4-iodo-3-aminopyridine

Amine groups are groups with unique chemical properties. They are active and play a key role in many chemical reactions.
Amine groups are basic, which is one of their important chemical properties. Because nitrogen atoms have lone pairs of electrons and can accept protons, they are alkaline. In aqueous solutions, amine groups can react with water to form ammonium ions and hydroxide ions. And with the different structures of amine groups, the alkalinity also varies. Generally speaking, fatty amines are more basic than aromatic amines. Such as methylamine, its alkalinity is stronger than that of aniline. The aliphatic hydrocarbon group has the electron-pushing effect, which can enhance the electron cloud density on the nitrogen atom and make it easier to accept protons; while the aromatic benzene ring has the electron-absorbing conjugation effect, which will reduce the electron cloud density on the nitrogen atom and cause the basicity to weaken. The
amino group can react with the acid to form a salt. This reaction is quite common, such as when hydrochloric acid meets methylamine, the two quickly combine to form methylamine hydrochloride. This salt is stable and has good solubility in water. The
amine group can participate in the nucleophilic substitution reaction. Under appropriate conditions, the nitrogen atom in the amine group acts as a nucleophilic agent to attack compounds containing active halogen atoms or other leaving groups. Taking halogenated hydrocarbons as an example, amine groups can replace halogen atoms to form new compounds. This reaction is widely used in the field of organic synthesis and can be used to prepare various nitrogen-containing organic compounds.
In addition, amine groups can also undergo acylation reactions. When contacted with acylating reagents such as acyl halides or acid anhydrides, the hydrogen atoms in the amine group are replaced by acyl groups to form amide compounds. Amide substances have important uses in many fields such as medicine and materials. For example, many drug molecules contain amide bonds in their structures.
Furthermore, amines also have unique behaviors based on oxidation reactions. Under the action of specific oxidants, some amine groups can be oxidized into corresponding oxidation products, such as nitro compounds, etc. This process enriches the transformation paths of organic compounds. In conclusion, the chemical properties of amine groups are rich and diverse, and they play an important role in the research and application of organic chemistry and related fields, laying the foundation for the synthesis and properties of many compounds.

Amino groups are the key constituents in various chemical synthesis processes. According to "Tiangong Kaiwu", although they were not described in the name of "amine groups" at that time, they were involved in the principle of many things.
Amine is based on the field of organic synthesis and acts as an activity check point for many reactions. It is nucleophilic and can react with many electrophilic reagents, such as halogenated hydrocarbons and acyl halides, to form new carbon-nitrogen bonds, which is essential for the construction of complex organic molecular structures. And amine groups can be converted into other functional groups through many reactions, such as oxidation to nitro groups, or reaction with acid anhydrides and carboxylic acids to form amides, etc., expanding the way of organic synthesis.
In the field of biochemistry, amine groups are also very important. Proteins are very important macromolecules in organisms, and their basic building blocks are amino acids, which contain amine groups. Amines are based on peptide bonds between amino acids, resulting in proteins with specific structures and functions. And amines are based on participating in many metabolic reactions in organisms, which are indispensable for the maintenance of life activities.
In materials science, amine groups are also useful. Using them as raw materials, a variety of polymer materials can be prepared. Such as polyamides and nylon, which are strong and wear-resistant, are widely used in textiles, engineering plastics and other fields. In addition, polymers containing amine groups can be used as surface modifiers to improve the hydrophilicity and adhesion of materials due to their reactivity.
In the field of medicine, amine groups are also frequently found. Many drug molecules contain amine structures, which may be related to the binding of drugs to targets, or affect the metabolism and distribution of drugs. Such as common antibiotics, analgesics, etc., amine groups play a key role in their pharmacological effects.

