Amine vs. Amide

Main Difference

The main difference between Amine and Amide is that Amines are the derivatives of ammonia that have one alkyl or an aryl group in their structure, whereas Amides are the derivatives of carboxylic acids that contain a carbonyl group attached with a nitrogen atom in their structure.

Difference Between Amine and Amide

Comparison Chart

Amine vs. Amide

Amines are derivatives of ammonia, i.e., are derived from ammonia, which are formed by replacement of one or more hydrogen atoms by alkyl or aryl groups, whereas amides are not derivatives of the ammonia rather they are derivatives from a carboxylic acid. Amines comprise a structure that contains carbon, hydrogen and, nitrogen as main elements; however, amides comprise carbon, hydrogen, nitrogen, and oxygen.

Amines do not contain a carbonyl group in their structure; however, amides have carbonyl group attached with nitrogen. Amines act more basic when subjected to a litmus test; however, amides act more acidic and have lower ph. Amines due to their structure comprising of nitrogen attached to alkyl groups are more soluble in water; on the other hand, amides are less soluble in water as their structure comprises of the carbonyl group in their structure.

Amines have lower boiling points, but amides have higher boiling points. Amines with lower molecular weight are usually liquids at room temperature due to their low boiling points, while amides having higher boiling points are solids at room temperature because of strong hydrogen bonding.

What is Amine?

Amines are derivatives of ammonia that are formed by the replacement of one or more hydrogen atoms by organic groups, which may be alkyl or aryl as they contain hydrogen bonding between its atoms in primary and secondary amines. And due to the presence of these hydrogen bonds, it makes them insoluble in water. Amines pose a characteristic ammonia type of odor normally; however, liquid amines have a fishy smell. Small aliphatic amines are greatly soluble in many solvents, but large aliphatic amines are lipophilic. Amines are bases like ammonia, but their basicity as weaker when compared with alkali metal hydroxides.

Its basicity index relies upon the electronic characteristics of the substituents. Amines are very important from a biological point of view; the breakdown of amino acids releases amines. Many neurotransmitters are also amines, including epinephrine, norepinephrine, dopamine, histamine, and serotonin.

Amines are prepared industrially by the alkylation of ammonia. The ammonia reaction with alkyl halide causes the structure or creation of amines. The amines formed can also further react with alkyl halides, which leads to the formation of distributed amine products. If this disubstituted product further reacts with an alkyl halide, it will lead to the formation of the distributed product. There are many other processes used for its formation. Some of them are Gabriel synthesis, in which potassium phthalimide is made to react with an alkyl halide, which causes the formation of N-alkyl phthalimide, which can be hydrolyzed in the presence of an aqueous solution of acids or bases into the primary amines. Other methods include the reductive alkylation of ketones, aldehydes, and reduction of nitriles. There is another method reduction of nitro compounds, which is also very important for the formation of amines.

There are three types of amines that are divided based on their alkyl or aryl groups. Primary Amines are the amine in which one alkyl group is attached to the nitrogen atom. If a methyl group is present in primary amine, it makes a primary amine and named as methylamine. Secondary Amines are the amines in which two alkyl group attaches to the nitrogen atom. Examples of secondary amines are N- ethyl -N- propyl amine, consisting of a nitrogen atom bonded to a hydrogen atom. Tertiary Amines are the amines in which one alkyl group attaches to each nitrogen atom. An example of tertiary amines is the tributylamine, in which the nitrogen atoms make the bond with three butyl groups.

Primary aromatic amines are useful as a substrate for the manufacture of the different type of compound called an azo compound. These compounds are of very bright colors such as methyl orange, direct brown 138, sunset yellow, ponceau used in dyeing industries. A large number of drugs are manufactured to emulate the action of natural amine neurotransmitters exemplified by amine drugs as in Ephedrine and phenylephrine, where these drugs are useful as decongestants. Chlorpheniramine, which is an antihistamine, helps to treat allergic disorders caused by cold insect bites and stings. Chlorpromazine is used to relieve anxiety, excitement, restlessness, or even mental disorders.

What is Amide?

Amides are the derivatives of a carboxylic acid with OH group replaced by amines or ammonia. They have high melting and boiling points because of the strong hydrogen bonding. The only methanamide is liquid at room temperature, having a melting point of 3-degree Celcius. Ethanamide is delinquent solid at room temperature, having a melting point of 82-degree Celcius. As it is delinquent, it picks up water from the atmosphere and dissolved in it; therefore, it looks wet.

The small amides are soluble in water because they can form hydrogen bonds with the water molecules around them. It requires energy to break the hydrogen bonds already present between the molecules of amides and between the molecules of water. Thus the energy is also released when the hydrogen bond formed between amide and water molecules to mix it and to make it soluble.

A lone pair of electrons is present on nitrogen, delocalized into carbonyl, forming a partial double bond between nitrogen and carbonyl carbon. A hydrogen bond is also present between hydrogen and nitrogen atoms. Amides are very weak bases. The conjugate acid of an amide has a pKa value of about 0.5. Therefore, amides do not have noticeable acid based properties in water.

There are many simple methods used for the formation of amides. The addition of ammonia in carboxylic acids as acetic acid causes the formation of amides. It is a single-step reaction, which is very slow at room temperature. As two reactants are taking part in a rate-determining reaction, so the reaction is 2nd order. Water comes out as a by-product, and the production of bond takes place between the carbonyl group of acetic acid and nitrogen of ammonia. Thus acetamide is formed.

Their classification is in three main categories based on an amino group attached to carbon atoms. Primary Amides are the amides in which the amino-group directly makes the bond with only one carbon. Secondary Amides are the amides in which an amine group makes a bond with two carbons. Tertiary Amides are the amides in which an amine group makes a direct bond with three carbons. These amides have common examples as carboxamides, phosphoramides, and sulphonamides, etc.

They are useful in the formation of drugs like Diazepam-tranquilizer, Thalidomide which is used to treat nausea in pregnant women, caused congenital disabilities such as flippers on feet and hands. Lidocaine is an anesthetic of the amide group that causes local or regional anesthesia by the intrusion of it intravenously. Oseltamivir is used to treat acute illness caused by influenza A and B. Cefotiam is an antibacterial drug used for the treatment of infections caused by bacteria. Amides are useful for the manufacture of nylon which has further use in the formation of nylon bags, ropes, carpets, clothing, tires, brushes, parachutes, etc. it can also be molded into pipes, sheats rings for the formation of valves, gears, bearings, and other useful equipment for electrical purposes.

Conclusion

Amines are the derivatives of ammonia that contain alkyl or aryl group attached to the nitrogen atom in the structure and act as basic, whereas, amides are derivatives of carboxylic acid that contain carbonyl group in their structure and act more acidic.