JEE Main · 2026 · 23 Jan 2026 · Shift 1 · Compounds Containing Nitrogen

Reading the sequence backwards, the final product is cyclohexyl isocyanide, which is formed by the carbylamine reaction of a primary amine with chloroform and alcoholic potassium hydroxide, so the amine entering that step is cyclohexylamine. The reagents $\text{KOH}/{\text{Br}}_2$ effect Hofmann bromamide degradation, which turns a primary amide into a primary amine with loss of one carbon, so the amide that produces cyclohexylamine is cyclohexanecarboxamide, and this is Q. Q is obtained when P is treated with ammonia and then heated, a route that converts a carboxylic acid into its amide through the ammonium salt. Hence P is cyclohexanecarboxylic acid, ${\text{C}}_6{\text{H}}_{11}\text{COOH}$.