Nitrogen → 5-(1-Butyn-1-yl)-3-fluoro-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole

Participants

Reaction Conditions

Reaction Steps

A 100 mL round bottom flask was charged with 5-bromo-3-fluoro-1-(tetrahydro-2H-pyran-2-yl) -1H-indazole (6.2 g, 20.7 mmol; Intermediate 39), DMA (20 mL), CuI (393.3 mg, 2.07 mmol), Pd(OAc)2 (465.0 mg, 2.07 mmol), dppf (1.1 g, 2.07 mmol), Cs2CO3 (10.8 g, 33.1 mmol), and but-1-yn-1-yltrimethylsilane (3.4 g, 26.9 mmol; Intermediate 35) sequentially while N2 was bubbled through the solution. The resulting mixture was heated at 80° C. for 10 h under N2. The reaction mixture was diluted with EtOAc (350 mL) and H2O (300 mL) and filtered. The organic layer of the filtrate was separated, and the aqueous layer was extracted with EtOAc (2×50 mL). The combined organic layers were washed with brine (3×100 mL), dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was purified on a silica gel column using EtOAc in petroleum ether (1:30) to afford the title compound as a yellow solid (3.9 g, yield 69.1%). 1H NMR (DMSO-d6, 400 MHz): δ 7.76-7.71 (m, 2H), 7.49 (d, 1H), 5.79 (dd, 1H), 3.88-3.85 (m, 1H), 3.74-3.71 (m, 1H), 2.44 (q, 2H), 2.24-2.21 (m, 1H), 2.01-1.91 (m, 2H), 1.70-1.65 (m, 1H), 1.57-1.54 (m, 2H), 1.18 (t, 3H); LCMS: 273 (M+H)+.

Provenance & Evidence