There are many methods for the synthesis of amine groups, which are described in this article.
One is the reduction of nitro compounds. Nitrobenzene is co-heated with iron filings and hydrochloric acid to obtain aniline. This is due to the interaction of iron and hydrochloric acid to produce new hydrogen, and the nitro group is then reduced to an amine group. The reaction is as follows: $C_6H_5NO_2 + 6 [H]\ xrightarrow {Fe + HCl} C_6H_5NH_2 + 2H_2O $.
The second is the aminolysis of halogenated hydrocarbons. Halogenated alkanes and excess ammonia are co-heated in ethanol solution, and halogenated atoms are replaced by ammonia to form amines. Taking bromoethane as an example, $C_2H_5Br + NH_3\ xrightarrow {C_2H_5OH} C_2H_5NH_2 + HBr $, the generated hydrobromic acid is combined with excess ammonia to synthesize ammonium bromide. However, this reaction often results in a mixture of primary, secondary, tertiary amines and quaternary ammonium salts, and it is difficult to separate.
The third is the reduction of nitriles. Nitriles are catalyzed by hydrogenation or reduction of lithium aluminum hydride to obtain primary amines. If acetonitrile is reduced with lithium aluminum hydride, $CH_3CN + 4 [H]\ xrightarrow {LiAlH_4} CH_3CH_2NH_2 $, this reaction has a high yield and good selectivity, and is often a good method for synthesizing primary amines.
The fourth is the Hoffmann degradation of amides. When the amide interacts with the base solution of sodium hypohalite, the carbonyl group of the amide group is removed to form a primary amine with one less carbon atom. Take acetamide as an example, $CH_3CONH_2 + NaOBr + 2NaOH\ xrightarrow {} CH_3NH_2 + Na_2CO_3 + NaBr + H_2O $. This reaction condition is mild and the yield can be observed.
The fifth is the Gabriel synthesis method. Phthalimide reacts with potassium hydroxide to form a salt, and then reacts with halogenated hydrocarbons to form N-alkyl phthalimide, which can be obtained by hydrolysis or hydrazinolysis. This method can effectively avoid the formation of secondary amines and tertiary amines, and is widely used in the synthesis of primary amines.

The method of processing is related to the effect of medicine and the health of people. There are also many points to pay attention to in the way of storage and transportation.
When storing, one needs to check the environment for dryness and dampness. If the medicine is placed in a humid place, it is prone to mildew and its medicinal power gradually loses. For example, the medicine of plants and trees absorbs moisture and rotts, and insects and ants also like to gather it, which destroys its essence. Therefore, it is time to choose a dry place, or use lime and other substances to absorb moisture to protect the quality of the medicine. Second, you need to be careful about changes in temperature. If it overheats, the ingredients in the medicine will evaporate and the medicinal power will decay; if it is too cold, some medicines may freeze and crack, and the shape will change, and the medicinal effect will not be at the beginning. Therefore, the place where Tibetan medicine is stored should have a moderate temperature to avoid the invasion of cold and heat. The third is related to air circulation. If it is too closed, the medicinal qi will accumulate and it will easily deteriorate; if it is over-circulated, it will be afraid that the odor will dissipate. It is necessary to grasp the moderation, so that the medicinal qi is always new without losing its character.
As for transportation, the first heavy packaging is sturdy. The medicine should be properly wrapped in wooden boxes, clay pots, etc., to prevent it from being damaged during the bumps in the road. And medicines of different medicinal properties should be placed separately, and should not be mixed and piled up. If warm and cold medicines coexist in one place, or affect each other, they will lose their original effect. Furthermore, you need to pay attention to the day of transportation, and you should not delay it for too long. Over time, the ingredients of the medicine may change, Those who are also escorted should be familiar with pharmacology, take care of them carefully, and be able to respond in time when the weather changes, etc., to ensure the integrity of the medicine. In this way, pay attention to all matters of storage and transportation, so that the concocted medicine can still have good effects when it reaches the hands of the patient, so as to benefit the common people.

Those with amino groups have their own impact on the environment and human health, and they cannot be ignored.
In terms of the environment, if compounds containing amino groups enter natural water bodies, they may cause eutrophication of water bodies. Covering such substances can be used as nutrients for microorganisms, causing them to multiply too quickly, reducing dissolved oxygen in water, and disrupting the ecological balance of aquatic organisms. If factory wastewater contains a lot of amino groups and is not properly treated, it will directly discharge rivers, algae will grow rapidly, and organisms such as fish and shrimp may die due to lack of oxygen. And amino compounds in the atmosphere, or participate in photochemical reactions, interact with other pollutants, affect air quality, and cause smog and other bad weather to intensify.
As for human health, amino groups also have two sides. An appropriate amount of amino acids is an essential nutrient for the human body. The composition of many proteins in the human body depends on the combination of amino acids. It plays an important role in human growth, repair of tissues, and regulation of physiological functions. For example, arginine, which helps in wound healing and immune regulation; tryptophan can be converted into serotonin, which is related to mood and sleep. However, if exposed improperly, it is also harmful. Some amino-containing chemicals are toxic and irritating. For example, certain aromatic amines or carcinogens, long-term exposure will increase the risk of cancer. And if inhaled in high concentrations of amino-containing gases, it can irritate the respiratory tract, cause symptoms such as cough and asthma, and even damage lung function.
Therefore, it can be known that the effects of amino groups on the environment and human health have both advantages and disadvantages. It is necessary to prevent the harm of its pollution in the environment, and to make good use of its nutritional benefits in the human body to avoid the danger of its toxicity. Only in this way can we achieve a state of harmonious coexistence.