Toluene → 5-(4-Hydroxy-2-methyl-phenyl)-benzofuran-2-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 5-bromo-benzofuran-2-carboxylic acid ethyl ester (275 mg, 1.02 mmol) and 2-methyl-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenol (239 mg, 1.11 mmol) in toluene (5.0 mL) and THF (5.0 mL) is added to a flask. The flask is evacuated and re-filled with N2 three times. Pd(OAc)2 (5 mg, 0.022 mmol) and 2-dicyclohexylphosphino-2,6-dimethoxy-1,1′-biphenyl (20 mg, 0.049) and potassium phosphate, tribasic, N-hydrate (432 mg, 2.04 mmol) are added and the mixture is heated at 85° C. for 8 hours. The reaction mixture is cooled to room temperature and filtered through a pad of diatomaceous earth. The filtrate is concentrated to a residue which is purified by silica gel chromatography eluting with 20-30% EtOAc/Hexanes to provide the title compound (179 mg, 56%). ES/MS m/e 297.0 (M+1), 295.0 (M−1).

Herkunft & Nachweise