Identify (Z) in the following sequence of reactions.
`CH_3CH_2COCloverset("HN_3")rarr(X)overset(Delta)rarr(Y)overset(H_2O)rarr(Z)`

Options

A. `CH_3CH_2NCO`
B. `CH_3CH_2NHCOOH`
C. `CH_3CH_2NH_2`
D. `CH_3underset(NH_2)underset(|)(CHCOOH)`

Answer

To solve the given problem, we will analyze the sequence of reactions step by step.

### Step 1: Identify the starting compound
The starting compound is an acid chloride, specifically propanoyl chloride (CH₃CH₂COCl).

### Step 2: Reaction with Hydrozoic Acid (HN₃)
When propanoyl chloride reacts with hydrozoic acid (HN₃), it undergoes a nucleophilic substitution reaction. The azide ion (N₃⁻) from hydrozoic acid attacks the carbonyl carbon of the acid chloride, leading to the formation of an azide intermediate.

**Intermediate X:**
The structure of X is CH₃CH₂CO(N₃), where the chlorine atom is replaced by the azide group.

### Step 3: Heating the Azide Intermediate (X)
When the azide intermediate (X) is heated, it undergoes a rearrangement. The azide group rearranges to form an amide while releasing nitrogen gas (N₂).

**Intermediate Y:**
The structure of Y is CH₃CH₂C(O)NH₂, which is propanamide.

### Step 4: Reaction with Water (H₂O)
Now, propanamide (Y) reacts with water. In this hydrolysis reaction, water attacks the carbonyl carbon, leading to the formation of an amine and a carboxylic acid.

**Final Product Z:**
The final product Z is ethylamine (CH₃CH₂NH₂) after the amide is hydrolyzed.

### Summary of the Reaction Sequence:
1. CH₃CH₂COCl + HN₃ → CH₃CH₂CO(N₃) (Intermediate X)
2. CH₃CH₂CO(N₃) (heat) → CH₃CH₂C(O)NH₂ (Intermediate Y)
3. CH₃CH₂C(O)NH₂ + H₂O → CH₃CH₂NH₂ + CO₂ (Final Product Z)

### Final Answer:
The final product Z is ethylamine (CH₃CH₂NH₂).

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