Explain the following : Hoffmann's bromamide degradation reaction
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Solution and Explanation
Step-down conversion of primary amides to primary amines.
Step 2: Meaning
The reaction removes the carbonyl carbon ($\gt C=O$) entirely from the amide chain.
Step 3: Analysis
Treating an amide with bromine in an aqueous or ethanolic solution of sodium hydroxide results in the degradation of the amide. The product is a primary amine containing one carbon less than the starting material.
Final Answer: Hoffmann bromamide degradation: An amide reacts with bromine and aqueous sodium hydroxide to form a primary amine that has one carbon atom less than the original parent amide. $R-CONH_2 + Br_2 + 4NaOH \rightarrow R-NH_2 + Na_2CO_3 + 2NaBr + 2H_2O$
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Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.
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(ii) Ethylamine is soluble in water whereas aniline is not.
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(iv) Although amino group is o– and p– directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline.
(v) Aniline does not undergo Friedel-Crafts reaction.
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- Assertion (A) : Aromatic primary amines can easily be prepared by Gabriel phthalimide synthesis. Reason (R) : Gabriel phthalimide synthesis is used to prepare only aliphatic primary amines.
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