Water → 7-Chloro-2-(4-fluorophenyl)-3-(4-pyridinyl)pyrazolo[1,5-a]pyridine

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Reaction Conditions

Reaction Steps

A stirred solution of 2-(4-fluorophenyl)-3-(4-pyridinyl)-pyrazolo[1,5-a]pyridine (from Example 26, 100 mg, 0.346 mmol) in dry tetrahydrofuran (4 mL) was cooled to about −78° C. under N2 and n-butyllithium in hexanes (2.5 M in hexanes, 0.27 mL, 0.7 mmol) was added dropwise. The mixture was stirred at −78° C. for about 30 min and a solution of p-toluenesulfonyl chloride (0.15 g, 0.76 mmol) in dry tetrahydrofuran (1 mL) was added. The mixture was allowed to warm to room temperature over 30 min and was stirred at room temperature for 1 hour. Water was added and the mixture was poured into a separatory funnel. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were dried using anhydrous magnesium sulfate, filtered and evaporated. Purification by silica gel chromatography yielded the title compound, 0.087 g (78.6%). 1H NMR (CDCl3): δ 8.65 (d, 2H, J=5.8 Hz), 7.55–7.69 (m, 3H), 7.30 (d, 2H, J=5.8 Hz), 7.11–7.21 (m, 1H), 7.04–7.13 (m, 3H). MS (ES+ve): 326 (25, M+3), 323 (50, M+), 290 (100).

Provenance & Evidence