186020-66-6

1663-39-4

112-27-6

186020-66-6

Synthesis of Compound 71; Step a: Sodium metal (0.10 g, 4.35 mmol) was slowly added to an anhydrous tetrahydrofuran (250 mL) solution of triethylene glycol (64.0 mL, 0.48 mol) at room temperature. After the sodium was completely dissolved, tert-butyl acrylate (24.0 mL, 0.164 mol) was added dropwise to the system. The reaction mixture was stirred continuously at room temperature for 20 h. The reaction was subsequently neutralized with 1.0 N hydrochloric acid solution (4 mL). After removal of the solvent by distillation under reduced pressure, the residue was suspended in saturated aqueous sodium chloride solution and extracted with ethyl acetate (3 x 70 mL). The organic phases were combined, washed with saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. After concentration under reduced pressure to remove the solvent, the tert-butyl acrylate adduct (40.23 g, 0.157 mol, 96% yield) was obtained as a colorless oil, which could be used for subsequent reactions without further purification. The product was analyzed by high performance liquid chromatography (HPLC): retention time t R = 10.2 min.