Question

The best method for preparing primary amines from alkyl halides without changing the number of carbon atoms in the chain is:

• A. Hoffmann Bromamide reaction
• B. Gabriel phthalimide synthesis
• C. Sandmeyer reaction
• D. Reaction with $N{H}_3$

Answer 1

The correct option is B Gabriel phthalimide synthesis

In Hoffmann Bromamide degradation reaction, the primary amine thus formed contains one carbon less than the number of carbon atoms in that amide.
In Gabriel Phthalimide method can be used to get primary amines from phthalimides without changing the number of carbon atoms.

In Sandmeyer reaction reaction, aryl halides synthesized from aryl diazonium salts using copper salts as reagents or catalysts.

Reaction of alkylhalides gives quaternary ammonium salt as a ultimate product, Initially formed $R-N{H}_2$, is itself acts as a nucleophile and can react with more alkyl halide to give mixture of primary, secondary, tertiary amines and quaternary ammonium salts.