2-Cyano-4-pyridinecarboxylic acid

The carboxyl group of the amino group is the most important functional group in the chemical compound, and its chemical properties are particularly high and rich.
Amine group, with chemical properties. Because the nitrogen atom contains solitons, it can accept molecules in the solution, and the acid can be reacted and formed. If methylamine ($CH_ {3} NH_ {2} $) is reacted to acid ($HCl $), it will form methyl chloride ($CH_ {3} NH_ {3} Cl $), which is a typical form of amine group. In addition, the amine group can be replaced by the nucleus, and the solitons of the nitrogen atom make it nuclear, which can attack molecules containing positive centers. For example, in some antibodies, the amino group can replace the antibodies of the antibodies to form new nitrogen-containing antibodies.
Carboxyl group, acidic. Because it can dissolve antibodies, the following equilibrium is established in aqueous solution: $R - COOH\ rightleftharpoons R - COO ^ {-} + H ^ {+} $. Different carboxylic acids have antibodies, and are subject to the effect of antibodies. Carboxyl groups can be antibodies to form carboxylic acid antibodies. This is a typical acid neutralization antibodies. For example, acetic acid ($CH_ {3} COOH $) antioxidates antibodies ($NaOH $) to form acetic acid ($CH_ {3} COONa $) water. Furthermore, the carboxyl group can generate esterification reaction, and under the catalysis of sulfuric acid and other catalysts, the alcohol can be reversed to produce ester water. For example, acetic acid and ethanol can be reversed to generate ethyl acetate ($CH_ {3} COOC_ {2} H_ {5} $) water. This reaction is commonly used in the synthesis of various ester compounds.
For this reason, the reaction properties of amine groups, nucleation, acidity of carboxyl groups, esterification, etc., play an important role in the synthesis, biosynthesis and other fields.

The nucleophilic substitution reaction between halogenated hydrocarbons and sodium cyanide (NaCN) occurs in an alcohol solution, and a cyano group can be introduced. The general reaction formula is: R-X + NaCN → R-CN + NaX (R represents a hydrocarbon group, X represents a halogen atom). The resulting nitrile compounds are hydrolyzed under acidic or basic conditions to obtain carboxylic acids, such as hydrolyzed under acidic conditions: R-CN + 2H 2O O + H < unk > → R-COOH + NH < unk >.
Taking the reaction of halogenated alkanes with sodium cyanide as an example, in solvents such as ethanol, cyanide negative ions (CN) attack the alpha-carbon atoms of halogenated alkanes as nucleophiles, and halogen atoms leave as leaving groups to form nitriles. For example, bromoethane reacts with sodium cyanide: CH < unk > CH < unk > Br + NaCN → CH < unk > CH < unk > CN + NaBr, and the resulting propionitrile is hydrolyzed under acidic conditions to obtain propionic acid: CH < unk > CH < unk > CN + 2H < unk > O + H < unk > → CH < unk > COOH + NH < unk >.
Hydroformylation of olefins with carbon monoxide and hydrogen under the action of a catalyst (also known as carbonyl synthesis) results in an aldehyde, which can be further oxidized to give a carboxylic acid. Taking ethylene as an example, the reaction is as follows: CH < 2 > = CH < 2 > + CO + H < 2 > → CH < 2 > CH < 2 > COOH (catalyst action). Carboxylic acids can also be prepared by oxidation of the side chains of aromatics. If the side chain of an aromatic hydrocarbon has an alpha-hydrogen atom, under the action of strong oxidants (such as potassium permanganate, potassium dichromate, etc.), regardless of the length of the side chain, it will eventually be oxidized to a carboxylic group. For example, toluene is oxidized to benzoic acid under the action of potassium permanganate acid solution: C H CH + 2KMnO + 3H ² SO → C H COOH + K ² SO + 2MnSO + 4H ² O.
The reaction of Grignard reagent with carbon dioxide is also a common method for preparing carboxylic acids. Grignard reagent (RMgX) reacts with dry ice (solid carbon dioxide) to form carboxylic acid, which is then acidified to obtain carboxylic acid. For example, bromobenzene and magnesium react in anhydrous ethyl ether to form phenylmagnesium bromide (C H MgBr), and phenylmagnesium bromide reacts with carbon dioxide and is acidified to obtain benzoic acid: C H MgBr + COOMgBr → C H COOMgBr, C H COOMgBr + H + H O → C H COOH + Mg ² + X.

