List-I contains various reaction sequences and List-II contains different phenolic compounds. Match each entry in List-I with the appropriate entry in List-II and choose the correct option.
- P-2, Q-3, R-4, S-5
- P-2, Q-3, R-5, S-1
- P-3, Q-5, R-4, S-1
- P-3, Q-2, R-5, S-4
Answer
(3) P-3, Q-5, R-4, S-1
Solution
P: alkali fusion of the sulphonic acid gives phenol; the strongly activated ring is nitrated at both o- and the p-positions:
[figure] molten NaOH, H3O+ [figure] conc. HNO3 [figure] → (3)
Q: -NO2 is meta-directing; reduction, bis-diazotisation and hydrolysis give resorcinol, which is nitrated at C-2, C-4 and C-6:
[figure] HNO3/H2SO4 [figure] Sn/HCl [figure]
NaNO2/HCl, 0-5 oC [figure] 2Cl- H2O [figure]
HNO3/H2SO4 [figure] → (5)
R: -SO3H groups block C-4 and C-6, so nitration goes to C-2; steam/acid then removes -SO3H:
[figure] conc. H2SO4 [figure] conc. HNO3
[figure] H3O+, [figure] → (4)
S: –COOH is meta-directing; the amide undergoes Hofmann bromamide degradation to the amine, which is converted to the phenol via the diazonium salt:
[figure] KMnO4/KOH, ; H3O+ [figure] HNO3/H2SO4, [figure]
SOCl2; NH3 [figure] Br2, NaOH [figure]
NaNO2/HCl, 0-5 oC [figure] Cl- H2O [figure] → (1)
P-3, Q-5, R-4, S-1
Answer: (C)