2-Dicyclohexylphosphino-2',4',6'-triisoprophylbiphenyl → 3,5-bis(6-cyclopropylpyrazin-2-yl)-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole

Participants

Reaction Steps

A microwave tube was charged with 3-(6-chloropyrazin-2-yl)-5-(6-cyclopropylpyrazin-2-yl)-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole (Ex. 243e, 111 mg, 0.256 mmol), Pd(OAc)2 (3 mg, 0.013 mmol) and 2-(dicyclohexylphosphino)-2′,4′,6′-tri-1-propyl-1,1′-biphenyl, (X-Phos) (12 mg, 0.026 mmol) and the tube was sealed. The tube was evacuated under vacuum and backfilled with N2 (3×). THF (1.7 mL) was added and the mixture was cooled in an ice-water bath. Cyclopropylzinc bromide solution (0.5 M in THF, 0.62 mL, 0.31 mmol, Sigma-Aldrich) was added and the mixture was warmed to RT and stirred for 2 h. The mixture was filtered and the crude was purified by silica gel chromatography, eluting with a gradient of 0-50% EtOAc in hexanes, to provide 24 mg of 3,5-bis(6-cyclopropylpyrazin-2-yl)-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole. The column was eluted with 2-10% MeOH in CH2Cl2 to afford 50 mg of 3,5-bis(6-cyclopropylpyrazin-2-yl)-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole. The two portions were combined to give 3,5-bis(6-cyclopropylpyrazin-2-yl)-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole (74 mg, 0.17 mmol, 66% yield) as a yellow foam. MS (ESI, pos. ion) m/z: 439.2 (M+1).

Provenance & Evidence