Which of the following reaction is involved in the preparation of primary amines :
(i) Hofmann's bromamide reaction and
(ii) Gobriel phthalimide synthesis

Options

A. (i)
B. (ii)
C. Both of these
D. None of these

Answer

To determine which of the reactions is involved in the preparation of primary amines, we will analyze both the Hofmann bromamide reaction and the Gabriel phthalimide synthesis.

### Step 1: Understanding Hofmann Bromamide Reaction
The Hofmann bromamide reaction involves the conversion of an amide to a primary amine. The general reaction can be represented as follows:

1. **Starting Material**: An amide (R-CO-NH2)
2. **Reagents**: Bromine (Br2) in the presence of an aqueous or ethanolic solution of sodium hydroxide (NaOH).
3. **Reaction**: The amide undergoes degradation, where the carbonyl carbon migrates to the nitrogen atom, resulting in the formation of a primary amine (R-NH2) with one carbon less than the original amide.

**Reaction Equation**:
\[ R-CO-NH2 + Br2 + 4NaOH \rightarrow R-NH2 + Na2CO3 + 2NaBr + 2H2O \]

### Step 2: Understanding Gabriel Phthalimide Synthesis
The Gabriel phthalimide synthesis is another method for preparing primary amines. The process can be summarized as follows:

1. **Starting Material**: Phthalimide (C6H4(CO)2NH)
2. **Reagents**: Alcoholic potassium hydroxide (KOH) is used to deprotonate the nitrogen in phthalimide, forming a nucleophilic species.
3. **Alkylation**: This nucleophile reacts with an alkyl halide (R-X) to form N-alkyl phthalimide.
4. **Hydrolysis**: The N-alkyl phthalimide is then hydrolyzed in the presence of aqueous NaOH, yielding the primary amine (R-NH2) and phthalic acid.

**Reaction Equation**:
\[ C6H4(CO)2NH + KOH \rightarrow C6H4(CO)2N-R + H2O \]
\[ C6H4(CO)2N-R + NaOH \rightarrow R-NH2 + C6H4(CO)2O^{-}Na^{+} \]

### Conclusion
Both reactions, Hofmann bromamide reaction and Gabriel phthalimide synthesis, are involved in the preparation of primary amines. Therefore, the correct answer is that both methods can be used to prepare primary amines.

### Final Answer
Both (i) Hofmann's bromamide reaction and (ii) Gabriel phthalimide synthesis are involved in the preparation of primary amines.

---