Question

The starting raw material for synthesis of lignocaine is:

• A. 2,6-Xylidine
• B. p-Nitroacetophenone
• C. 4-Amino-3-Nitroanisole
• D. 4-Chlorobenzyl cyanide

Hint:

Lignocaine synthesis begins with aromatic amines like 2,6-Xylidine that are modified through various chemical processes to form the anesthetic agent.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept.
Lignocaine is an amide-type local anaesthetic, and amide-type anaesthetics are generally built by attaching an acid chloride derived side chain onto a substituted aniline ring.

Step 2: Key Approach.
Identify which of the four listed compounds is an aniline derivative with the methyl substitution pattern that matches lignocaine's finished ring structure.

Step 3: Detailed Explanation.
Lignocaine's aromatic ring carries two methyl groups at the 2 and 6 positions relative to the nitrogen, which sterically shields the amide bond and gives the drug its stability.
2,6-Xylidine already has exactly this substitution pattern, since it is 2,6-dimethylaniline, so it needs no ring rearrangement, just an acylation step followed by amination with diethylamine to complete the molecule.
The other three compounds, p-nitroacetophenone, 4-amino-3-nitroanisole, and 4-chlorobenzyl cyanide, are precursors for entirely different drug classes and do not carry this 2,6-dimethylaniline ring system.

Step 4: Final Answer.
The starting raw material for the synthesis of lignocaine is 2,6-Xylidine.