tert-butyl(3,5-difluorophenoxy)dimethylsilane synthesis

Yield:917827-99-7 91%

Reaction Conditions:

with 1H-imidazole in N,N-dimethyl-formamide at 0 - 20; for 0.333333 h;

Steps:

Intermediate 19; 1-(terf-Butyldimethylsilyl)oxy-3,5-difluorobenzene. To a solution of 3,5-difluorophenol (CAS 2713-34-0) (9 g, 69.2 mmol) and imidazole (10.35 g, 152 mmol) in DMF (30 mL) was added TBDMSCI (11.47 g, 76 mmol) at O⁰C, and the mixture was stirred ar RT for 20 min. Water was added at 0⁰C, and aqueous layer was extracted with Et₂O. The organic layer was washed with brine, dried over Na₂SO₄ and evaporated in vacuo. The residue was purified by chromatography (silica gel 63-100 μ, 400 mL, Hex→ Hex/EtOAc 93:7) to furnish the title compound (15.3 g, 91%, 62.6 mmol) as a colorless oil. 1H NMR data (dmso-d6): 6.77 - 6.84 (m, 1H, H-Ar), 6.52 - 6.60 (m, 2H, H-Ar), 0.94 (s, 9H, /-Bu), 0.21 (s, 6H, 2CH₃).

References:

WO2006/136924,2006,A1 Location in patent:Page/Page column 136