Sodium Carbonate → 2-(4-Fluorophenyl)-3-(2-fluoro-4-pyridinyl)-pyrazolo[1,5-a]pyridine

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Reaction Steps

A solution of 3-bromo-2-(4-fluorophenyl)-pyrazolo[1,5-a]pyridine (Example le. 1.30 g, 4.5 mmol), 2-fluoro-4-pyridinylboronic acid (Example 46a. 694 mg, 4.9 mmol) and dichlorobis(triphenylphosphine)palladium (316 mg, 0.45 mmol) in DMF (100 mL) was placed in a pre-heated oil bath at 110° C. To the reaction was added, in a dropwise manner, 2M aqueous sodium carbonate (4.5 mL, 9.0 mmol). The reaction was allowed to stir for 2 h and then cooled to room temperature and filtered through a pad of Celite. The Celite pad was washed with ethyl acetate and the filtrate was concentrated to dryness at 50° C. under vacuum. The residue was partitioned between ethyl acetate and water. The layers were separated and the organic phase was dried (MgSO4). The drying agent was removed by filtration and the filtrate was concentrated and purified by silica gel chromatography to yield the title compound (378 mg, 1.23 mmol, 27%). 1H NMR (CDCl3) δ 8.57 (d, 1H, J=6.9 Hz), 8.22(d, 1H, J=5.4 Hz), 7.7(d, 1H, J=9.0 Hz), 7.75(m, 2H), 7.33(m, 1H), 7.14(m, 3H), 6.95(m, 2H). MS (ES+ve) 308 (100, M+).

Provenance & Evidence