Phosphorus oxychloride → 5-(4-Chlorobut-1-yn-1-yl)-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole

Participants

Reaction Steps

To a solution of 4-(1-(tetrahydro-2H-pyran-2-yl)-1H-indazol-5-yl)but-3-yn-1-ol (1.0 g, 3.7 mmol; Intermediate 20) in dry pyridine (10 mL) was added dropwise POCl3 (2.4 g, 14.7 mmol) under N2 atmosphere. The resulting solution was stirred at room temperature for 16 hours. Upon completion, the reaction mixture was concentrated in vacuo. The residue was poured into ice-water and extracted with EtOAc (2×10 mL). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo. The residue was further purified on silica gel column (0˜20% EtOAc in petroleum ether) affording the title compound (400 mg). 1H NMR (400 MHz, DMSO-d6): δ 8.11 (s, 1H), 7.86 (s, 1H), 7.72 (d, 1H), 7.42 (dd, 1H), 5.86 (dd, 1H), 3.90-3.86 (m, 1H), 3.81 (t, 2H), 3.77-3.70 (m, 1H), 2.93 (t, 2H), 2.41-2.34 (m, 1H), 2.05-1.94 (m, 2H), 1.75-1.71 (m, 1H), 1.60-1.55 (m, 2H); LCMS: 289 (M+H)+.

Provenance & Evidence