PHOrgChem (Lecture) | Module 10 (PART 2: REACTIONS OF AMINES, AMIDE, and NITRILES)

Acid-Base Reactions, Nucleophilic Substitution, Reaction with Aldehydes and Ketones (Schiff Bases Formation), Oxidation, and Electrophilic Aromatic Substitution (Aromatic Amines)

Reactions of AMINES

Hydrolysis, Reduction, and Formation of Nitriles

Reactions of AMIDES

Hydrolysis, and Nucleophilic Substitution

Reactions of NITRILES

Acid-Base Reactions

Amines act as bases, accepting protons (H⁺) from acids to form ammonium salts.

Ammonium Salts

ACID-BASE REACTIONS: Amines act as bases, accepting protons (H⁺) from acids to form?

Acid-Base Reactions

Amines react with hydrochloric acid to form an ammonium chloride salt

Ammonium Chloride Salt

ACID-BASE REACTIONS: Amines react with hydrochloric acid to form an?

Acid-Base Reactions

R-NH2 + HCl → R-HN3Cl

R-NH2

ACID-BASE REACTIONS: R-NH2 + HCl → R-HN3Cl

This acts as bases, when a base interacts with an acid, the base accepts protons or (H⁺) ion from the acids. This happens because the amines has a lone pair of electrons on the nitrogen atom which can grab the proton or (H⁺) ion.

HCl

ACID-BASE REACTIONS: R-NH2 + HCl → R-HN3Cl

This gives away a proton to the nitrogen in the amine, when this happens, the amine becomes positively charged turning into R-NH3, called an ammonium ion.

Ammonium Ion

ACID-BASE REACTIONS: R-NH2 + HCl → R-HN3Cl

HCl gives away a proton to the nitrogen in the amine, when this happens, the amine becomes positively charged turning into R-NH3, called an?

R-HN3Cl

ACID-BASE REACTIONS: R-NH2 + HCl → R-HN3Cl

The negatively charged chlorine from the HCl combines with the ammonium ion to form a salt, which is the?

Ammonium chloride

ACID-BASE REACTIONS: R-NH2 + HCl → R-HN3Cl

Chemical Name of R-HN3Cl

Acid-Base Reactions

The amine accepts a proton, from the acid, this turns the amine into ammonium ion, and pairs with chloride to form a salt, ammonium chloride.

Ammonium Ion

ACID-BASE REACTIONS: The amine accepts a proton, from the acid, this turns the amine into _____________, and pairs with chloride to form a salt, ammonium chloride.

Ammonium chloride

ACID-BASE REACTIONS: The amine accepts a proton, from the acid, this turns the amine into ammonium ion, and pairs with chloride to form a salt, _______________.

Bases

Amines act as ______; they accept protons, and form salts when they react with acids.

Nucleophilic Substitution

Amines are nucleophilic due to the lone pair on nitrogen and can undergo nucleophilic substitution reactions.

Alkylamines

NUCLEOPHILIC SUBSTITUTION: Amine reacting with alkyl halides to form?

Secondary Amine

NUCLEOPHILIC SUBSTITUTION: Alkyl halide react with an amine to form a?

Lone Pair

NUCLEOPHILIC SUBSTITUTION: In a nucleophilic substitution reaction, the amine uses its ________ to attack an atom that is bonded to a leaving group.

Nucleophilic Substitution

R-Cl + R-HN2 → R-NH-R + HCl

R-HN2

NUCLEOPHILIC REACTION: R-Cl + R-HN2 → R-NH-R + HCl
This part is nucleophilic, this means they have a lone pair of electrons on the nitrogen atom that they can use to react with other molecules, especially those that are electrophilic, like alkyl halides.

Electrophilic

NUCLEOPHILIC REACTION: R-Cl + R-HN2 → R-NH-R + HCl
R-HN2 (nucleophilic), this means they have a lone pair of electrons on the nitrogen atom that they can use to react with other molecules, especially those that are _________, like alkyl halides.

R-Cl

NUCLEOPHILIC REACTION: R-Cl + R-HN2 → R-NH-R + HCl

In this example, _____ is an alkyl halide, when the amine meets the alkyl halide, the lone pair of electrons on the nitrogen in the amine attacks the alkyl halide, carbon atom that is bonded to the chlorine, this is a nucleophilic attack.

Alkylamide

NUCLEOPHILIC REACTION: R-Cl + R-HN2 → R-NH-R + HCl

As a result, the chlorine leaves as chloride ion, the amine forms a new bond with the carbon atom, turning into an?

Hydrochloric Acid

NUCLEOPHILIC REACTION: R-Cl + R-HN2 → R-NH-R + HCl

This reaction results in the formation of secondary amide, and the release of __________ as a by-product.

New Amine

NUCLEOPHILIC REACTION: R-Cl + R-HN2 → R-NH-R + HCl

The amine attacks the alkyl halide with its lone pair of electrons, the chlorine atom leaves and the amine becomes bonded to the carbon forming a?

