Cesium carbonate → HCID 68704975, compound

Participants

Reaction Conditions

Reaction Steps

Pyrazole-4-boronic acid pinacol ester (1 g, 1 equiv, 5.15 mmol) was dissolved in dimethylformamide (15 mL) followed by the addition of Cs2CO3 (0.86 g, 1.5 equiv, 7.73 mmol) and 1-bromo-2-butanone (1.1 equiv, 5.67 mmol, 0.86 g). The mixture was heated at 90° C. overnight. The reaction was extracted into ethyl acetate and washed with water (3×) and brine (3×). The filtrate was concentrated in vacuo onto silica gel and purified by flash chromatography (SiO2, CH2Cl2:CH3OH 100:0-80:20) to return the title compound (0.19 g, 14% yield). 1H NMR 500 MHz (DMSO) δ 0.97 (3H, t) 1.26 (12H, s), 2.50 (2H, q), 4.71 (2H, s), 7.65 (1H, s), 8.04 (1H, s). MS m/z 265 (M+H+)+.

Provenance & Evidence