Question

Which of the following compound gives pink colour on reaction with phthalic anhydride in conc. $H_{2}S{O}_4$ followed by treatment with $NaOH$?

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Phthalic anhydride with compound (d) forms a derivative of phenolphthalein which gives pink colour on basic solution NaOH.
For the reaction to occur, the para position of phenol derivative should be free so that it attacks the carbonyl group in phthalic anhydride.


Hence, option (d) is correct.