Question

Which among the following methods is NOT suitable for the preparation of alkyl chlorides?

• A. Addition of HCl to alkene
• B. Treating alcohols with Lucas reagent
• C. By heating alcohols with thionyl chloride
• D. Chlorination of alkanes in presence of sunlight

Hint:

When asked about methods in organic chemistry, always recall the specific reagents and conditions used for each transformation. Certain methods, like chlorination in sunlight, may produce mixtures, while others are more selective for the desired product.

Answer 1

The Correct Option is D

Step 1: Understanding the question.
The question asks for the method that is NOT suitable for preparing alkyl chlorides. The preparation methods generally involve adding a chlorine atom to an organic molecule or modifying functional groups to introduce a chlorine atom.

Step 2: Analyzing the options.
(A) Addition of HCl to alkene: This method is suitable as alkenes can undergo electrophilic addition with HCl to form alkyl chlorides.
(B) Treating alcohols with Lucas reagent: This is a standard method for preparing alkyl chlorides from alcohols, as the Lucas reagent is a mixture of concentrated HCl and ZnCl₂.
(C) By heating alcohols with thionyl chloride: This is another effective method for converting alcohols to alkyl chlorides, using thionyl chloride (SOCl₂).
(D) Chlorination of alkanes in presence of sunlight: This method is not suitable for preparing alkyl chlorides as it results in a mixture of halogenated products, including chloroalkanes, but is more commonly used for chlorination of alkanes to form a variety of products.

Step 3: Conclusion.
The correct answer is (D) Chlorination of alkanes in presence of sunlight, as this method does not specifically target the preparation of alkyl chlorides in a controlled manner.