Uses of Amines

What are Amines?

Amines are one of the most prolific members of the nitrogen-based organic compounds which also constitutes the indirect source of ammonia. Amines are derived by replacing one or more Hydrogen molecules from ammonia with one or the other alkyl.  As a derivative of ammonia, amines serve several practical purposes across different industries. Be it the agrochemicals industries or the pharmaceuticals markets, amines are integral to the core as well as the by-products of these industries. There are many uses of amines in our everyday lives. But, before we delve into the uses of amines, let’s understand what amines are and familiarise ourselves with its structural properties. 


Amines Structure

An organic compound, belonging to the functional group comprising a basic nitrogen atom with a lone pair, are called amines. Amines compounds mainly form hydrogen bonds as a consequence of which they are highly soluble in water and have high boiling points. Amines are basically compounds of the nitrogen group which are attached to a carbonyl within the structure. As such, Amines have the following structure:


 R-CO-NR’R”


This salient structure of amines is to a large extent responsible for the multifaceted uses of amines. Some groups of amines also form an aromatic structure which in turn reduces their alkalinity. In general, the compounds of the amine groups are less reactive than the other organic compounds by virtue of their electron donating attribute. Fundamentally, the structure of amines comprise trivalent nitrogen atoms with an unshared pair of electrons. Depending on their bonding environments, amines can further be categorised three ways. When one of the three hydrogen atoms are replaced by an alkyl or an aromatic element, the amines are called primary amines. When two of the hydrogen atoms are substituted and one hydrogen atom bonded with a nitrogen atom, such amines are called secondary amines. Finally, tertiary amines are those whose hydrogen atoms have been replaced by an organic substitute. Secondary and tertiary amines can further be divided into cyclical amines when the compound forms a ring structure. If the substituent alkyls belong to the same group, then such amines are called simple and if it is constituent of more than one group, then they are called mixed amines. The structure and propensity to replace an electron makes it appropriate for a wide range of uses of amines. 


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Physical Properties of Amines

The uses of animes majorly stem from the structure as well as the  properties of amines. In order to gauge the extent of the uses of amines, let us first assess the physical properties of amines. Being hydrogen-based compounds, amines have elevated boiling points and a substantial degree of solubility in water. However, if there are more carbon atoms present in an amine compound, then the solubility in water will decrease. Amine compounds can exist in different forms depending on the number of carbon atoms present. Amines with lesser number of carbon atoms are typically gases and have a fishy odour while amines upto three carbon atoms are in liquid form. If an amine compound has more than three carbon atoms, it will be available in the solid state. Mostly, amines are colourless but might obtain some colour when subject to atmospheric oxidation. 


Chemical Properties of Amines

The most prominent chemical properties of amines include their basic nature. The basicity of the amines increases with the increase of the alkyl groups. Amines also undergo several chemical reactions through processes like alkylation, acylation, carbylamine reactions, electrophilic substitution among others. As a source of ammonia, amines also react with nitrous acid and aryl sulfonyl chloride, the end product is mostly a yellowish oil like substance. 


Alkylation

RBH2 \[\overset{RX}{\rightarrow}\]R2NH\[\overset{RX}{\rightarrow}\]R3N\[\overset{RX}{\rightarrow}\]R4N+X-


Electrophilic Substitution

2 R2ÑH   +   E(+)   ⇆   R2NHE(+)   ⇆   R2ÑE  +   H(+) (bonded to a base)


Now that we know the structure of amines, the physical properties of amines as well as the chemical reactions it enters into, let us delve into certain examples of amines and their uses. 


Uses of Amines In Daily Life

Some Uses are:

  • One of the most common uses of amines is in gas treatment, where amines are used to remove CO2 from combustion gases. 

  • Amines are a key ingredient in the preparation of material dyes. 

  • In the textile and garments industry, amines are commonly used in the preparation of azo dyes which in turn are critical for treatment of materials like leather and nylon. 

  • It is also a rich source for solubilizing herbicides and used as emulsifiers. 

  • In the chemical processing industries, amines are used as inhibitors of corrosion in boilers and lubricating oils. 

  • Another unique use of amines is as developing agents of photographs. 


Uses of Amines In Pharmacy

Some Pharmaceutical Uses are: 

  • Amines are frequently used in morphine and Demerol which are popular pain killers. 

  • Amines are also used as solvents for antihistamine diphenhydramine which are used in Benadryl syrups. 

  • Novocaine is one drug used as an anaesthetic which is hugely dependent on amines. 

  • Amines are important sources of amino acids which regulate the vitamin levels in our bodies.

  • Amines are useful stimulants for neurotransmitters like serotonin for our bodies.

FAQ (Frequently Asked Questions)

1. What are the Most Prominent Uses of Amines?

Amines are most commonly used in the pharmaceutical industries, followed by agrochemical industries. From pain killers to decongestants, from recreational drugs like Methamphetamines and amphetamines to polyfunctional drugs like ephedrine and epinephrine and the frequently used novocaine, amines in different forms are to be found in the drug manufacturing industries. Closely following this are its usage as industrial solvents and emulsifiers in crop and water treatment.

2. What do the Markets Forecast About the Demand for Amines?

Being an ammonium-based compound, the demand for amines is projected to grow in the foreseeable future. However, the rate of growth of the primary uses of amines will decline since the share of industrial demand for tertiary amines in the agrochemical and personal care domain is likely to increase extensively in the next few years.