Question

A compound x gives iodoform test. It reacts with KMnO₄, which on heating gives anhydride. The anyhydride is used in the preparation of phenolphthalein. The compound x is

Answer 1

Correct option: (3) 

Explanation:

Answer 2

OPTION (3) IS CORRECT.

The compound (3) is o- methylacetophenone (X) which contains keto methyl group (CH₃CO-). So it undergoes iodoform reaction when treated with KOH/ I₂.

Again on treatment with KMnO₄ both the side chains are oxdized to carboxylic acid group forming phthalic acid.

This acid can easily forms phtalic anhydride which is used to prepare phenol phthalien