Cesium carbonate → 6-(Thiazolo[4,5-b]pyridin-2-yloxy)-1H-indole-2-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution 6-hydroxy-1H-indole-2-carboxylic acid methyl ester (4.0 g, 21 mmol) and 2-chloro-thiazolo[4,5-b]pyridine hydrochloride (4.3 g, 21 mmol) in MeCN:DMF (4:1, 250 mL) was added Cs2CO3 (13.8 g, 42 mmol) and the reaction mixture was heated (60° C., 4 h). The reaction mixture was cooled (rt) and partitioned between EtOAc (300 mL) and saturated NH4Cl (200 mL). The organic layer was separated and the aqueous layer was extracted with EtOAc (2×200 mL). The organic layer was dried, filtered and concentrated in vacuo. The resulting residue was purified by silica gel flash chromatography using MeOH (0.2 M NH3):DCM (0-15%) to provide the title compound as a brown solid (3.6 g, 53%). MS (ESI): mass calcd. for C16H11N3O3S, 325.1; m/z found, 326.0[M+H]+. 1H NMR (400 MHz, DMSO-d6): 12.18 (s, 1H), 8.52 (dd, J=4.8, 1.7, 1H), 8.39 (dd, J=8.0, 1.7, 1H), 7.82 (d, J=8.7, 1H), 7.53 (d, J=2.2, 1H), 7.34 (dd, J=8.0, 4.8, 1H), 7.26 (dd, J=2.2, 0.9, 1H), 7.19 (dd, J=8.7, 2.2, 1H), 3.88 (s, 3H).

Provenance & Evidence