Benzonitrile is treated with (i) DIBAL-H (1 equivalent) in toluene at -78 degC, then aqueous work-up; the product is heated with (ii) N2H4, KOH, ethylene glycol, 180 degC. The final organic product is

JEE Advanced levelSingle correct optionDifficulty 3 of 3ro017

Benzonitrile is treated with (i) DIBAL-H (1 equivalent) in toluene at $- 78^{\circ} C$ , then aqueous work-up; the product is heated with (ii) $N X_{2} H X_{4}$ , KOH, ethylene glycol, $180^{\circ} C$ . The final organic product is

(i) DIBAL-H reduces the nitrile to the imine-aluminium species, which hydrolyses to benzaldehyde. (ii) Wolff-Kishner reduction converts

C = O

CH X_{2}

C X_{6} H X_{5} CHO C X_{6} H X_{5} CH X_{3}