MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

The given reaction shows the conversion of benzene to benzaldehyde using carbon monoxide (CO) and hydrogen chloride (HCl) in the presence of anhydrous aluminum chloride (AlCl_3) under high pressure. This specific transformation is known as the Gatterman-Koch formylation reaction. In this reaction, a formyl cation is generated in situ from CO, HCl, and the Lewis acid catalyst (AlCl_3), which then undergoes electrophilic aromatic substitution with benzene to form benzaldehyde. Let us review the other options: 1. Etard reaction: Involves the oxidation of toluene to benzaldehyde using chromyl chloride (CrO_2Cl_2). 2. Stephen reaction: Involves the reduction of nitriles to aldehydes using tin(II) chloride (SnCl_2) and HCl, followed by hydrolysis. 3. Rosenmund reaction: Involves the catalytic hydrogenation of acid chlorides to aldehydes using palladium on barium sulfate (Pd/BaSO_4). Therefore, the correct name for the given reaction is the Gatterman-Koch formylation reaction. Answer: Gatterman-Koch formylation reaction