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JEE Advanced levelSingle correct optionDifficulty 3 of 3si030

Three isomeric amines of formula are P, Q and R. P gives a foul-smelling isocyanide with /alcoholic KOH; Q reacts with benzenesulphonyl chloride to give a product insoluble in aqueous KOH; R does not react with benzenesulphonyl chloride. The correct assignment is

  1. AP = N,N-dimethylmethanamine, Q = N-methylethanamine, R = propan-1-amine
  2. BP = propan-1-amine, Q = N-methylethanamine, R = N,N-dimethylmethanamine
  3. CP = N-methylethanamine, Q = propan-1-amine, R = N,N-dimethylmethanamine
  4. DP = propan-1-amine, Q = N,N-dimethylmethanamine, R = N-methylethanamine

Answer: B

Only a primary amine gives the carbylamine test (P). Q gives a sulphonamide with no acidic N-H, so Q is secondary, N-methylethanamine. R is tertiary and does not react, so R is . The only primary amine among the options is propan-1-amine.
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