Non-catalytic alkylation of the 2-positioned methyl group in 3-acyl-2-methylindoles

Non-catalytic alkylation of 3-acyl-2-methylindoles upon the deprotonation with lithium diisopropylamide occurs at the 2-positioned methyl group. With the use of methyl iodide (dimethyl sulfate) or benzyl chloride, the reaction affords 3-acyl-2-ethylindoles or 3-acyl-2-(2-phenylethyl)indoles, respectively, with isolated yields up to 90%.