Salicylaldehyde is synthesized from phenol, when reacted with
- HCCl3, NaOH
- CO2, NaOH
- [figure]
- CCl4, NaOH
Answer
(1) HCCl3, NaOH
Solution
[figure]
Reimer–Tiemann reaction: CHCl3 + OH- :CCl2 (electrophile) attacks the ortho position of phenoxide; –CHCl2 is hydrolysed to –CHO
(B) CO2, NaOH ⇒ salicylic acid (Kolbe) ⇒ wrong
(C) HCOCl is unstable, not a reagent for this ⇒ wrong
(D) CCl4, NaOH ⇒ salicylic acid ⇒ wrong
Answer: (1)