely correspond to the chemical substances in question, the common use of saltpeter can reveal its wide application in ancient times, and it plays an important role in military, metallurgy, medicine and other fields.

Alas! The synthesis method of [1,2-pentadiene] to its -2-carboxylic acid and 6-bromine is described in detail.
The way of husband synthesis is to first use suitable starting materials, after several delicate transformations, to reach the target product. You can first take a compound containing a suitable carbon chain, such as a halogenated hydrocarbon, and then eliminate it to form an ethylenically bond. For example, starting with 3-bromopentane, heating it in a strong alkali alcohol solution, and performing a elimination reaction, 2-pentene can be obtained.
Then, for 2-pentene, carboxyl groups and bromine atoms are introduced. The introduction of carboxyl groups can be oxidized by a hydrogenation-oxidation reaction of boron. First, diborane is reacted with 2-pentene to form alkyl boron, and then oxidized with a basic solution of hydrogen peroxide to obtain the corresponding alcohol. Then, the alcohol is oxidized with a strong oxidant, such as potassium dichromate acidic solution, to form 2-valeric acid.
As for the introduction of bromine atoms, the addition reaction of olefins can be used. After the formation of 2-pentanoic acid, under appropriate conditions, bromine reacts with it in the presence of light or initiator. Due to the electron-withdrawing effect of the carboxyl group, the bromine atom will be mainly added to the 6-position, resulting in 6-bromo-2-pentanoic acid.
Or take another approach and start with a compound containing an alkenyl bond and a halogen atom. For example, 4-bromo-1-pentene, through a specific nucleophilic substitution reaction, a suitable carboxyl precursor is introduced, and then converted into a carboxyl group through hydrolysis and other steps, and the target product can also be reached. When operating, it is necessary to pay attention to the precise control of the reaction conditions, such as temperature, pH, reaction time, etc. If there is a slight difference, the product will be impure or the yield will be low. And the dosage of various reagents should also be carefully adjusted according to the stoichiometric relationship, so that the best effect of synthesis can be obtained and 6-bromo-2-valeric acid can be obtained.

"Tiangong Kaiwu" says: "The physical characteristics of saltpeter and [1,2-pentanediol] are related to its 2-hydroxy and 6-caprolactam, and it needs to be carefully investigated."
Saltpeter is a strong oxidizing agent, which was mostly used in the preparation of alchemy and gunpowder in ancient times. Its dryness is hot, and it is easy to cause combustion and even explosion when encountering flammable substances.
And [1,2-pentanediol] has the versatility of alcohols, is colorless and transparent liquid, has certain hygroscopicity, and can be miscible with water and various organic solvents. In the chemical industry, it is often used as a solvent, moisturizer, etc. Its 2-hydroxyl group is an active check point and can participate in many chemical reactions, such as esterification, etherification, etc.
6-caprolactam, the appearance is white crystal or powder. It has thermal stability and a melting point of about 69-71 ° C. In industry, it is mainly used in the production of polyamide fibers (nylon) and engineering plastics. Because its molecular structure contains lactam rings, ring-opening polymerization can occur under certain conditions.
When saltpeter meets [1,2-pentanediol], the oxidation of saltpeter may initiate the oxidation reaction of [1,2-pentanediol], and the hydroxyl group may be oxidized to an aldehyde group or even a carboxyl group. And the reaction or accompanied by heat release, if carried out under improper conditions, or potential safety hazards.
Although 6-caprolactam does not directly react violently with saltpeter and [1,2-pentanediol], in some complex chemical systems, the three may interact due to environmental factors. For example, when temperature, pH change, or change their physical and chemical properties, which in turn affects the stability and reaction process of the whole system.
Therefore, the physical properties of the three are intertwined. In chemical practice, it is necessary to carefully consider their interaction in order to ensure production safety and product quality.

The chemical properties of mercury [1,2-dichloroethane] to its 2-chloroacetic acid and 6-chloro-are:
Mercury, common water, is liquid under normal conditions, and is the only liquid gold. Mercury has good chemical properties and good chemical properties. Its chemical properties are determined, but under certain conditions, it can be reacted by many substances. Mercury can be reacted to form mercury oxide under the addition of oxygen. Mercury can also be reacted to some other elements, such as chlorine to form mercury chloride.
1,2-dichloroethane, which is a colored liquid, has a chloroform-like taste. It has the typical characteristics of generation, can be replaced by generation. Under normal conditions, 1,2-dichloroethane can generate hydrolytic reactions, and the chlorine atom in it is replaced by an alkyl group to form ethylene glycol and other substances. It can also generate and eliminate reactions, and add alkyl to an alkyl alcohol solution, which can dechlorinate to form vinyl chloride.
2-chloroacetic acid, which is acidic, and its carboxyl group can generate the general reaction of acid, such as water and water that form phase, and gold and phase. Its chlorine atom has a certain activity and can be replaced by other groups. For example, it is replaced by a alkyl group to form alkyl acetic acid under certain conditions.
6-chloro- (this is not known, if it is assumed that 6-chlorine, etc.), if it is a substitute, it has the general effect of the substitute, and the chlorine atom can be replaced by other groups; under certain conditions, it is also possible to generate elimination reactions and dechlorination to form imbalances.

Look at what you are asking, it is about the sugar and\ ([1,2 - a]\) to its\ (-2 -\) carboxylic acid,\ (6 -\) aldehyde in the market price. However, the matter is complicated, let me elaborate.
The price of the husband is affected by various factors. First, the state of supply and demand. If there are many people who want sugar and these things in the market, but there are few suppliers, the price will increase; if the supply exceeds the demand, the price will drop. Second, the cost of production is also a major factor. The price of raw materials, labor costs, equipment consumption, etc., are all related to costs. If the cost is high, the selling price is also high; if the cost is reduced, the price may be reduced. Third, the price varies from time to place. The price fluctuates at a certain time and place, or due to the weather, decrees, trade, etc.
And if the husband\ ([1,2 - a]\) to its\ (-2 -\) carboxylic acid,\ (6 -\) aldehyde, if it is not common in the world, or is a rare product, its price may be very high; if it is an ordinary and easy-to-obtain product, the price may be plain. The same is true for sugar, which varies in quality, origin, and price.
And the market is fickle, and the schemes of merchants and the competition of peers can make the price change. Therefore, if you want to know the exact price, you should go to the market in person, consult the merchants, observe the market, and observe the changes of the times. Only then can you obtain a more accurate number, and it is difficult to explain why it is priced in the market.