Nitrile hydrolysis
Acid-assisted water addition converts the nitrile through an amide before hydrolysis gives the acid. The nitrile carbon becomes the carboxyl carbon, while its nitrogen leaves the organic skeleton as ammonium.
- Reagents
- Dilute HCl(aq)
- Conditions
- Heat under reflux
- Reaction class
- Nitrile hydrolysis
- Equation
- CH3CH2CN + 2H2O + HCl -> CH3CH2COOH + NH4Cl
Overview
Acid-assisted water addition converts the nitrile through an amide before hydrolysis gives the acid. The nitrile carbon becomes the carboxyl carbon, while its nitrogen leaves the organic skeleton as ammonium.
Transformation
Propanenitrile → Propanoic acid
- Equation
- CH3CH2CN + 2H2O + HCl -> CH3CH2COOH + NH4Cl
- Reactants
- Propanenitrile + 2 Water + Hydrogen chloride
- Products
- Propanoic acid + Ammonium chloride
- Reagents
- Dilute HCl(aq)
- Environment
- Heat under reflux
- Reaction class
- Nitrile hydrolysis
- Mechanism
- acid-catalysed nitrile and amide hydrolysis
- Evidence level
- source-backed molecular example
Scope and limitations
- Scope
- Complete acidic hydrolysis through an amide intermediate.
- Limitations
- Base hydrolysis would initially give propanoate; nitrogen finishes as ammonium in acid.
Related reactions
- Oxidation: Propanal → Propanoic acid
Propanal is oxidised to propanoic acid.
- Oxidation: Propan-1-ol → Propanoic acid
Propan-1-ol is oxidised to propanoic acid.
- Cyanide substitution: Bromoethane → Propanenitrile
The carbon end of cyanide attacks the primary carbon of bromoethane as bromide leaves. The new C-C bond joins cyanide’s carbon to the original chain, giving a three-carbon nitrile rather than acetonitrile.
- Nitrile reduction: Propanenitrile → Propylamine
Hydride additions reduce the carbon-nitrogen triple bond; the separate aqueous work-up protonates the nitrogen-containing intermediates. The nitrile carbon becomes CH2NH2, preserving the enlarged three-carbon skeleton.
References
- 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.