5-BROMO-1H-BENZIMIDAZOLE-2-CARBOXYLIC ACID ETHYL ESTER

Ethyl ester is a common organic compound. It has special physical and chemical properties and has applications in many fields.
Looking at its physical properties, ethyl ester is a colorless and transparent liquid with a fragrant smell, similar to the fragrance of flowers and fruits, and volatile, easily dissipated in the air at room temperature. Its boiling point is about 77 ° C, the relative density is smaller than water, about 0.902, and it is insoluble with water, but it can be miscible with organic solvents such as ethanol and ether.
In terms of chemical properties, the first hydrolysis of ethyl ester. In acidic media, hydrolysis is reversible. Under the catalysis of acid, it reacts with water to form acetic acid and ethanol. This process is like a chemical change and proceeds slowly. In alkaline media, hydrolysis is more complete, because the reaction between the alkali and the hydrolyzed acid prompts the balance to shift to the right. This reaction is like an unstoppable torrent, generating acetate and ethanol.
Secondly, ethyl ester can undergo alcoholysis reaction, and new esters and alcohols can be generated by alcohol compounds. This reaction is like a change of phase, opening a new chemical pattern. In addition, due to the ester group in its structure, it can react with nucleophiles such as Grignard reagents, showing a unique chemical activity, just like the courage of strong, generating a variety of organic compounds, which play an extraordinary role in the field of organic synthesis.
Ethyl ester has the above chemical properties, so it is often used as a fragrance ingredient in the fragrance industry to enhance the fragrance; in organic synthesis, it is an important raw material and solvent to help synthesize a variety of organic products, just like a weapon in the hands of skilled craftsmen, playing an indispensable role.

The methods for making ethyl oxalate include the following.
First, oxalic acid and ethanol are used as materials, and a catalyst is added to co-heat to make esterification. Sulfuric acid is often used as a catalyst because of its good catalytic effect. However, sulfuric acid is highly corrosive, which causes heavy damage to equipment, and subsequent separation is also cumbersome. The corresponding formula is probably: oxalic acid and ethanol are catalyzed by sulfuric acid to heat ethyl oxalate and water. During operation, temperature control and material ratio need to be controlled to promote the direction of ester formation and increase the yield of ester.
Second, the acid chloride method can be used. First, oxalic acid and thionyl chloride are used to obtain oxaloyl chloride. Oxaloyl chloride has high activity and is easy to react to ethyl oxalate with ethanol. This way should be fast, and the yield can also be observed. However, thionyl chloride is toxic and corrosive, and the operation must be in a well-ventilated place, and it must be properly protected from the exhaust gas, and the environment is anti-fouling.
Third, the method of ester exchange is also feasible. Lower esters such as methyl oxalate are exchanged with ethanol under the action of a catalyst to obtain ethyl oxalate. The catalysts used are often organotin, etc. This way, the conditions are mild, the equipment is not harsh, and the raw materials are easy to obtain. However, it is necessary to constantly remove low boiling point substances in time, so that it should be moved to the side where the target ester is formed. < Br >
Fourth, enzyme catalysis is gradually emerging. Specific lipases are used as catalysts to esterify oxalic acid and ethanol under mild conditions. Enzyme catalysis has high selectivity, less side effects, pure products, and mild conditions, saving energy. However, enzymes are expensive and sensitive to the environment. They should be strictly required by the system, and their promotion is limited to a certain extent.
All kinds of production methods have advantages and disadvantages. In actual preparation, the appropriate method should be selected according to the availability of raw materials, cost, equipment conditions and product requirements.

"Tiangong Kaiwu" contains ethyl caseate, which is widely used. In the field of winemaking, ethyl caseate is the key fragrance substance, giving the wine a special aroma, making it rich in flavor and unique flavor. In Baijiu brewing, it can improve the quality of wine, increase its aroma complexity and richness, and make the wine more mellow.
In the food processing industry, it can be used as a food spice. Due to its pleasant fruity aroma and wine aroma, it can add a unique aroma to various foods and is widely used in the production of candy, beverages, ice cream, etc., to enhance the flavor of food and enhance consumer appetite.
In addition, in the fragrance industry, it is also an important raw material. With its aroma characteristics, perfumers combine it with other fragrances to create a variety of fragrances, which are used in perfumes, air fresheners and other products to impart a pleasant fragrance.
In addition, in the chemical industry, ethyl caseate may participate in some organic synthesis reactions, providing raw materials for the synthesis of other organic compounds, and has certain value in the research and production of organic synthesis chemistry. In short, ethyl caseate has important applications in winemaking, food processing, fragrances and chemicals, and has made great contributions to the development of related industries.

"Tiangong Kaiwu" has a saying: "Silk, hemp, fur, and brown in the world all have quality, so that the special color can still be used. I don't believe it if it is said that the creation of things is not laborious." Silk, hemp, fur, and brown things each have their own characteristics, and their prices in the market vary from time to time, according to quality, and also change according to supply and demand.
Today when it comes to the market price of ethyl caseate, it is difficult to say the exact number. Ethyl caseate has a fruity taste and is widely used in the fragrance and food industries. Its price is often affected by the abundance of raw materials, the simplicity of craftsmanship, and the supply and demand of the market.
If the production of raw materials such as butyric acid and ethanol is abundant, the price is relatively inexpensive, and the process of preparing ethyl caseate is advanced and the cost is reduced, the price of ethyl caseate in the market may also decrease. And if the market demand for it is strong, the supply is in short supply, and the price will tend to rise.
Looking at the changes in the market in the past, the price of ethyl caseate often fluctuates. In a good year, if the raw materials are sufficient, the price may be in the tens of yuan per kilogram; if the raw materials are not harvested, or the production is reduced due to changes in the process, the price may jump to more than 100 yuan per kilogram.
There is no constant price in the market, and there are high and low prices. Businesspeople move according to the times, observe the changes in the Therefore, in order to know the exact market price of ethyl caseate, it is necessary to study the raw material market, process progress, and market supply and demand in real time to obtain an accurate number.

In "Tiangong Kaiwu", ethyl caseate is the aroma component of wine, and its storage conditions are quite exquisite.
Ethyl caseate should be placed in a cool place. High temperature can easily cause its chemical properties to change, accelerate volatilization, dissipate aroma, and damage the flavor of wine. A cool environment can slow down the movement of molecules, maintain its stability, and retain aroma components. Ancient wine restaurants and workshops often hid wine in cellars. Because the underground temperature is constant and cool all year round, it meets the storage requirements of ethyl caseate.
also needs to be kept dry. Humid environment makes wine easily disturbed by microorganisms such as mold, causing deterioration. Moisture may react with ethyl caseate, changing its structure and properties, resulting in changes in aroma. In ancient times, most of the wine was made of pottery wine jars. The jars had a certain air permeability and could drain moisture. The mouth of the jars was tightly sealed to prevent the intrusion of external water vapor.
And light should be avoided. Light, especially strong light, contains high energy, can stimulate the photochemical reaction of ethyl caseate, change its chemical structure, and change its aroma. Therefore, the ancients often chose places to hide wine from light, such as deep cellars or dark rooms, to preserve the aroma of ethyl caseate in the wine, so that the wine became more fragrant as it aged.