Ethanol → HCID 10707117, compound

Participants

Reaction Steps

A mixture of the above ester (1.00 g, 3.52 mmol), CsCO3 (1.723 g, 5.29 mmol), 95% EtOH (20 mL), and water (10 mL) was stirred at reflux for 6 h. Water (15 mL) was added and the EtOH was evaporated. The solution was filtered through Celite and acidified with 2 M HCl. The precipitate that formed was collected by filtration, washed with water, and dried to give 6-(2-chloroethoxy)-5-methoxyindole-2-carboxylic acid (0.95 g, 100%) as a white powder, which crystallized from MeOH as white needles, mp 187-189° C. 1H NMR [(CD3)2SO] δ 12.63 (br s, 1 H, CO2 h), 11.47 (s, 1 H, NH), 7.12 (s, 1 H, H-4), 6.97 (d, J=1.6 Hz, 1 H, H-3), 6.91 (s, 1 H, H-7), 4.23 (t, J=5.2 Hz, 2 H, OCH2), 3.97 (t, J=5.2 Hz, 2 H, CH2Cl), 3.78 (s, 3 H, OCH3); 13C NMR 162.5 (CO2), 147.5, 145.6, 132.1, 126.9, 120.4 (C-2,3a,5,6,7a), 107.4 (C-3), 103.1 (C-4), 96.5 (C-7), 68.9 (OCH2), 55.7 (OCH3), 43.0 (CH2Cl).

Provenance & Evidence