Which of the following compound can from hydrazone and will give iodoform test but will not give Tollen's test ?

Options

A.
B. `H_(3)C-underset(O)underset(||)(C)-CH_(2)-CH_(3)`
C. `H_(3)C-underset(O)underset(||)(C)-CH_(2)-CHO`
D. `CH_(3)-CH_(2)-OH`

Answer

To solve the question, we need to identify a compound that meets the following criteria:
1. Can form hydrazone.
2. Will give the iodoform test.
3. Will not give the Tollen's test.

### Step-by-Step Solution:

**Step 1: Understanding Hydrazone Formation**
- Compounds that contain a carbonyl group (C=O) can react with hydrazine (NH2NH2) to form hydrazones.
- Therefore, we need to look for compounds with a C=O functional group.

**Hint for Step 1:** Look for compounds that have a carbonyl group (C=O) as they can react with hydrazine to form hydrazones.

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**Step 2: Identifying Iodoform Test Conditions**
- The iodoform test is positive for methyl ketones (compounds of the form CH3C(=O)R, where R can be any alkyl or aryl group).
- We need to ensure that the compound has a methyl group adjacent to the carbonyl carbon.

**Hint for Step 2:** Identify compounds that have a methyl group attached to the carbonyl carbon to pass the iodoform test.

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**Step 3: Evaluating Tollen's Test**
- Tollen's test is positive for aldehydes and some α-hydroxy ketones, but not for ketones that do not have a hydrogen atom directly attached to the carbonyl carbon.
- Therefore, we need to ensure that the compound does not have an aldehyde group or a structure that would allow it to give a positive Tollen's test.

**Hint for Step 3:** Check if the compound is a ketone without an aldehyde group to ensure it does not give a positive Tollen's test.

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**Step 4: Analyzing the Given Compounds**
- Now, we will analyze the options provided in the question to see which one meets all three criteria.

1. **Compound 1:** Cyclobenzene with C=O and CH2PS3
- This compound can form a hydrazone but does not fit the iodoform test criteria.

2. **Compound 2:** CH3C(=O)CH2CH3
- This compound can form a hydrazone, gives a positive iodoform test (as it is a methyl ketone), and does not have an aldehyde group, so it will not give a Tollen's test.

3. **Compound 3:** CH3C(=O)CH2C(=O)OH
- This compound can form a hydrazone and gives both iodoform and Tollen's tests.

4. **Compound 4:** Toluene
- Toluene does not have a carbonyl group, so it cannot form a hydrazone, nor can it give either test.

**Hint for Step 4:** Analyze each compound based on the criteria established in previous steps to find the one that meets all conditions.

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**Step 5: Conclusion**
- Based on the analysis, **Compound 2 (CH3C(=O)CH2CH3)** is the only compound that can form hydrazone, gives a positive iodoform test, and does not give a Tollen's test.

**Final Answer:** The correct compound is **CH3C(=O)CH2CH3**.

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