Which of the following compounds on decarboxylation with soda-lime will give toluene ?

Options

A. Phenylacetic acid
B. o-Toluic acid
C. m-Toluic acid
D. p-Toluic acid

Answer

To determine which compound, when subjected to decarboxylation with soda-lime, will yield toluene, we need to analyze the given compounds. The decarboxylation reaction involves the removal of a carboxyl group (-COOH) from a carboxylic acid, resulting in the formation of a hydrocarbon.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds under consideration are phenylacetic acid, ortho-toluic acid, meta-toluic acid, and para-toluic acid.

2. **Understand Decarboxylation**: Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). When a carboxylic acid undergoes decarboxylation with soda-lime (a mixture of sodium hydroxide and calcium oxide), it typically yields an alkane.

3. **Analyze Each Compound**:
- **Phenylacetic Acid (C6H5-CH2-COOH)**: Upon decarboxylation, the carboxyl group is removed, resulting in toluene (C6H5-CH3).
- **Ortho-Toluic Acid (C6H4(CH3)(COOH))**: Decarboxylation will remove the -COOH group, leaving behind ortho-xylene, which is not toluene.
- **Meta-Toluic Acid (C6H4(CH3)(COOH))**: Similar to ortho-toluic acid, decarboxylation will yield meta-xylene, not toluene.
- **Para-Toluic Acid (C6H4(CH3)(COOH))**: Decarboxylation will lead to para-xylene, which is also not toluene.

4. **Conclusion**: The only compound that, upon decarboxylation with soda-lime, yields toluene is **Phenylacetic Acid**.

### Final Answer:
The compound that will give toluene upon decarboxylation with soda-lime is **Phenylacetic Acid**.

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