Water → 1,7-Diacetyl-4-methoxyindoline

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-acetyl-4-methoxyindoline (4.02 g, 21 mmol) in dry 1,2-dichloroethane (30 ml) cooled in ice was added acetyl chloride (2.1 ml, 30 mmol). Powdered anhydrous AlCl3 (8.4 g, 63 mmol) was added portionwise with stirring. The mixture was stirred at rt overnight, then warmed to 50° C. for 2 h. The red/brown slurry was poured into acidified cold water (200 ml) and extracted with CH2Cl2. The combined organic phases were washed with 0.5 M aq. NaOH and brine, dried and evaporated to give a brown oil. Flash chromatography (EtOAc) followed by trituration with Et2O afforded 22 as pale yellow needles (2.22 g, 54%), mp 88-89° C., (Found: C, 66.89; H, 6.50; N, 5.95. C13H15NO3 requires C, 66.94; H, 6.48; N, 6.00%); δH (90 MHz) 7.33 (1 H, d, J 8.3, H-5), 6.61 (1 H, d, H-6), 4.17 (2 H, t, J 8.1, H-2), 3.85 (3 H, s, OMe), 3.05 (2 H, t, 3-H), 2.44 (3 H, s, 7-Ac) and 2.21 (3 H, s, N-Ac).

Provenance & Evidence