The general procedure for the synthesis of 6-methylindolone from 3-methylacetanilide and ethyl iodoacetate was as follows: first, 3-methylacetanilide (0.5 mmol), Pd(OAc)2 (11.3 mg, 0.05 mmol, 10 mol%), and AgOAc (83.5 mg, 0.5 mmol) were added to a 15 mL sealed tube fitted with a septum. Subsequently, the system was evacuated and purged three times with nitrogen. TFA (4.0 mL) and ethyl 2-iodoacetate (160 mg, 0.75 mmol) were added to the system, and the reaction mixture was stirred at 120 °C for 24 hours. After completion of the reaction, the mixture was cooled to room temperature, filtered through a short diatomaceous earth pad and washed several times with CH2Cl2. The filtrate was concentrated under vacuum and purified by silica gel column chromatography using hexane/EtOAc as eluent to give the final pure 6-methylindolone product.
