Potassium Carbonate → 3-Amino-6-chloro-2-(3-methoxybenzoyl)indole

Participants

Reaction Steps

A mixture of 3-amino-6-chloro-1-ethoxycarbonyl-2-(3-methoxybenzoyl)indole (step 1, 998 mg, 2.68 mmol) and K2CO3 (3.70 g, 26.8 mmol) in 70% aqueous ethanol (45 ml) was refluxed for 6.5 h and then cooled to room temperature. The mixture was concentrated to ca. 20 ml, diluted with ethyl acetate (150 ml), and the organic layer washed with water (50 ml×2) and dried (Na2SO4). After removal of solvent the residue was purified by flash chromatography eluting with ethyl acetate/hexane (1:4) to afford 549 mg (68%) of the title compound as a syrup. 1H-NMR (CDCl3) δ: 7.62 (1H, br s), 7.55-7.30 (5H, m), 7.23 (1H, d, J=1.5 Hz), 7.10 (1H, ddd, J=1.1, 2.6, and 8.1 Hz), 5.60 (2H, br s), 3.88 (3H, s)

Provenance & Evidence