N,N-dimethylbutanamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1-methyl-1H-indole (5.9 g, 45.0 mmol) in CHCl3 (150 mL) was added N,N-dimethylbutyramide (5.8 g, 50.4 mmol, 1.1 eq) followed by POCl3 (5.0 mL, 53.5 mmol, 1.2 eq) at 0° C. Then mixture was heated to reflux and stirred for 2 h. The reaction was quenched with saturated aqueous NaHCO3 then stirred for 30 min at room temperature. The mixture was extracted by CH2Cl2 (3×40 mL) and combined organic layers were dried over Na2SO4. The crude product was purified by flash column chromatography (0-50% EtOAc in hexanes) to afford 1-(1-methyl-1H-indol-3-yl)butan-1-one (6.53 g, 32.4 mmol, 72%). Then mixture was heated to reflux The reaction was quenched with saturated aqueous NaHCO3 then stirred for 30 min at room temperature The mixture was extracted by CH2Cl2 (3×40 mL) were dried over Na2SO4 The crude product was purified by flash column chromatography (0-50% EtOAc in hexanes)