Reaction of iso-propylbenzene with O2 followed by the treatment with H3O+ forms phenol and a by-product P. Reaction of P with 3 equivalents of Cl2 gives compound Q. Treatment of Q with Ca(OH)2 produces compound R and calcium salt S. The correct statement(s) regarding P, Q, R and S is(are)
- Reaction of P with R in the presence of KOH followed by acidification gives [figure]
- Reaction of R with O2 in the presence of light gives phosgene gas
- Q reacts with aqueous NaOH to produce Cl3CCH2OH and Cl3CCOONa
- S on heating gives P
Answer
(1) Reaction of P with R in the presence of KOH followed by acidification gives [figure], (2) Reaction of R with O2 in the presence of light gives phosgene gas, (4) S on heating gives P
Solution
Cumene process – cumene is oxidised to its hydroperoxide, which is cleaved by acid:
[figure] O2 [figure] H3O+ [figure] + [figure] (P)
All three α-H of the methyl group are replaced by Cl (acid-catalysed chlorination):
[figure] 3Cl2 [figure] (Q) + 3HCl
Haloform cleavage of the trichloromethyl ketone:
2CH3COCCl3 + Ca(OH)2 2CHCl3 (R) + (CH3COO)2Ca (S)
(A) CHCl3/KOH gives -CCl3, which adds to the C=O of acetone (then acidification):
[figure] [H3O+]CHCl3, KOH [figure] (chloretone) – correct.
(B) 2CHCl3 + O2 h 2COCl2 + 2HCl – correct.
(C) Q with aq. NaOH gives CHCl3 + CH3COONa, not the stated products – incorrect.
(D) Dry distillation: (CH3COO)2Ca CH3COCH3 + CaCO3 – correct.
Answer: (A), (B), (D)