2-Fluoro-6-nitrobenzaldehyde → 4-fluoro-2-(4-trimethylsilanyl-but-3-ynyl)-2H-indazole

Participants

Reaction Steps

2-Fluoro-6-nitro-benzaldehyde (180 mg, 1.06 mmol) was added to a solution of 4-trimethylsilanyl-but-3-ynylamine (200 mg, 1.40 mmol) in toluene (2 mL) and the reaction mixture was stirred under reflux for 30 min in a Dean-Stark. After evaporation of the solvent, the crude product was dissolved in triethylphosphite (1 mL) and the reaction mixture was stirred at 80° C. for 4 hours. After evaporation, the crude product was purified by flash chromatography (cyclohexane/AcOEt 92.5:7.5) to yield 4-fluoro-2-(4-trimethylsilanyl-but-3-ynyl)-2H-indazole (142 mg, 0.59 mmol, 52%) as a yellow oil.

Provenance & Evidence