Compound (A) with Molecular formula `C_(7)H_(6)O` does not reduce Fehling's solution. Compound (A) reacts with acetone in the presence of NaOH to give a compound (B), which is an `alpha, beta`-unsaturated compound. Further (A) reacts with dimethyl aniline in the presence of conc. `H_(2)SO_(4)` to give compound (C) which is a dye. Identify (A), (B) and (C). Explain the reactions.

Explanation

(i) Compound (A) does not reduce Fehling's solution, so it is benzaldehyde.
(ii) Benzaldehyde (A) reacts with acetone in the presence of NaOH to give on `alpha,beta` unsaturated compound (B).

(iii) (A) reacts with dimethyl aniline in the presence of conc. `H_(2)SO_(4)` to give compound (C).