Ammonia is unique in nature and has a wide range of uses. Ammonia has its uses in various fields, and it is now the domain of Jun Chen.
One is the domain of agriculture. Ammonia can make nitrogen fertilizers, such as urea, ammonium bicarbonate and the like. Nitrogen fertilizer, on which plants depend for growth, can promote the flourishing of crops stems and leaves, and the fullness of grains, which is the basis for a bumper harvest. Ammonia is synthesized into urea by reaction, which is applied in the fields to nourish crops, so that the whole grain is abundant and the people are full of food. Its contribution is great.
The second is the world of chemical industry. Ammonia is an important chemical raw material and is indispensable in the production of nitric acid. Ammonia is catalytically oxidized to form nitric oxide, which is repeated through a series of reactions to finally obtain nitric acid. Nitric acid has many uses and can be And ammonia can participate in the synthesis of a variety of nitrogen-containing compounds, which is a key position in the chemical industry chain.
Third, the refrigeration industry. Ammonia has good refrigeration performance. In the past, many cold storage and refrigerated trucks used ammonia as a refrigerant. Its boiling point is suitable, the latent heat of gasification is large, and the refrigeration effect is good. Although other refrigerants are available today, ammonia still retains a place in some large refrigeration systems due to its advantages.
Fourth, environmental protection. In wastewater treatment, ammonia can be used to adjust the pH of wastewater and help precipitate and separate harmful substances. And in the flue gas denitrification process, ammonia can react with nitrogen oxides to convert it into harmless nitrogen and water, reducing air pollutant emissions and protecting our blue sky. Therefore, ammonia plays an important role in many fields such as agriculture, chemical industry, refrigeration, and environmental protection, and is indeed an indispensable part of the world.

Today there is a question about the market price of hydroxybutanine. Hydroxybutanine, also known as threonine, is an essential amino acid for the human body and plays an important role in biological metabolism.
Its market value varies due to many reasons, one of which is related to purity. High-purity hydroxybutanine is mostly used for medicine and scientific research, and its price is high; if the purity is slightly lower, it is often used in feed and other industries, and the price is slightly cheaper. Second, it depends on supply and demand. When the market is prosperous and the supply is limited, the price will rise; if the supply exceeds the demand, the price will drop. Third, the origin and process are also affected. The cost of raw materials in different origins is different, and different production processes, energy consumption and efficiency are different, all of which affect the price.
Roughly speaking, the price of feed grade hydroxybutanine is in the tens of yuan per kilogram. For pharmaceutical grade and high purity, the price per kilogram can reach hundreds of yuan, or even higher. This is only an approximation, and the actual price must be referred to the current market situation and the negotiation between buyers and sellers.

The method of making cheese is related to the formation process of the casebase and its butyric acid, and there are many things that should be paid attention to.
Selection of the first raw materials. The quality of the casebase is related to the quality of the finished product. Pure and fresh milk must be selected, such as milk, goat milk, etc., and there is no deterioration or odor. Impurities in the milk, if not removed, will cause the formation of butyric acid to be blocked, or produce odor, bad cheese quality.
Times and temperature control. The generation of butyric acid depends on the fermentation of microorganisms, and the temperature has a huge impact on this. At the beginning of fermentation, it is necessary to maintain a warm temperature, preferably about 37 degrees. This temperature is suitable for the reproduction and metabolism of microorganisms and accelerates the generation of butyric acid. However, if the temperature is too high, the microorganisms may be in Therefore, it is necessary to monitor the temperature with an accurate tool and adjust it in a timely manner.
Furthermore, the degree of time should also be accurate. The fermentation time varies according to the type and environment of the cheese. If the time is short, the generation of butyric acid is insufficient, and the taste is not mellow; if the time is long, the butyric acid will accumulate excessively, taste sour, and lose its original taste. Those who make cheese must always observe the state of fermentation, and determine the appropriate time based on experience and skills.
Repeat, hygienic conditions should not be ignored. The whole process of making cheese should be kept clean, and the utensils used must be strictly cleaned and disinfected to avoid contamination by bacteria. Mixing bacteria, or competing for nutrients with beneficial microorganisms, can cause disorder in the production of butyric acid, and what's more, cause corruption and damage to the quality of the cheese.
The method of stirring at the end. Moderate stirring can make microorganisms fully contact with the casebase, which is conducive to the uniform formation of butyric acid. However, stirring too much, too often, or destroy the structure of the cheese, affecting the quality. Therefore, when stirring, the intensity and frequency should be controlled according to the fermentation stage and the state of the cheese.
The cheese making process, all links are interlinked, and the raw materials, temperature, time, hygiene, and stirring are all related to the production of butyric acid and the quality of the cheese. Cheese makers must use fine care and skilled skills to achieve a good product.