p -Cresol (4-methylphenol) is subjected to two separate reactions: Reaction 1: p -cresol reacts with CHCl ₃ and aqueous NaOH , followed by acidification to yield major product A. Reaction 2: p -cresol reacts with Br ₂ in CS ₂ at 273 K to yield major product B. Identify the major products A and B.

Step-by-step solution

In p -cresol, the - OH group is strongly activating and ortho/para directing, whereas the - CH ₃ group is weakly activating and ortho/para directing. The directing effect of the - OH group dominates. Since the para position is blocked by the - CH ₃ group, electrophilic substitution must occur at the position ortho to the - OH group. Reaction 1 is the Reimer-Tiemann reaction, which introduces a formyl group ( - CHO ) ortho to the - OH group. Thus, product A is 2-hydroxy-5-methylbenzaldehyde. Reaction 2 is brominatio