Cesium carbonate → HCID 68770255, compound

Participants

Reaction Conditions

Reaction Steps

To a solution 6-hydroxy-1H-indole-2-carboxylic acid methyl ester (4.7 g, 24.5 mmol) in DMF (250 mL) was added Cs2CO3 (8.0 g, 24.5 mmol) followed by 2-chloro-benzothiazole (3.0 mL, 4.2 g, 24.5 mmol) and the reaction mixture was heated (70° C., 12 h). The reaction mixture was cooled (rt) and concentrated in vacuo. The resulting residue was partitioned between EtOAc (200 mL) and brine (100 mL). The organic layer was separated and the aqueous layer was extracted with EtOAc (2×300 mL). The organic layer was dried, filtered and concentrated in vacuo. The resulting residue was purified by silica gel flash chromatography using EtOAc:hexane (0-40%) to provide the title compound as a colorless foam (3.6 g, 45%). MS (ESI): mass calcd. for O17H12N2O3S, 324.1; m/z found, 325.0 [M+H]+. 1H NMR (400 MHz, CDCl3): 9.17 (s, 1H), 7.77-7.63 (m, 3H), 7.46-7.42 (m, 1H), 7.42-7.34 (m, 1H), 7.30-7.26 (m, 1H), 7.23-7.19 (m, 1H), 7.14 (dd, J=8.7, 2.1, 1H), 3.94 (s, 3H).

Provenance & Evidence