Reduction

Overview

Nitriles can be reduced to primary amines, separating the amine feedstock route from later amide or materials chemistry.

Transformation

Nitriles → Amines

Equation

R-CN + 4[H] -> R-CH2NH2

Reagents

LiAlH4

Environment

dry ether, then aqueous work-up

Reaction class

reduction

Mechanism

reduction

Evidence level

textbook core

Scope and limitations

Scope

Nitriles can be reduced to primary amines.

Limitations

The displayed conditions are for LiAlH4 reduction. Catalytic hydrogenation with H2 and a suitable metal catalyst is an alternative process with different operating conditions.

Related reactions

• Cyanation: Chloroalkanes → Nitriles

  Cyanide substitution forms a nitrile and extends the carbon chain by one carbon.

• Cyanation: Bromoalkanes → Nitriles

  Cyanide substitution forms a nitrile and extends the carbon chain by one carbon.

• Cyanation: Iodoalkanes → Nitriles

  Cyanide substitution forms a nitrile and extends the carbon chain by one carbon.

• Amination: Chloroalkanes → Amines

  Ammonia substitutes chloride to form a primary amine; excess ammonia limits further alkylation.

• Amination: Bromoalkanes → Amines

  Ammonia substitutes bromide to form a primary amine; excess ammonia limits further alkylation.

• Amination: Iodoalkanes → Amines

  Ammonia substitutes iodide to form a primary amine; excess ammonia limits further alkylation.

• Alkylation: Amines → Quaternary ammonium compounds

  Amines can be further alkylated to permanent cationic quaternary ammonium groups used in antimicrobial and ion-exchange materials.

• Hydrolysis: Nitriles → Carboxylic acids

  Nitriles can be hydrolysed to carboxylic acids, splitting the old aggregate nitrile-to-amide route into a single functional-group conversion.

• Acylation co reactant: Amines → N-substituted amides

  Amines are acylated by acyl chlorides to form N-substituted amides.

• Weak base equilibrium: Amines → Aqueous alkylammonium ions

  Amines are weak bases in water and form alkylammonium and hydroxide ions.

• Salt formation: Amines → Amine salts

  Amines react with acids to form alkylammonium salts.

• Copper(II) complex formation: Amines → Copper-amine complexes

  Amines react with aqueous copper(II) ions and form a deep-blue complex in excess amine.

References

1. Organic Chemistry: Chemistry of NitrilesJohn McMurry · OpenStax Organic Chemistry · 2023

   Supports nitrile reduction by two hydride additions to imine-anion and aluminium-stabilised dianion intermediates, followed by aqueous work-up to a primary amine; also documents nitrile hydrolysis through amide intermediates.