Pyridine → Ethyl 3-(1,1-dimethylethyl)-1-(3-fluorophenyl)-1H-pyrazole-5-carboxylate

Participants

Reaction Steps

3-Fluorophenylboronic acid (0.70 g, 5.0 mmol), ethyl 3-tert-butyl-1H-pyrazole-5-carboxylate (0.981 g, 5.0 mmol), Cu(OAc)2 (0.908 g, 5.0 mmol), pyridine (2.45 ml, 30 mmol) and 4A MS (1.9 g) were combined in CH2Cl2 (48 ml) and stirred open to air at RT for 4 d. The reaction mixture was diluted with EtOAc (150 mL), washed with 3M HCl (2×50 mL), H2O (50 mL) and brine (50 mL), dried (MgSO4) and concentrated in vacuo. The crude product was purified by chromatography to afford ethyl 3-tert-butyl-1-(3-fluorophenyl)-1H-pyrazole-5-carboxylate (0.786 g, 54% yield) as colorless oil. MS (ESI) m/z: 291 (M+H+).

Provenance & Evidence