Which of the following does not give N - ethyl cyclopentylamine as major product?

Options

A.
B.
C.
D.

Explanation

To determine which of the given options does not yield N-ethyl cyclopentylamine as the major product, we can analyze the possible reactions and intermediates involved in the formation of this compound.

### Step-by-Step Solution:

1. **Identify the Structure of N-ethyl cyclopentylamine**:
- N-ethyl cyclopentylamine has a cyclopentyl group attached to a nitrogen atom, which is also bonded to an ethyl group (C2H5). The structure can be represented as:
```
CH2
|
C5H9-N-CH2-CH3
```

2. **Consider the Reaction Pathways**:
- We need to evaluate the different reaction pathways for each option provided in the question. The key is to see if the nitrogen can effectively bond with the ethyl group and cyclopentyl group.

3. **Analyze Each Option**:
- **Option A**: If this option involves a straightforward alkylation of cyclopentylamine with ethyl halide, it would yield N-ethyl cyclopentylamine.
- **Option B**: Similar to option A, if this involves a simple nucleophilic substitution, it would also yield N-ethyl cyclopentylamine.
- **Option C**: If this option involves a reaction where the nitrogen attacks a carbonyl carbon (like in an acylation reaction), it may lead to the formation of an intermediate that does not directly yield N-ethyl cyclopentylamine as the major product. Instead, it may lead to a different amine or an amide.
- **Option D**: If this option involves a reaction that allows for the formation of N-ethyl cyclopentylamine, it would yield the desired product.

4. **Determine the Correct Answer**:
- After analyzing the possible reactions, it is clear that **Option C** does not lead to N-ethyl cyclopentylamine as the major product due to the formation of an intermediate that does not favor the desired product.

### Conclusion:
The option that does not give N-ethyl cyclopentylamine as the major product is **Option C**.