Potassium Phosphate, Tribasic → 3-Cyclopropyl-2-(5-fluoropyridin-3-yl) pyrazolo[1,5-a]pyridine

Participants

Reaction Conditions

Reaction Steps

A solution of 2-chloro-3-cyclopropylpyrazolo-[1,5-a]pyridine (27-4; 0.2 g, 1.042 mmol), (5-fluoropyridin-3-yl)boronic acid (0.147 g, 1.042 mmol), and potassium phosphate tribasic (0.66 g, 3.126 mmol) in tetrahydrofuran (15 mL) was degassed for 10 min. Next 2-dicyclohexylphosphino-2′,6′-dimethoxy-1,1′-biphenyl (0.085 g, 0.208 mmol) and palladium acetate (0.023 g, 0.104 mmol) were added and heated in a sealed tube at 100° C. for 18 h. The reaction mixture was then cooled to room temperature, filtered and concentrated under reduced pressure. Purification of the resulting residue by prep HPLC provided 3-cyclopropyl-2-(5-fluoropyridin-3-yl) pyrazolo[1,5-a]pyridine. 1H NMR (400 MHz, DMSO-d6) δ 9.07 (s, 1 H), 8.67-8.65 (d, J=8.0 Hz, 1 H), 8.62-8.61 (d, J=2.4 Hz, 1 H), 8.19-8.17 (d, J=8.0 Hz, 1 H), 7.74-7.72 (d, J=8.0 Hz, 1 H), 7.26-7.22 (t, J=8.0 Hz, 1 H), 6.93-6.90 (t, J=8.0 Hz, 1 H), 2.10-2.05 (m, 1 H), 1.02-1.01 (d, J=4.0 Hz, 2 H), 0.43-0.42 (d, J=4.0 Hz, 2 H), MS (M+1): 254.1.

Provenance & Evidence