反应详情

5-(2-Chloropyridin-3-yl)-3-methyl-1H-indazole was synthesized in the similar manner to the preparation of 5-(2-chloropyridin-3-yl)-1H-indazole by heating the mixture of tert-butyl 5-bromo-3-methyl-1H-indazole-1-carboxylate (1.5 g, 4.8 mmol), 2-chloro-3-pyridine boronic acid pinacol ester (1.3 g, 5.3 mmol), Pd(PPh3)4 (390 mg, 0.33 mmol) and 2M aq.Na2CO3 (7 mL, 14 mmol) in 1,4-dioxane (40 mL). Upon work-up and purification procedure used in the prepartion of 5-(2-chloropyridin-3-yl)-1H-indazole provided 5-(2-chloropyridin-3-yl)-3-methyl-1H-indazole (0.52, 43%) as a white crystalline solid. 1H NMR (DMSO-d6): δ 12.75 (s, 1H), 8.41 (dd, 1H, J=1.7 and 4.7 Hz), 7.91 (dd, 1H, J=1.7 and 7.6 Hz), 7.77 (s, 1H), 7.52 (d, 1H, J=8.5 Hz), 7.51 (dd, 1H, J=4.7 and 7.6 Hz), 7.41 (dd, 1H, J=1.4 and 8.5 Hz), 2.49 (s, 3H).LCMS: rt 6.28 min (A), purity 97%, MS (m/e) 244.

1. temperatureby heating
2. customUpon work-up and purification procedure