3-Bromo-2-methylpyrazolo[1,5-a]pyridine → HCID 66855938, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-allyl-2-[3-(2,4-dichlorophenyl)-5-(tributylstannyl)-2-thienyl]-1H-imidazole (180 mg, 0.29 mmol) in DMF (4.0 mL) was added [3-bromo-2-methylpyrazolo[1,5-a]pyridine (50 mg, 0.2 mmol) (azeotroped from toluene) and Bis(triphenylphosphine)palladium(II) chloride (8.5 mg, 0.012 mmol). The resulting mixture was degassed and stirred for 1 h at 100° C. under an atmosphere of argon. The reaction mixture was allowed to cool, concentrated and the residue was partially purified by silica gel column chromatography (40 g, eluting with 30% EtOAc in hexanes to EtOAc to give 3-[5-(1-allyl-1H-imidazol-2-yl)-4-(2,4-dichlorophenyl)-2-thienyl]-2-methylpyrazolo[1,5-a]pyridine, 82 mg. To a solution of [A] 3-[5-(1-allyl-1H-imidazol-2-yl)-4-(2,4-dichlorophenyl)-2-thienyl]-2-methylpyrazolo[1,5-a]pyridine (70 mg, 0.2 mmol), tetrakis(triphenylphosphine)palladium(0) (8.5 mg, 0.0074 mmol) and acetic acid (0.4 mL, 7 mmol) in DCM (1.5 mL) was added slowly phenylsilane (0.1 mL, 0.8 mmol) and the reaction mixture stirred at 40° C. for 2 h. The reaction mixture was concentrated and the product was purified by column chromatography on silica gel eluting with 1-3% MeOH in DCM. The product was further purified by preparative hplc, formic acid gradient. The title compound was isolated as a colorless lyophilized solid, 25 mg. LC/MS (FA) ES+ 425.0, 427.6, 428.4, 429.3. 1H NMR (400 MHz, d4-MeOH) δ: 8.48 (d, J=8.3 Hz, 1H), 7.85-7.87 (m, 1H), 7.50-7.60 (m, 1H), 7.31-7.39 (m, 3H), 7.18 (s, 1H), 7.04 (s, 2H), 6.90-6.95 (m, 1H), 2.62 (s, 3H).

Provenance & Evidence