Dichloromethane → 5-chloro-1-methyl-3-(pyridin-4-yl)-1H-indazole

Participants

Reaction Conditions

Reaction Steps

To a pressure flask was added 3-bromo-5-chloro-1-methyl-1H-indazole (0.737 g, 3 mmol), pyridine-4-boronic acid (0.996 g, 8.1 mmol), PdCl2(dppf).DCM (0.490 g, 0.6 mmol), and K3PO4 (3.184 g, 15 mmol). The flask was flushed with argon for 5 minutes, then dry DME (15 mL) was added and the flask sealed under argon. The reaction was then heated to 90° C. for 4 hours. Additional PdCl2(dppf).DCM (0.245 g, 0.3 mmol) and pyridine-4-boronic acid (0.370 g, 3 mmol) were added, and heating was continued for another 14 h at 90° C. After cooling to room temperature, the crude reaction was filtered over a plug of Celite, concentrated, dissolved in DCM, and purified by column chromatography (gradient 0 to 75% EtOAc/hexanes) to afford the product. 1H NMR (400 MHz, CDCl3) δ 8.73 (d, J=6.0 Hz, 2H), 8.02 (d, J=0.6 Hz, 1H), 7.87 (d, J=6.1 Hz, 2H), 7.53-7.32 (m, 2H), 4.15 (s, 3H).

Provenance & Evidence