ethyl 2-(1-benzofuran-2-yl)-2-oxoacetate

反応条件: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of ethyl 2-(benzofuran-2-yl)-2-oxoacetate (Example 15a, 237 mg, 1.09 mmol) in EtOH (2.7 mL) was added o-phenylenediamine (117 mg, 1.09 mmol). The reaction mixture was stirred at 90° C. for 16 h (a yellow solid appeared quickly). The mixture was cooled to 0° C., filtered, and the solid rinsed with cold EtOH. The yellow solid was azeotroped with CHCl3 and benzene and dried to provide the title compound (268 mg, 94% yield). The mixture was cooled to 0° C. filtered the solid rinsed with cold EtOH The yellow solid was azeotroped with CHCl3 and benzene dried

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of benzofuran (0.250 mL, 2.32 mmol) in tetrahydrofuran (12.5 mL) stiffing at −100° C. (CO2, ether bath) was added n-BuLi (1.377 mL, 2.203 mmol, 1.6 M in hexanes). The reaction was stirred for 30 min (yellow color) and added dropwise via a canulated into a solution of diethyl oxalate (0.314 mL, 2.32 mmol) in tetrahydrofuran (7 mL) stiffing at −100° C. The reaction mixture was stirred for 1 h and then quenched with saturated aqueous ammonium chloride solution. The mixture was warmed to rt, diluted with dichloromethane, and washed with 0.1 N HCl. The organic layer was separated, dried over anhydrous magnesium sulfate, filtered, and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel (eluted with dichloromethane). The fractions containing the title compound were collected and repurified by flash chromatography on silica gel (25% acetone/hexane) to provide the title compound (ethyl 2-(benzofuran-2-yl)-2-oxoacetate, 237 mg, 47% yield). stiffing at −100° C. added dropwise via stiffing at −100° C The reaction mixture was stirred for 1 h quenched with saturated aqueous ammonium chloride solution diluted with dichloromethane washed with 0.1 N HCl The organic layer was separated dried over anhydrous magnesium sulfate filtered evaporated under reduced pressure The residue was purified by flash chromatography on silica gel (eluted with dichloromethane) The fractions containing the title compound were collected repurified by flash chromatography on silica gel (25% acetone/hexane)