Methyl benzoate can prepared by

Options

A. `C_(6)H_(5)COOH+CH_(3)OH overset(H^(+))to`
B. `C_(6)H_(5)COCl+CH_(3)OH overset("Pyridine")to`
C. `C_(6)H_(5)COOH+CH_(2)N_(2) to`
D. all the above methods

Explanation

To prepare methyl benzoate, we can use several methods. Here’s a step-by-step breakdown of the three methods mentioned in the video transcript:

### Method 1: Esterification Reaction
1. **React Benzoic Acid with Methanol**:
- Combine benzoic acid (C6H5COOH) with methanol (CH3OH) in the presence of an acid catalyst (like sulfuric acid).
- The reaction is an esterification process where the hydroxyl group (-OH) of the carboxylic acid reacts with the hydrogen of the alcohol (-OH) to form water and the ester.

2. **Formation of Methyl Benzoate**:
- The reaction will yield methyl benzoate (C6H5COOCH3) and water.
- The overall reaction can be represented as:
\[ \text{C6H5COOH} + \text{CH3OH} \xrightarrow{\text{H+}} \text{C6H5COOCH3} + \text{H2O} \]

### Method 2: Reaction with Acyl Chloride
1. **React Benzoyl Chloride with Methanol**:
- Benzoyl chloride (C6H5COCl) can be reacted with methanol (CH3OH).
- In this reaction, the alcohol attacks the carbonyl carbon of the acyl chloride, leading to the formation of the ester.

2. **Formation of Methyl Benzoate**:
- The chloride ion (Cl-) acts as a leaving group, and the product is methyl benzoate.
- The reaction can be summarized as:
\[ \text{C6H5COCl} + \text{CH3OH} \rightarrow \text{C6H5COOCH3} + \text{HCl} \]

### Method 3: Reaction with Diazomethane
1. **Formation of Diazomethane**:
- Diazomethane (CH2N2) can be generated from the reaction of nitrosomethylurea with a base.

2. **Insertion Reaction**:
- The diazomethane generates a carbene (CH2) that can insert into the hydroxyl group of benzoic acid.
- This results in the formation of methyl benzoate.

3. **Overall Reaction**:
- The reaction can be summarized as:
\[ \text{C6H5COOH} + \text{CH2N2} \rightarrow \text{C6H5COOCH3} + \text{N2} \]

### Conclusion
In summary, methyl benzoate can be prepared through:
1. Esterification of benzoic acid with methanol.
2. Reaction of benzoyl chloride with methanol.
3. Insertion reaction of diazomethane into benzoic acid.