5 Bromo 2 Iodobenzaldehyde

5-Bromo-2-thiophene acetic acid is an important pharmaceutical and chemical synthesis intermediate. Although its synthesis method is not directly recorded in the classic "Tiangong Kaiwu", it can be deduced according to ancient and modern chemical principles and related traditional technological ideas.
Ancient chemical synthesis is often based on natural raw materials and simple steps. Natural substances containing thiophene structures, such as some specific plant extracts or minerals, can be found through preliminary treatment to obtain substances containing thiophene basic structure. The solution of common natural alkali substances, such as plant ash (mainly containing potassium carbonate, etc.), is co-cooked with thiophene-containing raw materials at moderate temperature and time, and the thiophene structure is initially activated by the hydrolysis or addition of alkali.
At the same time, in another place, bromine is obtained from natural bromine sources. After the seawater can be concentrated in the sun, a specific reducing agent, such as a mixed system of iron powder and acetic acid, is added to reduce the bromide salt in the seawater to bromine elemental substance, and then purified by distillation to obtain more pure bromine.
The activated thiophene substance and bromine are catalyzed by natural clay or some metal oxides under sunlight irradiation or moderate heating conditions. In this reaction, the clay or metal oxide can adsorb the reactants, promote the contact of the reaction check point, and provide energy by light or heating, so that the bromine atom replaces the hydrogen atom at the specific position of the thiophene to obtain 5-bromothiophene intermediates.
5-bromothiophene intermediates react with reagents containing acetic acid groups to introduce acetic acid groups. Traditional chemistry commonly uses acetic anhydride or acetic acid in combination with specific dehydrating agents. Take an appropriate amount of 5-bromothiophene intermediates, mix them with acetic anhydride, and use a small amount of concentrated sulfuric acid or other natural acidic minerals as catalysts to heat and reflux. Under the catalysis of concentrated sulfuric acid, the acetic acid group in acetic anhydride is connected to the thiophene ring, and another part of acetic anhydride is converted into acetic acid. After the reaction is completed, the water-soluble impurities in the reaction system are dissolved in water by traditional separation and purification methods such as water quenching, extraction, and distillation. The target product is extracted with organic solvents such as ethers, and then the The whole process simulates ancient chemical conditions and thinking. Although it is different from modern precise synthesis, it can be synthesized according to the principle of chemical essence.

Mercury, or mercury, is one of the metals, with special properties and many physical properties.
Mercury is liquid at room temperature, like flowing silver, shiny, and unique among all kinds of metals. Its texture is smooth and cool to the touch, which is very different from common solid metals.
Mercury has a high density. Compared with many common substances, the mass of mercury in the same volume is significantly heavier. Its fluidity is excellent. If it drops on a plane, it will instantly spread out, forming round mercury beads that collide with each other, like lively elves, rolling freely and difficult to converge.
Furthermore, the boiling point of mercury is low, only 357 degrees Celsius. When heated, it is easy to vaporize and turn into curling mercury vapor. This mercury vapor is colorless and odorless, but it is toxic. If inhaled carelessly, it will endanger human health.
Mercury has a freezing point of minus 39 degrees Celsius. When the temperature drops below this point, mercury changes from liquid to solid. However, solid mercury is also different from common solid metals. Its texture is more brittle, and it is easily broken when a little external force is applied.
Mercury also has a unique surface tension, which allows mercury beads to maintain a nearly perfect spherical shape on a flat surface. This property makes it effective in many experiments and technological applications. For example, in ancient alchemy, mercury was favored by alchemists due to its unique physical properties and became an indispensable raw material in the process of alchemy.

The chemical properties of 5% mercury-2-phenylmercury acetic acid are as follows:
The presence of mercury in this compound makes it toxic to a certain extent. As a heavy metal, mercury compounds are often bioaccumulative and potentially harmful. In the chemical environment, mercury ions in mercury-2-phenylmercury acetic acid can participate in some ion exchange reactions. For example, if it is in a solution system containing other anions and can form a more stable precipitation or complex with mercury ions, mercury ions may react to form a new precipitation of mercury-containing compounds.
Its organic part, that is, the 2-phenylmercury acetic acid part, has some properties of aromatic hydrocarbons because it contains a benzene ring. The benzene ring is relatively stable and can undergo electrophilic substitution reactions. For example, under suitable catalyst and reaction conditions, it can undergo halogenation reaction with halogenating agents, and halogen atoms replace hydrogen atoms on the benzene ring. At the same time, due to the carboxyl group (-COOH) in the molecule, it exhibits the properties of carboxylic acid. It is acidic and can neutralize with bases to generate corresponding carboxylate and water. If reacted with sodium hydroxide, the hydrogen ion in the carboxyl group will combine with the hydroxide ion to form 2-phenylmercury sodium acetate and water.
In addition, the compound may also undergo hydrolysis reaction under certain conditions. The chemical bond between mercury and phenyl and acetic acid groups may be broken under appropriate acid-base environment or enzyme catalysis, causing the compound to decompose into smaller molecular fragments, thereby changing its chemical structure and properties. In the field of organic synthesis, if its chemical properties can be rationally utilized, such as the reactivity of carboxyl groups, it can participate in some esterification reactions and be converted into ester derivatives with different functions, providing more possibilities for organic synthesis.

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In the realm of raw food, it is also important to eat. Its meat taste is beautiful, and it has a nourishing effect. People often use the same meat as wolfberry and mountain, which is the best way to benefit the people.
In the world of culture, it also has its special status. The ancients used it as a mascot, and in some sacrificial rituals, it is one of the offerings, which means auspiciousness, wealth, and the prayer of a better life for people.
However, the source of natural resources needs to be reasonably protected and utilized. Due to its increasing demand, wild sources are being harvested. Today's compliance can maintain the original environment and promote artificial colonization, which not only ensures its application in the field, but also reduces biological diversity, so that the human body can maintain its unique value in terms of food, food, and culture.

In Guanfu City, the price of fifth-grade agarwood and second-grade partridge-spotted porcelain is related to the thinness and quality of the goods, and it also depends on the preferences of people at the time. The situation is quite complicated.
Agarwood, the fifth-grade agarwood, its fragrance may be slightly inferior to the best products, but it also has its own unique characteristics. If its fragrance is not rich and strong, but it can emit a light and elegant flavor in the faint, and the durability of the fragrance is acceptable, and the harvest time is appropriate, and the preservation method is appropriate, without damaging its fragrance. If its origin is a place where agarwood is famous, or due to the suitable water and soil climate, the aroma of the trees is unique, it can get a good price in the city. However, the supply and demand of the city is also the key. If a group of scholars gather for a while and prefer the use of agarwood, the demand for five-grade agarwood will increase greatly, and the price will also rise; on the contrary, if the demand is low, the price may drop.
As for the second product of partridge-spotted porcelain, the color of the porcelain is like that of a partridge feather, the texture is natural, and the density is consistent. Its firing method may have been exquisite, although it has not reached the realm of the best, it is still considerable. If its fetal quality is delicate and solid, there is a clear sound of knocking, and the glaze color is uniform and bright, without flaws. And if this porcelain comes from the hands of famous kiln craftsmen, or if it is inherited, it contains the skills and culture of the past, and it can add color to it. At this time, if collectors and scholars had a soft spot for ancient porcelain and competed to buy it, and the number of such porcelain in the market was limited, the price would be high.
From this perspective, the price of fifth-grade agarwood and second-grade partridge spot porcelain in the market cannot be generalized. It depends on the quality, source, market supply and demand and many other factors intertwined to determine its value. Times change, and prices change accordingly.