Pinacol → 2-Fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzonitrile

Participants

Reaction Conditions

Reaction Steps

A suspension of the crude 3-fluoro-4-cyanophenyl boronic acid (9.2 Kg, 55.8 mol) in cyclohexane (150 L) was treated with pinacol (13.2 Kg, 111.6 mol, 2.0 equiv) at room temperature, and the resulting reaction mixture was warmed to 40° C. for 4 h. When TLC and LC/MS showed that the reaction was deemed complete, the reaction mixture was cooled down to room temperature before being washed with water (2×75 L). The organic layer was then dried over magnesium sulfate (MgSO4) and concentrated under the reduced pressure to afford 2-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzonitrile (19, 11.8 Kg, 13.8 Kg theoretical, 85.6% yield) as a light yellow solid. For 19: 1H NMR (300 MHz, DMSO-d6) δ ppm 7.92 (t, 1H, J=7.00 Hz), 7.62 (m, 2H), 1.29 (s, 12H).

Provenance & Evidence