3-Bromo-2-iodothiophene

3-2 The main use of the kettle and the retort is the matter of cooking the cuan. "Tiangong Wuwu", the kettle is used for cooking the cuan, and it is of the utmost importance.
The kettle is mostly used for cooking, and there are also those who use it. Its shape is like the bottom of the mouth and the bottom, like the bottom of the basin. The use of the kettle is for cooking. In ancient times, people used the kettle on the stove, added firewood to make a fire, filled the kettle with water, and the ingredients were placed in the kettle, and cooked on the fire to make the ingredients cooked. Such as cooking soup and cooking meat, all of which are in the kettle. And the capacity of the kettle is different, which can be used to meet the needs of different people.
The kettle is often used in conjunction with the kettle. It is shaped like a basin, with seven holes or holes at the bottom. The retort is placed on the kettle, the water is boiled in the kettle, the water boils and the steam is raw, the steam is rising, and the hole at the bottom of the retort is penetrated to steam the things in the retort. It is often used for steaming and steaming. In ancient times, this method was often used for cooking, and it was used for steaming out of the retort.
The two of the kettle and retort, one boiled and one steamed, formed the basic utensils of the ancient people's cooking. In the food life of the people, for thousands of years, it was necessary for the people to cook every day. It is an inescapable village house or a rich family. Using the kettle to cook the cuan can make the ingredients have their own flavor, and add more flavor to the food, which is the wisdom of the ancients. It has made great contributions to the development of food culture.

The synthesis method of 3-bromo-2-butanone is quite complicated, and the main ones are selected here, as described on the left:
First, crotonaldehyde is used as the beginning, and then obtained after bromination and hydration. Crotonaldehyde is active, and when it encounters bromine, it acts as an addition reaction. Bromine atoms are added to the carbon-carbon double bond to obtain bromocrotonaldehyde. Next, the aldehyde group is converted into a hydroxyl group by hydration, and under suitable conditions, the hydroxyl group interacts with the bromine atom in the adjacent position to remove the hydrogen bromide, and then 3-bromo-2-butanone is formed. The process of the reaction, the control of the conditions, is the key. If there is a slight difference in the pool, the product will be impure and the yield will also decrease.
Second, 2-butanone is used as the substrate and is prepared by bromination. 2-butanone and bromine can undergo α-bromide reaction under specific circumstances. In the reaction system, the introduction of suitable catalysts, such as acids or bases, can promote the reaction. During acid catalysis, the formation of enol intermediates guides the attack of bromine atoms; alkali catalysis makes the α-hydrogen of ketones more acidic and easily replaced by bromine. However, this approach also has drawbacks, and the polybrominated products are easy to produce, making it difficult to separate and purify.
Third, ethyl acetoacetate is used as the raw material and obtained by multi-step conversion. First, ethyl acetoacetate is alkylated with halogenated hydrocarbons, and a suitable hydrocarbon group is introduced. Then hydrolysis, decarboxylation and other steps are taken to generate the corresponding ketone. After bromination, 3-bromo-2-butanone can be obtained. Although there are many steps in this way, the selectivity of each step of the reaction is good, the purity of the product is quite high, but the reaction period is long and the cost is relatively high.
The above synthesis methods have their own advantages and disadvantages. Users should weigh the availability of raw materials, the level of cost, the amount of yield, and the purity of the product according to actual needs, and then choose the best one.

3% to 2% alkali, the nature is also very special. If it is high, the taste is high, and its surface is concentrated in chlorinated water. In seawater, more of this substance is contained, and the method of frying and exposing can be used to obtain refined water, which can be used for the taste of food. Its cold nature, with the ability to lower, clear and detoxify.
To 2% alkali, alkali is dry and dry, and its polycarbonate is high. For work, it can be used as a melting aid, and it can also be used in manufacturing and manufacturing. For daily use, it can remove oil stains, add less food in cooking, and it can make the grain. However, its nature is violent, and it should not be used. If you eat too much, you may lose your spleen and stomach.
In terms of the nature of things, the taste of food is bad, and the five flavors can be good, so that the taste of food is bad. The nature of alkali is dry, and when it encounters acidity, it has the effect of neutralization. When the two meet, or it starts to melt. It is cold in nature, but dry in alkali, and there is a lack of food, and the effectiveness is different.
The world uses it to make it clear. The taste is not used to make the taste beautiful; decontamination and alkali are used to make utensils bad. However, the amount needs to be low, and it is not enough. If you use it carelessly, it will harm your life. Therefore, knowing the nature of matter and making good use of it is the way of the wise.

Mercury is the second thing, and there is no need to pay attention to it when it is in the process of storage. Mercury, liquid gold, is also good in its nature and has the nature of heat, and the steam is toxic. Therefore, it is necessary to use a secret device to prevent the leakage of mercury from evaporating and escaping, and to the people around it. And it is appropriate to place it in the air and through the air, so as to reduce its speed. On the way, it must also keep its container solid, so as not to be caused by shock and collision.
, It is not easy to be destroyed, but it is also toxic. Hidden in the water, it is isolated from the tide, because the tide environment is easy to cause corrosion, and it does not damage itself or contaminate the surrounding things.
In addition, it is necessary to use appropriate packaging to prevent it from being moved and affected, and to avoid the use of food, water and other materials to prevent staining.
In addition, mercury or mercury should be clearly defined, and all the equipment hidden in the environment should be clear about the toxic objects, so that everyone who is involved can be alerted and treated with the right method. Those who operate both should use anti-toxic materials, such as gloves, masks, anti-clothing, etc. After work, they must clean themselves and avoid the retention of poisons. In addition, it is necessary to be cautious when storing mercury to ensure safety and avoid poisoning.

In today's world, the price of three sets and two sets in the city is probably uncertain, but it can be said briefly. The price of such utensils often varies depending on the quality, craftsmanship and origin.
If the quality of the materials is excellent, the materials used are all the best, or gold, or silver, or beautiful jade, or good wood, the price is high. If pure gold is used as the setting, beautiful jade is made, the craftsmanship is exquisite, the carving is delicate, the lines are smooth, and the patterns are exquisite. If three sets and two sets are placed in the market, the price is not cheap, or it can reach thousands of gold.
And if the material is second, only copper and iron are used as inlays, and miscellaneous wood is used as handles, although the craftsmanship is also considerable, the price is inferior. It may be worth hundreds of dollars.
Furthermore, if this object comes from the hands of a famous craftsman, or has a special origin, if it has been used by a noble person, or has an allusion to inheritance, its price is another matter. Even if the material is ordinary, it can also increase the price due to the involvement of celebrities and the spread of stories, or it is worth more than a few dollars. < Br >
However, in the market, there are also shoddily made three sets and two sets, with poor quality materials and rough craftsmanship. Such people, the price is only a few dozen dollars, and they are only used by the common people in daily life.