`Ph -N =C=O overset((i)CH_3MgBr)underset((ii)H_2O)rarrPoverset(LiAlH_4)rarrQ`

Options

A. P is `PhN=overset(CH_3)overset(|)C-OH` and Q is `PH-NH-CH_3`
B. P is Ph - NH `-CH_3` and Q is `overset("**")NH_3`
C. P is `Ph-NH-underset(O)underset(||)C-CH_3and Q` is `Ph-NH-CH_2-CH_3`
D. P is `Ph-NH-underset(OH)underset(|)(CH)-CH_3and Q` is `Ph-NH-underset(CH_3)underset(|)(CH)-CH_3`

Answer

To solve the given reaction sequence, we will identify the products P and Q step by step.

### Step 1: Identify the starting compound
The starting compound is phenyl isocyanate, which can be represented as:
\[ \text{Ph-N} = \text{C} = \text{O} \]

### Step 2: Reaction with Grignard Reagent
The first step involves the reaction of phenyl isocyanate with methylmagnesium bromide (CH₃MgBr). In this reaction, the nucleophilic carbon (C) of the Grignard reagent attacks the electrophilic carbon of the isocyanate group.

1. The nucleophile (CH₃⁻) attacks the carbon atom of the isocyanate (C=O).
2. This results in the formation of a tetrahedral intermediate with a negatively charged oxygen.

The reaction can be represented as:
\[ \text{Ph-N} = \text{C} = \text{O} + \text{CH}_3\text{MgBr} \rightarrow \text{Ph-N}(\text{C}(\text{CH}_3)O^{-})\text{MgBr}^{+} \]

### Step 3: Hydrolysis
Next, we perform hydrolysis on the intermediate formed in the previous step. Hydrolysis will convert the alkoxide into an alcohol.

1. The alkoxide (O⁻) will be protonated by water (H₂O).
2. The Grignard reagent (MgBr) will be eliminated, leading to the formation of an alcohol.

The product after hydrolysis (P) will be:
\[ \text{Ph-N}(\text{C}(\text{CH}_3)OH) \]

### Step 4: Tautomerism
The product P can undergo tautomerism. In this case, the nitrogen can accept a hydrogen atom from the hydroxyl group, leading to a shift of the double bond.

The tautomeric form of P will be:
\[ \text{Ph-NH-C}(\text{CH}_3)=\text{OH} \]

### Step 5: Reduction with Lithium Aluminium Hydride
Now, we treat the product P with lithium aluminium hydride (LiAlH₄), which is a strong reducing agent.

1. The carbonyl group (C=O) in the tautomer will be reduced to a methylene group (C-H).
2. The nitrogen will remain attached to the carbon.

The final product Q will be:
\[ \text{Ph-NH-CH}_2\text{C}(\text{CH}_3) \]

### Summary of Products
- Product P: \[ \text{Ph-NH-C}(\text{CH}_3)=\text{OH} \]
- Product Q: \[ \text{Ph-NH-CH}_2\text{C}(\text{CH}_3) \]