Secondary Amine

NUCLEOPHILIC REACTION: R-Cl + R-HN2 → R-NH-R + HCl

Amine replaces the chlorine atom, and becomes this as the product.

Reaction with Aldehydes and Ketones (Schiff Bases)

Amines react with carbonyl compounds like aldehydes and ketones to form Schiff bases (imines)

Schiff Bases

Amines react with carbonyl compounds like aldehydes and ketones to form?

Imines

Schiff Bases are also known as?

Imines

An amine reacts with an aldehyde to form?

Reaction with Aldehydes and Ketones (Schiff Bases Formation)

R-NH2 + R’-CHO → R-CH=N-R’ + H2O

Deprotonated

REACTION WITH ALDEHYDES AND KETONES (SCHIFF BASE FORMATION): R-NH2 + R’-CHO → R-CH=N-R’ + H2O

The oxygen from the carbonyl group is initially bonded to the carbon, but when amine attacks the carbon, the oxygen becomes ________, and leaves as water.

Water

REACTION WITH ALDEHYDES AND KETONES (SCHIFF BASE FORMATION): R-NH2 + R’-CHO → R-CH=N-R’ + H2O

The oxygen from the carbonyl group is initially bonded to the carbon, but when amine attacks the carbon, the oxygen becomes deprotonated, and leaves as?

Water

REACTION WITH ALDEHYDES AND KETONES (SCHIFF BASE FORMATION): R-NH2 + R’-CHO → R-CH=N-R’ + H2O

As a result, the product of this reaction is called an imine or schiff base, where a double bond form between the carbon and nitrogen and ______ is released as a by-product.

Reaction with Aldehydes and Ketones (Schiff Bases Formation)

The amine uses its lone pair of electrons to attack the carbonyl carbon in the aldehyde. This forms a new bond between the nitrogen and carbon, creating an imine, and water is produced as a by-product during this reaction.

Imine

The amine uses its lone pair of electrons to attack the carbonyl carbon in the aldehyde. This forms a new bond between the nitrogen and carbon, creating an _____, and water is produced as a by-product during this reaction

Aldehyde

Essentially, amines react with ______, to form schiff base or imines

Oxidation

When amines are exposed to oxygen, they can undergo?

Lose

Amines have a nitrogen atom bonded to hydrogen atoms, when oxygen is present, it can react with the amine, when the amine will _____some electrons and the oxygen will be added to the nitrogen.

Oxidation

Amines can be can undergo this reaction to form nitroso compounds, nitrites, or even ammonia under specific conditions

Nitroso Compounds, Nitrites, or Ammonia

Amines can be oxidized to form ______, ______, or even ________ under specific conditions

Nitroso Compounds

Have nitroso groups attached to it. It is the result of adding oxygen to the nitrogen of the amine.

Oxygen

Nitroso Compounds have nitroso groups attached to it. It is the result of adding ________ to the nitrogen of the amine.

Water

______ is also produced as a by-product during this oxidation—Nitroso Compounds formation

Oxidation

R-NH2 + O2 → R-NO + H2O

Nitroso Compounds

The amine reacts with oxygen, the oxygen adds to the amine, turning it into?

Aromatic Amines

These are electron-rich and can undergo electrophilic substitution reactions, halogenation or nitration.

Electron-Rich

Aromatic amines are ________ and can undergo electrophilic substitution reactions, halogenation or nitration.

Electrophilic Substitution, Halogenation, or Nitration

Aromatic Amines are electron-rich and can undergo ___________, ________, or _________.

Brominated aniline

Aniline reacts with bromine to form?

Aniline

An aromatic amine like ____ is a molecule that has a benzene ring with an amine group attached to it.

Electrophilic Aromatic Substitution (Aromatic Amines)

In this reaction, an electrophile, a molecule that seeks electrons, attacks the electron-rich benzene ring, and replaces one of the hydrogen atoms attached to it.

Electrophilic Aromatic Substitution (Aromatic Amines)

Because the amine group is electron-rich, it makes the benzene ring even more reactive to electrophiles like halogen or nitro groups.

More Reactive

ELECTROPHILIC AROMATIC SUBSTITUTION (AROMATIC AMINES): Because the amine group is electron-rich, it makes the benzene ring even ____________ to electrophiles like halogen or nitro groups.

Electrophilic Aromatic Substitution (Aromatic Amines)

C6H5-NH2 + Br2 → C6H4-Br-NH2

Electrophilic Aromatic Substitution (Aromatic Amines)

Aniline reacts with bromine, the bromine molecule is an electrophile because it is looking to accept electrons. The amine group makes the benzene more likely to react to bromine.

Bromine

Aniline reacts with bromine, the bromine molecule is an electrophile because it is looking to accept electrons. The amine group makes the benzene more likely to react to?

