Which reaction will not form an amine ?

Options

A. `R-X+NH_3 to`
B. `R-CH=N -OH + [H] underset( C_2H_5 OH) overset(Na) to `
C. `R- CN +H_2O overset(H^+) to `
D. `R- underset( O) underset(||) C-NH _2 +4 [H] overset(LiAIH_4)to`

Answer

To determine which reaction will not form an amine, let's analyze each option step by step.

### Step 1: Analyze the First Reaction (R-X + NH3)
- **Reaction**: R-X (alkyl halide) reacts with NH3 (ammonia).
- **Mechanism**: The lone pair of nitrogen in NH3 attacks the R group of the alkyl halide, leading to the formation of a substituted ammonium salt (R-NH3^+X^-).
- **Further Reaction**: In the presence of sodium hydroxide (NaOH), the ammonium salt undergoes deprotonation to yield a primary amine (R-NH2) and water.
- **Conclusion**: This reaction **does form an amine**.

### Step 2: Analyze the Second Reaction (R-CHOH + H2)
- **Reaction**: R-CH=OH (an alcohol) reacts with nascent hydrogen in the presence of sodium and ethanol.
- **Mechanism**: This reaction reduces the alcohol to an amine.
- **Conclusion**: This reaction **does form an amine**.

### Step 3: Analyze the Third Reaction (R-CN + H2O)
- **Reaction**: R-CN (nitrile) reacts with water in the presence of H+ (acid).
- **Mechanism**: Hydrolysis of the nitrile leads to the formation of a carboxylic acid (R-COOH) and ammonia (NH3).
- **Conclusion**: This reaction **does not form an amine**; instead, it produces a carboxylic acid.

### Step 4: Analyze the Fourth Reaction (R-CO-NH2 + H2)
- **Reaction**: R-CO-NH2 (an amide) reacts with nascent hydrogen in the presence of lithium aluminum hydride (LiAlH4).
- **Mechanism**: This reaction reduces the amide to a primary amine (R-CH2-NH2).
- **Conclusion**: This reaction **does form an amine**.

### Final Conclusion:
After analyzing all the reactions, we find that the third reaction (R-CN + H2O) is the only one that does not form an amine. Instead, it produces a carboxylic acid.

### Answer:
**The reaction that will not form an amine is R-CN + H2O.**

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