In the following sequence of reactions, the compound C formed would be
`CH_(3)-underset(NH_(2))underset("| ")"CH"-CH_(3)overset(HNO_(2))underset(H_(2)O)rarr A overset([O])rarr B overset(CH_(3)MgI)underset(H^(+)//H_(2)O)rarr C`

Options

A. 1, 1 - Dimethylethanol
B. Butanol - 1
C. Butanol - 2
D. 2 - Methyl - propanol - 1

Explanation

To solve the given sequence of reactions step by step, let's break it down:

### Step 1: Reaction with HNO2 and H2O
The starting compound is CH3-CH(NH2)-CH3 (isopropylamine). When isopropylamine reacts with nitrous acid (HNO2) in the presence of water, it undergoes a reaction where the amino group (-NH2) is converted to a hydroxyl group (-OH) through the formation of a diazonium ion (N2+), which is a good leaving group. The reaction can be summarized as follows:

\[ \text{CH}_3\text{-CH(NH}_2)\text{-CH}_3 + \text{HNO}_2 + \text{H}_2\text{O} \rightarrow \text{CH}_3\text{-CH(OH)-CH}_3 + \text{N}_2 + \text{H}_2\text{O} \]

The product formed here is **A**, which is **CH3-CH(OH)-CH3** (isopropanol).

### Step 2: Oxidation of Alcohol to Ketone
Next, we oxidize the alcohol (isopropanol) to a ketone. The oxidation can be achieved using an oxidizing agent, which we denote as [O]. The reaction can be represented as:

\[ \text{CH}_3\text{-CH(OH)-CH}_3 \overset{[O]}{\rightarrow} \text{CH}_3\text{-C(=O)-CH}_3 \]

The product formed here is **B**, which is **CH3-CO-CH3** (acetone).

### Step 3: Reaction with Grignard Reagent
Now we react the ketone (acetone) with a Grignard reagent, which is CH3MgI. The Grignard reagent will attack the carbonyl carbon of the ketone, leading to the formation of a tertiary alcohol. The reaction can be summarized as follows:

1. The nucleophilic carbon from the Grignard reagent attacks the carbonyl carbon:
\[ \text{CH}_3\text{-C(=O)-CH}_3 + \text{CH}_3\text{MgI} \rightarrow \text{CH}_3\text{-C(OH)(CH}_3)\text{-CH}_3 \]

2. After the addition of water (H+ and H2O), the alkoxide ion (O-) formed will pick up a proton (H+):
\[ \text{CH}_3\text{-C(OH)(CH}_3)\text{-CH}_3 + \text{H}_2\text{O} \rightarrow \text{CH}_3\text{-C(OH)(CH}_3)\text{-CH}_3 \]

The final product **C** is **CH3-C(OH)(CH3)-CH3**, which is **2-propanol** or **tert-butyl alcohol**.

### Final Answer
The compound C formed would be **2-propanol (tert-butyl alcohol)**.

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