Attaches Itself

The bromine atom ___________ to the benzene ring, replacing the hydrogen. This results in brominated aniline. Where the bromine is now attached to the ring, and the amine group is still there.

Electrophilic Aromatic Substitution (Aromatic Amines)

The bromine atom attaches itself to the benzene ring, replacing the hydrogen. This results in brominated aniline. Where the bromine is now attached to the ring, and the amine group is still there.

Hydrolysis

Is the process where compounds react with water and break down into smaller parts, involving amides

Carboxylic acids, and Amines

Amides can be hydrolyzed (both acid and base catalyzed) to form?

Acidic Hydrolysis

R-CO-NH2 + H2O → R-COOH + NH3

Acidic Hydrolysis

In acidic conditions, when an amide reacts with water, the amide gets broken down into carboxylic acid and ammonia

Acidic Conditions

In __________, when an amide reacts with water, the amide gets broken down into carboxylic acid and ammonia

Carboxylic acid, and Ammonia

In acidic conditions, when an amide reacts with water, the amide gets broken down into?

Hydrolysis

The amide molecule reacts with water, the water helps to break down the bond between nitrogen and the carbonyl group or the carbonyl carbon.

Acidic Hydrolysis

As a result, the carbonyl carbon becomes carboxylic acid and the amine becomes ammonia.

Basic Hydrolysis

R-CO-NH2 + OH- → R-COO- + NH3

Basic Hydrolysis

In basic conditions, when an amide reacts with an hydroxide ion, it also breaks down into carboxylate ion and ammonia

Basic Conditions

In ___________, when an amide reacts with an hydroxide ion, it also breaks down into carboxylate ion and ammonia

Carboxylate Ion, and Ammonia

In basic conditions, when an amide reacts with an hydroxide ion, it also breaks down into?

Basic Hydrolysis

The amide molecule reacts with the hydroxide ion, the hydroxide ion breaks the bond between the nitrogen and carbonyl carbon, but instead of forming carboxylic acid it forms a carboxylate ion, which is negatively charged. The amine group is converted to ammonia.

Ammonia

BASIC HYDROLYSIS IN AMIDES: The amide molecule reacts with the hydroxide ion, the hydroxide ion breaks the bond between the nitrogen and carbonyl carbon, but instead of forming carboxylic acid it forms a carboxylate ion, which is negatively charged. The amine group is converted to?

Acidic Hydrolysis, and Basic Hydrolysis

Two Types of Hydrolysis in AMIDES

Carboxylic acid, and Ammonia

In acidic hydrolysis, the amides break down into?

Carboxylate Ions, and Ammonia

In basic hydrolysis, the amides break down into?

Reduction

Is a chemical process where a molecule gains hydrogen or loses oxygen, often resulting in the formation of a simpler or more reduced compound.

Lithium aluminum hydride

Amides can be reduced to amines using reducing agents like?

Primary Amine

Reduction of an amide to a?

Reduction

R-CO-NH2 + LiAlH4 → R-CH2-NH2

Lithium aluminum hydride

It is a powerful reducing agent that donates hydrogen atoms to the compound it reacts with.

Reduction

When LiAlH₄ reacts with amide, it adds hydrogen to the carbonyl group of the amide.

Hydrogen

In reduction, when LiAlH₄ reacts with amide, it adds _______ to the carbonyl group of the amide.

Methylene Group

This removes the oxygen from the carbonyl group, and as a result, the carbonyl group is transformed into a _____________, and the amide is converted into a primary amine.

Primary Amine

This removes the oxygen from the carbonyl group, and as a result, the carbonyl group is transformed into a methylene group, and the amide is converted into a?

Nitriles

Under dehydrating conditions, amides can be converted into?

Formation of Nitriles

R-CO-NH2 → R-C≡N + H2O

Dehydration

In certain conditions, amides can be converted into nitriles through a process called?

Nitrile Group

The carbonyl group in amide is then transformed into a __________, which has a triple bond between the carbon and the nitrogen.

Water

As a result, the amide is converted into a nitrile, and ______ is produced as a byproduct.

Carboxylic acids, or Amides

Nitriles can undergo hydrolysis to form?

Break

When a nitrile reacts with water, the water molecules _____ the triple bond between the carbon and nitrogen.

Double-Bonded to Oxygen

When a nitrile reacts with water, the water molecules break the triple bond between the carbon and nitrogen. As a result, the carbon becomes ______________, forming a carbonyl group.

Hydrolysis

R-C≡N + H2O → R-COOH

Hydrolysis

A nitrile reacts with water, and the water breaks the triple bond in the nitrile, turning the nitrile into a carboxylic acid.

Carboxylic acid

Hydrolysis of nitrile results in the formation of ____________ while breaking down the triple bond and adding water.

Amines

Nitriles can be reduced to ______ using reducing agents like lithium aluminum hydride