2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 2-(2,6-Difluoro-3,5-dimethoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

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Reaction Steps

To a solution of 2,4-difluoro-3-iodo-1,5-dimethoxybenzene (1.50 g, 5.00 mmol) in tetrahedrofuran (THF, 20 mL) was slowly added 2.0 M isopropyl magnesium chloride in THF (2.87 mL, 5.75 mmol) at −10° C. under an atmosphere of nitrogen. After 10 min., 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.27 mL, 6.25 mmol)(Aldrich, Cat. No. 417149) was added. The reaction mixture was then stirred at ambient temperature for 2 h. The mixture was quenched with sat. NH4Cl, and extracted with ethyl acetate. The combined organic layers were washed with water and brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue (solid) was treated with ethyl ether, filtered, and dried under reduced pressure to afford the desired product (1.20 g, 80%). 1H-NMR (400 MHz, CDCl3): 6.70 (t, J=8.2 Hz, 1H), 3.85 (s, 6H), 1.38 (s, 12H). LCMS (M+H)+=301.1.

Provenance & Evidence