Trimethyl borate → HCID 67410628, compound

Participants

Reaction Conditions

Reaction Steps

5-Bromo-1-[3-(tert-butyl-diphenylsilanyloxy)-propyl]-1H-indazole (3s) (200 mg, 0.41 mmol) was dissolved in 4.0 mL THF and cooled to −78° C. A solution of n-butyl lithium in hexanes (2.5M, 0.17 mL) was added slowly. The yellow solution was stirred for 30 minutes. Trimethyl borate (130 mg, 1.2 mmol) was added and the reaction was warmed to room temperature and stirred for 30 min. The reaction was quenched with 10 mL of a 0.3% aqueous HCl solution and the resulting mixture was stirred for 30 min. The reaction was diluted with Et2O and the layers were separated. The organic phase was washed with brine. The aqueous phases were extracted once with Et2O. The organic phases were combined, dried (MgSO4), filtered, and concentrated in vacuo. The crude product was partially purified on silica gel with 3% MeOH/CH2Cl2 to afford (4s) (97 mg, 52%). MS (ESI+) m/z 459 (M+H)+. HPLC (5 to 95%) 3.74 min. This mixture was carried on to the next step without further purification.

Provenance & Evidence