Identify A and B in each of the three reaction sequences shown in the figure.(i)(ii)(iii)
Answer: Each printed arrow's reagent fixes A then B by its standard diazonium/amine transformation.
Solution
Work each displayed line: diazotisation gives the diazonium (A); the second printed reagent then replaces –N₂⁺ (CuCN → nitrile; H₂O → phenol; KI → iodide; H₃PO₂ → arene) or couples it — write B accordingly.
