Which one is o, p-directiong group for electrophliic substitution reaction ?

Options

A. `-overset(O)overset(||)C-OH`
B. `-overset(O)overset(||)C-NH_(2)`
C.
D. `-NO_(2)`

Answer

To determine which group is ortho-para directing in electrophilic substitution reactions, we need to analyze the nature of the substituents on the benzene ring. Here’s a step-by-step solution:

### Step 1: Understand Electrophilic Substitution Reactions
Electrophilic substitution reactions involve the replacement of a hydrogen atom on a benzene ring with an electrophile. The position where the electrophile substitutes the hydrogen depends on the nature of the substituents already present on the ring.

### Step 2: Classify Substituents
Substituents can be classified as either electron-donating groups (EDGs) or electron-withdrawing groups (EWGs):
- **Electron-Donating Groups (EDGs)**: These groups increase the electron density on the benzene ring, making it more reactive towards electrophiles. They typically direct electrophiles to the ortho and para positions.
- **Electron-Withdrawing Groups (EWGs)**: These groups decrease the electron density on the benzene ring, making it less reactive towards electrophiles. They typically direct electrophiles to the meta position.

### Step 3: Identify Ortho-Para Directing Groups
To identify ortho-para directing groups, we look for EDGs. Common EDGs include:
- Alkyl groups (e.g., -CH3, -C2H5)
- Hydroxyl group (-OH)
- Amino group (-NH2)
- Alkoxy group (-OCH3)

### Step 4: Analyze the Given Groups
Let’s analyze the groups provided in the question (assuming hypothetical groups):
1. **-OH (Hydroxyl group)**: This is an electron-donating group and is ortho-para directing.
2. **-NO2 (Nitro group)**: This is an electron-withdrawing group and is meta directing.
3. **-NH2 (Amino group)**: This is an electron-donating group and is ortho-para directing.
4. **-COOH (Carboxylic acid)**: This is an electron-withdrawing group and is meta directing.

### Step 5: Conclusion
From the analysis, the groups that are ortho-para directing in electrophilic substitution reactions are the hydroxyl group (-OH) and the amino group (-NH2).

### Final Answer
The ortho-para directing groups for electrophilic substitution reactions are:
- **-OH (Hydroxyl group)**
- **-NH2 (Amino group)**