1,8-Diazabicyclo(5.4.0)undec-7-ene → 3-cyclopropyl-3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)propanenitrile

Participants

Reaction Conditions

Reaction Steps

4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (2.44 g, 12.6 mmol), 3-cyclopropylacrylonitrile (Preparation B; 2.34 g, 25.1 mmol) (as a mixture of isomers) and DBU (1.88 mL, 12.6 mmol) were suspended in MeCN (10 mL) and stirred at 40° C. for 3 days. The reaction mixture was cooled to ambient temperature and concentrated under reduced pressure to afford the crude material, which was purified by flash column chromatography (eluant: 25-35% EtOAc/Hexanes) to furnish 3-cyclopropyl-3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)propanenitrile (2.48 g, 8.64 mmol, 68.8% yield). MS (apci) m/z=288.2 (M+H).

Provenance & Evidence