Question

Compound A on reaction with chlorine in presence of UV light gives B, which when reacted with \(\text{NaNO}_2\) in the solvent N,N-dimethylformamide gives 2-nitrobutane. The compound A is

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

Reaction of alkyl halides with \(\text{NaNO}_2\) in DMF gives nitroalkanes via nucleophilic substitution.

Answer 1

The Correct Option is A

Step 1: First reaction analysis.
Chlorination in presence of UV light indicates a free-radical substitution reaction. n-Butane undergoes chlorination to give a mixture of chlorinated products, mainly secondary butyl chloride.

Step 2: Second reaction analysis.
Alkyl halides react with \(\text{NaNO}_2\) in polar aprotic solvent (DMF) to give nitroalkanes. Secondary butyl chloride gives 2-nitrobutane.

Step 3: Identify compound A.
Since 2-nitrobutane is formed, the intermediate halide must be secondary butyl halide, which is obtained from chlorination of n-butane.

Step 4: Conclusion.
Therefore, compound A is n-butane.