1-Methyl-2-(methylsulfonyl)benzimidazole

Experimental procedure: to a solution of 1 (0.076 g, 0.36 mmol) and p-methoxyacetophenone (0.045 g, 0.30 mmol) in DMF (1.5 mL) under argon is added tert-BuOK (0.101 g, 0.90 mmol) at room temperature. After stirring for 1 h, the reaction is quenched with an aqueous NH₄Cl solution and the mixture is extracted with AcOEt (2 x 10 mL). The combined extracts are washed with H₂O (3 x 10 mL), brine, dried (MgSO₄), and concentrated. Column chromatography (silica gel; hexane : AcOEt = 10 : 1) provides 2-(4-methoxyphenyl)propene (0.041 g, 92%) as a colorless solid.