An organic compound `[A](C_(4)H_(11)N)`,shows optical activity and gives `N_(2)` gas on treatment with `HNO_(2)`. The compound [A] reacts with `PhSO_(2)Cl` producing a compound which is soluble in `KOH`.The structure of `A` is :

Options

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B.
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D.

Answer

To determine the structure of the organic compound \( A \) with the formula \( C_4H_{11}N \), we will follow these steps:

### Step 1: Analyze the Given Information
The compound \( A \) is an organic amine with the formula \( C_4H_{11}N \). It shows optical activity and releases \( N_2 \) gas upon treatment with \( HNO_2 \). The optical activity indicates that the compound has a chiral center.

**Hint:** Look for a structure that has a chiral carbon atom.

### Step 2: Determine the Type of Amine
The release of \( N_2 \) gas when treated with \( HNO_2 \) indicates that \( A \) is a primary amine. This is because primary amines react with nitrous acid to produce nitrogen gas.

**Hint:** Recall that only primary amines can produce \( N_2 \) gas when treated with nitrous acid.

### Step 3: Identify Possible Structures
The molecular formula \( C_4H_{11}N \) suggests several possible structures for a primary amine. However, since \( A \) must also show optical activity, it must contain a chiral carbon.

One possible structure is \( CH_3-CH(CH_3)-CH_2-NH_2 \) (2-aminobutane), which has a chiral center at the second carbon.

**Hint:** Consider the structure of 2-aminobutane and check for chirality.

### Step 4: Reaction with \( PhSO_2Cl \)
When \( A \) reacts with \( PhSO_2Cl \) (the Hinsberg reagent), it forms a sulfonamide. The resulting sulfonamide must be soluble in \( KOH \), which is characteristic of primary amines.

**Hint:** Sulfonamides derived from primary amines are typically soluble in bases.

### Step 5: Confirm the Structure
The structure \( CH_3-CH(CH_3)-CH_2-NH_2 \) (2-aminobutane) meets all the criteria:
- It is a primary amine.
- It has a chiral carbon, which accounts for optical activity.
- It can react with \( PhSO_2Cl \) to form a sulfonamide that is soluble in \( KOH \).

Thus, the structure of compound \( A \) is:

\[ \text{2-aminobutane: } CH_3-CH(CH_3)-CH_2-NH_2 \]

**Final Answer:** The structure of compound \( A \) is 2-aminobutane.