Answer:
The structrues are shown below.
Explanation:
The compound 3-methylbutylamine has 4 carbons at the principal chain with simple bonds between then (butyl), has a ramification with a CH₃ group at the carbon 3 (methyl), and at the carbon 1 has the amine group NH₂, as shown below.
A nitrile is a compound that has the bond C≡N at the structure, so the nitrile that originates the amide must be the 3-methylbutylnitrile, with the structure shown below (only eliminated the hydrogens from N and carbon, and then added the triple bond).
The alkyl bromide must react with a cyanide salt, which will replace the Br for CN in the compound, so we must replaced the CN for Br in the structure shown below, having the Bromo-2-methylpropane.