Easy Practice — Set 2

Quick Recap — Preparation & Basicity

• Preparation: reduction of nitro ($H_2$/Ni or Sn/HCl), nitriles and amides ($LiAlH_4$); Hoffmann bromamide (amide $\to$ 1$^\circ$ amine, one C fewer); Gabriel (1$^\circ$ aliphatic amines).
• Basicity (aqueous, methyl/ethyl): 2$^\circ$ $>$ 1$^\circ$ $>$ 3$^\circ$ $>$ $NH_3$ (balance of $+I$ and solvation/steric effects).
• Aromatic amines weaker (lone pair into ring); electron-withdrawing groups (e.g. $-NO_2$) lower basicity further.
• Reactions with $HNO_2$: 1$^\circ$ (aliphatic) $\to$ alcohol; 1$^\circ$ (aromatic) $\to$ diazonium; 2$^\circ$ $\to$ nitrosamine; 3$^\circ$ $\to$ no reaction.