Cesium carbonate → tert-Butyl 2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)acetate

Participants

Reaction Steps

To a solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (400 mg, 0.002 mol, Aldrich, Cat. No. 525057) in acetonitrile (10 mL) was added tert-butyl 2-bromoacetate (0.36 mL, 0.0025 mol, Aldrich, Cat. No. 124230) and cesium carbonate (1.0 g, 0.0031 mol). The suspension was stirred at r.t. overnight. The reaction mixture was partitioned with AcOEt and water. The organic layer was separated, washed with water and brine, dried over MgSO4. After filtration, the filtrate was concentrated to afford the desired compound which was directly used in the next step reaction without further purification. LCMS (M+H)+: m/z=309.1.

Provenance & Evidence