CBSE Class 12 · 2008 · All India · Compounds Containing NitrogenShort Answer

Write one chemical reaction each to illustrate the following:
i) Hofmann bromamide reaction
ii) Gabriel phthalimide reaction

Answer: (i) RCONH₂ + Br₂/4NaOH → RNH₂. (ii) Phthalimide + KOH → K-salt; + RX → N-alkylphthalimide; hydrolyse/hydrazine → RNH₂.

Solution

(i)

C H_{3} CON H_{2} + B r_{2} + 4NaOH \to C H_{3} N H_{2} + N a_{2} C O_{3} + 2NaBr + 2 H_{2} O

(ii) Phthalimide → potassium phthalimide (KOH) → N-alkylphthalimide (RX) → alkaline hydrolysis:

C_{6} H_{4} (CO)_{2} NK + RX \to C_{6} H_{4} (CO)_{2} NR NaOH (aq) RN H_{2} + phthalate

(gives pure 1° amines; fails for aryl halides).

CBSE Class 12 Board · 2008 · All India · Subjective