Which of the following is ortho para directing

Options

A.
B.
C.
D.

Answer

To determine which of the given groups are ortho-para directing, we need to analyze the electron-donating or electron-withdrawing nature of each substituent on the benzene ring. Here’s a step-by-step solution:

### Step 1: Understand Ortho-Para Directing Groups
Ortho-para directing groups are those that increase the electron density at the ortho and para positions of the benzene ring. These groups typically have lone pairs of electrons or exhibit +I (inductive) or +M (mesomeric) effects.

### Step 2: Analyze Each Option
Let’s analyze each option provided in the question:

**Option 1: C=O NHCH3**
- The carbonyl group (C=O) is an electron-withdrawing group. It pulls electron density away from the benzene ring, making it less nucleophilic. Therefore, this group is not ortho-para directing.

**Option 2: NHCOCH3**
- The nitrogen (N) in this group has a lone pair of electrons. Although it is involved in resonance with the carbonyl, it can still donate electron density to the benzene ring. Thus, this group is ortho-para directing.

**Option 3: COOCH3**
- The carbonyl group (C=O) here is also an electron-withdrawing group. It decreases the electron density on the benzene ring, making it less reactive towards electrophilic substitution. Therefore, this group is not ortho-para directing.

**Option 4: O**
- The oxygen atom has lone pairs of electrons and can donate electron density to the benzene ring. This makes it an ortho-para directing group.

### Step 3: Conclusion
From the analysis:
- **Ortho-para directing groups**: Option 2 (NHCOCH3) and Option 4 (O).
- **Not ortho-para directing groups**: Option 1 (C=O NHCH3) and Option 3 (COOCH3).

### Final Answer
The ortho-para directing groups among the options provided are **Option 2 (NHCOCH3)** and **Option 4 (O)**.

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