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

Answer 1

The Correct Option is A

The correct option is (A): 2,6-Xylidine.

Answer 2

The question asks which raw material begins the synthetic route to lignocaine. Let's check each option against what it is actually known to build in drug synthesis.

1. 2,6-Xylidine: This aromatic amine, 2,6-dimethylaniline, is reacted with chloroacetyl chloride to give an intermediate anilide, which is then treated with diethylamine to build the full lignocaine molecule. It supplies both the aromatic ring and the two methyl groups found in the finished drug, which is why it is the true starting material of the synthesis.
2. p-Nitroacetophenone: This compound is the classical starting material for the synthesis of chloramphenicol, not lignocaine, since it provides the para-nitrophenyl group seen in that antibiotic.
3. 4-Amino-3-Nitroanisole: This nitro-anisole derivative is used to build other aromatic amine and dye intermediates. It does not carry the dimethyl-substituted aniline ring that lignocaine's synthesis requires.
4. 4-Chlorobenzyl cyanide: This nitrile is typically used to build phenylacetic acid type side chains for other drugs, not the anilide backbone that defines lignocaine's synthetic route.

Only 2,6-xylidine already carries the exact ring substitution pattern that appears unchanged in the finished lignocaine molecule.

The correct answer is 2,6-Xylidine.