Indium → N-(3,5-dichloropyrid-4-yl)-4-difluoromethoxy-8-amino-dibenzo[b,d]furan-1-carboxamide

Participants

Reaction Conditions

Reaction Steps

First, N-(3,5-dichloropyrid-4-yl)-4-difluoromethoxy-8-aminodibenzo[b,d]furan-1-carboxamide was prepared by reacting N-(3,5-dichloropyrid-4-yl)-4-difluoromethoxy-8-nitro-dibenzo[b,d]furan-1-carboxamide (prepared using the procedure of Example 4) with indium in ethanol and saturated ammonium chloride. To a 1 L 3-neck round bottom flask, fitted with a mechanical stirrer and reflux condenser was added N-(3,5-dichloropyrid-4-yl)-4-difluoromethoxy-8-nitro-dibenzo[b,d]furan-1-carboxamide (22.00 g, 46.99 mmol), ethanol (308.0 mL), sat. aq. NH4Cl (132.0 mL) and indium (32.37 g, 281.93 mmol). The reaction mixture was heated to 80° C. for 4-5 h (reaction monitored by HPLC). Additional indium (5.40 g, 47.03 mmol) was added to the reaction and heated to 80° C. until HPLC indicated completion. After cooling to room temperature the reaction was evaporated to dryness. DMF (200 mL) was added to the solids and heated to 70-75° C. The solution was filtered, washed with DMF (100 mL) and concentrated to a volume of 50 mL in vacuo. Water (3 L) was added to the reaction mixture, the solid was filtered, washed with water (66 mL) and dried in a vacuum oven (65° C.) overnight. The dried product appeared as a yellow solid (17.77 g, 77.4%). Purity 87.84% by HPLC; 1H NMR (500 MHz, DMSO-d6): 5.11 (bs, 2H), 6.86 (dd, J=2.3, 8.8 Hz, 1H), 7.46-7.51 (m, 3H), 7.53 (t, J=73.0 Hz, 1H), 7.82 (d, J=8.0 Hz, 1H), 8.80 (s, 2H), 10.93 (bs, 1H) ppm. m/z 437.1 (M+).

Provenance & Evidence