The best method for preparation of `Me_(3)C``CN` is

Options

A. To react `Me_(3)COH` with `HCN`
B. To react `Me_(3)CBr` with NaCn
C. To react `Me_(3)CMgBr` with CICN
D. To react `Me_(3)Cli` with `NH_(2)CN`

Explanation

To prepare `Me₃C`CN (tert-butyl cyanide), we can consider the following steps based on the provided options and the general reactivity of the compounds involved.

### Step-by-Step Solution:

1. **Identify the Target Compound**:
We want to prepare tert-butyl cyanide, which has the structure `Me₃C`CN. This indicates that we need a tert-butyl group (three methyl groups attached to a carbon) and a cyanide group (CN).

2. **Consider the Reactants**:
The potential reactants given in the options include:
- Tertiary alcohol `Me₃COH`
- Grignard reagent `Me₃CMgBr`
- Alkyl halide `Me₃Cl`
- Cyanide source `KCN` or `NaCN`

3. **Evaluate the Best Method**:
- **Option A**: `Me₃COH + HSCN` - This is not ideal as it involves an alcohol which may not directly lead to the desired cyanide.
- **Option B**: `Me₃CMgBr` with `C≡N` (cyanide) - This is a good option because Grignard reagents are strong nucleophiles and can react with cyanide to form `Me₃C`CN.
- **Option C**: `Me₃Cl` with `NH₂CN` - This could lead to an acid-base reaction rather than forming the desired cyanide.

4. **Select the Best Option**:
The best method for the preparation of `Me₃C`CN is through the reaction of the Grignard reagent `Me₃CMgBr` with cyanide (C≡N). This will allow the nucleophilic attack of the Grignard reagent on the carbon of the cyanide, leading to the formation of the desired product.

### Final Answer:
The best method for the preparation of `Me₃C`CN is through the reaction of `Me₃CMgBr` with cyanide (C≡N).

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